A Dead Easy 50 mhz Preamp by VK3CJS
6M Preamp - Page 2
The TV tuner will cover 50 mhz on Lowband VHF. If the local oscillator is disabled and the mixer/IF output transformer peaked to 50 mhz, the mixer itself will be an amplifier. Add the dual-gate mosfet front end with variable gain and varactor tuning and we have a beautiful two-stage preamp.
The Tune and Gain pots can be anything from 4.7k to 20k. In a TV set, 0 - 40 volts is applied to VT to span the whole range of channels, but 50 mhz can easily be reached on Low VHF with less than 12 volts. BU, BH and AFT are no connection. The metal case is negative 12 volts and EARTH of course.
Reach in with a pair of fine sidecutters and snip the VHF Low oscillator tank coil as shown. Your tuner may not be exactly the same as this Sharp model, but you'll get the drift of it if you study it under the old maggie light.
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