Sonntag, 23. Januar 2011

FPV - Range of 35MHz radio

If you start asking about range you get pushed to 2,4GHz very quickly! FPV Video however uses this band already - at least in my case - so these two things don't work well together (Video and Radio on the same band get's you interference and probably lower range also).
 So when I bought a new radio last year - I chose the Futaba TC10 (or FF10 here in Europe) with the 35MHz option installed (switchable to 2,4GHz later). With 35MHz I trust them Futaba PCM receivers most (RDP149). You get 150m in the Range test - this can be multiplied by 10 to around 1,5km - which is also what the vendor says. If you extend the antenna cable to 2,06m you'll barely notice any difference. Maybe more stable signal far out, but not much more range. If you then go to 4,13m this is where the range gets really good! TIPP: I used one of the eight small cables inside an standard network cable! Today I got 800m and more range (with leaving the TX Antenna fully retracted!).

 Test setup:
  • Radio mounted on a tree branch about 2m over ground, vertically facing the path I'll later go
  • set up failsafe to see fully deploeyd ailerons if the signal is lost - this way you can make the test alone! But you'll not be able to check range with running motor this way...
  • GPS starting waypoint stored - as reference
  • gone away with the model and waited for the first sign of a lost signal:
    at 160m I got the first failsafe with the 2,06m antenna
  • Now I did the extension to 4,13m and then walked away further. I thought it would give me another 100m or so. But as I reached the natural ending of my test site (a hill) I stopped the test at awesome 800m (now multiply that with 10!). 
  • as I said: only weakness on this test - no running motor - this might reduce the range...
With this numbers I dared to go out further than ever with my maxi. Now maybe seeing how far my video signal range is :-)
The first longrange flight was from ground to the mountain station of a cablecar on a nearby mountain (around 2000m high - 1000m alt difference from starting height, 3,2km line of sight to the target)
This vid will follow soon...

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