[NJARC] Microphonics in 34 AKA VT-54 tubes

[Robert Flory]

I have a half-dozen  34s that are all microphonic to a degree, with one spectacular individual  that rings for about 10 seconds (a Philco)  Others are Ken-Rad and National Union(the only one of the bunch that is also labelled VT-54)

All of these tubes were purchased as used, and I suspect they were pulled from their previous application due to the microphonics.

Is this a known problem?

Does anyone local(central NJ) have any?  I would be especially interested in ones labelled VT-54 and/or from different manufacturers than the above esp. RCA on the hope that they may be better.

Rob