[ARC5] Glass or Metal Tubes Preferred for Receivers?

[Richard Knoppow]

    I don't know. Metal tubes seem to have been introduced c. 
1937 or perhaps it was 1935. I think that by the 1940s the 
problem had been solved. Also, my RCA AR-88 has all metal tubes 
except for rectifier and VR tube. The one glass tube is a 6SA7GY 
but its not original.

On 2/6/2018 3:56 PM, D C _Mac_ Macdonald wrote:
> Would 1943 vintage metal tubes not have the
> leakage problem?
>   
> 73 de Mac, K2GKK/5 in OKC
> 
> Sent from my iPhone
> 
> On Feb 6, 2018, at 16:15, Richard Knoppow <1oldlens1 at ix.netcom.com> wrote:
> 
>    Early in the life of metal tubes they had a bad reputation for leakage. I think this was solved after a short time but the reputation stuck.
> 
>> On 2/4/2018 7:25 PM, J Mcvey via ARC5 wrote:
>> Don't know about the lifespan, but the metal does provide shielding that will not be present with the GT....
>> On Sunday, February 4, 2018 9:07 PM, D C _Mac_ Macdonald <k2gkk at hotmail.com> wrote:
>> Is there a performance and/or lifespan difference between the tubes?  I.E., 12SK7 or 12SK7GT preferred?
>> 73 de Mac, K2GKK/5
>> (Since 30 Nov '53)
>> Oklahoma City, OK
>> USAF Retired 61-81
>> FAA Retired 94-10
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> 

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL