Transponder power up ON

BH1166 · #1 05-14-2022, 06:28 AM

Moving from stone age to digital age. Replaced King 76a for a new Garmin GTX 327. Using existing wiring for Power, same circuit breaker. I’d like the Garmin to power ON like the King did when Avionics Master is flipped. As of now, I have to press a button (on, ALT, etc) for the Garmin to come on. I have a pin AVIONICS MASTER, but am unsure where/ how to wire. Is this needed to get the GTX to power up when Avionics Master is flipped. The breaker/power is ON/ available when Avionics Master is on, but unit itself does not come on.

lr172 · #2 05-14-2022, 07:08 AM

It would be my assumption that applying 12VDC (likely wired from the avionics master switch) to the avionics master pin would force the unit to turn on. However, I have never installed one. If the 12V source is already from the avionics master switch, you can just bridge the pins.

BH1166 · #3 05-14-2022, 07:22 AM

Thanks Larry, the 12VDC is coming directly from the circuit breaker. Im weak in knowledge concerning electronics/electrical things. So I think you are saying “tie the Avionics Master pin to the power that I’m
using (from CB)“ , in essence, two power pins ?

Thanks

Longez · #4 05-14-2022, 07:22 AM

Quote:

Originally Posted by BH1166

Moving from stone age to digital age. Replaced King 76a for a new Garmin GTX 327. Using existing wiring for Power, same circuit breaker. I’d like the Garmin to power ON like the King did when Avionics Master is flipped. As of now, I have to press a button (on, ALT, etc) for the Garmin to come on. I have a pin AVIONICS MASTER, but am unsure where/ how to wire. Is this needed to get the GTX to power up when Avionics Master is flipped. The breaker/power is ON/ available when Avionics Master is on, but unit itself does not com on.

Butch,

Yes, if you wire power to the GTX 327 like shown here, the GTX 327 will power up when power is applied without having to press a button.

Click image for larger version

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Steve

BH1166 · #5 05-14-2022, 07:27 AM

Quote:

Originally Posted by Longez

Butch,

Yes, if you wire power to the GTX 327 like shown here, the GTX 327 will power up when power is applied without having to press a button.

Attachment 25806

Steve

Thanks Steve…, seems simple enough, cut, twist POWER and AVIONICS MASTER together, then to power from CB, solder, shrink tube, test !

BH1166 · #6 05-14-2022, 10:12 AM

All is good now! Thanks again Larry and Steve

BobTurner · #7 05-14-2022, 11:21 PM

Since the FAA requests all transponders to run in ALT mode all the time, that’s how it should be programmed to boot up. It’s in the manual.

catmandu · #8 05-15-2022, 07:26 AM

Is there a reason to send power to both? Does not solely applying power to Pin 1 Avionics Master accomplish the same thing?

g3xpert · #9 05-15-2022, 07:10 PM

Wiring power to pin 15 provides ship power to run the transponder. You are able to power the unit on/off using the buttons of the front of the unit. By wiring 12v to pin 1, the unit will automatically power on when voltage is sensed on the pin.

Thanks,

Justin

BH1166 · #10 05-16-2022, 04:33 AM

Quote:

Originally Posted by BobTurner

Since the FAA requests all transponders to run in ALT mode all the time, that’s how it should be programmed to boot up. It’s in the manual.

I see a setting for boot up mode, where upon a change in altitude, the unit goes from STBY to ALT . Set to NO, you have to manually change/press ALT button. I didn’t find a setting where it boots to ALT.