critterhunter

Troglotech, did some tests today and the results are interesting. I'll try to keep it short and to the point...

Stuck a rubberband on the plane's controller joystick to put flaps in downward position. Plugged the camera/tx/regulator combo into the X-port. Walked about thirty yards away and lost contact with the controller (flaps returned to level position). Started moving tx and camera into various positions on the plane. No help, sometimes the engine would come on and off (even though I had it off) and the flaps would loose control off and on depending on where the TX and camera was placed. I could find no happy medium and the random engine fires really bothered me. Back to the soldering room...

Quickly hacked one of the 220uf 16v capacitors (paying attention to polarity) across the power lines between the Xport and the regulator. Went outside and tried the range test again. Same results as above. Back inside to tinker some more...

Cut off the voltage regulator and hacked on a 9V battery as the camera power source, just to see if it was the camera TX transmission that was blocking the plane RX or something other. Went outside for another range test. No loss of control of the plane even at great distance. Also tried putting the camera TX in various spots on the plane to see if I could get the interference to come back. No loss of plane control was experienced. Great...atleast the camera TX doesn't appear to be the cause. Back in the house for more...

Re-attached the X-Port plug with NO voltage regulator but this time I used the simple noise filter circuit you described prior in this thread (diode and capacitor). Went back outside and experienced NO loss of plane control. Looking better, now to test this setup for engine noise with the video. The video remains stable all the way up until about half throttle. Beyond that I get video interference (not as bad as it was without anything buffering the Xport/cam connection, but with the regulator I had no engine video interference). While still testing this quick hack job (IE: bear wires soldered together) I notice a soft small glow out of the corner of my eye. Yikes, one of the diode/capacitor tangle leads was touching the outside metal shell of the camera TX, causing a glowing short! Power it all down, re-position my wires, and then turn it back on to make sure I didn't fry something. Camera was working.

So, what I've found: Camera/TX without regulator or diode/cap. buffering Xport produces useless video with any engine use. Camera/TX with regulator only produces perfect video at all engine speeds, but plane TX gets blocked. Camera/TX with regulator and a capacitor does not fix the range problem. Camera/TX with a 9V battery causes no range problems and probably good video (didn't test it). Camera/TX with diode/capacitor appears not to have range problems but produces bad video at above half engine speed.

The next logical step in my mind would be to use the diode WITH the regulator, placed between the X-Port and the regulator on the + wire? Would this be the same rated diode used above in the noise filter circuit? Also, should the capacitor also be used before the regulator or just the diode with the regulator and no capacitor? If the diode/regulator combo works (waiting on your feedback to try it) then it would look as though the diode is preventing some kind of backflow to the X-Port that is messing up the plane's RX range? Can you explain you're best guess on whats going on?

If worse comes to worse and some combination of the above doesn't solve my two range/video quality problems then I have two options: Run the cam/tx off the diode/cap setup (no regulator) and just live with lack of video above half engine throttle. Or, I could bite the bullet and run the cam/tx off a 9V battery. This is my least favored option as a 9V adds weight. There might be one more option. I thought I read somewhere that you can use a rechargable (or is it just a non-rechargable lithium?) battery to power the camera. It was somewhere in one of these threads, relating to it providing more stable video and/or run time and/or weight. Can't remember but will look for the reference.