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Old 23-10-2016, 05:44   #61
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

Originally Posted by btrayfors View Post
Yep, they both should work well.

Thank you!

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Old 14-05-2017, 15:26   #62
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

Answering another question here, the poster said there should be a sticky with a shopping list of what's needed...
And, I might just start working on that...
But, until then, here is what I wrote to him, regarding an M-802 install on a bene 411, going on a circumnav...


Thanks for replying with more details...and I'll answer you in specifics as well...

[I REALLY mean a BIG Thank You, for giving me all these details!!!
It really helps when answering questions!!]

In addition to what I write here, there is a "sticky" right at the top of the Marine Electronics page, that has almost all of this info in it!!

Also, if you want a shopping list....that's a problem, because every boat is different, and every sailor might have a different application / desire...
But, the closest you can come is to contact someone that actually sells/installs marine HF radio systems on sailboat...
Such as Gary at Dockside Radio...

1) But, first off, I'll address the "primary HF antenna" choice...
I understand your reasons for not wanting to use your backstay for an antenna (if you get dismasted, there goes your HF antenna)....and of course good rigging insulators are very pricey!!
And, if you've made your decision, you're good-to-go...

But, you should understand a few other things about this as well:
a) a dismasting is VERY rare....I've seen the aftermath of a few over the past 40 - 50 years, and every one was caused by faulty or corroded rigging wire or wire terminal, not because of a rigging insulator, nor a 360* roll-over...(yes, a 360* roll-over can happen, and it can tear your mast off, but they are damn rare!)
{btw, unless you're racing, or planning high-latitude sailing (especially out-of-season), you are much more likely to experience calm weather / light winds, than "storm force" winds...and this is also why dismastings are rare..}
b) when a dismasting occurs, the chances are very good that any SSB "whip" antenna (whether the venerable 23' Shakespeare whip, or Morad, etc.) will be swept over as well, or at best severely damaged...
c) just about any length of wire, stretched-out and/or supported some how above the deck, etc. can be used and an emergency antenna...
(I actually have a 25' length of GTO-15, and an old MFJ manual antenna tuner, in a big zip-lock bag, as my emergency HF antenna, and also have a couple of deep-sea fishing rods, usually stowed below deck, which could serve well as antenna supports)
d) if you have any reservations about rigging insulators, use the Hayn Hi-Mod insulators....they're "fail-safe" and will last a lifetime...but they are very pricey!!!
e) I believe the Bene 411 has twin backstays? So, while loosing a backstay isn't a good thing, it's certainly possible to break one backstay, and still have the mast standing fine...(probably not good to stress the other stay, with lots of canvas, but the mast could still be standing fine)

Okay, now that I got that out of the way, there is no question that a "longer" antenna (40' - 50') versus a shorter antenna (23' whip) will work much better on the lower frequency bands (4mhz - 12mhz), because of the antenna's efficiency...and lower losses in the remote tuner...and because of the antenna's generally higher-impedance, making some of the antenna ground losses less detrimental...
And, with the majority of maritime HF comms on 4 thru 12mhz, and majority of cruising nets on 4 thru 8mhz (and majority of sailing ham nets on 7mhz and 14mhz), and with the 11-yr solar cycle on its 3 - 4 year down-swing, it makes sense to optimize your primary HF antenna for these bands....hence an antenna of 40' - 45' overall, is the generally accepted standard that all others are compared to...

Here's a internet-sourced photo of a Bene 411...(I think??)

The fact that the Bene 411 backstay length is about 56' - 58' (???) putting a upper insulator a few feet (~ 6') from the top, and a couple feet of GTO-15, would give you a fairly good ~ 50' long primary HF antenna, whether you use a lower insulator or not...or most-typically, placing the upper insulator about 10' - 15' from the top, to allow and overall antenna length (including the GTO-15 wire to the tuner) of about 40' - 45'.....

But, the good news is that you can also rig a long "rope-tenna"...
Do NOT buy a "rope-tenna", you can build your own for 10% - 20% the cost, and it will work just as good!!

While you can use GTO-15 wire the whole way (40' - 50'), but that is costly, and you could just use any good quality 14ga insulated stranded copper wire (I prefer PE insulated / polyethylene insulated stranded copper wire....and most will also recommended "tinned" copper, as well..)
You just take a length of double-braided polyester line (Sta-Set, etc.) that is long enough to secure from the mast head to the transom or stern-rail, etc.....and then insert a ~ 40' length of this copper wire inside the line (sealing up the top end of the wire), and either the bottom end of the wire exits the double-braided line and connects to a short run of GTO-15 wire that runs to your remote antenna tuner, or if the wire is of high enough voltage rating (such as, if you used GT-15 wire the whole way) goes directly to the tuner...

And, that's a "rope-tenna"!!
That's all there is to it!!
There is no magic, nothing precision at all!!

But, you can also make up an "alternative backstay antenna", which uses a length of "lifeline wire" or smaller-size rigging wire, instead of the above-mentioned double-braided line and copper wire...and, then with a short length of GTO-15 going to your remote tuner...
This is a great, heavy-duty, long-lasting approach...(and has been recommended by Bill / "btrayfors" for years here and elsewhere)

Just like the "rope-tenna", this works very well, and is even more weather-proof / fool-proof, than the rope-tenna...

But, as you can see that if you already have two backstays, and then want to add a "rope-tenna" or "alternatve backstay antenna", you've got to find room for it, keep it from interfering with your sails, keep it from shading solar panels, etc. etc...
So, I insulated one of my backstays, and am very happy with the results, going on 13 years now on my current boat, see photos...note the first pic is really old, before I even got my solar array up! But, note that my "SSB Antenna" (my insulated backstay) runs right past my solar array (four 130-watt Kyocera panels), and is just a couple inches away from a couple panels...with no RFI issues, either way!!

See post #17 here...

And, this entire thread...

And, here is some more...

And, here is a bit more....from Practical Sailor...

So, as I continue to ramble on and on, you're thinking "why in the world can't I just use a whip. because this rope-tenna or alt backstay antenna stuff is way too complicated?"
Well, the answer is, of course you can use a 23' whip....I just wanted you to be aware of why it might not be the best choice...

2) Now, how about I answer your question about what to use for a HF-DSC-receive antenna??
{VHF-DSC uses your primary VHF antenna, along with your VHF-FM Voice communications...and this has nothing at all to do with this discussion...}

HF-DSC receive antennas do NOT need to be mounted on the mast....
Most are either a simple piece of rigging wire, or a stern-rail-mounted / arch-mounted SS whip antenna...
{please note that this HF-DSC SS whip antenna looks like a VHF marine antenna, but it is NOT!!!}

I've personally used two different DSC receive antennas...

a) The first one was a Metz stern-rail-mounted 54" (1.4m) long SS whip antenna, specifically designed just for HF receiving of HF-WeFax and HF-DSC..
It worked okay, did the job, and was inexpensive and unobtrusive...(but, not that great in the WeFax receiving, and just "okay" in the, I went to onto plan "b")

b) My plan "b" was to use one of my aft lower shrouds as my HF-DSC Receive antenna / HF-WeFax Receive antenna....and it works great!!
It turns out to be about 22' long, and I insulated the upper end (just to keep it electrically separate from the rest of the rig, and eliminated any potential RFI pick-up), and have it fed with coax directly from the chainplate....just the center-conductor of the coax attaches to the chainplate,....(while this simple set-up works great, you can do this in addition, as I have, about 8 turns of the coax around an F240 toroid as a cheap balun.....or you can simply use a cheap commercial-made balun...)

I have written about all of this, in some detail, in the past....have a look here...
See post #10 here...

And, see post #12 here....

And, see post #2 and especially post #12 here...

c) A plan "c", would be the same as "b", but without insulating the shroud...
Others have done as I have, but NOT insulated their shroud, and in effect have used their entire rig as their HF-DSC receive antenna....and they report good results....
(If you decide to try this, I advise doing a receive RFI check and signal strength check, to compare the overall signal-to-noise ratios between your "primary HF antenna" and your HF-DSC Receive antenna....thereby proof-of-performance testing this set-up...)

Now, as you know, I'm a radio nut....and as such what I do (and some of what I recommend) might be a bit over-the-top, and might be more than most others would consider "adequate"....
So, while my plan "b" works for me, and I get many "all-ships" HF-DSC calls, and a few Distress HF-DSC calls, and I would recommend this for someone doing a circumnav, etc....the 54" Metz whip (plan "a") should work fine for most sailors, as an HF-DSC-Receive antenna...

3) Virtually no difference between the AT-140 and AT-141....(I think the 141 is supposed to have a "back-up 2182 manual-matcher", built-in???)
But, whatever the case, it will not matter at all to you, so either one will be fine...
But, I will caution you to not place the remote tuner (AT-141) near the autopilot corepak/course computer, nor near the fluxgate, nor autopilot wiring!!
Understand that the antenna starts right at the remote tuner, the GTO-15 wire (or whatever antenna wire you use) IS your antenna!! And, you cannot place any ferrites on this!!!
So, placing the remote tuner (which is the start of your antenna) near the autopilot is not a good this can cause transmit RFI issues, meaning your autopilot might malfunction / disconnect / change course / etc. when you transmit...and this is of course not a good thing!!
(fortunately the good news is that most autopilot course computers don't generate much RFI of their own, but sometimes the drive motors do...)

If you can mount the AT-141 elsewhere, I would do that....
But, remember that other system can be cause of RFI as well....such as refrigeration compressors causing receive RFI, so try to keep the AT-141 away from them too...
There is no need to have the radio and tuner on the same side of the boat, so if there is another location for the AT-141, choose that other location....or make some on-air transmit tests, before permanently mounting/installing the AT-141, to verify that all is good there...

4) On a similar vein....RF ground / Antenna Ground (sometimes called a "counterpoise")
Wow, what a long, involved and usually controversial subject!!
But, it shouldn't be so...
Please know that we are talking about a matter of degree.... i.e. how well one system works versus another....
(even systems with NO rf ground / antenna ground's just how poorly versus how well other systems work...)

a) First off, your best overall rf ground / antenna ground for HF radio on a small boat is the sea water (unless you have an aluminum or steel hull)...
Sea water is a great conductor of RF energy, and makes an excellent antenna ground...BUT...
But, you need a short, low-impedance connection to some decent underwater metal (like Dynaplate or bronze thru-hulls)....
This is typically done with a 3" wide copper strap, of 8' - 10' in length or less (shorter the better!!) to a Dynaplate (or two) or bronze thru-hull (or two)....
If you do not have bronze thru-hulls (mine are Marelon), or do not have any in close proximity to where the remote tuner is located (more than 8' away), then Dynaplates are a great underwater connection! (they are pricey!! but they do work well....but work no better than a solid bronze plate...

b) If you cannot make a decent low-imp connection to the sea water, your next best approach is use whatever you have on-board already...
-- Alum toerails make a good counterpoise (but, you will need to drill/tap, and attach to the raw alum, not try to make a connection thru the anodizing)...
-- SS stern rail, pushpits, pullpits, lifelines, etc. all make good counterpoises as well...
-- Some boats have "rubrails", and they make good counterpoises as well...
{although, I prefer to use copper strapping to attach to any/all of these, you can use copper wire to good results...}

-- tanks, especially large, flat tanks, make good counetrpoises too...

-- external lead keels are "okay"....but mostly only "okay" / "marginal", as they're usually quite a ways from the tuner and with such a long run, the connection to them does as much of the antenna ground current conducting as, while attaching some copper strap to a keel bolt is good, unless this is rather close to the tuner, it's only an "additional" counterpoise, and not your primary one...

c) Artificial counterpoise / radials...
These are quite easy to make, and install...
Basically, just a bundle of wires from the tuner's ground lug, strung out as best you can thru the bilges, and/or under the cabin sole, and/or under the cabin headliner, under-deck, etc...
You can makes these very cheaply (less than $5 USD, or for free), in less than 5 minutes...and they will work better than the KISS Ground!!
While cutting them to approximate 1/4-wavelength on some of the popular marine HF and ham HF frequencies is good, please understand that once placed in close proximity with each other, and close proximity to ground, and close proximity to other wires and metallic objects, their "tuned" resonance no longer exists....

The KISS Ground is just a few wires stuffed into a nice black hose....
It has no real tuned resonances (see my quite detailed test results)... 016bb34a486e68809ff01
Re: KISS-SSB Counterpoise
You can build your own version for about $5 USD (or free) in less than 5 minutes!!

5) As for videos....
Please watch these playlists....they will help

HF-DSC Comunications

Maritime HF Communications (in general)

Icom M-802 Instruction Videos

Offshore Weather


I hope this helps...

Fair winds...


Here are some other offshore sailing videos....just for fun...

John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
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Old 23-05-2017, 13:21   #63
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

During a recent discussion regarding a sailor not being able to make contact with a new and newly installed M-802, it was clear that except for the speech compressor being turned off, there was little chance of the radio being the cause of the troubles....

Although, the 12vdc wiring was less than optimal, most of the problem was the weaker talk power without the speech compressor On
IC-M802 Compression
And lack of understanding of how HF radio communications works...
Maritime HF Comms
Icom M-802 Instruction Videos
Offshore Weather

A local Icom dealer had a tech come out to the boat, switched On the speech compressor for this sailor, and briefly showed him how to make contacts....
Problems solved...for the most part...

But, I got to thinking....what if everyone could benefit from a "teachable moment"???
So, here is a link to that thread....and some of my final observations there...
New ICOM M802 SSB won't transmit - urgent advice needed

In just our messages back-n-forth you seem like a good guy, and shouldn't mind everyone using your experiences (and my observations, too) as a "teachable moment"??
Anyway, here goes...

1) As I've been saying for years (decades??) HF radio communications are actually quite easy and reliable, and fairly predictable, too....and while these words surprise many laypersons, once they learn about it, they usually see that these are truism's...

But, just like most things in life, we are not born with this knowledge / experience....we must learn it and do sailing itself!
As I continue to preach, you needed to learn how to sail, navigate, trim sails, flush the head (and repair it), etc. well as so many other things in life, like learning to walk, talk, read, math, etc....
Why do many think learning about radiowave propagation and HF radio comms would be any different??
They simply need to learn the basics, and use the radio!
I am still amazed that so many of my fellow sailors think/say that since they can't just tap on an App icon, and get what they want instantly, that "this stuff just doesn't work", or "it must be broken"...

In addition to my words above (and for many years) and my continued observations, please read what JR wrote here:

Originally Posted by jr_spyder View Post
Well I've got good news. I called my local marine electronics hop and they sent a technician over mid-day today. He enabled the compression feature very quickly and then checked everything out. He was a very skilled and dedicated HAM so he briefly opened the HAM channels and made a contact. He thought everything was working as it should. He disabled that HAM capability before he left. Maybe I'll get back to that someday.

Later I was able to reach WLO on 1212 with a reasonably good signal. I'm much happier now with the rig and feel more confident in it doing its job as I learn more.

You see....knowing just a little of what the radio does, somewhat how the radiowaves propagate, and some basic instructions on operating / talking on the radio...JR successfully made contact with a station about 1200 miles away, and feels confident that radio is doing its job (which it is doing well, now that the speech compressor is turned On)!!

Now, I would have insisted that this guy proof-of-performance-test the whole system, and provide JR with a chart showing power output, reflected power, VSWR, DC voltage/power to radio, etc. on each and every marine MF/HF band (as well as the ham bands), and an observation of how these exact power output measurements correlate to the radio's own power output display....and a list of various stations contacted on-the-air live, the times/freqs and their locations, as well as their signal strengths and the signal reports they gave your vessel...
Also this should include any observations of on-board RFI (both transmit and receive RFI), as well as any anomalous behaviors of the radio system, or any other system on-board while transmitting...

But, hey at least he has confirmed that it is working!!

Yes, he got professional help...but how many of you learned advanced mathematics without a teacher?? or even never watched a sailing video??
So, we ALL get help....we all learn stuff everyday, from everyone...
{As a teenager at a Mensa meeting, I was reminded that "Everyman is my teacher, in that I may learn from him."....but, as I got older I realized that not only does this go both ways, but also requires BOTH parties to be willing to learn and teach....
I know, I know....way WAY off topic! Sorry! }

My point here, to everyone, is:
Don't think everything in life is now done for you by some electronic microprocessor....don't forget to use your own "microprocessor" (your brain) and learn!

And, use the radio!!!
The more you use it, the better you be at using it!!
Yes, read the threads and watch the videos....they are good tools to help, but using the radio is where you will actually be putting this knowledge to work AND learning at the same time...
So, use the radio!!
[As I wrote earlier, the IMO (international Maritime Organization) and the GMDSS recommendations, clearly say that mariners should regularly use their HF/MF-DSC-SSB Radiotelephones, for routine signaling / messages, so that they will be familiar with the system in times of Distress and easily recognize radio system issues, before they fail at critical moments!!
And, these are for professional mariners, with specialized, pleasure-boat sailors with little to no professional maritime / communications training should take these recommendations as "requirements"....
Use the radio!! ]

2) As for the technical stuff...
I caught some flack for a recent comment "that anyone should be able to walk on-board, turn the HF radio on, spin the dial, and make contact with someone within 30 - 60 seconds"....
Some have called bullshit on, allow me to clarify..

I stand behind my words, but need to add some qualifiers...
a) this assumes you're within a couple thousand miles of civilization
b) using ham and/or maritime freqs (especially ham for HF Voice comms and have Maritime HF-DSC capability)
c) have a working radio system on-board
d) have more than a basic understanding of radiowave propagation
e) have more than a basic understanding of who is listening where, what band/freq. what time-of-day, etc. etc.

3) As an about I eat some of my own words from a couple years ago...
Using my experience from yesterday afternoon (22 May 2017)...
{a couple sentences of background....for 25 years Herb Hilgenberg ran his weather net, primarily on 12.359mhz...and during his last few seasons, I was there on-the-air monitoring from my boat at the dock, and assisting with radio relays / radio issues....part of my routine was to check propagation (and sometimes I got bored, even during the Net, so would spin the dial to see what else was on-the-air)...and sometimes, some boats would be "off-frequency" a bit, and I'd tune around to see....and one afternoon I bumped into Australian Maritime Voice Weather Broadcasts on adjacent channels, 12D (12.362mhz) and 12E (12.365mhz), form 11,000 miles and 9600 miles away...sometimes I'd check 16.528mhz as well...
(Oh, and I also heard them at nighttime on 8.176mhz!!)}

So, I've occasionally commented that if you know about radiowave propagation, and have little (or no) RFI, (and a decent antenna system), you can communicate with stations a long ways away, without much trouble....
Schedules and Frequencies for HF Marine Radio Voice Services
Australia Marine Radio Broadcast Areas

Now, nobody would recommend trying to contact AMSA from Florida, especially on 12mhz...but, just the fact that I would hear and understand their weather broadcasts from 1000 watt transmitters 9000 - 11,000 miles away, is telling of my comments that you can make HF communications work, if you know the "when" / "where" / "how", etc...

So, here is where I must confess my own forgetfulness...

A few years have passed and the solar cycle has been declining steadily during that time, and we are headed further down for the next 2 years and another 2 years (maybe even 3 years) after that of the doldrums, before things start to, propagation has changed since I was hearing those Australian BoM / AMSA weather broadcasts so clearly...
And, with higher A-indices this month, etc., things have changed...
And, yesterday, when I tuned in to listen to them (as I was hoping to talk to JR on 12.359mhz, I tuned around to hear my Australian weather broadcasts), I found them weak and barely readable...(I forgot to check 16.528mhz, but suspect that I would've heard 'em there, too)

Now to be clear, VMC, in Charleville, AUS, is 9600mi (8350nm) from me, and VMW, in Wiluna, is 11,170mi (9700nm) from me....and I'm using just my 60' backstay, nobody would expect "perfect copy"....
But, things on the higher bands are getting tougher these days!


And, then...

4) And then, I was on 40m (7mhz) ham band just tuning around, waiting for the Doo Dah Net on 8.152mhz, and heard some stations quite a ways away....remember this was afternoon, about 3.5 - 4 hours before sunset, where D-layer absorption is still pretty high, and I made contact with stations in west Texas (1000nm away) and Connecticut (900nm away), on 7mhz, during the to certain these guys had great stations and their signals were stronger than everyone else's, but still these distances, at this time of day, on this band, was unheard of just 2 - 3 years ago...

So, here again, I'm reminded that things have changed...yes, they will change back...but for now and the coming 2 to 4 years, we can expect 12mhz to be useful less (and mostly for longer ranges) and 8mhz to be useful more....
Although NY Radio Volmet (13.270mhz) is still booming in here, as well as NMF WeFax on 12.750mhz, just be aware that one band lower is also working now for daytime use, well beyond NVIS range...

So, when watching my videos....any comments about "exactly" what freq/channel should be understood to be based on the solar cycle at that time, and know things do change a bit....
Still use the highest freq/channel's just that it might be one band lower than is shown in the videos, and in the coming 2 - 4 years, I will try to remind everyone!

5) One final caveat, reminded by my own observation yesterday...
Anything can happen!!
Yesterday afternoon, as usual I found USCG WeFax transmissions loud and clear from NMF (Boston) on both 12mhz and 9mhz (12 was stronger, of course), and from NMG (New Orleans) on both 12mhz and 8mhz (about the same, but slight edge to 8mhz, less fading...)
But, when tuning around, I found USCG WeFax transmissions on 13.089mhz (the coast station transmit freq of ITU channel 1205, assigned as an SSB Voice working channel to the USCG)!!

With all US Mainland USCG HF transmitters now being remotely controlled from CAMSLANT / NMN in Virginia....I assumed they accidently patched the WeFax input into the wrong transmitter (cuz NMF, NMG, and NMC were all on-the-air transmitting at the time....and I surmised that they simply / accidently switched the WeFax input to their NMN 13.089mhz transmitter...
I made a phone call to them (CAMSLANT / NMN) in Virginia and told 'em what was going on....after a few "hmm's" and "oh's", they said, "sorry, we must've gotten something switched wrong"...
After a few minutes of them discussing what to do, I said I had to go and said my goodbye....I assume they fixed the problem, but I really did need to go, so I didn't stick around on-the-air to see...

My point here is:
Anything can happen!!
Even the USCG screws-up communications sometimes....
Now, to be clear this was NOT their GMDSS transmitters, so nobody's safety was effected....and as soon as they needed to use that particular transmitter for something (they had a SSB Voice Offshore Waters Weather Broadcast coming up in an hour), they would've seen this error and I assume fixed it without incident....just saying...

Okay, enough of my ramblings....

To sum-up...
Most problems with HF systems on-board, if the sailors are new to HF comms, can be traced to lack of education regarding HF comms and not to equipment failures...
Secondarily, it is the installation / wiring / programming / commissioning / etc that makes the stuff work...

Fair winds to all...



Hope this helps...
Fair winds to all...

John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
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Old 08-08-2017, 10:46   #64
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Re: Marine SSB Stuff (including some Sailmail info / setting drive levels, etc.)

I got a nice e-mail saying thanks for all this info here, and also asking me for any updates. I smiled at that request, as radiowaves still travel the same as they always have...

And, since the initial implementation of the GMDSS in 1992, and its Jan 1999 international compliance requirement for all signatory nations and all SOLAS vessels....
And, with the USCG finally changing their Voice SSB Radio watchstanding freqs/schedule in 2005 (note that they are NOT required to actually have a "Voice" radio-watch, at all, only DSC)....
And, with the USCG finally giving up on all MF / 2mhz comms, ceasing their 2087.5khzDSC watch and their 2182khz Voice watch, in 2013....
(be sure to read and print-out this USCG page)

I thought there really hasn't been much to update here.

But, I also thought, oh yeah...Yep, there ARE things that can be updated!
So, here are a few important things to note:

1) While using the highest frequency / channel that supports your communications, is still a good rule....fact is, that with dwindling sunspot numbers the higher bands are already being used less, and with lower D-layer absorption, 8mhz is getting to be a daytime longer-range band, like 12mhz is (and 16mhz was/is), while use of 8mhz for daytime long-range comms can still be limited, it is getting better and should continue to improve in the coming 2 - 3 years (and 12mhz and higher bands will become daytime-only and perhaps even unusable)

2) Secondly, there has been an ironic occurrence of sorts....

a) With the increase in inexpensive (and poorly-manufactured) electronic devices populating so many folks lives these days, where these devices add to the Receive RFI issues for users of HF Radio...
{Heck, even COSPAS-SARSAT has found increases in terrestrial 406mhz "background noise", especially in Asia and the increase in HF / SW RFI in populated areas (like marinas, and even residential areas, etc.), is not surprising! }

b) Mother nature has cursed HF radio users with the lowest (worst) "11 year solar cycle", since 1906!! Our current Cycle 24 actually "peaked" in early 2014, after it's first peak in 2012.
And, it looks like the nominal "11 year" cycle, this time around might be more like 12 - 13 years, or so...meaning we might have another 2 to 3 years of a down-slope, and levels not getting back to "average" until a couple years after that!

Combining these two occurrences means that HF radio users need to be extra vigilant in routing out RFI....of course when at sea or in remote areas, this is fairly easy, as the RFI is generated on-board our own boats! Note that RFI on the lower freqs is sometimes harder to eliminate, but is doable...but many HF installs suffer from this unknowingly, as the natural band noise of these lower freqs masked the RFI, but with quitter bands and many using the lower freqs in the coming years, AND with the plethora of RFI generating crap on-board these days, on-board RFI will be more of an issue for some!!

Please be sure to have a look at all the previous info (especially the links in post #1) regarding RFI, as well as some more here.

3) And, with new websites and new servers....some links might not be completely useful...and some info has been moved/lost...

But, here is a good URL for the Sailmail Primer

And, here is some Sailmail App Notes, etc., that are no longer linked-to, from the "Primer"...

For those with RFI issues, in addition to the links to RFI cures / references in post #1, have a look at this excellent paper by Jim Corenman, you know the guy that wrote the "AirMail" program and helped start Sailmail....(this mostly deals with transmit RFI and RF / Antenna Grounds):

Also, for those looking for "drive level settings" for radios other than those listed in Airlamil, etc...or troubleshooting of low-transmit speeds / poor connectivity...have a look here:

If your sending speeds are consistently slow then there is something wrong on the transmit-side of your equipment– an incorrect setting, a problem with the radio itself, or perhaps a problem with the tuner or antenna. Check your equipment carefully, or find a qualified radio technician to help (and have him read this also). In order to send at optimum speed your needs to be transmitting full power (or some reasonable fraction) and the antenna must be working efficiently.
Start with the radio power-settings and make sure that your radio is set to hi-power mode, power-level “3” for an Icom-M710. (Note that these comments are general but include some specific details for the Icom M710, other radios will vary). One of the myths is that low-power works just as well, this is only true when the station is relatively close- and definitely NOT the case from the middle of the South Pacific.
Next check the tuner connections- make sure that the ground and antenna connections are clean and tight. It is a good practice to remove, clean, and reconnect these connections every year or so, and make sure they are protected from the weather. Also make sure that the wire from tuner to antenna is as short as possible and spaced away from other wiring and metal by at least 2-3″, do not strap this wire into a harness bundle or to the lower backstay for example.
Next check the tuner function: Most marine radio’s have a “TUNE” indicator which indicates when the tuner is active, and when it has properly tuned. For an M710 and M802 radios the “TUNE” indicator on the display will flash for a few seconds when first transmitting as the radio completes its auto-tune cycle, then “TUNE” will remain ON steady. If “TUNE” flashes and goes off then the tune-cycle failed, and the radio will be transmitting very inefficiently and only with a few watts. This is either a tuner problem, or a problem with the control-cable, or a corroded antenna or ground connection.
Next check the transmit power-output. Most radios have a power-output indicator, the M710 has a “bar-graph” of 8 segments. For a M710 the power-out indicator should indicate 7 bars on steadily when calling the station, with the 8th bar (above the “SQL” label) flickering). (You can initiate FSK-transmission with Airmail’s “Set-PTC Aplitude” control, under the Control menu on Terminal window).
If you have a battery monitor which shows DC amps used from the battery, then another good way to check transmit-power is to check the INCREASE in DC amps while transmitting (with battery-charger OFF). For an M710 or M802 this should be 8-14 amps, 100W radios will be a bit lower. For example, if the battery-monitor shows 5 amps when listening, then it should show about 15 amps (a 10-amp increase) when the radio is transmitting.
If the transmit power is low, then this likely indicates that the “FSK” and “PSK” amplitude settings in Airmail are not correct for your radio. (These settings control the modem’s audio “volume” control for the signal sent to the radio, and this in turn controls the transmit-power. The FSK setting is used for calling, PSK once connected. PSK should always be about 30% higher than FSK).Open Airmail’s Tools/Options menu, connection tab, and check these settings in the lower-right. (You can also access these settings when Terminal-window is open, via Control/Set PTC amplitude menu). Older Icom M710’s are usually 140/170 for FSK/PSK, newer M710’s and M802’s are usually 250/330, systems which Marc Robinson set up usually have special cables and are set to 600/1000, Furuno radios are usually 1500/2000.
If increasing the FSK/PSK levels does not increase transmit power then the radio may be set to low-power mode (see above), or there may be a failure in the radio’s power-output transistors. You can verify the transmit function independently of the modem by finding an unused voice-frequency (e.g. 12,359.0) and whistling into the mic while watching the power-out indicator and/or battery-monitor. You should be able to reach full-power output no problem.

4) I also thought I'd post some direct links to relevant Video Playlists, that allow the viewer to watch videos in a logical order (skipping any duplicate or non-applicable videos, if needed).

{Please remember that these videos are not done in a lab or studio, nor by some "talking head" ....
Nope, these videos are done in the real-world, for real sailors....done on-board a real offshore cruising boat, LIVE, as it script, no BS...
Yes, these are LIVE, real-world, demonstrations of how/why all this stuff works....not some boring engineer talking "tech speak", nor some "spokesman" following a script...just me, my ~ 45 years of experience, and my M-802...
So, please understand that you're not getting high production values here, just the display and buttons of the M-802, and some of the Nav Station, WeFax machine, WeFax Charts, etc., along with real-world, live, unscripted narration (and some noises / voices from the radio, too), please be kind. }

"Maritime HF Communications"

"HF-DSC Communications"

"Icom M-802 Instruction Videos"

"Offshore Weather" (sources and methods of obtaining good weather info, when offshore)


"Offshore Sailing" (a couple of my Atlantic crossings) Just for fun!

Now, I'm sure there is more that I could add, but please remember my intent here is use this thread as a reference / source, for those looking for info.....not to debate any specific issue (start a new thread for that)

If anyone else has some more reference info to share, please do so!

Fair winds.

John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
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Old 08-08-2017, 14:54   #65
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

FYI, for those who don't have good internet access on-board, don't forget that you can download the videos from YouTube, store 'em on your computer, and play them whenever you need.

I'm usually not one to recommend software, but I've found "savefrom" to work great...
The fastest free YouTube Downloader

Fair winds.

John, KA4WJA
s/v Annie Laurie, WDB6927
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Old 08-08-2017, 17:15   #66
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

Thank you, John!

(formerly N6VFJ - which I didn't know had expired. argh)
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Old 07-12-2017, 09:13   #67
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

Thanks, your threads and posts are excellent kc1bkm
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Old 04-03-2018, 20:45   #68
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

Hello to all,
This is intended to be an addendum / update to the overall reference sticky, "Marine SSB Stuff (how-to better use / properly-install SSB, & troubleshoot RFI, etc."...

Here, I'd like to cover / reiterate three important things here, regarding HF radio systems on-board (all of which apply equally to: ham or maritime / SSB; voice or data; monohull or multihull; ...although those with steel or aluminum hulls, please note that the "grounding" topic doesn't really apply to you....that is all about fiberglass/GRP or wood boats):

1- proper installation tips/techniques (including wiring; antennas; and the "ground" system, etc.)

2- understanding of what HF communications work easiest for laypersons

3- importance of learning "how-to" use your HF radio system properly (just like learning to navigate, trim the sails, anchoring, etc.)

[Please understand that anecdotal reports of "this set-up works great", and/or "do this, it's what I did", and/or especially "this guy down the dock, or this 'expert', told me this", and/or the worst "the ad / brochure for this product says it works better than anything else", all need to be taken with a grain-of-salt!! I'm not saying that someone is intentionally lying to you, but I myself have dozens of personal experiences that would seem unlikely, such as using a vhf/uhf police scanner antenna (inside a house in Florida) on the HF ham bands and talking with dozens of stations all over S. Amer and Europe...or siting an HF radio on a cockpit cushion, with 12vdc power wires clipped to the batteries and just a random 25' - 30' piece of wire stuck in the antenna jack, thrown up on a flag halyard, and working dozens of stations all over Europe, US, Carib, and S. Amer, while sailing between Carib and US east coast...these are all true and many others too....but, this doesn't mean that anyone should assume these are reliable examples of HF communications, nor should anyone spend their time/effort/money installing an HF radio system the wrong way 'cuz some guy down the dock did it that way and he said it works great!! ]

1) With today's equipment (such as M-802 and AT-140, or even when installing an older M-700pro/M-710, or Furuno, or Sailor, etc.), as long as it is working "out of the box", if you follow a few simple installation rules, you should have a good working system (assuming you learn how to properly use it)!!

Some of the installation recommendations from the manufacturers are legal-liability-based, as well as based on shore-side installations where the antenna system (and all transmit energy) is easily radiated by the antenna and/or shunted to ground....this not always the case on our boats, where we have not just the radio, but other ancillary equipment, computers, misc. sensitive electronics (as well as other devices actually radiating their own RF energy, causing us RFI), all within a few feet of the transmit antenna!! So, over the past few decades many have found by both scientific means and simple "trial-n-error", what works and what doesn't....{fyi, I assisted in my first Marine SSB install, as a kid, in 1973....joined the ARRL and spent a few years studying not just for my ham license, but also studying antenna system design, radiowave propagation, receiver design, etc...actually continue to study these things today, even though I teach seminars on these topics, there is always something else to learn, ya' know. }

So, before I delve into the specifics of what to do / how-to do it, please accept these few facts:

--- despite what the Icom (and other manufacturers') manuals state, do not connect any RF ground strap between your remote tuner and the main transceiver....yes, do connect the green ground wire (and other wires) as prescribed, but do not add any other grounding connection between the tuner and radio...doing so can cause ground loops and RFI (both transmit and receive RFI), some have not had an issue and if it's done perfectly it can be a great thing, but most find it's not a good idea at all...and it has not been recommended for over 20 years now, but the manuals still show it.

--- despite the old wife's tail of needing "100 sq ft of copper", understand that this is not needed at all, and is a total waste of time, effort, and money....(more details on antenna grounds / RF grounds below), a low-loss/low-impedance direct sea water connection for your antenna ground / RF ground is best...

--- despite the nice long 12vdc power wiring supplied with the radio, do not use this entire length of wire....if you need wiring this long, use larger gauge wire...(details below)

--- despite what they claim, the KISS-SSB Ground is not a "tuned counterpoise", and does not work any better than (actually worse than) a few random length wires tossed into your lazarette / bilge for a counterpoise!! And, is significantly inferior to a direct sea-water connection / antenna ground...(details below)

--- despite what some may think, most marine electronics dealers/installers (including those at shipyards, yacht manufacturers and commissioning locales) do NOT understand HF radio communications even a little, and most do not follow proper / accepted procedures in the installation and commissioning of an HF radio system matter how much you just spent on your new boat, this is a fact of our lives these days...I've seen $1million+ yachts whose radio installs are crap!! And, I've heard (not seen first-hand) that there are some "mega-yacht" installs that work so poorly their commissioning reports are "fudged" so they say they meet GMDSS spec, when they don't!! {FYI, the only "factory-installed or commissioned" HF systems that I've ever seen done correctly were from Hinckley and Swan...some of their older SGC and Sailor set-ups were awesomely done, and some of their newer Icom, Sailor, and Furuno installs were wonderful too!! Was on a Swan 57 that had just finished a factory re-fit and its Sailor HF system looked/worked like it was off the Sailor's engineering floor!} So, just because you have a new boat and/or a new "professionally-installed" HF radio system, this doesn't mean it was done correctly...

Please remember that the Sailmail Primer, and their app notes, include significant radio installation and wiring recommendations / tips...and all I write here is confirmed there. Notes

Now, some details:

a) Starting with the radio....find a secure location to mount the main transceiver unit, where it will be away from the weather, but still be accessible to connect wiring to and have adequate ventilation (usually at the Nav Station, or a locker nearby), and securely screw it in place with the supplied mounting bracket (it needs to stay-put in a heavy sea!)...mount the control head (M-802 or M-710RT) at your Nav Station, where you can easily see it and use it!! And, if you ned data comms, and decide to spend the outrageous $$$$ for a PACTOR modem (or will be using a "soundcard digital comms" mode, such as WINMOR, PSK31, etc.), keep the transceiver main unit close to your operating position / Nav Station and near your PACTOR modem, where you can keep the connecting wiring short (~3'), (and where you will be able to see the modem's status lights)....especially the USB cable between modem and computer, to keep your transmissions from interfering with your computer...

b) Always connect the 12vdc power wiring directly to the main house battery bank, this allows for the strongest transmit signal, the least transmit interference (transmit RFI) to other systems on-board, and reduces receive RFI as not connect your HF transceiver's power thru your main 12vdc distribution/breaker panel!! (Use large enough wiring to keep voltage drop for the 30amp load to a max of 3%)

c) Keeping the radio close to your main house battery bank is a good idea, thereby reducing the 12vdc power wiring length (always good)....but, unless your radio is very close (< 3' - 4') you will want to use a larger gauge wire from the radio to the main house battery bank...most installs on average 40' - 50' cruising boats will use 6ga wire from the radio's short (~ 12") pig-tail or dedicated breaker/fuse, to the house battery bank...if you'll be using a PACTOR modem or a "soundcard data mode", place the transceiver main unit so that your USB / comm wiring is short (~ 3') and use longer (and heavier gauge) 12vdc power wiring...

d) Use ferrites on any additional wiring to/from the HF radio (such as tuner control wires, modem, computer, etc.)....btw, I use ferrites on all the cables to/from the HF radio main transceiver unit, they're cheap and cannot cause any issues, only help!

Use a "Line Isolator" on the coax, at the tuner end of the coax...this is like stacking dozens and dozens of ferrites on the reduces transmit RFI and allows your antenna ground / RF ground to work properly (more on grounds later)....use a ferrite or two on the tuner control wiring, at the tuner end (or on both ends)...

e) Although they are designed to be weather-tight, install the remote tuner below decks if at all possible....for most boats, this is in the lazarette, stern locker, or even in the aft cabin, etc...

f) Some details about HF antennas on our boats...a simple fact is, that they are all a compromise of some sort! No matter what, our boats are boats....they move, they sail, the get pounded by waves / wind / etc...and we want an antenna that works well from 2mhz thru 26mhz, day and night, in all weather, for communications from 50 miles to 5000 miles (and farther), 24/7/365....and we do this, quite well!! But, we compromise in the process....a few more facts:

--- our antennas start at the remote antenna tuner!! (actually the tuner is part of the antenna!)

--- for many years the "typical length" of our HF antennas is 40' to 45'...and for good reason....this allows decent efficiencies on the lower frequencies (4mhz, 6mhz, 8mhz, and 75m and 40m ham bands) and still allow low-angle-of-radiation for the middle HF freqs (12mhz, 14mhz, and 16mhz) aware that longer antennas (55' - 65') are better for the lower freqs at a slight sacrifice for 14 -16mhz....and shorter antennas (20' - 25') are better for the higher freqs (21mhz, 22mhz, 25mhz, 28mhz), but at sacrifice in efficiency at some middle HF freqs such as 12mhz, and a serious sacrifice in efficiency in freqs of 8mhz and below....this is why those with "23' whips" are at a serious disadvantage versus those with backstay antennas twice as long, on the "regional cruising nets" on 4mhz, 6mhz, and 8mhz (or 75m and 40m ham bands)...
Take note that with the solar-cycle on a down-slope for next 2 years and won't be back to where we are today until 2022, and the predictions are that things might not be as good as "normal" even in 2025, worrying about the higher end of the HF spectrum (above 20mhz) for next few years is a fool's errand, and if you're considering a whip antenna for your catamaran, I'd recommend a "rope-tenna" or insulating a stay/shroud, anything that will allow you a 40' - 45' long antenna...

--- Since our antennas start at the tuner....the GTO-15 wire (and the tuner) are the start of your antenna!! And, this lower part (the high current part) is a significant part of the radiation of the antenna, especially on the lower freq bands...
So, keeping the tuner and GTO-15 wiring away from other systems and wiring is important!

Now, as I wrote above, our antennas are a you won't get perfection here....just know that you do NOT want to install the tuner (and GTO-15 wire) near your refrigeration compressor, nor autopilot core-pak/computer... And, you should never run the GTO-15 wire along any other wiring....(having it run near / across another wire at a right angle is usually not a problem, but never run near / parallel other wiring!) Ignoring these recommendations will usually cause significant RFI on-board, both transmit RFI (your radio's transmit signal causes other systems on-board to malfunction, etc.) and receive RFI (other systems on-board cause noise / interference in your HF receiver)...

{On my current boat, my AT-140 is in the starboard side lazarette, with my Adler/Barbour Cold Machine in the port laz, about 9' away, and my pilot core-pak is about 8' - 9' forward of the AT-140....that's the best I can do....and, with about 3.5' of GTO-15 wire running pretty clear, but crossing my 110vac shore-power wiring and some other wiring at a right angle, about 6" away....due to excellent antenna ground / RF ground, I have no transmit RFI at all....but I do get some receive RFI / beeps from the fridge I said, this is a compromise!}

--- For our fiberglass boats (assuming you remove any chainplate bonding/grounding wire from your backstay chainplate), there is no need to use any "backstay standoffs"! Whatever transmit energy is coupled to the backstay below the lower insulator will be use of backstay standoffs to keep the GTO-15 an inch or two away from the backstay, is unnecessary!! (if you have a steel or alum boat, or have your chainplate grounded, then using some standoffs is good practice, but other than that, they serve no purpose...and are ugly and lines can catch on 'em, etc.)

--- There is NO difference in antenna efficiency between using a large SS rigging wire, versus a 14ga copper wire, for your antenna....yes, copper is a better conductor, but since the RF flows on the surface, the increased surface area of the rigging wire compensates for SS less conductivity!

g) The sea water not only provides a great antenna ground / RF ground, allowing most of your antenna return currents to be radiated....but also the sea water provides a very low pseudo-Brewster angle, that is the angle below which signals fall-off quickly....and in the mid-HF region, over sea water, this about 1 degree!! Yep, that's not a typo, one-degree!! This means that even poor antennas work very well over sea water, compared to on-land!!! (fyi, the pseudo-Brewster on-land, with very-good rf ground conductivity is 14 degrees) So, when I and others comment on how great things work on-board and how much of the optimizing is: a) a matter of degree and b) making improvements in receive signal-to-noise'll see what we mean!

h) RE: the antenna ground / RF ground:

Install the remote tuner near the base of the antenna (whether backstay, whip, "alternative backstay antenna", rope-tenna, etc.)....and install the tuner near where you can have a direct sea water connection for the antenna ground / RF ground (whether that contact is via Dynaplate, bronze thru-hull, keel bolt, etc.)

Hmmm, you say...what is "near"?? And, how can I be "near" both of these??

Well, please remember this is all a bit of a compromise, and that every boat is a little, I can only give you guidelines, not absolute specifics to what is "near" and and how to be "near" to both...

--- typically we think of 8' to 10' as the maximum distance you can effectively run a low-loss/low-impedance antenna ground / RF ground connection (typically 3" wide copper strap, 0.012" to 0.022" thick, NOT copper foil) from the remote tuner to a direct sea-water contact (Dynaplate, bronze thru-hull, keel-bolts)...shorter is better....longer does work, but fyi as you go longer note that this copper strap starts to become a more significant part of your antenna ground / RF ground, rather than just be the way you connect to the antenna ground / RF ground (the sea water), so in these cases where you have a longer run of copper strapping, it is recommended to also tie-in any metal tankage, lifelines / pushpits / run-rails / toe-rails (be sure to connect with a tapped screw to connect into the alum, not on top of the anodizing)...

--- Dynaplates (sintered-bronze) are no better than the same size solid plate of bronze...but they're stream-lined, easily mounted, have all the hardware (even "gold-plated" hardware)....they're pricey, but for those of us with Marelon thru-hulls (or no thru-hulls close-by the tuner), an underwater bronze plate is a great idea, whether a Dynaplate or otherwise...

--- typically the less GTO-15 wire inside the boat, the better....the better for both RFI and for actual transmit effectiveness, it's all about the distance from antenna to everything else, 'cuz on our fiberglass boats, it's not about shielding I usually think of 5' to 6' as the maximum....but, here again, every boat install is a compromise....shorted is better, but do not mount the tuner 15' away from the sea water ground contact just to get it 2' away from the backstay...

--- Use of wide copper strapping here is important to allow a low-loss/low-impedance connection to the sea water, as you are using the sea water as your antenna ground / RF ground, where it represents the "other half of your antenna", and you want as much of your antenna return currents radiated by your antenna and not lost in some wire / radiated inside your boat / shunted to ground...(please note this is not about using "radials" / counterpoise, where there is nothing at all wrong with using even small gauge the case of using the sea water for your antenna ground / rf ground, you want to use copper strapping, as even 2" - 3" wide strap has significantly less RF loss than 0000ga wire!!)

In addition to the many decades of practical use on-board by myself and many many others, there was significant work done in the 1930's thru 1950's regarding vertical antenna grounds / rf grounds for both MF and HF, on shore and near ocean....

And assuming you have short, low-loss connection to the sea water, the use of the sea water as our antenna ground on a mid-sized fiberglass boat has proven to be best solution (those on steel or alum boats, you don't have these issues)....and is always recommended as the first, best solution!

This is followed in second and third place, by the use of strapping to keel bolts, and metal tanks....and/or connecting in lifelines, rub-rails, toe-rails, pushpits, arches, etc...which approach beats the other for 2nd place vs. 3rd place, depends on the boat, and it can vary with different freqs too..

In fourth place are "tuned radials" (they really aren't tuned once you put 'em in your lazarette/bilge/etc.) my opinion, this is rather distant 4th place, and should be considered only as a stop-gap measure, such as when doing a temp install for a delivery, etc..(this is what the KISS advertises it is, but it as can be easily seen, they aren't really tuned at all...)

A close fifth place is probably connecting to engine block, etc., or no antenna ground at all...I actually recommend no antenna ground at all rather than using the engine block, as that can just increase on-board receive RFI...

[BTW, please note that you can make contacts and use an HF radio on-board with a vertical antenna, without any antenna ground / RF ground at is of course not recommended ever....and will usually cause problems on-board, but you can still use the radio...and both science and actual real-world testing shows that the difference between the best overall antenna ground (the sea water, with a short, low-loss connection to it) and no antenna ground at all is 4db to 6db...possibly more if higher than typical tuner losses present themselves...

When doing the tests of the KISS-SSB Ground, I found no difference in antenna current between no antenna ground and the KISS....and about 3 to 4 times the antenna current with my direct sea water antenna ground, using my Delta TCT-N rf current transformer and Tektronics scope...this represents 5db to 6db difference...and on-air tests (although subjective and anecdotal) also showed significant difference of appox. 6db...(understand that while my modern spec analyzer does allow me to save the spectral scans and post 'em, which I old Tek scope does, you'll just need to take my word for what I saw on the screen)....these antenna current readings show how much energy is actually getting to your antenna and being radiated, and they represent the same thing as using a fluorescent light tube along the backstay, where the brighter the light the higher the antenna current...the better the antenna ground, the more antenna current, and the better your signal is!! And to digress a bit to the 1970's, before the advent of microprocessor-driven remote auto-tuners, HF systems on-board used remote antenna "couplers" (which is actually what we should be calling our tuners, but that's a whole 'nother discussion!), which typically had 12 positions, switched by a 12vdc solenoid/motor, controlled by the radio's channel knob switch...each of these positions had to be set-up / adjusted, by placing a tap on a coil and tuning/adjusting two capacitors...and while they used a Bird 43 wattmeter watching the reflected-power, final tweaking was done with the radio transmitting a carrier and watching how bright the fluorescent tube got! No kidding, I personally watched this procedure with my own eyes in the 1970', the more things change the more they stay the same, huh?]

Have a look here for lots of detailed test results on the KISS: 23c07bed5242&start=75

Actual results in the open air: 03b2344eb03a&start=75#p74444

Actual results in my lazarette: 03b2344eb03a&start=75#p74499

Please also have a read of Gordo's old, but still very viable, tests comparing various antenna grounds....and what Sailmail recommends...

Please take note that while I'm fully confident that in addition to the science behind all of this (which I've studied for ~ 45 years now), the actual real-world practical results back-up the science quite well! And, also please remember that when comparing transmit performance, this is a matter of degree, but understand that a 6db difference is the same as going from a 150-watt radio to a 37-watt radio...and there are times when this small difference will be the difference between making contact or not... Further, remember that anything you can do to improve your receive signal-to-noise ratio (by improving antenna and ground system, reducing on-board RFI, etc.) is always worth it, always!!

Please take note that I use the word "strap" or "strapping" and not "foil"....this is because foil is too thin, too fragile, and too difficult to protect from corrosion, to be considered a long-term ground connection...If you use 0.012" think copper strapping it will last a long time even if you leave it bare! I recommend painting a few coats of clear lacquer on it before you install it (except of course for the ends where you make the connection, where you can paint or cover those connections later)....btw, if you use even a ticker strapping (0.022", etc.) like I did with my 6" wide strapping that runs from my AT-140 about 7' to my two Dynaplates (all Marelon thru-hulls), and my 3" wide strapping to the keel bolts, it will last decades even if you don't paint it! Please don't use foil, don't buy your copper from West Marine, but it from a copper company! (in the US, I recommend Georgia Copper!) Oh, and never, ever use braid!!

--- Remember what the antenna ground / RF ground is supposed to do:

1 - provide "the other half of the antenna"....allow antenna return currents to be radiated..

2 - assist an antenna couple / antenna tuner in making an adequate match, and reducing tuner losses....
3 - reduce/eliminate feedline radiation.....
4 - shunt "un-radiated" RF to ground (reducing RFI, etc.).....

(although, some may question the "necessity" of this item #2 these days, as our modern auto-tuners could match a "coat-hanger", etc.....what this gives us is, the ability of the auto-tuner to find a more efficient tuning regime, thereby allowing more of our transmitted power to be properly coupled TO the antenna...)

But, also remember that the effectiveness of our antennas is a matter of, arguing about "proper" antenna grounds can be a frustrating have the factual info, and the recommendations of those using/installing HF systems on yachts for decades, but it's up to you to decide what you want...

I hope the above will help clarify what are the accepted practices and best installation techniques for HF-SSB-DSC Radios...


2 & 3) Over the years I have often stated that learning about HF radiowave propagation and "how-to" properly use your HF radio (whether for ham or maritime...whether voice or data), is overwhelmingly the most important part of an HF radio system on-board!!

And, I continue to stand behind these views (but, there is a caveat)!

An old, crappy HF radio, poorly installed and/or maintained, in the hands of a skilled/experienced operator will work / will make contacts, and usually with some ease....But, conversely, a new, perfectly-working radio, properly installed, etc., in the hands of an inexperienced layperson, will have difficulty in making contacts...but, there is that caveat!!

What is this caveat??
It's HF-DSC!

Oh no, he's not going to rant again about HF-DSC, is he? The answer is: No...but..

But, the fact is that the GMDSS (Global Maritime Distress and Safety System) was adopted by the IMO and SOLAS conventions in 1988 and implemented in the 1990's to allow for better Safety Of Live At Sea (SOLAS), and part of this was both redundancy and ease of use / ease of signaling distress / ease of communications...The GMDSS consists of multiple parts that we as pleasure boaters can use very effectively!!

HF-DSC signaling can be done by any layperson sailor....and a DSC-Distress Call (especially a six-freq DSC-Distress Call) will get thru to just about everyone (every SOLAS vessel in your region, as well as coast stations / RCC's), without any real operator technical knowledge!!
But, with the exception of HF-DSC, the above recommendations to learn about the radio, how to use it, and about radiowave propagation, all still hold!!

FYI....those interested in the GMDSS, DSC, and how you can use these inexpensively and effectively on our boats....have a look here: 4e67cdf721f3

Here's a excerpt:
Parts of the GMDSS system that most find easy/affordable/useful (all within easy reach / affordable parts of the GMDSS for cruising boats...):

--- 406mhz EPIRB's (relatively inexpensive at $400 - $700, and easy to "sell" to cruising sailors..)

--- Marine VHF-DSC-FM (cheap and almost ubiquitous now-a-days...anyone that doesn't have a Class D VHF-DSC-FM radio, really needs to spend the few hundred dollars now!!

--- Marine MF/HF-DSC-SSB (HF-DSC is a VERY robust/reliable means of signaling.....and with reasonable costs of ~ $1800 new, ~ $1000 used, for an Icom M-802 MF/HF-DSC-SSB Radiotelephone....and simple-to-use, robust and is an easy "sell", almost a no-brainer!!)

--- NAVTEX (inexpensive and very useful for most coastal sailors and/or those plying the Med, etc., with typical forecasts for waters out to 150 - 200 miles....but in some areas the forecasts are only for the next 24 hours, so other weather sources, such as HF-WeFax are recommended...) (and in US waters, the VHF-based NOAA Weather Radio system is widely used, so NAVTEX hasn't caught on in the US, as it has in Europe and the Far East...)
- WeFax....And while HF WeFax was not adopted officially as part of the GMDSS, according to a 2012 survey by the Joint WMO/JComm group, HF comms, DSC, voice, and data are used daily by a majority of ocean going vessels, and HF wefax being reportedly used daily by > 85% of, for offshore/hi-seas weather info/forecasts beyond the "text" weather info provided via INMARSAT-C and some HF coast stations, HF WeFax still rules as the predominate "1st choice" when offshore, even in 2012, even for large ships / SOLAS vessels....)

Parts of the GMDSS that are a bit more expensive:

While INMARSAT-C might seem to some to be a bit pricey, at ~ $3000 - $3500, is a VERY viable communications tool to have on-board long-range cruising it gives, thru its FREE "SafetyNet" service, offshore/hi-seas weather info/forecasts (in plain text), position reporting and weather reporting thru NOAA and AMVER, and Distress Signaling....ALL FOR FREE....
NO monthly/annual subscription, NO Fees at all, until/unless you use it to send regular e-mails, and then you're just billed by the character/letter....
(and it is very robust/reliable....many orders of magnitude better than a handheld sat phone!!)

--- INMARSAT Fleet systems (such as F77) are pricey at $15,000 - $20,000 and are big/heavy, and use significant amounts of electrical power....
So, here if cruiser's desire hi-speed data / broadband internet access / etc., Iridium Pilot or INMARSAT Fleet Broadband systems (at ~ $4500 - $5000) are usually the typical choices....
FYI, INMARSAT is phasing-out their Fleet33 and Fleet55's and both the FleetBroadband and Iridium have submitted their systems for GMDSS certification...

--- SART's (X-band radar Search And Rescue Transponders) are reasonably priced at $600 - $800.....but are often over looked by many cruising boats, as they figure a working EPIRB in their liferaft will do them better...
And, if deciding between a second 406mhz EPIRB and a SART, I'd choose the second EPIRB...(but, if you're cruising in heavily-trafficked areas, with poor visibility, such as UK/North Sea, etc. then a SART would be a GREAT idea, and I'd recommend one before a second EPIRB...)
Also, note that while an AIS transponder is great for the vessel, the MOB-AIS devices might be good to find you if you're a mile or two away, the second EPIRB or a SART, will be better!

Anyone talking about "Marine SSB" in the last decade or two, should be talking about MF/HF-DSC-SSB....and those that are talking about 25 year old radios and "Voice radio watchstanding", etc. are unfortunately either ignorant of the changes in the past 25 years or are laboring under some serious misconceptions???

While it is not a requirement for our pleasure craft, the GMDSS has been a mandatory system for all SOLAS vessels, and all signatory nations, since Jan 1999....over 15 years ago...and regarding "SSB", please remember that nobody (except the USCG, Aus and NZ, and Bermuda Harbour Radio) does any "SSB Voice" monitoring or watchstanding anymore...and haven't for decades....
As for learning how to use the radio, and radiowave propagation, etc. please read this sticky...and watch these videos...

"Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, etc.)"

And, please watch these video playlists (where the videos are laid-out in an easy-to-understand and logical order):

HF-DSC Comms

Maritime HF Comms

Icom M-802 Instruction Videos

Offshore Weather sources


Offshore Sailing

I do hope everyone finds this reference helpful..

And, finally....
Please read what happens when you activate your EPIRB, etc...
EPIRB Activation? What happens/How to improve rescue odds

Fair winds.

John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
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Old 07-03-2018, 10:28   #69
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Re: Marine SSB Stuff (how-to better use / proeprly-install SSB, & troubleshoot RFI, e

Not sure how I deleted all the paragraphs of info dealing with the DSC receive antenna and GPS connection to the HF-DSC radio (M-802)...oppss.
But, here 'ya go!

--- On all Class E (and Class A) MF/HF-DSC-SSB Radiotelephones (the M-802 is a Class E), you have the main antenna, which handles all transmitting (Voice, data, morse, etc.) and all receiving, except for the continuous monitoring of the six GMDSS DSC calling freqs (2187.5khz; 4207.5khz; 6312khz; 8414.5khz; 12577khz; and 16804.5khz) all the time the radio is turned on....

Even though you do not see it doing so, the radio has a separate, dedicated six-channel scanning receiver, built-in, that is continuously monitoring these six Int'l GMDSS DSC calling freqs, and this separate, built-in receiver has its own separate antenna connection ("DSC antenna"), and therefore requires its own separate HF-DSC receive antenna...

[fyi, this DSC-receive antenna is needed to receive an "ACK" (acknowledgement) of your DSC-Distress Call...and, while you receiving this "ACK" is not an absolute necessity for a SAR operation to get underway, the fact is that your radio will continue to transmit your DSC-Distress Call until either an "ACK" is received, or you cancel the DSC-Distress Call yourself, and unless you receive this "ACK" you will not necessarily know what SSB-Voice freq/channel to coordinate your distress / SAR operation on, as the "ACK" will be received on the best freq/band for comms, and your radio will then automatically being standing-by on that SSB-Voice, having a DSC-receive antenna is a good thing!!]

Due to the robustness of the HF-DSC signal, compared to SSB-Voice signal (and of course, most replying to any DSC-Distress Call, will be more powerful coast stations and/or large SOLAS-grade merchant vessels), this "DSC-receive" antenna does not need to be as large, nor as efficient, as your primary/main antenna...

So, many have found the small (54" tall) Metz "DSC / WeFax" receive antenna, mounted in the clear on the stern rail or arch, etc., to be a very usable solution!! (I used this myself for about 4 - 6 months, and it did work fine...but I changed things to allow for better WeFax reception, as well as better HF-DSC reception..)

In theory with HF-DSC being 100 baud SITOR-FEC, and the M-802 DSC receiver bandwidth of 500hz (or less), you should have a S/N advantage of 12 - 15 db. versus an SSB voice transmission using the same power, distance,

So, in theory, if your DSC Receive antenna was no worse than 12db down from your main SSB antenna, whatever comms you could successfully complete on SSB (voice), should also be capable on DSC...

And, having your DSC-receive antenna mounted out in the clear, away from RFI sources on-board, etc., should improve your DSC-receive signal-to-noise ratio!!

Please watch these videos in this playlist...where you'll learn a lot about HF-DSC..

HF-DSC Comms

{So, installing anything better than the above antenna is probably over-kill....but, you know me, I'm a radio nut....and since I wanted better WeFax reception, I changed things on my boat....I found a 22' long vertical wire (an insulated aft-lower-shroud) to be an excellent HF-DSC-receive antenna (and WeFax receive antenna)....but, this is over-kill and most will never do this!! }

There are other options of course, and if you do not have access to the Metz antenna, or do not wish to spend the $$ on it, you can try just using your entire rig as a DSC-receive antenna....(not the best approach, but is do-able)
By just running a coax from the M-802's DSC receive antenna jack, to a shroud chainplate, and just attaching the center-conductor of the coax to that chainplate, thereby using that shroud, and your whole rig, as your HF-DSC receive antenna...(or using a balun at the shroud, and attaching only one wire from the balun to the chainplate, or attaching the other wire from the balun to a keel bolt, is a good idea....or at least a few ferrites on the coax, at the chainplate end of the coax)

In this case, as you're using your entire rig as a receive antenna, it is likely that you will have some added receive RFI with this antenna, but the narrow-bandedness of the DSC signal and its robust nature of demodulating, should partially compensate for this...(again, this is not the best approach, but is workable)

[A good way to tell how well your DSC-receive antenna is working:
Compare your on-board receive RFI between your main antenna and DSC-receive antenna, by simply swapping the cable on the back of your M-802, and listening to your RFI...AND..
And, tune-in to an active station that is transmitting for a few minutes (USCG HF Voice Weather broadcasts, WLO, WWV, etc.) and compare the signal strengths and noise levels, when swapping antennas back-n-forth, a few times over a few minutes...
Remember, even if the smaller antenna's signals are weaker, the noise pick-up might be less as well, and this is the important is all about the signal-to-noise ratio!!]

--- GPS data input to your MF/HF-DSC-SSB-Radiotelephone...

The M-802 requires NMEA 0183 vers 3.01, NMEA position sentence GGA..

This in input via the BNC connector on the main transceiver (an odd connector for this, but it works), with NMEA + on the center pin, and NMEA - on the shield...

I recommend a separate, dedicated GPS receiver to feed this NMEA data to your DSC radios (both HF and VHF), as this allows your radios to always have accurate/up-to-date position data in them 24/7, without the need to have any other marine electronics operating (such as when sailing offshore on long passages, such as across oceans, when you will not be running a chartplotter, etc...and/or in the case of distribution / breaker panel issues, as you have your HF radio wired directly to the house battery bank, so as long as you have 12vdc of some sort, the radio will work and if you have a dedicated GPS receiver driving NMEA data to it, you can always send a DSC call with accurate position data...

I use a Garmin GPS-76 series handheld GPS, mounted at the Nav Station and powered thru the ship's 12vdc (and also has internal battery power) need for an external antenna on fiberglass boats..

Fair winds...

{ P.S. Please note my reasoning for doing what I did was both serendipitous (my aft lower shroud allowed me a good length for what I wanted, about 20' - 22'), and met my easy / no-muss (and no failure) design criteria....

My design thoughts were: with my primary WeFax freqs being 8.5-9mhz and 12.7mhz (with some daytime 17mhz and some nighttime 4mhz and 6mhz)...and with 8414.5 being a primary HF-DSC freq, (with 2187.5khz being a secondary, and a primary in Europe), and end-fed vertical antenna of 30' or less would do well, and provide a decent low-angle....and an end-fed wire of 18' - 27' long would be excellent, easy / low-loss match to 50-ohm coax on 12mhz thru 8mhz freqs, and still not be that low impedance on the lower freqs....and since atmospheric noise rises significantly on these lower freqs, any possible (and small) mismatch loss would actually be a positive....
So, in my case, my aft lower shroud worked perfectly for my application...
BTW, the first MF/HF-DSC-Distress Call I received (actually a Distress Relay Call) was in summer of night, rafted to the quay in Horta, Azores....I was listening to some SW stations (with headphones on), and the damn Distress Alarm went off...scared the crap out-of-me!! and woke my crew up, thinking we were on fire or something!! }
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
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Old 07-03-2018, 10:33   #70
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US Coast Guard "Marine Safety Alert", signaling/calling USCG, SOLAS vessels, etc.

I'd like to highlight a few "US-Based" pieces of info, but they do effect most offshore sailors worldwide!

The USCG published a Marine Safety Alert last year, advising all mariners of their recommendations for proper signaling / calling of the USCG, SOLAS vessels, etc., along with links to their specific MMSI#'s and freqs...

Have a look (the red bold-type is the USCG, not added by me!):

Know your high seas comms equipment and how to use them.
You just might save your own life when in trouble offshore!

And, of course their announcement from June 2013, of their discontinuation of all MF/2mhz more 2182 SSB, nor 2187.5 DSC...

USCG Discontinued ONLY 2mhz Distress Watchkeeping 8-1-2013

I hope the above helps....

And of course, this is a reminder, that HF-DSC signaling (or MF/HF-DSC signaling) is what is needed in almost all places around the world, at sea....and except for the few SSB-Voice freqs monitored by USCG, AMSA, NZMA, WLO/KLB, (and Bermuda Harbour Radio), everyone else is monitoring MF/HF-DSC, not SSB-Voice...[there are > 450 MF-DSC coast stations in operation world wide, and > 80 HF-DSC coast stations worldwide, and 1000's of SOLAS-grade merchant vessels around the world, and while they do have SSB-Voice capability, they're all monitoring DSC, not SSB-Voice channels!]
Of course, there is always the ham radio bands, where you're sure to find someone....but in a "Distress" situation, I'd rather my Distress Call gets to all other vessels in my area and directly to the RCC...and include my accurate position data, along with MMSI# (which gives them all details of my boat, my safety gear, my comms gear, etc.)

Fair winds.


P.S. Sorry if this sounds like a rant about DSC....not intended to be! Just some info...

John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
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