[Amps] PL172 (8295)

[Carl]

The original PL-172 with glass seals is NOTORIOUS for air leakage and not 
outgassing from the anode.....big difference.

Carl


----- Original Message ----- 
From: "RAY FRIESS" <rayfrijr at msn.com>
To: <Amps at contesting.com>; <chris at g3vbl.co.uk>
Sent: Saturday, May 06, 2017 11:32 AM
Subject: Re: [Amps] PL172 (8295)


>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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