Amateur Radio Pages
updated November 2014
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LF and MF Experiments etc - 16
X2 Multiplier for Class D 137 and 500 kHz Transmitters by J Rusgrove W1VD
Harmonic Amplifier  (Frequency Doubler) continued from previous page.....

Unfortunately the further testing of the latest version did show that certain conditions did cause the multiplier to show it’s instability and would need drive level adjustments and therefore for safety reasons would require continuous monitoring.

There is another version on the drawing board, suggested by Graham G0NBD to be built and tested which uses a full wave Schottky diode bridge to produce the doubled frequency but I have not pursued it as  I came across a tried and tested design by Jay W1VD, (link below).

The circuit board was constructed and fully bench tested, so next was to run it with the Class D transmitter.
LF & MF experiments 17 LF & MF experiments 15