Page 1 of 1

JR RF Board ppm wiring

Posted: 13 Oct 2020, 21:54
by Wavemeter
Hi guys I’m salvaging an 35mhz FM RF board from a redundant JR tx . The RF board works perfectly.
Now this will become the RF stage in a Reeduino Reed Tx.

I need to know the wiring colour code - simple I would have thought : Orange = PPM
Brown = earth and Red = +VE

HOWEVER ! before I connect it up in this fashion my multimeter suggests this is NOT correct!!! Seemingly indicating the reverse

Can somebody sort me out ? :roll:
C99172D5-6FEC-4E25-A066-332A1A5A24A9.jpg
B99CBC4F-98D4-462C-824B-B82524839B27.jpg

Re: JR RF Board ppm wiring

Posted: 14 Oct 2020, 00:12
by bluejets
How did you test with the multimeter?
Which multimeter?
What settings did you use?
One would imagine tracing the brown back to the battery negative would be sufficient.
If using a low ohm setting on the multimeter, it is possible your meter (whatever it is) might be supplying enough bias to turn on certain semi's and give you an apparent incorrect reading.

Re: JR RF Board ppm wiring

Posted: 14 Oct 2020, 04:57
by Wayne_H
Jonathan,

I found similar when I did my Ceptimus (i.e Martin) "super" s/c tx build into a Controlair Mule case. The JR RF board I used is slightly different to yours (mine is 29 Mhz FM) - you can see that I changed the wiring to more conventional colours so I wouldn't trip myself up later on :oops: I've labeled the pin connections on the board.
from bottom of board, pins are negative, signal & positive
from bottom of board, pins are negative, signal & positive
JR RF board connections.jpg (86.86 KiB) Viewed 1788 times
internals 2 RF boards.jpg
Regardless, as Bluejets said, chase the orange wire back to the main board - it should go to ground if its the same as mine.

Good luck ;)

Re: JR RF Board ppm wiring

Posted: 14 Oct 2020, 07:53
by ozrs
on my 36mhz, from bottom of board: pos sig neg

Same as Wayne's - noting that Wayne's is installed upside down in the Mule.

Re: JR RF Board ppm wiring

Posted: 15 Oct 2020, 00:36
by bluejets
Seems a fairly conventional wiring numbering...attached pdf is a JR631 and shows 31 as Positive (off the switch), 32 as Signal and 33 as Ground.

Rotate the pdf and connections are half way down on the left.
I'd suggest you trace your colours back to the main board to verify, even then, I'd double check.
It not that difficult to check.