Whitebox Oscillator Diode Replacement.

Mark - M1MPW

Opps... forgot to mention it is the 10ghz whitebox 

Mark - M1MPW

I recently bought a whitebox system which arrived in a very poor state.
The oscillator 1st stage had several burnt out resistors and the 2nd stage transformer was shorted.
All these easily fixed.
But the diode CR3 on the output of the transformer has a crack in it which has rendered it useless.

Does anyone know of a suitable replacement for the diode?
None of the schematics I can find give part numbers.