[Amps] PL172 (8295)

[Roger (K8RI)]

I agree with Carl, I haven't seen a good PL172 (glass seal) in ages. The 
ceramic versions seem to hold up well.
I have an HT32B

73, Roger (K8RI)


On 5/6/2017 Saturday 11:46 AM, Carl wrote:
> 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
>> _______________________________________________
>> Amps mailing list
>> Amps at contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>> Amps Reflector - Contesting.com Ham Radio Mailing 
>> Lists<http://lists.contesting.com/mailman/listinfo/amps>
>> lists.contesting.com
>> Welcome to the Amplifier mailing list! This list is intended for the 
>> exchange of information on HAM RADIO Amplifiers related topics ONLY. 
>> Our goal is to keep ...
>>
>>
>> _______________________________________________
>> Amps mailing list
>> Amps at contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps 
>
>
> ---
> This email has been checked for viruses by AVG.
> http://www.avg.com
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus