i got one of those cheep wireless video cams from ebay its 900mhz-1200mhz output power 200mw i was wondering if thare is aney way 2 build a transmitter amp to boost its range im puting it on an rc car
Messing with transmitters without FCC approval can be a problem for you. While you are unlikely to get caught unless you cause interference, if you do, the fines can be pretty high.
Secondly, the FAA (and presumably other agencies) are looking at implementing very tight restrictions on unmanned, remotely controlled vehicles and models. If you want a scary update, read the current Model Aviation from the AMA.
With that backdrop, I think a hobbyist attempt to increase range and possibly make an out of sight remote vehicle is very ill advised.
The more clutter between you and the transmitter the weaker and more scattered the signal becomes. A time honored method of increasing range is to elevate the antenna.
If you have the equipment and ability, "cheep" video cameras are not tuned too tightly, so if you can get the xmtr and your rcvr tuned to spot-on frequency, you may -- as in might get a wee bit better performance.
Aside from that, it's best to take the advice of the the guys here, and not lock horns with the FCC..You will lose.
Give them attitude, you will lose bigtime, 'cuz they don't play games....they can impound and / or destroy your "toys"....and fines are hefty.
The PN918 is a good RF amplifier with a wide frequency range. The MPF-901/NTE64 is an RF amp in the DC to 2 GHz range. You can feed a signal into the MAR-3+ drop-in amp to boost your signal to 400mA.
Since the circuit in your camera is already tuned, adding an RF amp would likely de-tune the circuit, so you probably wouldn't be able to receive the signal without a fair amount of alignment to get it right.
Read http://www.fcc.gov/oet/info/rules/ carefully before you modify commercial off the shelf equipment to make it operate outside the scope of its intended function.