[Amps] PL172 (8295)

[RAY FRIESS]

I would not be too concerned about leakage.  It happens, but very very seldom.  I have tubes that are still new in box from way back in WW2 that I have used and none have ever shown air leakage.  Easiest way to determine if they are still good is to plug them in and fire up the rig.

Ray  wa7itz


________________________________
From: Amps <amps-bounces at contesting.com> on behalf of Chris Pedder <chris.g3vbl at gmail.com>
Sent: Saturday, May 6, 2017 8:11 AM
To: Amps at contesting.com
Subject: [Amps] PL172 (8295)

For the last 37 years my Hallicrafter HT33A has been sitting on the floor
in the garage with an 8295A (Ceramic) fitted. I have a pair of 'new in the
box' PL172s one of whose boxes is still sealed. Packing date was 6/67 so
that's almost 50 years.
I suspect that the glass seals will have leaked but is there anyone with
experience of these tubes after such a long period of time. If I were to
construct a hi-pot device, what sort of values should I expect from a
'good' tube? Thanks.

Chris G3VBL
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