[Elecraft] KTCXO3-1 knock offs

[hbjr at optilink.us]

Hey Folks…

I’ve posted here before with issues I’ve had with 2 factory Elecraft KTCXO3-1 crystals – one I replaced and one the factory replaced.  The factory graciously sent me a new standard 5PPM crystal that works as designed – it is a smidge better than the original factory crystal according to a 4 hour drift test using WSJT-X.

 

I had lots of offline conversations with guys wanting to know if the eBay 1PPM crystal was any good.  I asked that question here and got lots of input with some indicating it would introduce phase noise.  I have no way of measuring that that I know of 😊

 

Someone offered to buy me the eBay knock-off to try it.  I went ahead and bought it just for fun.  I installed it today and calibrated it with an external GPSDO using the K3EXREF input.  It so far seems a bit better than my “new 5PPM crystal doing the drift test for 3 hours.  The real difference I can see is on 2 meters SSB (I have the K144XV Ref Lock installed).  With the 5PPM crystal, I had to tune down just a bit for the other station to sound “normal”.  With the eBay part it “sounds” dead on.

 

One interesting thing to note for those interested in the eBay crystal, it has USA stamped on it in the corner.  I can’t quite make out the name brand – something like Symmbi (sp??) and 49.380001 also stamped on it.  The crystal’s case looks like the original 5PPM part and not the flat square box like the KTCXO3-1.

 

Is it just a copy?  Is it an original US part tuned to the correct frequency?  It came from Hong Kong.

 

How can I test phase noise?  Someone live close to NW GA that would like to test it?

 

Thanks,

Hank