Hints , important points and notes on retro-fitting into other multiplier chains:

- All capacitors marked * are frequency related.

The Values given apply to 90 MHz +/--

-L1 = 0.1uH or thereabouts. The old TOKO "Green" coils with the Al cores were perfect but the newer TOKO coils in the shielded cans work very well.

- The 4.7pF interstage coupling capacitor CANNOT be any larger than this value or the oscillator will "misbehave".

- If there are problems with "netting" the crystal on frequency OR getting to restart once netted the following can / have been tried and do work:

- 100-200 nH of inductance across the crystral

- 10pF in series with the crystal

- 470 ohm resistor in parallel with L1

- the ratio of 12pF to 47pF caps can be altered.

-A lot will depend on the "Quality" and ageing characteristics of the crystal but usually 1 of the above or a combination will get the LO starting and netting on to frerquency properly.

- With 0-12V on Voltage tune input, and with the component values given, a typical 93MHz crystal should pull > +/- 60 Hz.

- All Spurri on the output are < 60dB down on the fundamental

- When using with a VE1ALQ board it was found that a 47 ohm resistor to gnd on the sample port provides a better response ( ie less signal to the LO input on the VE1ALQ board)

- The signal output of +4 - +6 dBm is perfect for feeding into a "G4DDK" board / multiplier chain. This level also works well into other multipliers.

- Those with a G4DDK board or any LO that uses a 2 stage butler oscillator will find that by adding this circuit in place of the original crystal, the oscillator chain will be more stable and less subject to any pulling and any other such effects.

- To feed the signal into an existing multiplier chain that uses a 2 stage type Butler, feed the RF from the LO into the 1st stage (where the old crystal was) via ~ 1nF and add a 1nF bypass capacitor across the emitter resistor on the 2nd stage.

- For improved stability I build the LO in a box with "R2-Pinkbats " insulation inside and out and place a crystal warmer to keep the temperature in th LO enclosure fairly constant. Even with a PLL system this helps maintain better stability and relies less on the PLL