[time-nuts] Wenzel 245MHz OCXO Low noise power supply and mounting environment

[Gerald Molenkamp]

Hi All,

 

I recently purchased a Wenzel 245MHz OCXO from ebay. It appears to work
very well and shows good stability after 2 weeks on the bench.

 

I would like to use it as the primary reference for a DDS 1st Lo in my
homebrew HF transceiver. I have come to the conclusion the unit requires
a very low noise 9 volt supply to ensure the phase noise is kept
controlled around the spec.

 

Although I am not able to measure phase noise, ensuring the unit is fed
with a clean supply can only be good. I looked at the Wenzel Finesse
approach, this article all makes sense and confirms my view the need for
an exceptional low noise supply.  

 

I have noticed environmental changes/package temp stability is quite
sensitive, the block is only 2" square therefore not a lot of mass, even
handling the package shows drift +/-  5 to 10 Hz. I am thinking the best
option is to box up the OCXO and low noise power supply in a Diecast
box, insulated with Styrofoam to ensure external excessive temperature
swings do not affect the package, however I am open to any suggestion.
This is similar to the double skin 10811. 

 

I am not able to measure Phase Noise as per spec, I am looking for
assistance from this group on the best method for measuring phase noise
and stability using what equipment I do have in my Lab. I have a
TDS2022B with FFT, HP 53131 and Tek492BP. My standard's reference is
one of Tom's Thunderbolt with John's mods ( 10811 ) and a good quality
linear power supply.

 

Regards

 

Gerald

VK3GJM

 

Gerald Molenkamp
CTO - Director 

 

 

CommTel Network Solutions Pty Ltd
46 Ovata Drive. Tullamarine. Victoria. Australia. 3043
T. +613 9330 4722  /  F. +613 9330 4277  /  M. 0408 544 657

ServiceDesk. 1800 99 78 76
E. geraldm at commtelns.com  /  W. www.commtelns.com

 

 

 

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 1977 bytes
Desc: image001.jpg
URL: <http://www.febo.com/pipermail/time-nuts/attachments/20100923/74035700/attachment.jpeg>