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Ref Oscillator instability problem

N4KS Ken Stuber
 

My K3 SN 8025 appears to have a ref oscillator instability problem. I must do the Reference Oscillator calibration procedure daily to keep it within reasonable limits. Leaving the K3 turned on continuously helps. I have replaced the original oscillator with the Elecraft KTCXO3-1 1-ppm oscillator. The problem still persists. Any suggestions would be appreciated.

73, Ken
N4KS

redarlington
 

How far is it drifting over the course of the day?  An hour?

-Bob

On Thu, Apr 16, 2020 at 1:51 PM N4KS Ken Stuber via groups.io <stuberkenneth=yahoo.com@groups.io> wrote:
My K3 SN 8025 appears to have a ref oscillator instability problem. I must do the Reference Oscillator calibration procedure daily to keep it within reasonable limits. Leaving the K3 turned on continuously helps. I have replaced the original oscillator with the Elecraft KTCXO3-1 1-ppm oscillator. The problem still persists. Any suggestions would be appreciated.

73, Ken
N4KS

John Canfield
 

How do you know the oscillator itself is drifting? Like Bob asked, more details would be helpful.  Maybe Elecraft can send you a schematic of the (I assume) VCO area - perhaps it's going out of lock.

Michael Foerster
 

Ken,

I suspect that you have a KTCXO3 that the internal oven is not working.  If your rig is still under warranty (I suspect not, judging by the SN) you could contact Elecraft, though I doubt that they have any working 1ppm oscillators (I tried to order one recently).  

The other option may be to order one from eBay.  There is someone in China that is selling a knock-off of the KTCX03 for about $50 that may work for you. 

You can actually test the drift on your device by installing WSJT-X and using the "FreqCal" function in the "Mode" menu and select 7.850 CHU or 10 MHz and watch the drift over an hour, as you start your K3 up from cold.  If you get fancy, you can even put the data into an Excel spreadsheet and plot it in a graph. 

73,
Mike, W0IH

Drew Vonada-Smith K3PA
 

Mike,

These are TCXOs.  There is no oven.

73,

Drew K3PA

N4KS Ken Stuber
 

Thanks for the replies. Elecraft is replacing my defective KTCXO3-1 1 ppm ref oscillator. I appreciate their mighty fine service.

73, Ken N4KS