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View Full Version : Use transmitter's radio instead of cable with sim! HOWTO


costalotta
12-25-2007, 06:40 PM
OK some folks may think this is kinda cheesy, but it really does add a further degree of 'reality' into simulator flying.

I use a giant projector screen and stand in front, TX strapped around my neck and antenna extended. Look mom, no wires !
All you need now is a blowfly or two hanging around your ear - this shouldnt be too hard to replicate.

I am sure this has been done before, but couldnt find anything on Google, so this morning I decided to make this happen.

The cool thing is I have found 2 ways to do this. They both work GREAT!
The downside is you need a good old PPM/FM TX do do it. I use a 40mhz Futaba 6EXH.

Wireless howto #1 - RX mod:
You can buy or make a cable that joins your TX to your PC right ?
All this does is take the PPM signal direct from your TX and pass it to your PC either through printer port, USB, sound card, or serial.

What I decided to do was take the PPM signal from an old RX instead of from the TX, this way you have the exact same PPM signal, but without wires !

I modified a cheap old Align RC-RX6 ($20) receiver. It was REALLY simple. You only need to cut one track and add one jumper wire inside the RX. In fact, this way the RX is still totally useable as in this case I modified spare channel 6 so that the RX plugs into your PC using just ONE of the servo cables. What we are doing here is cutting the channel 6 'servo drive' track and 'jumpering' the 'PPM output' to what used to be the CH6 servo signal pin. CH6 is now PPM out + Power In.
PPM output at your RX is identical to your PPM output at theTX. Now just make a normal TX-PC cable, but use the RX PPM instead of the TX PPM.
I made a printer port cable from these instructions, and use it with PPJOY: http://www.heliguy.com/nexus/fmsinterface.html
however I used the PPM signal from my recievers modified CH6 instead of the PPM signal from my TX.
I used a USB cable to get 5v from PC to power the RX through CH6 + and - pins.
USB is for nothing but to supply the RX with power, and share the earth.
You could use a BEC and a LiPo or whatever, but if this is the case youll need to also join the RX earth to the PC's earth.

A picture tells 1000 words - below should hopefully be self explanatory.

You should be able to use any old FM/PPM receiver - just probe around inside the RX until you find the PPM signal. It'll be one leg of one of the chips. If you dont want to 'cut' one of the servo outputs off then just hang the PPM wire out the side of the case after you solder one end on to the chip.


Wireless howto #2 - Using a scanner radio:

First you need a radio receiver (yep, like actual radio with a speaker, and audio output jack) and you need to 'tune in' to your frequency. I have a Yaesu scanner and I simply dialled in my transmitter frequency - 40.830mhz.
Dont forget to select NarrowBand FM.
Then you plug the scanner's output into your PC's sound card audio input using a jack cable. My case I only needed a 3.5mm to 3.5mm cable.
Install SmartPropoPlus and PPJOY to get your wireless TX 'mapped' to a game device within Windows 98/2000/XP etc.
Google is your friend. You are simply 'injecting' the PPM as audio into your sound card from your scanner receiver, SmartpropoPlus decodes the audio to PPM signal, then PPJOY maps the PPM signal to a windows game device.

Enjoy !

r40734
12-26-2007, 01:16 PM
Brilliant work! :thumbup: Too bad I'm running 2.4Ghz... I just can't bring myself to cut up one of my overpriced Rx's.