GR-912 Lightwing vhf/UHF switch

[Ben_luke9]

Good morning,

 

i have a Lightwing 912 that has had a radio change prior to my ownership, and the internal switches for uhf/vhf switch over, cuts out all headsets (no mic/intercom nothing). It still has the UHF onboard but when turned on remains in transmit 100% of time, with nothing on headsets.

 

does anyone have information on PCB and it's wiring from factory, as it has a lot of wires cut away from it and floating behind the panel.

 

i am an electrician and have solved a grounding issue in this radio before. 

 

thanks in advance

 

ben

[Ben_luke9]

Found this

 

http://www.skiba.com.au/data/resources/av_art/microair.pdf

Under costs heading mentions rb-01 transmit module

Edited March 29, 2021 by Ben_luke9

[FlyBoy1960]

I would get rid of everything that is there because it is unnecessary. When I built my old plane I had an XCOM with a VHF and UHF.  There is an intercom switch which is on/off/isolate  and then there is another switch which moves the microphone from VHF to UHF.

 

This means you cannot transmit on UHF and VHF at the same time which is obvious but you can receive on both.

 

The wiring harness was nothing at all like what you have got in there. I think the aircraft may have had another brand of radio but you certainly don't need anything like this with the XCOM.

 

somewhere, I still have the diagrams,   sorry this is all I can find now but I  do know there is one for UHF connection. I will have a look later on for you.

 

 

XCOM Harness How to Check Out.pdf

[FlyBoy1960]

Thank goodness for Glacier Backup

XCOM-Radio-UHF-WD.pdf

[Ben_luke9]

Just printed a hard copy, will be reading now.

 

Thank you very much!!!

 

BEN

[FlyBoy1960]

looking at the holes above the radio it appears to me that your aircraft was originally set up for a microair using a separate intercom system because you can see the holes there for something like a Sigtronics SPA-4S or something similar. I would pull everything out including that extra board which is not needed with the XCOM and just wire it up according to the diagram which I sent through. This is exactly what I did and it worked perfectly for years until I sold the aircraft and is probably still working fine today

[Ben_luke9]

Thank you. 

 

The second drawing you sent through, wiring diagram, there's just a few lines that don't have a reference point to terminate to.

 

could you elaborate on the drawing a bit more.

 

what is the thing that looks like a triac and the PTT buttons arrangements please?

 

Much appreciated

 

ben 

 

 

[FlyBoy1960]

Sorry Ben, i cant remember.  Kylie Communications on this site would know