-> I never worked with TV/UHF, though I have an FM transmitter that drains a 9V
-> transistor battery way too fast .

 Wel lthe 9 volt batteries are saddly lacking in MAh capacity. And one
should suspect that becasue of their compact size. 
As an example in the rechargable Nickel-Metal-Hydride battery the 9 volt
cell is rated at 150 mAh while the "AA" is rated at 1500 mAh     
The 9 volt cell is really only practical for a Reciever only. If one is
talking about Transmitters or Actuators forget it. The operating time
will as you have found out will be quite short.
--- Platinum Xpress/Win/WINServer v3.0pr5