[time-nuts] Frequency divider design critique request
bruce.griffiths at xtra.co.nz
Sat Jul 12 19:03:15 EDT 2008
Bruce Griffiths wrote:
>> I was only thinking that maybe there ought to be a buffer from the input
>> to the rectifier, or else higher frequency energy will escape out
>> towards the
>> source. At least some isolation should be there.
If one uses a common base stage to drive the diode frequency doubler
transformer primary, then the high impedance drive minimises the effect
of diode thresholds and mismatches, however it is necessary to connect a
resistor in parallel with the shunt inductor in the diode doubler to
provide a well defined relatively low load impedance at the 10MHz output
Reverse isolation of 40dB or so is possible when using a common base
stage at frequencies of around 10MHz or so.
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