Toobuilder
Well Known Member
Strange problem with my radio that I can't seem to get my head around:
GTN 650 that is perfectly quiet in Tx/Rx on the ground with battery power only. Engine running, alternator on does introduce a little whine with increasing electrical load but not objectionable. In flight, at any power setting with airspeed below about 90 KIAS the radio is fine. However, as soon as I get above this speed, the Tx picks up an electrical sounding crackle that increases with intensity up to about 135 and above, where the radio is all but useless as a transmitter. Rx is fine in all cases.
I have changed antennas. I have inspected and wiggled the headphone jacks. I have shut down the alternator. I have covered the mic boom with my hand. I have switched off the intercom - all with zero change in behavior.
However, I can fly along at pattern speed with good radio performance, but as soon as I drop the nose (same power and RPM) and pick up some speed, the crackle appears again.
This is a fairly new behavior. The only thing I've messed with recently however is changing out one of the (non radio) switches in the Infinity grip.
Any ideas? I'm stumped.
GTN 650 that is perfectly quiet in Tx/Rx on the ground with battery power only. Engine running, alternator on does introduce a little whine with increasing electrical load but not objectionable. In flight, at any power setting with airspeed below about 90 KIAS the radio is fine. However, as soon as I get above this speed, the Tx picks up an electrical sounding crackle that increases with intensity up to about 135 and above, where the radio is all but useless as a transmitter. Rx is fine in all cases.
I have changed antennas. I have inspected and wiggled the headphone jacks. I have shut down the alternator. I have covered the mic boom with my hand. I have switched off the intercom - all with zero change in behavior.
However, I can fly along at pattern speed with good radio performance, but as soon as I drop the nose (same power and RPM) and pick up some speed, the crackle appears again.
This is a fairly new behavior. The only thing I've messed with recently however is changing out one of the (non radio) switches in the Infinity grip.
Any ideas? I'm stumped.
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