How to increase the range of an RC Transmitter:
In order to boost the output power of my Spektrum DX7-S for use as a longe range FPV remote control, I have modified it with a 2.4GHz WiFi Amplifier. It is better (if you can afford it) to utilize a UHF/FHSS signal converting transmitter as a piggyback on your radio (like DragonLink), but they are cost prohibitive to some of us at $300+. This WiFi Amplifier System costed me under $50 to build.
The normal output of the DX7-S is 135mw, which gives you about 3,000ft range (dependant on your RX system utilizing at least one satellite RX). With my modification, output is now 2000mw (2 watts ) for a range of 2 miles. Keep in mind that in the USA, RC TX output power is limited to 200mw by the FCC. As a result, I only use the amplifier when I am flying alone in areas that are some distance from other communications systems.
This power increase is not normally nessesary in RC because you can't see the aircraft that far out. But in FPV, you can easily exceed the normal range of your TX while still seeing clearly. Also, the FPV transmitter signal reduces the control range of your RC system (even if they are on different frequencies). This is because it creates a shield effect. So, lest you find you still have FPV signal but no RC controls and get a...Continue Reading
This is a nice setup for me because I do not want Aileron & Rudder coupled unless necessary, but it usually doesn't matter when in FPV. When I need to uncouple A & R, the camera centers and locks automatically when switched. Also, with the added weight of the FPV equipment, the Floater Jet weighs in at 1.5lb. This means that flaps are really nice to have on launch when you are in immersion. It takes a bit harder toss to get her in the air. On landing with a bit of added down elevator, she floats right in with very little elevator input.
Plane has stock power system with a 2100mah main battery, and 3S 180mah FPV battery. 800mW/900MHz FPV system w/ 3dbi antenna. Add weight to the tail to maintain CG (it should remain dead center on the wing spar).
You need to setup your Ailerons on separate R & L Aileron RX channels to get Flaperons to work. Then, plug your Camera's Pan Servo into the Gear RX channel.
RADIO SETUP ( DX7-S)
1. FLAPS switch: Three position flaps (Off, Launch, Land)
2. F Mode switch: Aileron / Rudder mixing
3. GEAR switch: Camera Pan to Rudder
4. I still have more switches available if I decide to add camera Tilt.