Hi, I just picked up an old manual trim Airtronics V600 to install the DIY Frsky adapter on.

I am not sure how to locate the PPM, positive or negative locations on my board. Was wondering if there is a method I could follow to accomplish this as I havent seen it installed on my radio before only the v6000 which although similar, still has a different board.

Check for any other system conversion of your radio, the same will apply to Frsky too.
Else, post a picture of boards here, please.

Post pics of radio, Please.

ross

Does it have a buddy box plug in socket ?

ross

Yes it has the plug, I'm posting pics of the front and then of the board. You can see the plug dangling to the left of the board.

Also I wrote down what each numbered wire on the back of the buddy box plug goes to:

1 Power
2 Ground
3 Mod out
4 Power
5 Mod in

So would I be able to cheat and just splice into these wires or use them to trace to a good solder spot on the board?

If you look on the back of the VG600 case for the FCC ID you might be able to go to the FCC web site and get the schematics for the main board where the RF circuit resides. I have done that on my RD6000 and VG6000.

Back when they were getting FCC certification for these "older' radios the manufacturers didn't usually invoke confidentially to keep the schematics from being accessed by the public.

If you try to trace back from the trainer plug you may find the PPM for the trainer output goes through an IC switch so you won't be able to find its origin at the 72 MHz RF section where you need to get it for the FrSky.

I located the schematics with your help but I honestly can not decipher the information I need from them.

I'll give them a full look though, and if I can, I will post them here for others.

Originally Posted by flomofo

I located the schematics with your help but I honestly can not decipher the information I need from them.

I'll give them a full look though, and if I can, I will post them here for others.

Post the schematics link, what is mistery for you could be an easy lecture for others

downloading them now

vg600-1 by flomofo, on Flickr

vg600-2 by flomofo, on Flickr

3, 3, 4, splice into these, and pull crystal. DIY module tapes inside back of case, mount antennae on top where 72 ant. is.

ross

pardon me, 2, 3, 4, leads.

ross

Thank you for the help, I soldered my DIY kit to the buddy box plug and got it working.

My digital servos are really twitching like crazy, especially at center, but my analog Futaba s3004 works fine with it.

But this morning after testing the digital servos with my new RDS8000, I tried the VG600 with the DIY kit again but it is no longer powering on.

Kind of stumped as to why because it was working fine just seconds earlier and I didnt see any magic smoke or anything when turning it on.

I already tried using different power sources, maybe this thing just shorted out.

If you come off 2,3 & 4 on the trainer jack, the PPM signal on 3 is only alive when the trainer switch is pushed. I would think you want to intercept the PPM signal off the collector of DT3 (arrow labeled RF at the center right of schematic sheet #1).

That is essentially what I did on my RD6000. Also, better than just pulling the 72 MHz crystal, find and open the 9.6 volt battery feed to the 7 volt regulator in the stages of the RF on schematic sheet #2. This will kill the 72 MHz RF and save a power drain on the battery. Also the TP8 on the RF circuit of sheet #2 is the PPM after going through two stages of buffering/amplification. If you back up two transistors (can't read their tags) you have the ideal point to pick up the PPM.

Doing these things requires translating the schematic to the actual circuit board traces and components. The two schematics you have represent what is on the lower main circuit board. The power and encoding of the PPM is on the left half when you look from the back. The RF circuits are on the right half of the board. A good reference is the antenna which taps off in the center. My RD6000 actually had jumpers to bring the PPM and 9.6 volt power from the encoder side to the RF side which could be readily unsoldered and both break the 72 MHz circuits and give an attach point for the FrSky wires.