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Azur Electronics

HP 11720A 2-18GHz
PULSE MODULATOR
I bought this just to make use of the parts, to build a different circuit in the case. However, this 11720A is in too good a condition to scrap. It also has the paper Operating and Service Manual. The original cost was $2,500 in 1980.

Front view
Rear view
January 2011

Downloaded the same Operating and Service Manual. Will decide what to do with the 11720A when I have time to test it.


January 2016

Cleaned up and checked mains input ok. Removed covers to test.

Top view with cover removed
Bottom view with cover removed
Power supplies are ok although the 12V bulb in the line indicator light is blown. Checked that 2GHz RF CW passes through input to output ok.

The Performance Tests call for a second RF Signal Generator and a Double Balanced Mixer to produce a 20MHz IF, so that the output can be viewed on an Oscilloscope. As I don't have the Mixer available I can only check the output on a Spectrum Analyser. With the pulse input switched on and off, you can clearly see the effect on the Spectrum Analyser. This would indicate that the Modulator is working ok.

As I don't have any need for the 11720A this will be for sale along with the
Operating and Service Manual. NOW SOLD.