Skyview indications affected by comm 1 or comm 2

jacktunnell

I love flying!
Joined
Jan 19, 2013
Messages
41
I have a Sportsman with dual 10" Skyview, SL-40 comm 1, and PAR100EX Comm 2 and audio panel.

The discrepancy: When I key the mike on #1 or #2, the EGT & CHT rise and the altitude goes up about 20-30 ft and the VSI indicated about 300 fpm up.

Initial panel wiring done by SteinAir. #1 comm antenna is a Comant bent whip on the belly between the main gear and goes to the SL-40 mounted in the panel above the Skyview displays. #2 antenna is a dipole mounted in the vertical stab and goes to the QAR100EX radio mounted behind the baggage compartment.

Have worked with Stein on troubleshooting, ringing wires, and ops checks with no good results.

Is there any chance the displays are not hardened against stray RF energy enough to prevent the indication changes?

Any suggestions?
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
Jack,
Some of us at Dynon have our own Sportsman with no issues, so we should be able to get it working.

First, the displays show what comes in digitally from the EMS module and the AHRS module, so the sensitivity is not in the displays.

When did you buy your equipment? The earlier EMS modules did have an issue on the EGT/CHT that does what you describe in some installs. We can modify your EMS module to fix this issue.

The AHRS issue is much rarer. We have our main com antenna right next to our AHRS which is right behind the rear bulkhead, and it has no issues. The second com in the vertical stab is the same.

In the 2-3 cases of this we have seen before, the issue appears to be RF getting into the cable going to the AHRS, not getting into the AHRS directly. Some people have had luck putting an RF filter on the AHRS connector.

Contact us via email or phone and we can set up an RMA for the EMS module and get you an RF filter to try.
 
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