Here's a new issue for my plane. I recently installed a UAvionics wingtip unit, and I'm experiencing intermittent radio noise associated with its strobe. The unit is wired in accordance with the instructions and operates correctly.
I know that strobes are the culprit because if I turn off all strobes the noise stops. I know that particular strobe is the culprit because if I turn off the ADSB unit by turning off the nav lights (which also turns off that strobe) while leaving the remaining strobes on and operating, the noise stops.
My radio is a Garmin SL30
The noise does not occur on all frequencies, and it will come and go on some frequencies. Freqs I have heard it on are 121.1, 124.2 and 126.5 - all Olympia Wa area freqs for Seattle Center and Seattle approach.
But the noise is intermittent - seems to be location dependent, and also seems to be when the transmitting station is a bit distant, based on voice clarity from that station. The noise has not shown up on 122.8, 122.9, 124.4 (Olympia tower), 121.6 (Olympia ground) or 118.1 (Portland Approach) , for example. The noise goes away when someone is talking on the frequency. It acts like something is "helping" the strobe hiss to break squelch at some times / places and not others.
I have not called UAvionics yet, but am thinking someone here may have experienced the issue and can offer advice. Hope so!
Edit: The noise is also new. The ADSB unit has been installed for almost two months, but the problem has cropped up in the last couple of weeks. Could there be some sort of issue with the transmitting stations which have been problematic?
Further edit: Two days ago I was at an Olympia avionics shop (unrelated reason involving a friend's plane) so asked the techs there. Unfortunately, the problem would not replicate on the ground there. Of course!
Thanks - -