[NLRS] If I wanted to be a beacon...

[Dr. Gerald N. Johnson, electrical engineer]

For a $20 or so you could replace the crystal in the DB6NT signal source
to put it on a frequency you wish.

If you phase lock a voltage controlled crystal oscillator, the crystal
still maintains most of the phase noise control. You do have the chance
of adding noise if the loop bandwidth is wide or there's a large R in
the control line. (the source of the wild phase noise of the IC-211 is a
large R where there should be an RF choke feeding the varactor). But
since the phase lock loop needs only to correct for the relatively slow
drift of the crystal, it can have a narrow bandwidth and so the phase
noise it adds can be limited.

You could start with a Frequencies West LO and multiplier.

You could start with the channel element from a Motorola Micor UHF
receiver. Its temperature compensated, generally in the 48 MHz region
and has a DC coupled AFC input for the PLL and maybe for manual tuning.
It could be in a portion of the Motorola receiver board to multiply up
to about 432 (from a 48 MHz crystal). That could drive a 1105 MMIC and a
diode multiplier to say 3 Ghz, then one of the modular multipliers from
England could get you to 12 Ghz. Then a 2x multiplier from epay. You
would probably want to provide the TCXO with a temperature controlled
environment for better stability. You could run a test of frequency vs.
TCXO case temperature, or better AFC correction voltage vs temperature,
then build a compensator that read that data from an EPROM (probably
using a PIC chip micro) and used one of the A/D inputs of the PIC chip
to determine TXCO case temperature and thus the correct correction
voltage to apply to the AFC input. That's how one of the frequency
standard's makers claims rubidium accuracy with a crystal. They don't
get the long term low drift of rubidium but they do get very good
frequency stability in changing temperatures.

73, Jerry, K0CQ

-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.