Eliminating static on SSB

[ka4wja]

George,

You're welcome....and have fun on your cruise (and good luck on your testing)
No worries about taking a few days...we all have lives...


A couple quick thoughts:

1) You should ignore any reference to checking your VSWR between your AT-140 and your antenna...because there is no "between you tuner and antenna", because your tuner (AT-140) is part of your antenna....

And, of course there is no "coax" between your tuner and antenna...(the wire that looks like coax to some is GTO-15 hi-voltage wire)

Just ignore these suggestions, as they are confusing the matter...



2) As you may already know, you can easily check your M-802's power output and your tuner's ability/capability to "tune" (check the approx. VSWR that it is providing to your M-802), by just looking at the M-802's display....{as mentioned in detail in the stickes}

All you need to do is, Press the Func key and then 9 (which selects the M-802 to high-power transmit)....

Then select a few different channels on various bands (I always suggest using a channel that you have not used before, or that you haven't used in a long time....on each of the HF marine bands), and do the following on each:

a) select a channel and then press the TUNE button

b) press the MODE button to select FSK mode (FSK will show at the top center of the display)


c) the use the microphone's Push-To-Talk (PTT) button to transmit a solid carrier

d) make note of two things on the display....the "power output meter / bar-graph" (on the bottom of the display)....and the "TUNE" indicator (on the top line of the display, near the left side)

--- If your VSWR at the M-802 is approx 1.7:1 to 1.8:1 (or below), the top line (near left side) should display "TUNE".....if it is flashing "SWR", your VSWR is approx 2:1 or so....if it shows a solid "SWR", your VSWR is over 2:1.... (if it shows "THRU", then the tuner is not operating properly, and/or not connected, and/or the M-802's internal 5amp fuse is blown)

--- If the power output bar-graph shows all 8 segments, you have 140-150 watts output....4 segments is approx. 60 - 65 watts ("mid"-power from the M-802)....and 2 segments is approx 20 watts ("low"-power from the M-802)...


In order to check your output and approx. VSWR, that's all you need to do....



3) As for your lightning strike....consider yourself darn lucky! 'Cuz usually a direct hit to your mast, melts / explodes your VHF whip, fries the masthead lights, damages the VHF radio (and coax) beyond repair, and usually fries the AT-140 as well....(as I wrote my M-802 survived, but did have some damage of the tuner control circuit, etc...but my AT-140 had some of its coils and caps looking like bits of charcoal!!)

If you didn't see the scorch mark on the masthead, and/or didn't have an exploded VHF antenna (or an burnt lightning rod, if so equipped), then chances are you suffered a side-flash / close strike, rather than a direct hit....of course, I'm not there, and I haven't surveyed your boat, so I'm not going to be arrogant and say that I know for sure what happened, just passing on my experienced thoughts....

And, my advice is to get a complete electric / electronics evaluation done by a reputable marine electronics shop.....just to be sure...



4) As for the Renogy MPPT controller (assume the new tests you do at anchor show it is producing significant RFI)...unless you get a nice response back from them offering to replace it, my advice is that you return it to the dealer you got it from and ask for a brand/model that doesn't produce RFI (BlueSky, Morningstar, etc.)....

And, then install it away from the AT-140 and GTO-15 wire.....install it close to battery switch / close to batteries / close to bus bars / close to nav station...



5) As for the Link Pro? I've not heard about them causing RFI....so, I'm assuming its your particular unit....

But, let's wait to see what HF noise levels you get when at anchor, with everything off....and if your Link Pro is causing significant RFI....then let's see If they have a solution for you? (if it is producing a good deal of RFI, I suggest replacing it)




6) As for Icom, they'll take good care of you....but, depending on what their Covid19 operations look like, it might take a few weeks...



7) As for the videos.....as long as they're for your own personal use, you can download 'em and store them in your computer....so, you can watch 'em when away from good internet service....
Of course, you can watch them first, then just download the ones you think are important to you...






Again, good luck.....and report back here your results (it helps everyone to see what you find and what we can do solve problems)

John

[ka4wja]

n5ama,
A few quick points of clarification here:

1) This one is generic...
Checking VSWR on the output side of any "tuner" (antenna coupler, tuner, transmatch, tuning network, etc....whatever we call 'em), is only ever done to determine the mis-match thru any further transmission line (feedline) that goes from the "tuner" to an antenna...

Unless you have an antenna that is a perfect (non-reactive) match to the feedline, there will always be some mis-match between the antenna and feedline, and hence always be some "SWR" on the feedline...

And, in most HF systems, this mismatch isn't an issue...'cuz, of course the reflected power is sent back to the antenna and radiated (minus the loss of the transmission line, which in most HF systems is low)

Except for calculating this additional loss in the feedline/transmission line (resulting from this feedline SWR) this feedline SWR is fairly irrelevant....and in many HF systems (where feedline loss is negligible) this additional loss in minor and can be ignored altogether....

{although, in some situations, such as when the feedline SWR is extreme (close to infinite?) like trying to use a coax-fed 20m dipole on 80m, this additional feedline loss can be 20db or more....so, sometimes it matters....but usually irrelevant!}




2) This one is specific....
I think you may be confusing a few things here...perhaps you're not familiar with the AT-140 tuner??

The AT-140 is a single-end (aka "long-wire") remote tuner....
It is actually part of the "antenna"...

There is no "coax" on the output of the AT-140....but rather a single wire...and the AT-140 and this wire IS the antenna...

In most maritime installs, this "single wire" is GTO-15 (hi-voltage wire) which is typically a PVC outer-jacketed, polyethylene-dielectric, 14 ga stranded, tinned copper wire....


So, as you can see....there is no additional transmission line that would have an additional loss to calculate, and certainly none to insert a VSWR meter into, to measure anything....



3) I understand the many myths and misconceptions that abound in the world of "radios"....so, no worries here!

Heck, I know guys that have been hams for 30 - 40 years, that still don't have a clue about what I just wrote above in #1....

And, in the world of HF radios on-board boats there are way wayyyyy too many of these myths to spend much time explaining....but, since you brought up this point (about SWR on the tuner output), twice in this discussion, I thought it best to put it to rest...



I hope this helps clear up the confusion?

Fair winds

John

[n5ama]

I didn’t know how the 802 and it’s antenna was set up.

Checking between a tuner and a antenna tuner and the rest of the RF chain can in some situations be helpful if the coax is faulty or the antenna has issues.

Please forgive my ignorance of the 802. I certainly didn’t intend to confuse the issue.

[Bycrick]

Two data points for consideration.

One on boat, the owner was complaining about an irritating noise on his VHF radio. It sounded like a clock ticking. All the time. After a lot of chasing around, it turned out to be the Xantrex battery monitor. He ultimately replaced it since none of the simple solutions worked. He did have an HF radio, so we didn’t look for HF RFI.

Another boat with an Icom 710/AT130 setup had a lightning strike, but the HF stuff seemed to still work. Over a period of several months, her transmit signals seemed to degrade. Then she couldn’t control the radio from the Pactor modem. Ultimately, nobody could hear her when she transmitted.

When we first opened up the tuner, there was no visible damage. But when we opened the internal shield box around the circuit that measures the SWR presented to the radio, every component was black and the box itself was full of black dust. But it took several months before it "quit working."

So, keep looking. You’ll find it eventually.

[continuouswave]

An SSB signal contains amplitude modulation. Demodulation of an SSB signal will also demodulate any amplitude modulated noise or other signals.

To determine if the source of "static" or undesired amplitude modulated noise signals is from local sources, the method is quite simple:

--move the boat to a remote location, miles away from any other boats or noise sources;

--shut off every device on the boat except the SSB receiver;

--observe the noise floor level; it should be quite low, as long as you are not conducting the test in Summer during periods of thunderstorms which will produce very strong "static" or noise;

--begin to restore power to other devices on the boat, while monitoring the SSN receiver for a sudden increase in noise.

This method should allow any local noise source to be quickly identified.

Remedy of HF noise created by a local device is a complicated topic, so until a specific device is positively identified as the noise source, it makes little sense to offer general advice on reduction of local noise sources.

[gchabs]

OK folks, an update on the equipment. One significant find, I don't have a Link Pro, but a Link 10 (that may be an older model) so maybe a new one would obviate that issue? I shall make some inquiries. I also talked to Xantrex and they said to try re-connecting the Link so that it is connected at the opposite end of the battery bank where the MPPT controller is attached to the batteries (something about the battery bank then acting as a capacitor and reducing RFI?). If that doesn't help, they suggested ferrites on the cabling to and from the Link. So don't know if that changes peoples thoughts on correcting the static emanating from that piece of equipment. I did remove the fuses leading from the solar panel to the MPPT and from MPPT to the batteries, but that did not seem to diminish the noise emanating from that piece of equipment.

Renogy did respond and indicated their equipment is certified to create minimum RFI, but what is minimum, may be too much. In any event, they did suggest having a cut off switch from the solar panels to the MPPT might help. Why wouldn't disconnecting the fuses from solar panel fuse box to MPPT do the same thing?

Moreover, though all navigation electronics were off, once again using an AM radio, I got a significant bit of static from the Garmin "brain" which controls the connections for radar, speed, depth equipment, etc. It is located right next to the controller. So don't know what that is about. I'll contact Garmin and find out if that unit emits RFI when not operating any instruments.

Also, while three solar panels are not currently attached or connected, the cables for those panels are attached to a fuse bar which in turn leads to the MPPT. The active solar panel is also attached to that fuse bar. I found RFI on the cable from the active solar panel to the fuse bar connecting to the MPPT controller. Curiously, I also found RFI on the inactive cables. So I wonder, if they are reflecting the RFI back from the operating solar panel or the MPPT controller. Will disconnect them next time from the fuse bars and see what happens.

Anyway, now as to performance. Went out the last three days and anchored in an out of the way spot away from marinas, other boats etc. Turned everything off, except the Renogy MPPT Controller and the Link monitor. I really don't feel comfortable enough to start monkeying with my electrician's installations right now so I didn't disconnect them from the batteries. I'll address that issue with him in the near future. The difference in static while anchored out and at the marina was night and day. Volume and intensity of static decreased by a good 2/3rds. With the new level of static (1-2 on the sound bar), I was able to hear stations on the Chubasco, Waterway and 24-Hour nets, in Florida, Missouri, New York and New Jersey as well as Canada. I also heard WLO on 5 and 10 MgHz quite clearly. I could have probably heard more, but those were the ones I tried to listen to. This weekend seemed to be "Field Day" for amateur radio hobbyists, so I was able to hear a lot of traffic. I was also able to talk with several stations both at night and in the a.m. Some heard me better than others. When listening, the sound bar levels showed in the 1-2 range before someone spoke, and 3 and 4 when folks braodcast. Curiously, however, when transmitting and actually speaking to folks, the sound bar on my radio never got above 1 or 2 and in some cases, I didn't see any indication I was transmitting at all (though from previous tests, I know I am getting 140-150 watts at the tuner). Also, before I started listening and talking I checked my radio settings. Significantly, I found the sound compression on my 802 was turned OFF . Don't know how that happened, but it was. I changed it to ON. In addition, I made sure I was listening and talking with power set to high, Squelch off, Noise Blanking off and AGC off.

So, I now know transmitting and receiving is better away from my marina. I don't know however, if my 802 control head, 802 main body and tuner have been damaged. So, in order to be sure, I disconnected them and brought them home to send to ICOM. I'll do that this week. I didn't disconnect the cabling from the radio to the tuner as that would have involved significant below decks work in tight spaces in 90 heat. But my thought is, if either the 802 control head or main body or tuner demonstrate any damage that could be from lightning, I shall replace the cables anyway and do that crawling around in lockers then. If, however, neither exhibits damage, then I think the likelihood is that the cabling didn't get damaged either, and will re-connect everything at that time. Does that make sense?

As for the static from the MPPT controller, Link, solar panel and wires, Garmin brain, etc., I will work on ironing those issues out while my system is in the shop. Any further hints on how to do that would be welcome.

Any other questions, comments, suggestions, please do not hesitate to let me know. Thanks once again for all the assistance I have received. George

[Auspicious]

I knew when John got to this thread there wouldn't be much left for me other than to run around with a dust pan and brush. *grin*

Like John, I've found a number of MPPT controllers that are RF quiet. Many are quite horrible.

Originally Posted by n5ama

I didn’t know how the 802 and it’s antenna was set up.

Checking between a tuner and a antenna tuner and the rest of the RF chain can in some situations be helpful if the coax is faulty or the antenna has issues.

Please forgive my ignorance of the 802. I certainly didn’t intend to confuse the issue.

It's just an end-fed long wire. SWR at the output of the tuner is not meaningful since the instrument you are using is certainly a 50 ohm unit. As John pointed out, the antenna starts at the output terminal of the tuner. It's just wire. You can think of the tuner as a dynamic balun the matches the impedance of the GTO-15/backstay (which may be several hundred ohms) to the 50 ohms required by the radio.

With an antenna analyzer you can measure the impedance at a frequency of interest, but that information is not particularly helpful.

The only thing John didn't bring up--unless I missed it--is to check the connection between the GTO-15 and backstay. Those are often hose clamps (which are stupendously bad electrical connectors) and in a lightning strike your antenna could just be the GTO-15 taped to but not connected with the backstay.

[ka4wja]

George,
BTW, do take Dave's advice here....if you haven't done so (I think you mentioned that you did?), please check / repair the GTO-15 connection to your backstay....


Okay...now the loooonnnggg part.... LOL


George,


1) Well, good on you for getting out and doing some testing....and making some contacts!
And, good that you see/hear the difference when away from the marina!!

BUT>>>>
WHOA!!!!

Do NOT turn off the M-802's AGC!!!!
Please let me repeat this....'cuz, you sort-of "buried-the-lead" here....putting this info way down at the bottom of your posting!



Do NOT turn off the M-802's AGC!!!!

Leave the AGC "on" all the time!!! (there might be a 0.000001% of time, when switching off the receiver's agc, and riding the volume control, when using headphones, just might give you some minor receive advantage, but in 50 years of operating HF radios, on-land and at-sea, I've only done it once, and I can count on one hand the number of HF radio ops that have ever done so, even only once, in > 50 years.....so, please leave the AGC on!!!)
I'm not sure where / how you were given the advice to turn off the AGC, but please just leave it on!! Always leave it on!!! ALWAYS!!!


{oh, and on 5mhz and 10mhz, that's WWV, not WLO.... }





2) I really, really, wished that we has set-up a sked to speak on the air (or that you had internet out there in that anchorage, so we could have communicated by email, while you were out there), 'cuz there are many confusing / conflicting things you mention here in this new post, which could've easily been clarified with the M-802 on-board....(and ignoring some other info)

And, I will get to them in a sec....


~~~~~~~~~~~
Note that, in my opinion, some (much?) of the problems you're having figuring all of this out is because you haven't actually isolated everything (removed power from everything), and have also seemed to take some response from the Renogy as helpful?
My opinion, it's just them BS'ing you....if their product passes FCC Part 15 specs, either A or B spec, they'd quite happily supply you with that documentation....I could be wrong, but regardless, it is causing you problems on-board, so you have a choice:
a) replace it;
b) live with it;
c) move it, change where/how it's installed, and try to mitigate its RFI...



BTW, Part 15 Class B spec is the tighter, more stringent spec....yep, doesn't sound logical, but that US gov't rules/specs....
Oh, and further, a GREAT DEAL of these "unlicensed radiators" sold these days have never really been tested / officially certified....most manufacturers lie/cheat, provide false docs/test results, or just apply to "self-certify"....which is why I recommend staying way away from the mass-marketed made-in-china crap, and only recommend stuff designed, tested, certified, and sold by reputable companies....


Just saying....if you take all of my advice, and do all of these things, one-step-at-a-time, and ignore much of what might seem like logical advice....you will get it all figured out, and rather quickly....(usually takes no more than an hour, and mostly only about 30 minutes....but, I've heard of some sailors spending hours and days trying to figure all this out, as they didn't want to spend the time to do it right.... LOL)

George, I know, I know....that makes me sound like a jerk.....sorry about that....I'm not trying to be rude, just really just trying to make a point (if you don't follow the steps, it will be a pain in the ass, be frustrating to all involved, and can take days / weeks, instead of an hour!)
~~~~~~~~~~~~~~~




3) Again, a few reminders/clarifications....as I wrote earlier, when testing for RFI, etc....it is not sufficient to just have things "turned off"...rather you must remove power from these devices / systems, as there is usually something running in many devices these days, even when "turned off" (think about your TV set, your microwave oven, your telephone, your smartphone, your car stereo, etc....these are things you see, touch, use daily, that are using power / operating some circuits, even when you turn them "off")....

I'm not there, I'm not on your boat, and I cannot see / hear what is happening....so, they only way to know what is going on / the only way to evaluate RFI is to have everything powered down, not just "turned off"....

So, whatever your results were, I'm not sure how to evaluate them, as you mention still getting RFI from some things that you say are "off"...

Heck, I've heard from some sailors that their "AA-battery-powered" digital clock / weather station was causing their on-board RFI....and another who thought their sat phone charger was "off", but it wasn't....and have heard from others that electronic bilge water level switches, caused their RFI...
Bottom line, before testing for on-board RFI, everything (except the M-802) should be disconnected from power...and that's usually pretty easy-peasy, by just switching off the main battery switch and switching off the solar panels.....(there should be nothing else connected to the batteries at all, except in some cases like yours the power/sensor wires from your shunt to the Link 10....so, just disconnecting those wires to your Link 10, and pulling the fuses from your solar array/mppt controller, should have powered down everything???)

If you still had power going to some things/devices, it's difficult to know what's going on in regards to RFI...

We can come back to this in a moment....




4) As for the Link 10....two pieces of good news there (well, actually one and a half!)...

Yes, having the shunt and its wires on the opposite end / opposite side of your battery bank as the wires connecting your MPPT controller(s) is good advice from an RFI stand-point!! BUT.... But, if you have your MPPT controller output going to the batteries directly, not going thru the shunt, this pretty much defeats the purpose of the Link 10....as it will not be counting any amps coming into the battery bank, from your solar panels.... So, this is like one-half a piece of good news....Xantrex actually seems to know something about RFI (yes, the battery bank does act like a big capacitor)...

The other piece of good news here is that I've not seen Link 10's producing significant RFI....so, if yours is, then yours is most probably damaged by your lightning strike, and hence can be replaced.....

So, as for the Link 10.....you may have a rather easy fix...replace it....and also maybe add some ferrites on its wiring!!




5) As for your MPPT controller.....have you contacted the person you bought it from and asked to exchange it? (as I originally suggested)???
Exchange / return for a different brand / model that does not produce RFI, regardless of what Renogy says.....or has Renogy offered to refund / exchange this??

If not, I still highly recommend you do that asap....if you have and they refused, I understand not wanting to spend more $$$....


Please know that if you remove power from the MPPT controller (usually just the output, to the batteries, but some of them will need the input from the panels disconnected too), you will not have any RFI from it....nor will any decent solar panel produce RFI just sitting in the sun, not connected to anything....
(although, technically it is possible for some of the cheap, made-in-china crap panels, to produce RFI on their own, as they may have poor internal connections, etc. poor internal bypass diodes, etc....I've never heard of this happening, and it is very, very unlikely, but I guess it is possible)

In my experienced opinion, the reason Renogy suggested a "cut-off switch" for your panels is so you would simply switch off their inferior product when you desire to use your radio (like we'd all have the forethought to do this in emergency situations?)....and you'd not demand a refund and still be able to use your radio....

But, as I wrote last week....you should not have your MPPT controller(s) near your antenna / near your AT-140....and again, not knowing how/why you decided to install it nearby your AT-140, makes it difficult to fully blame Renogy here....

Again, I'm not there....so, I can only advise on what is the best practice, not on what/how/why you made the decisions to install an MPPT controller near the AT-140?




6) Back to #2....
a) You make no mention of what band / frequency you were tuned to, and at what times of the day you were tuned to those bands/freqs, when you saw only one to two segments of the M-802's receive S-meter illuminated, with noise??

I wrote in quite detail as to what it should show on various bands/freqs during daytime and nighttime, but you make no mention of the details here...

Yes, we see that your noise level is lower at anchor / away from the marina....which is good....and that is all but an accepted fact-of-life.....
But, we don't know what your noise level was on various bands/freqs, at daytime and nighttime on each of these various bands/freqs....
Without that info, and without having everything powered off (you mention a "Garmin brain" being powered.....this could be an autopilot corepak, or a NMEA2000 buss, or ??), it's darn impossible to know what RFI you have on-board....

Yep, we know it's less than what you have at the marina....and yep, you can hear stations and make some contacts.....but, is it easy-peasy, or still noisy?? And, what noise is there? Is it still objectionable?




b) Also, you mention "sound compression" being off....I assume you mean the M-802's internal DSP-based Speech Compressor??
If so, how are you verifying it is "on" or "off", and how are you turning it "on" and "off"?? Do you have a hardware mod to your M-802? or are you using the CS-802??
[BTW, leave it "on" all the time, unless you're operating from a very noisy environment, like near a running engine! Other than that, there is no need to turn it off...]


c) Also, you now mention you weren't transmitting much power at all, but in previous tests you showed 140-150 watts out....I assume those previous tests were "post lightning strike"?


But, whether pre or post lightning strike, this is another reason to send the M-802 off to Icom for evaluation and repair as needed...



d) BTW, I suspect your transmitting is better out at anchor for only two reasons:
---you switched "on" your M-802's Speech Compressor
---and you can hear other stations, so you can call/contact them.
....that's it....

Yeah, there is a slight improvement being out in the clear, away from buildings, etc....but, the variations in day-to-day (or even hour-to-hour) radiowave propagation are much larger than the minor improvement in transmit being away from marina....

Just saying again, HF comms is very easy-peasy and very predictable....but sometimes seems illogical to laypersons....



e) You may find frustration (wasting time) when trying to track down and eliminating RFI, without your M-802 on-board.....yes, your AM radio can be useful....but as you have already seen, you can get some misleading info from it.....

It's better to use an SSB (or CW) radio.....it should have a BFO....but, if all you have on-board is an AM radio, you can try it...

And, while moving it around to find offending devices is good.....you may also need to connect it to your backstay, and then do as I prescribed earlier regarding removing power from everything (except in this case, your AM radio), and using your AM radio's receiving of RFI to help you mitigate it....
Of course, using your M-802 is best....and this is why I wished we have talked while you were out there at anchor....(btw, I will be away from the boat for a couple weeks.....so, it'll be online here, until mid-July)



f) I concur with your approach on changing the tuner control cable and coax, from the M-802 to the AT-140....that can wait 'til you get the M-802 back from Icom....
(yes, I know it's a pain to snake new cable in....but, fyi, you may need to do this anyway with DC power wiring from your solar panels, down to your Nav Station, etc....where you should have the MPPT controller installed...away from the AT-140 / GTO-15)


g) Also, not knowing if your "Garmin brain" is new or not.....but, as you write that it is right next to the 'controller" [assume you mean the Renogy MPPT controller?], and you previously wrote that the Renogy MPPT controller is near by your AT-140? (in a locker / lazarette, near the AT-140?)
FYI, you may need to move this "Garmin brain" as well....as it appears to be a source of RFI? (if it is a source of RFI, it should be no where near the AT-140 / GTO-15....and should be close to batteries, breaker panel, etc...)


Gosh, there is a lot more....but, I'm pretty hampered by the limited info I have here to work with....





7) Oh, and also while using an AM radio to sniff out RFI can be good....but....
It can also hear noise when placed close to wiring/cables that are not connected to anything....as it's picking up noise....whether RFI or atmospheric noise, I don't know, 'cuz I'm not there...(but, yes, you can be hearing re-radiated RFI)


Usually not a good idea to place the AM radio along/next-to wiring, unless this is wiring coming from an RFI producer, as this can have you chasing-your-tail....LOL

Fyi....this is another reason why it is vital to actually disconnect things, not just power them "off"....that way you know what you're hearing (above any atmospheric noise that I detailed earlier) is actually RFI....





8) BTW, you now mention something new...you mention something about an electrician??

You never mentioned this before....who is he/she? Where are they?
Were they involoved in some (all?) of the new electronics since the lightning strike??
Was it they who sold you all the new equipment?? (especially the Renogy MPPT controller?)

What have they done to eliminate / mitigate your RFI?

I wasn't aware that a "electrician" was involved in any of this, as I would've had you talk to him/her immediately upon noticing this RFI, and if they were unable to do much, I'd have had them give me a call, so I could point them in the right direction....




George, again, I know it might sound like I'm being a jerk here....demanding this, asking that....
I mean nobody would blame you for saying out loud "Hey, I'm trying....who does this guy think he is?"
So, please just know, you did good....just wish you'd done a bit more....



Good luck and Fair winds.

John

[Auspicious]

Back with my dust pan and brush. *grin* Please note that John and I have worked together like this before. If I skip over something I said it’s because I agree and don’t have anything to add.

Originally Posted by ka4wja

Note that, in my opinion, some (much?) of the problems you're having figuring all of this out is because you haven't actually isolated everything (removed power from everything), and have also seemed to take some response from the Renogy as helpful?

Agreed. What I have done in the past is disconnect the main cables to the batteries completely and use jumper cables to power the HF/SSB radio. That gets everything except solar panel chargers and battery operated stuff off the air. Disconnect wires from your MPPT charger (don’t trust switches). Pull the batteries from anything electronic. Label EVERYTHING.

Originally Posted by ka4wja

I know, I know....that makes me sound like a jerk.....sorry about that....I'm not trying to be rude, just really just trying to make a point (if you don't follow the steps, it will be a pain in the ass, be frustrating to all involved, and can take days / weeks, instead of an hour!)

If John was being a jerk you’d know it. *grin*

Originally Posted by ka4wja

3) Again, a few reminders/clarifications....as I wrote earlier, when testing for RFI, etc....it is not sufficient to just have things "turned off"...rather you must remove power from these devices / systems, as there is usually something running in many devices these days, even when "turned off" (think about your TV set, your microwave oven, your telephone, your smartphone, your car stereo, etc....these are things you see, touch, use daily, that are using power / operating some circuits, even when you turn them "off")....

See my note above. This is also why it is important to get off the dock. You have an unknown number of inverters, battery chargers, refrigerators, pumps, air conditioners, power supplies, and no end of other things on boats around plus shop gear at your marina including welders, air compressors, wood working and metal working tools, and more. Get off the dock. I don’t know which side of Deltaville you are on. If to the South there is good anchoring in a number of places in Fishing Bay. To the North you can anchor inside 7R.

My preference is to do testing during grayline in the morning. You might want to head out in the afternoon, anchor, have dinner, watch a movie, go to bed early, and get up in the morning for testing. Disconnect everything and start by getting a baseline for static in all the bands of interest to you (probably 4, 6, 8, and 12 MHz and 40, 30, 20, and 17 meters). Listen to a local AM radio station (see https://radio-locator.com/cgi-bin/lo...ville&state=VA and scroll down for AM). Then listen for WWV. https://www.nist.gov/pml/time-and-fr...o-stations/wwv - probably 10 MHz for you. Then Waterway Radio Net on 7268 MHz LSB. Then Cruiseheimers on 8152 MHz USB. WWRN is good because you have net controls with outstanding radios and huge antennas. Cruiseheimers is talking to other boats. Write everything down – don’t count on memory.

If everything seems to work your static problem in the marina is off the boat. I still worry about long-term issues from you lightning strike as John mentioned.

Originally Posted by ka4wja

I'm not there, I'm not on your boat, and I cannot see / hear what is happening....

I’m not there either but I’m closer. Deltaville is a haul for me but if you can get up to Herring Bay (HHN for example) I can come help.

Originally Posted by ka4wja

f) I concur with your approach on changing the tuner control cable and coax, from the M-802 to the AT-140....that can wait 'til you get the M-802 back from Icom....

There is a natural tendency to pull the small connector on the tuner control cable. Don’t do that. That connector is fragile. Pull the big end through. It’s much more robust. You’ll still want to support the heck out of the connections with tape. Use hitches on your cable and support the connector. Don’t pull on the connector.

[gchabs]

Once again, thanks for all the info and advice. To begin with, I take no offense at any recommendations to do certain things to help with my problem and don't consider anyone "jerky" for taking the time out to offer their suggestions. Rather I really appreciate the assistance. So, no worries.

Let me now address some of the questions and comments raised and I hope they provide some more background.

I turned the ICOM Speech Compression feature on by accessing the unit's set mode B and changing the feature on. I know that it is on having returned to the feature and insured that it remained on.

Ok with keeping AGC on.

I changed the GTO wire about a week ago, prior to my shakedown cruise.
It looked a little corroded, so I decided to buy new GTO wire and replace it.
I used a Go To Bug bolt on clamp to connect the GTO wire to the antenna wire. That too was cleaned prior to attaching the new GTO wire.

The tests using an SWR meter showing broadcasting at 140-150 watts, etc. were all done several weeks ago, post lightning strike and if I remember, post new GTO wire.

As for the Garmin "brain" I talked to Garmin and they indicated that with all electronics turned off at the panel, they see no way that the unit itself is receiving any power or producing RFI. As they told me, when they are off, they are off.

Any mention I made of an electrician in prior posts refers in fact to the mechanic I have used for years who has been putting the boat back together. While he knows quite a bit about electronics, he would admit to not being an expert on RFI and SSB's and has indicated a willingness to implement whatever recommendations are made to solve the problem. He recommended the Renogy MPPT controller as it is very efficient. However, he also is aware of my concerns re: RFI and is looking to see what other options might also be available.

The MPPT controller is currently located in the port cockpit locker next to the Garmin brain. The AT-140 is located in the starboard cockpit locker, probably some 8-9 feet away. To move the MPPT controller into the salon closer to the batteries, would then place it within four feet of the SSB radio control head and main unit. So, would that be an improvement?

I took some notes about some of the frequencies I was on and what type of results I obtained, but did not do a thorough review of others because I felt if the radio was malfunctioning, any results would be invalid. So, I stopped further efforts. I plan on doing a thorough review along the lines suggested once I get my radio and tuner back and assuming it is ok. I hope that was not a mistake.

Finally, I am taking the entire thread with me tomorrow as we do another four day cruise. I shall attempt to unplug and disconnect everything I can and try to find the source of the RFI if at all possible using an AM radio. I shall report back when I return. One final question, I have been using the AM radio set to the highest AM frequencies. Is that appropriate, or should I try the lower frequencies.

Anyway, once again, thanks for all the help. George

[ka4wja]

George,
You're very welcome!

I few specifics here in red...

Originally Posted by gchabs

<snip> ...
I turned the ICOM Speech Compression feature on by accessing the unit's set mode B and changing the feature on. I know that it is on having returned to the feature and insured that it remained on.
Cool....that's good...
(fyi, not sure if Icom will ship unit back to you with it stll turned on, or not....I think they will, but be sure to check it upon reinstalling your M-802)



Ok with keeping AGC on.
Yep, leave it on....and you'll be good-to-go...



I changed the GTO wire about a week ago, prior to my shakedown cruise.
It looked a little corroded, so I decided to buy new GTO wire and replace it. I used a Go To Bug bolt on clamp to connect the GTO wire to the antenna wire. That too was cleaned prior to attaching the new GTO wire.
Sounds good!



The tests using an SWR meter showing broadcasting at 140-150 watts, etc. were all done several weeks ago, post lightning strike and if I remember, post new GTO wire.
This is also good!
(and, btw....I know you've made some post-lightning contacts. so we know your M-802 is working [which is wicked lucky!]....we just don't know how well it is working, and/or if something internal is damaged / close-to a failure....which is why it's good to send it off to Icom...)



As for the Garmin "brain" I talked to Garmin and they indicated that with all electronics turned off at the panel, they see no way that the unit itself is receiving any power or producing RFI. As they told me, when they are off, they are off.
I'd usually assume that a manufacturer knows there stuff well enough to take this as gospel....but...

But, two things here make me wonder...
a) there is a difference between turning something "off" and removing power from it...
b) you suffered a lightning strike, so there can be some weird things going on....

So, while it's possible that your reception of "noise" on your AM radio, when placed next to the Garmin "brain", is just an increase in natural noise or other radiated RFI, because you're coupling the AM radio to this "brain" and its wiring, and therefore just receiving more noise/signal....
While that is possible (and probable) it is also possible that there is still power applied to that "brain"....

You see, this is one of those issues / stumbling blocks that come up when we try to troubleshoot from long-distance!

{if you can find out what this "brain" is, and you can find out what electrical power it uses (NMEA2000, 12vdc, etc. etc.??), then you can make sure it doesn't have get any power, when doing your tests...}




Any mention I made of an electrician in prior posts refers in fact to the mechanic I have used for years who has been putting the boat back together. While he knows quite a bit about electronics, he would admit to not being an expert on RFI and SSB's and has indicated a willingness to implement whatever recommendations are made to solve the problem.
That's good....


He recommended the Renogy MPPT controller as it is very efficient.
All MPPT controllers basically do the same thing....and, yes some are better / more efficient (but a percentage point or two difference in efficiency can be hard to see/realize in the real world)


However, he also is aware of my concerns re: RFI and is looking to see what other options might also be available.
Depending on your solar array....number of panels.....number of MPPT controllers....wattage of each panel....wattage of total array......parallel, series, or parallel/series combined....voltage of panels.....multiple runs of wiring, etc. etc....
All of those would determine what MPPT controllers to look at....and I freely admit that I haven't personally tried some of the newer ones on the market, but I have used and personally recommend Blue Sky MPPT controllers (some models) and Morningstar MPPT controllers (some models)...




The MPPT controller is currently located in the port cockpit locker next to the Garmin brain. The AT-140 is located in the starboard cockpit locker, probably some 8-9 feet away. To move the MPPT controller into the salon closer to the batteries, would then place it within four feet of the SSB radio control head and main unit. So, would that be an improvement?
Well, 8 - 9 feet away should be okay....(but, farther is better, especially if you have a noisy MPPT controller....distance is the most important factor in RFI mitigation....orders of magnitude more important than "ferrites"!)

In general, getting any RFI producing device as far away as possible from your antenna (AT-140, GTO-15, and backstay, etc.) is always best!!
(And, we are assuming that your Renogy MPPT controller is producing RFI..)

The exception is when you'd be adding additional wiring to a system, and this wiring would have RFI flowing/radiating from it...and if this additional wiring was to run near and/or parallel to your antenna (AT-140, GTO-15, Backstay)....

Of course, since I'm not there, and since we don't have a real accurate way to tracing/measuring the RFI, this can be a crapshoot...but, most times, the general rule applies...

Please see pics below, showing my solar array, my backstay and GTO-15 wiring passing right thru my solar array....and showing my two Blue Sky 2512ix MPPT controllers, installed just inches away from my M-802 main unit and control head....NO RFI issues here...


FYI, the M-802 is a great radio, and is designed for marine use where close proximity to other things / devices / systems is considered (unlike many modern ham radios)....and as such, if you use proper wiring / cables, it is usually not an issue having other devices near / next-to the M-802...(again, this is "usual" and "typical", so there are exceptions...)


Since, when using modern marine HF radios, most on-board receive RFI, is "radiated RFI" (meaning it is radiated / transmitted by other devices / systems on-board, and received by your HF radio antenna.....the goal is to get any RFI producing devices and their wiring as far away from your antenna (backstay, GTO-15, AT-140) as possible....
(again, there are exceptions, but the general rules apply most of the time!)


Btw, you really need to get a good grasp of what electronics you have on board....please have a look and figure out what that "Garmin brain" is...



I took some notes about some of the frequencies I was on and what type of results I obtained, but did not do a thorough review of others because I felt
if the radio was malfunctioning, any results would be invalid.
No worries here....but just fyi, any noise you hear is important to note, and any reduction in noises (whether due to be away from the marina, or due to having removed power from RFI producing devices) is good!! No matter if your radio is malfunctioning or not, noting the noises and any reductions are valid pieces of info....


So, I stopped further efforts. I plan on doing a thorough review along the lines suggested once I get my radio and tuner back and assuming it is ok.
Sounds good!

I hope that was not a mistake.
No mistake here....you're doing good...
(heck, you're doing better than many professionals!)



Finally, I am taking the entire thread with me tomorrow as we do another four day cruise. I shall attempt to unplug and disconnect everything I can and try to find the source of the RFI if at all possible using an AM radio. I shall report back when I return.
Again, sounds good...


One final question, I have been using the AM radio set to the highest AM frequencies. Is that appropriate, or should I try the lower frequencies.
In general, yes the higher freqs of the AM broadcast band is a good way to use it....no need to change, nor worry about this...
FYI, due to the nature of AM radio (versus SSB, CW, etc.) "noise" can be difficult to assess / difficult to measure....so, even if you don't get a definitive answer to your problems, just take a breath and enjoy your cruise! (and remember you can get it working when you get your M-802/AT-140 back)

Anyway, once again, thanks for all the help. George

For examples of MPPT controllers installed next to the M-802, and not having RFI....Have a look at these pics....

My Nav Station....
--- the M-802 Main Unit is installed immediately behind the M-802 control head....
--- the Blue Sky 2512ix MPPT controllers are installed on the locker / panel bulkhead (within inches of the M-802), just behind and to the left of the stereo and chartplotter...













Have a look at the inside of these panels (these pics taken during my installation, while still working on things, so forgive the mess)...

Here you can see the M-802 Main Unit....




And, here are my two Blue Sky MPPT controllers (the two silver boxes)






-Here you can see my backstay as it passes an inch or two from two panels of my solar array....
-And, see my main GPS receiver, my AIS-VHF antenna (aux/spare VHF antenna), and my Bullet2HP Wi-Fi system, all immediately aft of my solar array (just 2 feet from my backstay)...
-Also, note the two grey cables (solar array wiring), just a couple feet from the backstay, that I ran as little parallel to the backstay as possible....
-Further, my AT-140 tuner is inside the lazarette / under the helm seat, just a couple feet from the backstay....













Sorry about the quality of photos....these are just what I have available on-line...


As you can see, if you use MPPT controllers that don't produce much (or any) RFI....like some Morningstar and Blue Sky models....and install them as far away as possible from your antenna (backstay, GTO-15, and AT-140), you should be fine...


Also, please note that MPPT controllers will adjust their load on panels to maximize the panel output power....and, while we desire as little voltage drop as possible (within reasonable cost and low complexity), whatever voltage drop we do accept should be between the panels and the MPPT controller, not between the MPPT controllers and batteries....and depending on your solar array and controllers, you'll likely have more current in the wiring between the controllers and batteries, where you'll need to take into account this additional voltage drop, and hence desire tom use larger wire gauge (and hopefully only a short length, versus the longer length going to the panels)

So, placing the MPPT controllers nearer to the batteries / farther from the AT-140 / antenna....is good practice for two different reasons...
{of course, many times both of these are ignored by (or unknown to) many sailors....and unfortunately even many "professionals" are ignorant of these facts...



So, George....good luck and happy testing!!

John

[Auspicious]

... and here I come with a dust pan and brush behind John. *grin* He didn't leave me much.

Is your MPPT controller in a plastic or metal box? If plastic, can you open it up and look inside for an aluminized coating? If plastic and unshielded you can make a metal box to improve shielding. Power is often floating so shields need independent grounds.

While you are doing homework, look up "single point ground."

[gatorman49]

I got in this VERY late. I apologize if this has been covered. First, I would attempt to turn off everything on the boat with a direct connection to a battery. Listen in the marina and outside the marina. IF you're lucky and its quiet, start turning things on one at a time and see what happens.



I didn't notice if this was mentioned but HF is generally very noisy these days, especially in a marina. However, propagation is about as bad as it gets right now. I am on the air quite a bit on the DHS SHARES system and we continually check comms and it is tough. Same goes with the propagation indicator on RMS Express if you use Pactor. You can see, with some degree of certainty, how bad things are.



Regarding SWR, you can have significant loss in coax to include a short and still get a flat reading. The only way to know for sure is to measure your power at your rig and at the antenna. You might be surprised. Of course, on a boat, your run is very short and this is probably not an issue.



All of this being said, HF conditions are about the worst I've seen in 50 years of operating. There might be nothing wrong with your system. One last thing. If you think another boat in the marina has a properly installed system, do a comparison.


Good luck. HF comms can be frustrating.


Oh, before I go, I'm sure someone on here will find an error in my advice in their manner of thinking. That's fine, no problem. I learn from mistakes.

[gchabs]

This is a follow up to the prior post seeking help. I have sent my 802 unit and tuner to ICOM to be checked out (no reply thus far), but was wondering if I could do something more while waiting for its return.

The 802 (main unit and control head), are normally housed near my nav table (port side middle of boat), and the tuner is in the stbd aft locker - approx 30-35 ft away. The coax and power cable from the 802 to the tuner travel along the port side headliner and are zip tied to other cables (stern light, solar panels to battery, AIS cable, VHF cable to hand mic, DSC antenna coax cabling and others). This bundle travels along the port side liner and into the port aft locker where the 802 cables split off and go over into the stbd locker and up to the tuner. As I have indicated, a new Renogy MPPT controller was recently installed and is located immediately next to the bundled wires in the port side locker right where the 802 cables split off from the bundled ones. Also located at that point is the Garmin Course Computer Unit (in prior posts I called it the Garmin "brain"). I have detected very noticeable RFI when checking with an AM radio emanating from the MPPT controller and Course computer. So here are my questions:
1. From reading a number of other posts on the forum, it seems that it would make for a better installation to re-route the 802's coax and tuner control cable so that they are not bundled to and in parallel with all those other wires. Option 1, I think I can direct the 802 cabling directly down into the bilge (our bilge is normally dry), aft and under the engine and then up to the stbd locker and the tuner. This route, however, will place the cabling near some wiring that connects the house batteries to the battery switches and other feed points in the boat.
If that is not a good idea, Option 2, I can direct the 802 cables back along the port side parallel to the bundled wires for about two feet (but about four feet below the headliner and from the wires), then down and under the aft bed into the port locker and then over to the tuner. The coax and control wires would always be parallel to and about four feet below the bundled wires until reaching the port locker where they would be directed to stbd and the tuner.
Option 3, is to route the 802 cabling back along the port side parallel to the bundled wires for about two feet then down and under the aft bed, then direct them immediately to stbd and then aft to the tuner. This would take the cabling away from the bundled wires altogether except for a two feet run. Please note, the routes under the aft bed would run the tuner control and coax two-three feet from the auto pilot flux gate compass module, which I assume would not pose a problem since I would not be using the auto pilot while transmitting on the 802. Which option sounds best.
2. If re-routing is a good idea, I may have to get a longer piece of coax to connect the 802 and tuner as well as a longer control cable from the 802 to the tuner. If so, does it matter if I buy a longer assembly of coax than needed (a pre-made assembly of say 40 ft.), and simply wrap any excess coax into a loop and attach it in the stbd locker somewhere out of the way? Or would it be better to be coiled and situated behind the main unit? Is the answer the same for the tuner control cable? For a length of approximately 40 feet, would I need to change the coax that came with the 802 (I think it is RG8). Would I need to change the control cable?
3. The DSC cable from the back of the 802 main unit to the DSC antenna is also part of the bundle of wires mentioned above and hidden in the head liner. If I understand correctly, keeping that coax away from possible sources of RFI is also recommended. So, the fact that it is bundled to those other wires seems like it would pose a problem for the DSC function? Should I re-route it as well? If so, would it be a problem to bundle it with the 802 coax and control cable to the tuner or should I keep them separate as well?
4. Currently, I have a 3" strap of copper from the base of my tuner running from the stbd locker to the rudder post and attached to the post via a tapped screw into the base of the post. I also have a Frigoboat keel cooler unit, which has a bronze plate attached to the underside of the boat on the stbd side. There are studs on the inside of the boat approx. five feet from the tuner, which attach the cooler to the hull. Would it help and improve my ground plane to attach a second copper strip to the keel cooler studs? Would it hurt?
I recognize this is a lot to ask, but I appreciate your willingness to provide much needed insight to my set up. Again, I thank everyone in advance for their assistance. George

[ka4wja]

George, I just saw your PM and your recent posting here....(I've been busy with family matters)

1) I understand the desire to "solve" the problems, and I commend you on your perseverance, but since you have no way of actually measuring your RFI until you get your M-802 back from Icom, I'm going to caution you to not waste too much time chasing-your-tail...yet!
And, FYI....much of the answers to these questions are there in the stickies (and the links therein), at the top of the Marine Electronics page here on Cruiser's Forum....hint: have a look, and be sure to read the Sailmail Primer as well...





2) Remember, I'm not there, so I can't see what you have, nor where the cabling is now, nor where it can go....so, you're going to have take these rules/facts and apply them to your boat and your installation....

Short answer: In general, don't bundle your HF radio wiring (yes, this includes your DSC antenna wiring) with any other wires....and do not put them, nor your antenna, anywhere near RFI producing devices...hint: get rid of that Renogy controller, and install a new/better one, away from the AT-140/GTO-15, and away from the HF radio wiring, if possible...and if your Garmin Course Computer (Garmin Corepak) is also causing RFI, get it as far away from the AT-140/GTO-15 as possible as well....



Long answer:

There are 3 basic approaches (and some additional guidance) to answering these questions on coaxial cable / shielded cable routing....


a) "in theory"
b) "in the lab" (measurable)
c) "in the real world"
d) additional advice/guidance



a = "in theory", there would be no RFI ingress into the coax / shielded-cables, nor egress RFI (transmit RFI) from your coax into adjacent cables/wiring, nor devices in close proximity to your coax / shielded cables....also there would be no common-mode RF flowing on the outside of your coax, nor would any device attached to any of these adjacent wires not have sufficient common-mode rejection filters/isolators....
So, "in theory", there is no problem running transmit/receive coaxes in the same bundle as other electronics cables/wires...




b = "in the lab", coaxial cable shielding can be measured (as can the shielding / isolation of other cables), and while the old adages handed-down for decades (by most of my fellow hams) about most single-shielded coax having 80-90db of isolation, and double-shielded coax being ~ 110-120db, these are actually unrealistic myths....
[Remember, isolation is all about distance and shielding....if you have no shielding, such as two antennas placed in the same plane, you'd need ~ 8 - 9 wavelengths of separation between them just to get 40db of isolation!! (one-wavelength is about 20-21db....and, luckily we don't generally have many devices or their associated wiring in the same plane as our antennas, so we gain a couple dozens of db of additional isolation here....which is good, 'cuz, I don't have a 500' long boat!) ]

The actual measurable isolation of "good quality" / name-brand single-shielded coax is ~ 60db to 70db...cheap, off-brand cable (marine chandlery / "Radio Shack"-type coax), is usually 10 - 20db less....and high-quality double shielded / continuous-shielded coax having about 90db - 95db of isolation (some as high as 100db, in controlled lab conditions)...
And, if you control any common-mode RF flowing on the outsides of the coax and other cables, and choke-off/isolate any common-mode RF as these coaxes/cables enter the equipment enclosures, then you can have a decently RF-tight system...
So, "in the lab", you could have RF cables running next to each other, without much interference...





c = "in the real world" (on our boats)....there are quite a few "if's" that determine what can happen...
--- "if" you have good coax
--- "if" your other wiring is well-shielded

--- "if" you control all common-mode RF on BOTH your radio cables/coax, AND on all other electronics cable/wiring (difficult to do, but possible)


If you attain these things, then it's likely that you have more "radiated" RFI (RFI from other electronics on-board [your MPPT controller and/or Garmin autopilot corepak, etc.] that is transmitted thru the air, and picked-up by your antenna causing receive RFI....and/or your HF radio transmit signal leaving your antenna and being picked-up by other electronics on-board and their wiring/cables, causing transmit RFI), than you will have "coupled" RFI (RFI getting into your radio or your radio's transmitter getting into your other electronics, via the cables being run together)...
BUT...


But, to be clear, it is generally "good engineering" (and what we hams traditionally call "good amateur practice") to NOT install any transmit cabling in close proximity to any low-level / sensitive RF wiring/cabling (to protect from transmit RFI)....and also "good engineering" to NOT install any RFI generating devices, nor their wiring, anywhere close to receiving antennas / systems...


So, this means keep your HF transceive cabling (transceiver coax, tuner control wiring, and DSC receive antenna) away from anything that can interfere!

But, on a boat, how in the heck do you do that??


Well, in the "real world" here (just like in the lab) this is all a matter of degree, and "good engineering"...
The farther away the better....if the wires are all bundled together now (touching each other, or within a inch of each other), then moving them so they are as little as 6" to 12" apart is a good improvement!

And, if you can route them a few feet away from each other, that's darn good, and should be great...especially keeping them from running parallel to each other, and/or keeping them as far apart as possible if they do run parallel to each other...



But again, this is a matter of degree....so, just do the best you can....get them as far way from other wiring/cable as possible, and also keep them from running parallel to each other as much as possible, and you should be good!



d = additional advice / guidance....
--- Bottom line: don't bundle your HF radio wiring (coax, tuner control wiring, DSC antenna, M-802 control head cable, SP-24 speaker wire, etc.) with other wiring on-board!! Keep them as far away as possible...


I'm not sure I should be making any specific recommendations, again 'cuz I'm not there, but also I don't know your boat, nor its systems (such as where is your heading sensor / fluxgate? and where does its wiring run? are you going to choke-off/isolate its wiring?, etc. etc.)

Also, I'm not clear if your "option 3" runs the cables bundled together for this "2 feet", or just parallel with them but 4 feet away?? If the former, then "option2" is the better approach, but if the latter, I'd say "option 3" is the best of the three approaches....although, again, I'm NOT there, and I do NOT know your boat, nor its systems, so it might just make things worse by introducing transmit RFI into your autopilot....not likely, of course, but again I don't know your boat and its systems....
So, please use the facts I present here and look at your boat closely....and do the best you can...

Finally...
Finally, go back to what I wrote earlier...your RFI is most probably all (or mostly) "radiated" RFI, and in that case, moving the wiring will make no (or very little) difference...
SO...
So, get the radio back, install it, and finish your RFI testing first, before you try to figure out what to do!

Unless you have time to waste, I cannot stress too much that until you finish your RFI testing (which requires your M-802 / AT-140 set-up and working), you'd likely be chasing-your-tail here!

{FYI, there is no issue coiling-up some ~10' of excess coax (and/or tuner control wiring), and, as you should have a "line isolator" on the coax at the tuner end (and adequate ferrites on the tuner control cable, back at the tuner end), both providing common-mode choking of RF.....then coiling coax, etc. nearer to the main unit will usually be okay, but you can also make use of this excess coax, etc., by running it a few turns thru a ferrite core / torroid, thereby giving you some additional common-mode choking...

Further FYI, while it's doubtful that you will, if you do find it necessary to move / re-wire your HF system, please do NOT buy any "low-loss" coax cable for this installation....do NOT use any LMR-type cable, etc....simply use a high-quality / name-brand RG-213 or RG-8x cable, made/assembled by a reputable company (DX Engineering, etc.)....some will go all out and use RG-214 (double-shielded), but usually unnecessary... }



--- I'm much more concerned about having RFI producing devices, MPPT controller and "Garmin Corepak" (especially your Renogy MPPT controller) in such close proximity to your antenna!!
Please remember your AT-140 is the start of your antenna, and your GTO-15 is also your antenna....not just the backstay....


{Again, I have to reiterate a caveat here...."I'm not there", and hence I cannot see/hear what is going on on your boat, so of course some of this advice/guidance is "general" and based on decades of experience, not based on your specific installation....so, while I'm 100% certain of the generalities, I cannot be 100% certain they all apply to you / your boat....case-in-point, your "Garmin brain" / Corepak should not be radiating much RFI, and if it is, it is defective and/or lightning-damaged, but, I'm not there, hence I cannot see/hear/know what is going on....and, since you don't have your M-802 there on-board either, you cannot really proceed much further on the "Garmin brain" / Corepak, yet...

I hope you understand this?

You're asking great questions, but they are questions you need to ask the guys that are there....not 1000 miles away....
I know, I know....they guys there, don't understand much of this....so, this is why you (and others) ask here....
Just be aware that unless someone with knowledge/expertise is actually there working on this, hands-on, all you can get here are generalities... }




--- More specifically.....I stand by my earlier recommendation to exchange the Renogy controller for one that produces less (little) RFI (like Morningstar or Blue Sky, etc.), and/or one that is FCC Part 15 Class B certified...

Also, move the darn thing (and any other RFI producing device, such as maybe your Garmin Corepak) as far away from your AT-140, GTO-15, and backstay as you can....as I wrote before, putting the MPPT controller closer to your battery switch / batteries as possible (not close to the solar panels), while still keeping it clean/dry and accessible to attach wires/work on it...




---- Further, I think I may have forgotten to mention a darn easy-peasy test to determine how much receive RFI you have is "radiated", versus how little may be "coupled"/conducted-in?
Of course, this also requires you to have your M-802 / AT-140 connected and working...
1- Away from marina, where you found lower noise levels, turn things (MPPT controller, "Garmin brain", etc.) on, and observe your ambient noise levels, on a few different bands/channels...

2- Then disconnect the GTO-15 wire on the top of the AT-140, so all you have for an antenna is the AT-140 itself....and observe your ambient noise levels again, on the same various bands/channels...
(are you noise levels significantly lower?)
3- Then disconnect your main antenna coax, at the rear of the M-802 main unit....and again, observe your ambient noise levels again, on the same various bands/channels... If your noise levels are even lower now, compared to #2 (where all you had was the coax and AT-140 connected), then you DO have some "coupled" / conducted receive RFI, and you must move those bundled cables, and choke/isolate your wiring to/from the M-802 / AT-140....(as well as doing the same to all of those other wires/cables, as these will be the ones "radiating" the "radiated RFI" that you're picking-up thru your antenna...)

{FYI, my guess is that most of your RFI is "radiated" and not "coupled"....but again, I'm not there. }





3) George, this all may seem like a lot to do (certainly is a lot to write!), but in actual practice this isn't a long process....
You just need to have a known working radio/tuner, and good cabling, etc...get the boat away from the marina....and spend 30min to 60min testing / playing around....






4) Antenna grounds....well, this subject fills many captures in engineering textbooks and manuals, and as such I'm not going to ramble on too much here, mainly because we have covered this many times in the past....and RF flows the same, and radiowaves travel the same, now as they did 10 - 20 years ago, and the same as they did in the 1920's and 30's, etc. etc.....
This is not new!

(and, here again....I'm not there....and you have the facts in the stickies and the links therein...)



Some brief comments:
a) Having a better antenna "ground", better connection to the sea water, and/or more connections to the sea water, etc., are never bad....and while there is nothing wrong with being a fanatic here (I am one, you know), once you've made a good low-impedance connection (or two) to the sea water, there is the law of diminishing returns....
It can't hurt, but once you've made one or two good connections, anything else won't show much (if any) improvement....
{FYI, while a good low-impedance direct sea water antenna ground is almost always discussed in terms of transmit antenna system efficiency/effectiveness, it can also help shunt/disapate some receive RFI, not usually necessary, but it can help in some situations...}



b) Do not mess with your keel cooler....just doesn't make sense and it's not necessary...


c) I have no clue how much of your rudder post is exposed to the sea water, so I cannot comment on whether you have an adequate direct sea water antenna ground or not....
{btw, on my boat there is very little, to none, of the rudder post exposed to the sea water, so this would not be a good antenna ground for my boat....but, I don't know your boat....so, I have no clue what your antenna ground is like...}



d) Do you have any underwater bronze thru-hulls?? Connecting another copper strap from your tuner to an underwater bronze thru-hull, that is within a few feet (less than 8' to 10') is always a good approach...
{btw, I have all Marelon thru-hulls, so I use two big Dynaplates, 18" x 6", each...}







5) As for HF DSC signalling you inquired about?

Finally, I have looked at all your videos and have some questions about DSC operation. As I understand it, when broadcasting a test, routine, safety, urgency or distress call using DSC, the signal is sent out by the 802 via the antenna you have hooked up to your AT-140 tuner (your shroud or a long wire). Is that correct?

a) Yes...ALL transmitting, on all modes (SSB, DSC, CW, FSK, PACTOR), uses your main antenna....all the time....no exceptions!


b) BTW, for you now (and for most sailors with a M-802), don't worry about the "DSC Watch Mode", nor "routine" DSC signalling....
Unless you (and some other sailors) have predetermined a set of frequencies to use to send/receive "routine" messages (such as for an offshore rally or a regional group), you will not be sending/receiving any "routine" messages....
(as I have mentioned in the past, "routine" DSC messages were intended to be for coordinating "public correspondence"/phone calls/messages, for ship-to-shore and shore-to-ship comms....and/or coordinating ships/fleet business....and since being designed as such, 20+ years ago, most of this is now handled by sat com and/or scheduled FSK/PACTOR comms)




c) So, concentrate your "DSC education" on "Safety", "Urgency", and "Distress" signally....
FYI, while the USCG has set-up automated DSC test acknowledgements (ACK's), these are only set-up on 4207.5khz, from 3 locations....so, the USCG staff has accepted that "testing" your DSC system using a "Safety" DSC call is now okay with them...(although some GMDSS purists will question this, the USCG has specifically told me direct, on the phone, that this is acceptable....as they don't always have propagation on 4mhz to allow automated DSC test calls to be acknowledged, just do it once-a-year, or once-per-season, and everyone will be happy!)


{Further, FYI....the IMO has specifically stated / encouraged the regular use of DSC signalling / the GMDSS system for routine signaling / messages and for testing, in order for the vessels' crew to become more familiar with DSC / GMDSS operations, AND to better maintain the DSC / GMDSS / MF-HF Radio equipment in good working order, so that both the equipment and crew are ready to use in case of emergency....}





d) Facts on the M-802's DSC operations....
--- All DSC transmissions (all transmissions of all modes) take place with the "Main Antenna" (the one connected with the AT-140)


--- DSC "Safety", DSC "Urgency", DSC "Distress", messages are received via the built-in/separate dedicated DSC receiver / your DSC receive antenna....(not the "main antenna")


--- All SSB Voice receiving is via the "main antenna"


This means if you send either/or a DSC "Safety" message, DSC "Urgency" message, or DSC "Distress" message, these are all transmitted by the "main antenna".....and the acknowledgements (ACK's) are received by your DSC receive antenna....and, the "main antenna" (and main receiver) is waiting for SSB Voice comms on the associated SSB Voice frequency (the one you designated as your traffic frequency....or in the case of a DSC Distress call, the corresponding GMDSS SSB Voice Safety/Calling frequency)


An example:
You send/transmit a DSC "Safety" message to USCG on 8414.5khz, via the "main antenna"....your "DSC receive antenna" and dedicated DSC receiver is waiting for a DSC acknowledgment (ACK)....your "main antenna" (and main receiver) is waiting for SSB Voice comms on the designated SSB Voice Frequency, 8291.0khz USB....


This is how the system is designed to work, so you don't really have to do much, other than press a button and have your message sent, and have them calling you / offering the assistance you need....


Hence, this is why you must have a DSC Receive antenna connected to the radio, otherwise you'll not receive any DSC calls / messages....and never even receive an acknowledgement of your own DSC calls....




{"Routine" DSC messaging with the M-802, which you're unlikely to ever do, is done in the DSC watch mode (and, you'd need to re-program the M-802's DSC watch scanning frequencies, as well), and while waiting for the ACK of a routine DSC call, your "main antenna" and main receiver are the ones waiting for the DSC ACK....
Again, this is not what you'll typically be doing....so, don't worry about it...

I'm sorry about the confusion....just don't worry about "Routine" DSC calls, as you're not going to be doing them!! }


As for DSC "Test" calls....I think they work the same as "Safety", "Urgency", and "Distress" DSC calls....but, I'm not on-board this week, and I haven't done a "Test" call in a long while....except when in 4mhz range of USCG, just use DSC "Safety" call for testing, and you'll be good to go...



As for what frequencies to use? You use the ones that are being monitored....and these should already be programmed into your M-802...

Now, it's been years since I looked at a factory-virgin M-802, and I don't know what additional frequencies your M-802 has had programmed in....but, I feel confident writing that the six int'l GMDSS DSC Safety/Calling frequencies [2187.5khz; 4207.5khz; 6312khz; 8414.5khz; 12577khz; 16804.5khz] should be there in your M-802....
And, these are the frequencies to send your DSC call on...

{What "traffic" frequency (SSB Voice frequency) to select/use after your party acknowledges your DSC call, depends a bit on "who" you're sending the DSC call to....if it's going to everyone (an "All Ship's Call, etc.) or going to a Coast Guard, then of course use the matching / associated int'l GMDSS SSB Voice Calling/Safety frequency (as everyone is required to have this frequency available).....
Although, if you're sending a DSC call to a friend, then you can select another ship-to-ship channel/frequency (one that would allow you to chat a while, without worry), for your "traffic" frequency....
And, of course if you were sending a DSC call to a shore station / public coast station, then selecting / requesting to use their assigned traffic channel/frequencies is typical....}


Examples:

a) if sending a DSC message to USCG, daytime I'd use 8414.5khz or 12577khz, depending on time-of-day / distance....(nighttime depending on distance, I'd use 8414.5, or 6312, or 4207.5)....the default is 8414.5khz anytime, day or night....
I'd request/select the traffic frequency to be the corresponding GMDSS SSB Safety and Calling freq....which for 8mhz band, would be 8291.0khz....
(And, I'd do the same if sending out a regional group call)



b) if sending a DSC message to a friend in Bahamas, I'd use use 8414.5khz [or 6312khz]....and I'd probably request/select the traffic frequency to be 8294.0khz (8A) [or 6224.0khz (6A)]




Further DSC info is dealt with in detail in the stickies, my thread directly dealing with HF-DSC, in the videos, and (gasp!) actually in the M-802 manual!!
Please have a look in those places....as we are getting way, way off topic here.





I do hope this helps?


Fair winds.


John


P.S. Contrary to what "Gatorman" wrote, I do not find HF radiowave propagation to be the worst I've experienced in the past 50 some years....and, if you have a look at the historic solar indices / sunspot numbers charts I posted a couple weeks back (along with the details of my operations at solar minimums over the years), you'll see what I mean...
{of course, the plethora of RFI producing devices in our lives these days on-shore, means that these higher ambient noise levels do complicate shore-side-based HF comms these days.....but propagation is actually very good! }

Have a look here:
https://www.cruisersforum.com/forums...ml#post3164479

(lots there on RFI, too....but scroll down to item 5, for the specifics on solar indices / sunspot cycles)




Also, I don't find HF comms to be frustrating at all....and, I provided video proof of random HF comms, within a minute of walking on-board, all at the solar minimums....have a look at the video, and read the text where I wrote about the excellent HF comms I was having when others are complaining about "bad propagation"....


No worries here, everyone has different experiences....