[R-390] Cosmos Drift

[Barry Hauser]

Jon wrote:

<snipped>
> The onset of restoration I 'retubed' I'm sure that I put in a better
> tube,that is higher transconductance. I will certainly tried other tubes.


I seem to recall reading in one of the manuals or a thread on this list a 
few years back, that it was not advisable to use a "hot" tube in the PTO. 
It was better to select a new tube with more typical transconductance 
readings, or a used one rotated in from another socket in the rig that was 
well broken in.

You might try that and repeat the readings and see if they're more stable. 
Be sure to test for gas/grid emissions, not just transconductance.

Barry