What is the best FPV Tx for a beginner?
Surely the idea is to get the most powerful transmitter ? why do people use less powerful - smaller - video Tx?
Beginners sometimes think their very first maiden flight of their first Quad will be FPV with all kinds of advanced OSD running on the maiden flight - bad idea - this is an over-ambitious idea as you will go thru a crash phase while you learn, and could injure yourself on goggles as you wont see it coming - noob learner pilots should use a FlightSim first, then fly LOS (line of sight) to at least 0->50m for a few weeks - LOS is more effective than FPV - Beyond 50m is where FPV can really start to be a huge advantage - so the FPV zone of 50m->600m is the sweet spot.
Tech wise, the best V-Tx for a beginner is the 100% citizen legal 25mw herehttp://www.multiwiicopter.com/products/25mw-32ch-fpv-transmitter then add the boofhead omni antenna herehttp://www.multiwiicopter.com/products/fpv-5-8ghz-tx-rx-skew-planar-cloverleaf-boofheads - be aware of ERIP issues as well
this 22ch 25mw above, will give you 300m LOS with Helical Rx on the ground side antenna, and peace of mind. Be sure to point all OMNI mushroom antenna up - or down - don't ever point omni antenna sideways or at 45° - only UP or DOWN - Then for a Helical Rx ground side point these at the aircraft
Once you are flying further than 250m, i.e. after a few months - then consider a HAM licence, Telecommand / telemetry V-Txs like 200mw http://www.multiwiicopter.com/products/200mw-32ch-fpv-transmitter, 400mw (these are only 8ch 400mw but actually better than most 32 channel as their signal is clearer give ~1000m)http://www.multiwiicopter.com/products/band-a-fpv-tx-5-8ghz-400mw-8ch - but realise that these 400mw dont give as much range as you might think(compared to a 25mw) as range is not exactly proportional to V-Tx power - range=√power - so to get 500m you would need 200mw and to get 1000m you need 400mw etc ;; Don't get fooled by forums into running a an oversize Tx like 600mw, 1000mw or 2000mw. An oversized Tx will swamp your RC when you fly far away, will swamp adjecent channels and if your antenna are not perfectly setup they won't help at all - antenna setup is best learnt with a 25mw system airside + a Helical on the ground side - so first option above 25mw with good antenna is the best for first FPV flyers imo - Later you can go to the advanced HAM option for other bands (the Advanced HAM band is wider than the Noob band)