RE: Power Decrease Using Exhaust Deflector.
PH,
Tower hobbies have quite [link=http://www3.towerhobbies.com/cgi-bin/wti0095p?FVSEARCH=tachometer&FVPCODE=RF&search3=Go]a broad choice[/link], for pretty good prices.
Even the cheapest (I have had it for 7 years) does a pretty good job. You don't really need a TNC, if your hearing can distinguish between reasonable (perfectly accurate) figures and those that are 'off the charts'.