?

Obi Wan, you have increased my knowledge.

?

I started this thread because I thought 2 of Rod Elliot’s projects would be of interest to members herein.

?

My EE friend described a RF test set that analog two-way radio stations used that did many of the tests of Mr. Elliot’s PC based audio test system.

You could verify frequency, deviation, use SINADD to check signal to noise and align RF front ends, check the receive audio for power and I think he said THD and an RF spectrum analyzer. Oddly he said it was manufactured by Singer.

?

I thought Mr. Elliot’s design might prompt others into considering their own.

?

The “test patch bay” looks interesting in its own right, add outputs for frequency counter, a dedicated and disposable SDR for spectrum analyzer, either a very stable RF generator with calibrated outputs or something like the Elecraft XG-1 1uV/50uV signal source.

Sort of a one stop “box” that would allow quick and repeatable testing without having to look for that missing patch cord.

?

?

While a GPS DO costs less then $200(us) and offers amazing frequency accuracy with low jitter, my EE friend showed me a neat if obsolete “different way” to get sub-hertz accuracy.

?