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Converting a Pistol grip radio using FrSky DIY module

PostPosted: Mon Jul 12, 2010 2:55 pm
by beau0090_99
Hi Guys,
I have a 3-PM Futaba radio that I want to convert. Here are some of the pictures. I believe I can remove the entire yellow board (cutting the red white and black wires to it), since this is the entire RF section of the radio. I see the GND, VCC, and MOD signals, I assume these are the ground, power, and PPM signals that I need to connect to the DIY board. Am I correct on these assumptions?

The big issue is the following:
I want to use this radio with boats, where the Rx is buried in the hull and it would take a couple of inches to reach the antenna tube. Has anyone lengthened the 4 channel antenna wire to give a better aerial? I have considered using the 8 channel Rx with dual antenna exits, but would like to save a couple of dollars.

On a side note, this conversion is really just so that I can keep this radio with 10 model memory and get Rx's cheap (cheaper than 2 ch Rx's after shipping and the Xtal - crazy).
Thanks,
Curtis

Edit: I can't seem to upload photos properly.

Re: Converting a Pistol grip radio using FrSky DIY module

PostPosted: Mon Jul 12, 2010 8:18 pm
by RCModelReviews
I think there's a minimum-post requirement before you can upload images.

Lengthening the antenna on the 4-channel receiver may be a bit tricky but it could be done by using a (coax) flylead. It will have a small effect on range.

I really think you'd be better off using the 7 or 8 channel receivers -- there's not that much difference in price but they also offer diversity and greater sensitivity.

Re: Converting a Pistol grip radio using FrSky DIY module

PostPosted: Mon Jul 12, 2010 8:33 pm
by beau0090_99
C'mon Bruce, let me post some pics. Maybe it because it has been so long since I have been here. I hope there are no hard feelings (Only joking). I actually have two other threads that I have pics posted to, but i am not sure if I initiated them or not. I was questioning the lengthening part, and you are right, the 7/8 ch are not that much more expensive.
Does the preceding sound correct about the signals? It is only 3 channels, but I assume that wouldn't matter as you can do the hack on a 4, 5, 6, 7 etc. radio.
Thanks,
Curtis
Edit - nevermind, I missed the big red letters telling me the file size needs to be under 256kb. :roll:

Re: Converting a Pistol grip radio using FrSky DIY module

PostPosted: Tue Jul 13, 2010 2:09 am
by JMP_blackfoot
beau0090_99 wrote:Does the preceding sound correct about the signals? It is only 3 channels, but I assume that wouldn't matter as you can do the hack on a 4, 5, 6, 7 etc. radio.

I got this reply from FrSky about the minimum number of channels and minimum synch pause length:
"The minimum acceptable number of channels is 3, and the sync-pause time is 4ms or more."
So, you should be okay with the 3-channel pistol grip Tx.
(For the record, FlySky Tx RF PCB works down to 2 channels and 3.4 ms synch pause.)