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Dynon Radio Static

glenn v

Member
I have an RV-8 with a Skyview Classic and two Dynon SV-COM-425's and the Dynon intercom. I have about 67 hours TT on the plane. I have recently over the past 10 hours or so developed a constant static problem over both comm's and the intercom. During startup, engine run-up and taxi the radios perform without issue, however once I reach a few hundred feet after takeoff the static becomes constant during receiving other aircraft transmissions and intercom communication with my passenger. If I press the PTT to transmit, the static stops and I transmit fine. Once I release the PTT, the static starts again.

I have tried different headsets to no avail. I have checked all radio and intercom connections, RG-400 coax connections, grounds, headset jack isolators, cleaned the antennas, etc., and all seems in order. I have also fiddled with the Skyview com settings but no change.

I also reached out to Dynon Tech Support, and their response yesterday was "It sounds like a radio problem, which can be solved by upgrading to one of our newer models", at a cost of course. They said they do not repair the -425 models anymore. Granted I purchased both radios and the intercom new in 2016, but I did not finish the build and fly the plane until May 2021. I have a hard time thinking both radios crapped out at the same time after only 67 flight hours.

At this point I am at a loss and looking for additional thoughts on what to try. Thanks in advance for any suggestions.

Glenn Vokac
RV-8 repeat offender
 
When you say "static", are you saying that its breaking squelch? In other words, when you hear the static, do you see the [<RX] indication in the status bar at the top of your display?

Or, is it a hum or growl in the headset that does not break squelch? If this is the case, have you tried to isolate the source by turning stuff off, like strobes, or varying the RPM?
 
Thats bull**** that Dynon is pushing you to buy new radios by not offering repair to a 5 year old unit. It not old at all.
That is not good to hear. My panel is all Dynon.
 
Thats bull**** that Dynon is pushing you to buy new radios by not offering repair to a 5 year old unit. It not old at all.
That is not good to hear. My panel is all Dynon.

The -425 transceiver is the early Dynon radio that was designed (and I think built) by Dynon. It had some issues and had a high return rate to Dynon because of those. I don't think Dynon has the capability to repair those units, and don't want to due to the inherent issues they had with them.

The -T25 transceiver is a Trig radio. The -T25 transceiver replaced the -425 transceiver in late 2019.

You should be able to exchange the -425 transceiver for the -T25 transceiver under the out-of-warranty fixed rate repair price of $450. Also ask for the conversion harness (P/N 103827-000) to go between your existing SV-COM-PANEL and the new -T25 transceiver.



+++++++++++++++++++++

A side note on the nomenclature:

Both transceivers below have 25kHz frequency spacing.

- The SV-COM-C25 is an integrated VHF Com Radio consisting of two modules, the SV-COM-PANEL and the SV-COM-425 transceiver.

- The SV-COM-X25 is an integrated VHF Com Radio consisting of two modules, the SV-COM-PANEL and the SV-COM-T25 transceiver.
 
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Yes, both com1 and com2 are breaking squelch and the RX is indicated on the Skyview status bar. It is the same scenario with both radios.

I have tried turning off and strobes, mags, etc., with no joy.

Dynon has offered the exchange for the $450 per unit. Hate to have invested $3K into two units that only lasted 67 hours and now another potential $1k+.

Thanks,

Glenn Vokac
RV-8 repeat offender
 
SNIP
Dynon has offered the exchange for the $450 per unit. Hate to have invested $3K into two units that only lasted 67 hours and now another potential $1k+.

Thanks,

Glenn Vokac
RV-8 repeat offender

$450 to exchange a six year old radio for a brand new one - cheap.

Just think what Garmin would have charged….

Carl
 
Kent, thanks for the article. I am not convinced the radios are bad. Not when both of them became affected at the same time. It has to be a ground issue, crimp or something else that has come loose. I'll just continue to search one connection at a time.

No, I have not added any USB power devices.

Thanks for all the suggestions.

Regards,

Glenn Vokac
RV-8 repeat offender
 
Kent, thanks for the article. I am not convinced the radios are bad.
Glenn Vokac
RV-8 repeat offender

I wouldn't be either. The fact that static only appears once in the air kind of takes the radio out as the culprit, as nothing inside the radio changes in any different flight / ground states. Clearly there is a wiring issue, either in the wires/terminals or in a device like an antenna. You want to be looking at sources that develop static electricity from the fast moving air around them, as the static only appears at high speeds. If the ground has failed, it will struggle to shed that energy properly to ground and instead introduce into the radio. I would ohm out the comm ant coax and measure in and around the antenna, ensuring a low resistance from ant frame to airframe.

Simple test - grab an old coax and antenna (temp mounted in cockpit with a wire to ground it's metal base to the airframe and go fly. If all is good, you know where your problem is.

Larry
 
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After looking at the new comments, I too suspect the radios are just fine. A radio problem will present itself on the ground as well as the air.

So - look elsewhere for the culprit. Taking a handheld radio and powering first from its battery then ship's power is a good approach.

One easy thing to try, use your favorite solvent and wipe down the antennas.

Carl
 
Dynon

Thanks for the report and sorry to hear about your issue. I am getting ready to start my panel for my RV-10 project and hadn’t quite decided Garmin or AFS/Dynon. Dynon not supporting your 5 year old equipment is very concerning and may have very well helped me make Garmin the right choice for me. Good luck on your issue I hope it ends up being something simple.
 
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