SSB Troubleshooting

[belizesailor]

My trusty old ICOM 710RT is giving me a little trouble. Looking for troubleshooting ideas.

Rest of rig consists of an AT-140 tuner, dynaplate, and an uninsulated side stay as antenna. This has worked very well for many years.

Boat got laid up longer than planned (about a year). SSB was working fine before, but after re-launching my SSB would "glitch" on transmit. "Glitch" meaning the LCD display would flicker in random ways, sometimes flash "Error", but not always. Transmission is interrupted during glitch. I checked and cleaned connectors. All looked good...no moisture/corrossion found. Found a couple of slighly loose ground connections....cleaned and resecured. This helped.

Now I can transmit fine on 6mhz on low, med, and high power with no glitch. On 8mhz I can transmit on low or med power, but high will glitch.

[Paul L]

Did you clean the back stay antenna connection?

[belizesailor]

Originally Posted by Paul L

Did you clean the back stay antenna connection?

Yes, though I may give that one another go.

I changed out all the standing rigging so this is an obvious point of change.

[transmitterdan]

How is the antenna part of the rigging insulated from the rest of the boat? It sounds like you make have some arcing between the antenna wire and some other metal part of the rig that is bonded to the dynaplate somehow. If it were an insulated stay using those inline insulators I would first suspect that the insulators are caked with salt.

[belizesailor]

Originally Posted by transmitterdan

How is the antenna part of the rigging insulated from the rest of the boat? It sounds like you make have some arcing between the antenna wire and some other metal part of the rig that is bonded to the dynaplate somehow. If it were an insulated stay using those inline insulators I would first suspect that the insulators are caked with salt.

It is an uninsulated side stay so it does radiate into the rig. However, its a catamaran so the rig has no path to ground or to the dynaplate (at least it should not).

Background: Years ago I had a side conversation with a radio tech who expressed a preference for uninsulated stays as antenna. This did not comform to what I know about antennas, but I did not have the opportunity to follow up on the details of this with him. When installing this SSB on my current boat (17 years ago!) I decided to give it a try...sure nuff, it worked great...so I never did insulate the side stay. Its worked great for many years. I replaced the standing rigging recently, but there were no changes to the configuration.

I suppose I could rig a separate temporary wire antenna to isolate whether this is related to the new rig.

[transmitterdan]

When the new rig went in maybe something changed at the mast step. If the stay is not insulated then the mast is “hot” (as well as the other stays). Perhaps something is shorting under higher power at the step or at another chain plate.

My money is on some change made when the new rigging was installed. It may be something non-obvious.

[belizesailor]

Agree, thats a likely, but not obvious, source of problem. All wire was replaced with new of same. Only thing different is a new roller furling.

Rigging a temporary wire antenna should isolate if its the new rigging or the radio at least.

[Jim Cate]

FWIW, I too use the whole rig as a radiator, feeding a shroud via a chainplate. I've tried it both with the mast base grounded to the keel and with it isolated. It does change the tuning somewhat (manual tuner), but still will tune on all the frequencies between 3.5 and 28 MHz that I have tried (mostly ham bands, but some marine frequencies at times).

It is kinda hard to visualize how changing the wires would have such a great effect, so I'm initially inclined to blame the tuner in your case... but not convinced!

Jim

[belizesailor]

Originally Posted by Jim Cate

FWIW, I too use the whole rig as a radiator, feeding a shroud via a chainplate. I've tried it both with the mast base grounded to the keel and with it isolated. It does change the tuning somewhat (manual tuner), but still will tune on all the frequencies between 3.5 and 28 MHz that I have tried (mostly ham bands, but some marine frequencies at times).

It is kinda hard to visualize how changing the wires would have such a great effect, so I'm initially inclined to blame the tuner in your case... but not convinced!

Jim

Yep, same way Im set up. Mast sits on a step supported by a short stout compression post...no connection to ground. The rigging is the same except for new wire & furler...so a bit of a mystery how that could be it. Maybe the connection to the side stay, so will give that another look. Chain plates were removed and all bolts replaced...so that connection was disturbed.

Will rig a temporary wire antenna and test...if problem persists, then its not the rigging.

[Pizzazz]

My suggestion, as mentioned above, would be to try a simple long wire attached to the halyard, direct connection to the tuner. If that does not solve the problem, check the ground. Easiest way is to take an aluminium cooking folio and roll it out in the water (this by the best ground ever). If this still does not solve the problem, disconnect the tuner and cut the long wire to a suitable wavelength, test the radio on that particular wavelength.

Also, check if new wires may have been put around the radio or parallel to the antenna feed. Once I moved my shore power cord and it came close to and parallel to the antenna between the tuner and the chainplate. The radio was giving me similar symptoms as yours and sometimes it would just trip the shore power breaker. It was an easy fix .

SV Pizzazz

[Triumphant]

I had a similar problem after my Icom 802 was installed by a “professional” I could talk to Herb mid Atlantic on 12 megs BUT only on low and medium power, high power corrupted the sound. I faded in and out

The fault was traced to a very loose connection of the wire from the ATU to the insulated backstay,

I now use a Wire clamp on the back stay, I put an eye in the end of the GTO cable from the ATU and attached it very tightly to one of the cable clamp nuts

[RaymondR]

Leaving it turned off for a long period may have allowed moisture to penetrate, maybe leaving it turned on for a week or so might help.

[belizesailor]

Originally Posted by RaymondR

Leaving it turned off for a long period may have allowed moisture to penetrate, maybe leaving it turned on for a week or so might help.

I did pop in every few months to work on the boat while it was laid up...and powered up all electronics while I was there.

A long layup could also facilitate connection corrossion...thus my going down that path. Pulled the remote control head yesterday (the RT model is two parts: head and base) and found some gunk in the power lead connection to the head. Cleaned it up and it did better today. I could xmit on high power on an 8Mhz channel without it glitching. Makes sense that it might be a bit power starved on high (draws 32 amps!) due to this corrossion.

Still apparently some noise in my signal, but making progress.

[ka4wja]

Sorry I missed this earlier...

I'll add more later....but briefly:

--- Yep, loading the whole rig will work....but transmit RFI is much more prevalent, and can be intermittent (as you're finding out!)....due to many reasons, not the least of which are the "semi-conductors" created in all the rigging junctions...


--- Yep, check the RT's remote connections closely...as well as your antenna ground / RF ground connections...

--- You may find that you will need more ferrites on your control wiring / remote head cables, etc....(you do have some now, yes??)
Even the mic cord may need a ferrite, in some cases...


--- Also be aware that with the antenna, radio, tuner, ground system, etc. all within feet of each other, our boats (esp. fiberglass boats) present frustrating situations for hi-power HF comms....use of line isolators, ferrites, excellent antenna grounds / RF grounds, clean connections, etc. are usually very important for optimal operation...
(the plethora of those who have lights blinking, autopilots disengaging, etc. has been reduced greatly over the years, by these procedures)


Gotta go...More later.

John

[belizesailor]

Thanks for chiming in. There are some ferrites in the system now, but I do have some others on hand that I could add. I will take a look at that.

Maybe the new rigging could have changed some of the semi-conductor behavior. There were some end fittings replaced which might have different conductivity characteristics. (Hmmm...maybe detailed RFI conductance tests could be used to test rigging condition? [emoji6])

Yes, I do get some RFI when transmitting on high. I usually turn off non essential stuff like the stereo. Almost all my transmissions are on regional nets so high power isnt likely necessary anyway.