Hi everyone,
The RV-6 that we bought flying has just come out of Covid-19 lockdown and seems while just sitting around to have developed a nasty radio problem that is a devil to troubleshoot. So I thought I'd try the VAF brains trust to see if anyone has experienced something similar, or has any ideas that could help us figure out what is wrong.
Our setup is a Garmin GMA 340 audio box, with 2 radios connected, an old Bendix King KX155 configured as COM1, and a new Icom IC-A220 configured as COM2. Most of the time we use the Icom since it is 8.33 capable and we are in the UK where unfortunately that is required. PTT buttons are on each stick.
The problem is that intermittently, usually very soon after takeoff, both radios indicate that they are transmitting and there is a rhythmic tic-tic-tic sound in the headset with a frequency around 1 or 2 Hz which is not normally there. The other symptoms are that sometimes the sidetone is missing when PTT is pressed, and that if I flip channels on the Icom while the problem is occurring the display shows the channel swap happening very slowly as if the radio is preoccupied with some other task which it prefers!
Nearly all the time there is no problem at all when the aircraft is on the ground, which makes troubleshooting very difficult! Wiggling the GMA340 in the rack does seem sometimes to have an effect, which together with the fact that both radios seem to have the same issue, makes us suspect that the Garmin unit might be the culprit. But it would be annoying to ground the aircraft and send the unit off for repair only to find out that it is a wiring or radio issue instead. So I'm posting this in the hope that someone says "I had that problem and here is what I did!"
Thanks,
The RV-6 that we bought flying has just come out of Covid-19 lockdown and seems while just sitting around to have developed a nasty radio problem that is a devil to troubleshoot. So I thought I'd try the VAF brains trust to see if anyone has experienced something similar, or has any ideas that could help us figure out what is wrong.
Our setup is a Garmin GMA 340 audio box, with 2 radios connected, an old Bendix King KX155 configured as COM1, and a new Icom IC-A220 configured as COM2. Most of the time we use the Icom since it is 8.33 capable and we are in the UK where unfortunately that is required. PTT buttons are on each stick.
The problem is that intermittently, usually very soon after takeoff, both radios indicate that they are transmitting and there is a rhythmic tic-tic-tic sound in the headset with a frequency around 1 or 2 Hz which is not normally there. The other symptoms are that sometimes the sidetone is missing when PTT is pressed, and that if I flip channels on the Icom while the problem is occurring the display shows the channel swap happening very slowly as if the radio is preoccupied with some other task which it prefers!
Nearly all the time there is no problem at all when the aircraft is on the ground, which makes troubleshooting very difficult! Wiggling the GMA340 in the rack does seem sometimes to have an effect, which together with the fact that both radios seem to have the same issue, makes us suspect that the Garmin unit might be the culprit. But it would be annoying to ground the aircraft and send the unit off for repair only to find out that it is a wiring or radio issue instead. So I'm posting this in the hope that someone says "I had that problem and here is what I did!"
Thanks,