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Old 13-05-2017, 14:12   #1
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AOR SA-7000 antenna for Icom IC-M802 ?

Hi everyone,

I've just been recommended an AOR SA-7000 whip antenna for my want-to-buy Icom IC-M802 unit.

The specs for the antenna can be found here: http://www.universal-radio.com/catalog/wideant/3755.pdf

This antenna was recommended by a professional Icom dealer, but I have my doubts. Looks too short to me ??

I explained the shop I wanted a seperate antenna for my M802 (Don't want to use the backstay and I prefer not to start a discussion about it). I also explained I want to use all features of the radio, so voice, DSC and e-mail via the pactor 3 modem.

The AOR SA-7000 is what's been recommended...

Is this a good idea ? Any better ideas ? What IS the best DSC (passive) antenna for the M802 ?
(I know it's only to receive DSC calls)

Thanks guys !

Brgds,
Safc
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Old 13-05-2017, 18:38   #2
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Re: AOR SA-7000 antenna for Icom IC-M802 ?

Safc,
Do NOT buy that antenna!
It is not what you need, not even close!
(and, in my opinion, you should seriously think of not doing business with this "professional Icom dealer", because his/her advice is seriously flawed!)

I will give you some more input and recommendations in a few, but I wanted to answer your primary question first!

Please tell us where you are located, and where / how you will be sailing/cruising?? (this is important, in order to make recommendations)

Also, please answer these other questions...

a) And, you made no mention of your vessel?? type? layout? your proposed antenna system design/layout?
b) Where your M-802 will be installed?
c) Where the AT-140 will be installed?
d) Will you have an adequate RF ground / Antenna ground (such as a low-imp connection directly to the sea water)?
e) Are you aware that you will need two antennas (one "primary", for everything except DSC reception...and another for DSC receiving)??
f) Do you have the room / have you planned for these two antennas??
g) Are you aware that you do NOT need "tuned"/"resonant antennas"??


More to come....but, do NOT buy that antenna...

Fair winds...

John
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Old 14-05-2017, 08:08   #3
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Re: AOR SA-7000 antenna for Icom IC-M802 ?

Hello John,

After reading most of your info on the M802, I was kind of hoping you'd answer here :-). I'll answer in RED:


Quote:
Originally Posted by ka4wja View Post
Safc,

Please tell us where you are located, and where / how you will be sailing/cruising?? (this is important, in order to make recommendations)
I'll be buying the radio in the Belgium/Netherlands/Germany region. My boat is located in France (Mediterranean Sea). Intention is to make a cruise around the world in the coming years.
Also, please answer these other questions...

a) And, you made no mention of your vessel?? type? layout? your proposed antenna system design/layout?

We have a 2002 Beneteau 411. We have a custom constructed arch on the back which holds 4 x 100 watt sunpower panels. For the antenna I'm still doubting between a whip antenna, a rope antenna or if it's really the best option, a backstay antenna. Reason why I don't like this, is the fact that an emergency on a sailing yacht oftens means a demasting; hence a loss of your antenna.... Our backstays are not isolated (yet...).

b) Where your M-802 will be installed?

The M802 will be installed at the navigation desk, SB side near the entrance into the cabin. (see google - we have a 3-cabin layout beneteau 411). Other equipment there is a Garmin chart plotter, a furuno radar and an Icom IC-M505 DSC-enabled VHF.

c) Where the AT-140 will be installed?

We'd like to go with the AT-141 instead of the AT-140, this appears to be cheaper with our current dealer... It will be installed in the SB aft, near the auto pilot and very near to the potential whip antenna and about 2 feet from the SB backstay.

d) Will you have an adequate RF ground / Antenna ground (such as a low-imp connection directly to the sea water)?

We want to purchase the KISS ground cable... Unless you strongly disagree with this. It's the easiest and cheapest option for us.
e) Are you aware that you will need two antennas (one "primary", for everything except DSC reception...and another for DSC receiving)??

Yes, I definately am. Unfortunately, our dealer doesn't seem to understand this completely.... PM me for his details. My plan was to mount a seperate DSC antenna (in the mast??) for the HF and VHF DSC recievers. Good plan ? Do I need a splitter ? What kind?

f) Do you have the room / have you planned for these two antennas??

We have the room I suppose, but not planned yet where to install these...

g) Are you aware that you do NOT need "tuned"/"resonant antennas"??

Even though I have my GOC, I cannot say I'm a HF professional. I'm not familiar with antenna types, and I'm afraid I mostly depend on advice and google


More to come....but, do NOT buy that antenna...

Fair winds...

John
Thanks a lot for the answers already John, and also a huge thanks to your videos. They're awesome.

The only thing I'm still missing in the entire HF story is a clear "shopping list" for items which have to go with the M802. It'd be awesome for me, and others on this forum, to go to an (online) shop and knowing exactly what to buy exactly.

A detailed list with ALL items to be bought (incl. which cables, how thick, what grade, ferrites yes or no ?, extra fuses, etc etc.) would be awesome and would definately be nice to have as a STICKY. A next step would then be a step-by-step manual in how to (DIY) assemble all these purchased parts and make it all work.

I'll be installing my radio in September, and I'd be more than happy to document the entire installation and share it here, but first I need to figure out exactly what to buy and, later on, how the h*ll I'm going to install it all without a technical background :-)


Thanks for the reply again John,
Fair winds !

Safc
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Old 14-05-2017, 16:21   #4
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Re: AOR SA-7000 antenna for Icom IC-M802 ?

Safc,
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!!
http://www.cruisersforum.com/forums/f13/marine-ssb-stuff-how-to-better-use-proeprly-install-ssb-and-troubleshoot-rfi-etc-133496.html

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...
http://www.docksideradio.com/Icom%20SSB%20Radios.htm



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...

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....
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...
http://www.cruisersforum.com/forums/f13/optimal-ssb-antenna-e-147034-2.html#post1838896

And, this entire thread...
http://www.cruisersforum.com/forums/f13/optimal-ssb-antenna-e-147034.html


And, here is some more...
http://www.cruisersforum.com/forums/f13/recommended-coax-for-triatic-stay-ham-antenna-147339-2.html#post1840889





And, here is a bit more....from Practical Sailor...
https://www.practical-sailor.com/blo...B-11559-1.html

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 DSC-receiving...so, I went to onto plan "b")
http://metzcommunication.com/weatherf.htm
http://metzcommunication.com/

http://www.docksideradio.com/Icom%20SSB%20Radios.htm

http://www.landfallnavigation.com/ecr201.html
http://www.radios.net.au/marine-radio-packages/marine-antennas/metz-weatherfax-/-dsc-receive-antenna-only-135cm-high/prod_1293.html


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...
http://www.cruisersforum.com/forums/f13/ssb-dsc-antenna-idea-175681.html#post2257738

And, see post #12 here....
http://www.cruisersforum.com/forums/f13/ssb-dsc-antenna-idea-175681.html#post2258484

And, see post #2 and especially post #12 here...
http://www.cruisersforum.com/forums/f13/wire-antenna-for-hf-dsc-147650.html


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...
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 idea....as 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 work...it'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 anything...so, 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)...
https://www.ssca.org/forum/viewtopic.php?f=5&t=13490&start=75&sid=8aabedb8416 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
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2n3z5nlv-ga2zYuPozhUXZX


Maritime HF Communications (in general)
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nPNdApNsZDo_Jk3NB_Bt1y


Icom M-802 Instruction Videos
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2npivDjoFrC-8QKVyMb4tVr


Offshore Weather
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2mPZAx2vWzdjTJjHlChruyY


VHF-DSC
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2m-IejYg7J6QugtO2epizxF



I hope this helps...

Fair winds...

John

P.S.
Here are some other offshore sailing videos....just for fun...
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nbwAGh5DKgTCj15iyl6qoY
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Old 16-05-2017, 08:12   #5
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Re: AOR SA-7000 antenna for Icom IC-M802 ?

Hi John,

Thanks a LOT for the info again !

Definately helps !

Just ordered the radio, tuner & pactor modem. I'm gonna take my time to decide what to do with the antenna & ground, but that'll be for later.

I like your antenna ideas, I'm probably gonna go with the self made rope antenna & the uninsulated shroud as DSC reciever antenna.

As for the ground, I'm still in doubt... Seems easy to make a KISS myself, not worth spending a lot of money on that... On the otherhand, a dynaplate still gives better results I guess...

For the AT-141 unit: ok, not near the autopilot. My other option is near the gas bottles... Also not very sexy to have HV near the gas tanks... Not much other options I'm afraid.

Brgds,
Safc
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Old 16-05-2017, 12:35   #6
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Re: AOR SA-7000 antenna for Icom IC-M802 ?

Safc,
You're quite welcome!

FYI, I forgot something and should clarify a couple of things, too...
--- I forgot to comment on the PACTOR modem...
--- Clarification regarding AT-141 placement...
--- RF / Antenna ground...
--- Antenna with twin-backstay rig...
Quote:
Originally Posted by Safc View Post
I explained the shop I wanted a seperate antenna for my M802 (Don't want to use the backstay and I prefer not to start a discussion about it). I also explained I want to use all features of the radio, so voice, DSC and e-mail via the pactor 3 modem.

Any better ideas ? What IS the best DSC (passive) antenna for the M802 ?
(I know it's only to receive DSC calls)

Thanks guys !
Quote:
Originally Posted by Safc View Post
Hi John,

Thanks a LOT for the info again !

Definately helps !

Just ordered the radio, tuner & pactor modem. I'm gonna take my time to decide what to do with the antenna & ground, but that'll be for later.

I like your antenna ideas, I'm probably gonna go with the self made rope antenna & the uninsulated shroud as DSC reciever antenna.

As for the ground, I'm still in doubt... Seems easy to make a KISS myself, not worth spending a lot of money on that... On the otherhand, a dynaplate still gives better results I guess...

For the AT-141 unit: ok, not near the autopilot. My other option is near the gas bottles... Also not very sexy to have HV near the gas tanks... Not much other options I'm afraid.

Brgds,
Safc
1) Regarding a PACTOR modem...they are nice pieces of kit, and do work well....but for most sailors/cruisers their only real use is to connect with Sailmail (a great service, BTW) and thereby give you e-mail connectivity when at-sea and/or in remote locales (away from terrestrial cellular/moble networks and/or Wi-Fi)...
Just wanted you to be sure that you have some specific need for this remote e-mail connectivity before you spend ~ $1500 - $2000 USD on a PACTOR modem...
Fyi, if you perceive needing the PACTOR modem to access offshore weather when at-sea and/or in remote locales, understand that it is not necessary at all....unless you are planning some rather obscure cruising, most sailors/cruisers (including circumnavigations), have free access to some of the best offshore weather info/forecasts:
--- NAVTEX (for near-offshore),
--- HF-WeFax (world-wide coverage....and that from US, Aus, NZ, UK, etc., considered the "gold standard" of offshore weather info/forecasts),
--- HF-Voice weather broadcasts (US, Aus, and NZ, covering almost 1/2 the world),
--- SafetyNET text forecasts (either via HF-SITOR or INMARSAT, mostly covering large ocean areas without too much detail)....
--- and of course the abundance of HF radio "cruising nets" / "passage nets" (both marine and ham, covering many popular cruising areas and routes)....
None of these require any PACTOR modem, nor any fees / subscriptions...
Again nothing wrong with wanting a PACTOR modem, they're nice....and Sailmail is a great non-profit service....just wanted to remind you that you don't need it to "get weather"...




2) Clarification regarding AT-141 placement...etc...

I don't have a Bene 411....and have never been on one...
So, I will defer to you as to "where" you can fit equipment / install things...
But, I did go on-line and looked at some photos and read some interesting postings from some bene owners....

a) I didn't intend to force you to totally abandon your planned mounting location for the tuner, just wanted you to be aware of the potential for interference (primarily from the radio / when transmitting....interfering with the autopilot)
This is not an absolute....and since I don't have a Bene 411 with a marine HF radio and tuner mounted near autopilot course computer / corepak, I cannot offer an absolute....(understand that it is the close proximity of the tuner's output, to the autopilot corepak AND to the autopilot wiring, that is the issue...)
You may find no issue at all...
You may find that ferrites on the autopilot wiring eliminate any problems...
Or you may find it to be a real problem that isn't easily solved without moving the tuner (and antenna?) further away...
[This is why I recommended testing the whole system out before final install/mounting.]

b) Also, while I've never heard of any high-voltage RF sparks causing any propane problems / fires / explosions.....I honestly never even thought about it until I read your words above...
Although my gut says it's not something to worry about, my brain (and my decades of electronics experience) says "you never know"...
But, in your case, I doubt there is enough room to mount the AT-141 in your propane bottle locker....certainly not enough room if you have two bottles in there (as I assume you will)...


So, with these prefaces, please confirm that these photos accurately depict your Bene 411, or are pretty close to it???
















It seems there is a lazarette on the starboard side (opposite the propane locker)??
And, this is where you had originally wanted to install the AT-141???

Again, this might be okay....you will need to check this out yourself...but be aware of the potential for RFI (especially into the autopilot) if it is mounted close to other electronics systems / wiring...

Also, it appears that there is also a cockpit locker and possibly adequate room to install it in the aft cabin (either on stern bulkhead or overhead)??

Or, possibly under/inside the transom/swim-platform?? Or inside the upper part of the "sugar-scoop" / transom?? (I can't tell from the pictures I have)

Also, remember that the AT-141 is weatherproof on its own and can be mounted outside (such as attached to the sternrail or arch)....I would recommend an additional outer cover / box to add additional weather protection, and it should be fine....although this is not ideal as it does expose the wiring to the weather, and provisions should be made to protect them, as well...

The point I'm making here, in addition to showing you that you do have options....
Is that like I wrote earlier...."every boat is different" and "every owner has different applications / desires"....and everyone has different compromises to make!

Just be sure to get a good antenna ground!


3) Regarding RF / Antenna ground...
When you write:
Quote:
Originally Posted by Safc View Post
As for the ground, I'm still in doubt... Seems easy to make a KISS myself, not worth spending a lot of money on that... On the otherhand, a dynaplate still gives better results I guess...
I can't help but to cringe a bit... (sorry)
But, again, I don't have a Bene 411....but don't you have bronze thru-hulls??? (mine are Marelon, but I thought yours were bronze?)
If you have good-quality bronze thru-hulls, and one is within 8' - 10' of where you'll install the tuner, you're in good shape...all you need is <$50 worth of 3" wide copper strapping, and at most a couple hours of your labor, nd you'll have a good RF / Antenna ground...
(yes, Dynaplates work, but no better than a solid bronze plate of the same size....and it has been proven that while the contact area is smaller, bronze thru-hulls work as a way to connect to the sea water, too!)

AND/OR...

And/Or, run some strapping (or wire) to the alum toerail (be sure to make connection into the alum, not on the anodized outside of the alum), pushpit bases, stanchion bases, your arch bases, your metal tanks (?), etc...and then even run a strap up to your keel bolts...
And, you'll have a good RF / Antenna ground....

Only if you don't have bronze thru-hulls, and cannot afford Dynaplate, and do not have the time to crawl around and connect all the above metal items to your RF / Antenna ground system....then can you spend 5 minutes making up some radials (i.e. a better KISS)
And, depending on how many radials you make, you can also have a good RF / Antenna ground using them...(more is better, strung out as best you can is better...but just about anything is better than the KISS)
Please have a look here, for lots of info...
Re: KISS-SSB Counterpoise



4) HF-Antenna with twin-backstay rig...
Well, while I like the "rope-tenna" and "alternative backstay antenna", for most boats with twin backstays, they just don't make too much sense...
(yes, they can work...but..)
You will need to find a place to rig them that is not too close to the other stays, and still clear of your mainsail leech and toping lift (on all points of sail)...
For boats with in-mast furling mainsails with no mainsail roach (and some even have a hallow / negative roach), this isn't too hard, but it you have a standard main, you're out-of-luck...

Further, I'm a fan of not cluttering....

For me, on my twin-backstay boat, with its massive rigging / mast / chainplates, etc., I went with Hayn Hi-Mod insulators...
And, while I know you wrote up-front that you have decided against them, I still place this as my number 1 recommend here...(again, based on having twin-backstays, an arch, etc...all on a 41' boat...)

I'd place the "rope-tenna" or "alt-backstay ant" as number 2...
(understand they usually will perform the same as an insulated backstay, and hence would be tied for "number 1"....but when placing a rope-tenna or alt-backstay antenna nearby two other backstays on a 41' boat, there will likely be a performance detriment compared to another like boat with an insulated backstay antenna of the same length....my guess the difference would be slight, just wanted to throw it out there...here again, I cannot give an absolute "number", but just offer advice based on my knowledge and years of experience...)

And, a nice long whip as number 3...(remember as I wrote earlier, complete dismastings are very rare....but if it does happen, chances are any "whip" will be gone or destroyed, as well...)




5) Again, for some of this "boat specific" info/recommendations, I cannot offer absolutes...as I don't have a Bene 411....but you may wish to read what others have done....
If it were me, I'd join the owners group(s) and ask existing owners what they have done....
Many times it's appropriate to ask the guy selling/installing the radio, but in your case I wouldn't trust him to take the radio out of the shipping box, let alone trust his recommendations (or experience???)

In just a quick few seconds, here is what I found....(via google)
https://groups.google.com/forum/#!ms...4/cnKl4g4ngeoJ

I suspect there is a lot more out there....just didn't look any further...




I hope all the above helps...

Fair winds...

John
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