G3UUR crystal oscillator data

 I finally found some 470 pF caps, hundreds of them, polystyrene, what was I going to do with them ?  Anyway, that was the part I was missing for the G3UUR oscillator.

I tried searching for the published source of the G3UUR circuit on the internet, no luck.  I dug out the "Technical Topics" book I have, these were columns from Radcom, the magazine of the Radio Society of Great Britain, nothing found.  I did find articles by G3UUR in QEX magazine but none had the circuit.  Finally I looked at W7ZOI's article in the June 1995 issue of QEX, that seems to be the first mention of the circuit in ham radio literature.

I built the 2 transistor circuit on a small white breadboard as seen here:

G3UUR circuit at lower left, imperfection in the cover hides a 3 so 4,915,379

The output is a decent 1 volt or so square wave, plenty to drive the ebay counter.

Here are the results:

included all the digits

As expected the correlation with either the NanoVNA or the Butler oscillator weren't that great.  I did do the second measurement for each crystal by unjumpering a 38.1 pF cap (used instead of the 47 pF cap used by W2AEW, here is a doc from his video with the circuit:  

https://www.qsl.net/w2aew/youtube/crystal_measurements_nanovna.pdf).

So, nothing much different for a conclusion, will stick with the NanoVNA, that seems to be the best method.

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm