Transmitting on GNS430W causing CHT/EGT reading to rise

[liuk]

Hello all, I have an RV6A with Dynon Skyview, GNS430W as the 1st COMM, Icom A210 as my 2nd COM. The system has been working very well for quite some time now and recently developed some weird problem.

I first noticed that the Icom A210 started to constantly break squelch about 6 weeks ago, I had to max out all the squelch threshold settings in the configuration page to make it work normal again. Then I found that whenever I pressed the PTT, the CHT and EGT readings would rise instantly by 10-20 degrees and drop back to before as soon as the PTT was released. Other than that, everything seemed to be fine, the radio quality was good still.

Today I tried some initial check on the ground without the engine running, the problem was still there. But the EGT/CHT rises only happened when I transmit using the 1st COMM (GNS430W). Other engine instruments (like fuel flow, oil temp/pressure) was not impacted. I checked the cable connections, and it seems everything was pretty tight.

It does not seem to be too big a problem, but it's super annoying to look at and I'm worried it might only get worse. I would really appreciate any suggestions about what I should try next. Thanks!

 

[BobTurner]

These types of problems are a bear to trouble shoot, it's mostly trial and error.
1. The ICOM and the EGT rise may be related, or maybe not.
2. The EGT rise on transmit is typical of an "RF in the cockpit" problem. Since it's a new problem, I'd really look hard at the coax from the 430 com to the antenna. Disconnect it from the antenna. Any signs of corrosion? Make certain the pins are making proper contact. Make certain the coax shield is properly terminated to airframe ground, at or very close to the antenna connection (e.g. the base of the antenna needs a good electrical path to the airframe). If possible borrow some known good coax and temporarily install it between the 430 and the antenna, as a test.

 

[GalinHdz]

The EGT issue you describe is a known issue with the Dynon EMS module. I had to send mine in to Dynon and it has worked great ever since so contact them for repair.

I had the same Icom A210 issue and after having Icom work on it 3 times, I went back to an Icom A200. Good luck!