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Radio not TX out...

dmat

dmat

Well Known Member
Advertiser
So, good news.... airplane after 7 months of full upgrades flies and handles well. I was a bit rusty behind the stick and the airspeed tapes on the new (to me) g3x non-touch will take some getting use to but I will manange.

Bad news, we couldn?t get the radios to Tx out. My copilot and I could hear each other on the radio and the gtr200 showed ?Tx? when I pressed down on the PTT but when I called for a mic check, ... NOthing.

My setup is this...
1)GMA 240
2) grt 200
3)430w

Tried to trouble shoot by changing comms, tried using the copilot PTT. Still nothing.

Can anyone help?
 
Yes, radios are both receiving. I can key the mic to receive ATIS as well but when I speak, no one can hear me.

I?m wondering g if it?s the 240 master squelch?
 
dmat said:
I can key the mic to receive ATIS as well but when I speak, no one can hear me.
Click to expand...

OK, carrier but no modulation.

Sounds like a disconnect from the audio panel to the radio.

Try the simple stuff first........

You did select a radio on the 340, didnt you?
 
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Yup, tried both radios to double check it wasn?t one of the radios
 
1st, research: Does the GMA240 do audio 'passthrough' if it fails? (If properly designed, it should pass audio both ways to one (should be primary) radio, if the GMA240 itself fails dead.)

Assuming the above: Pull power to the GMA240, and check operation from mic to radio in transmit (look for the xmit indicator) and monitor with another radio.

If the receiving radio receives, the GMA240 likely has an internal issue.

If still no transmit, you may well have a wiring issue.

If this is new behavior (system used to work before your upgrades), my bet would be something got inadvertently altered during your upgrades.

Stuff is so reliable these days that most of us don't do this, but it used to be common to have a backup mic jack, PTT, and headphone jack paralleled directly to a radio, so any audio panel/intercom/etc could be 'out of the loop' when comm is lost in flight and a failure is suspected. When portable intercoms were the 'norm', it was automatic. :)
 
One scenario that fits the data is if the ?mike audio output to com 1? wire was inadvertently plugged into ?mike output to com 2? pin, and vice versa.
 
rv7charlie said:
1st, research: Does the GMA240 do audio 'passthrough' if it fails? (If properly designed, it should pass audio both ways to one (should be primary) radio, if the GMA240 itself fails dead.)

Assuming the above: Pull power to the GMA240, and check operation from mic to radio in transmit (look for the xmit indicator) and monitor with another radio.

If the receiving radio receives, the GMA240 likely has an internal issue.

If still no transmit, you may well have a wiring issue.

If this is new behavior (system used to work before your upgrades), my bet would be something got inadvertently altered during your upgrades.

Stuff is so reliable these days that most of us don't do this, but it used to be common to have a backup mic jack, PTT, and headphone jack paralleled directly to a radio, so any audio panel/intercom/etc could be 'out of the loop' when comm is lost in flight and a failure is suspected. When portable intercoms were the 'norm', it was automatic. :)
Click to expand...

It doesn't pass-through when I turn off the audio panel. It should be wired to allow for the 430 to continue transmitting. But I get dead air.

The panel is new to my ship but I purchased used on VAF.

D
 
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Should go direct to main comm (430W in my case). It must be a wiring issue. Will need to pull the dsub and check.
 
Walt said:
It defaults to com 1.
Click to expand...
Unless it is wired wrong.

BobTurner said:
One scenario that fits the data is if the ‘mike audio output to com 1” wire was inadvertently plugged into ‘mike output to com 2’ pin, and vice versa.
Click to expand...
^^^^^THIS^^^^^

So check to see if with the audio panel off, the audio pass through is going to Com2 instead of Com1. But if everything is wired correctly, except the mic audio output, then even this won't work. You will have to follow the wires and check the pinout is correct. Good luck.

:cool:
 
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