[TenTec] Omni VI calibration

[Paul Christensen]

> The xtal oven went bad and I sent the O VI into TT to have a TCXO put in, 
> and a realignment done.. Now it's about 50hz low.. I can adjust for this, 
> but, that just doesn't set right with me.. I'm assuming the problem is 
> ageing of the Master Oscillator (TCXO)..

Ten Tec's TCXO is actually quite good.  You may only need to re-adjust it 
one last time after initial aging.  I also retrofited mine and its frequrncy 
did not vary more than about 10-20 Hz over time.

> My setup is a "Closet Kilowatt", and it's a (PITA) to take apart and 
> readjust the MO.. There are some more conveniet and long term options..
>
> 1. Move the TCXO/Xstal Oven outside the cabinet..
> 2. Install a better MO unit..
> 3. GPS timing system..
> 4. Bottom line a remote MO..

I would be apprehensive about moving the TCXO too far from its present 
location.  I do not recall the TCXO's frequency, but if it's 10 MHz, you can 
use a GPS-locked disciplined oscillator, like the HP Z3801A.

Another option is an ultra-high-stability, low phase-noise OCXO like this 
one from Wenzel:

http://www.wenzel.com/catalog/4to24.html#onyx

Either of these options is going to be a bit pricey with the OCXO probably 
requiring the least amount of modifying to the rig.

Paul, W9AC