There better not be any continuity between any pins except the filament.
If they are 5-500A pentodes, which seems most likely, they also work well in
GG and better than a 4-400. Ive used Penta PL-175A's in a fully GG SB-220
and they are as easy to drive as 3-500's.
Carl
KM1H
----- Original Message -----
From: "Alek Petkovic" <vk6apk@bigpond.com>
To: "mike stokes" <mike9v@gmail.com>; "Amps" <amps@contesting.com>
Sent: Monday, November 29, 2010 3:15 AM
Subject: Re: [Amps] Help identifying tubes
> You should be able to tell with an ohm meter.
>
> The filament pins are easy to identify. They are the same for the
> triode, tetrode and pentode.
>
> If it is a triode, the 3 other pins will have 0 Ohms between them
> If it is a tetrode, only two of the other tree pins will show 0 Ohms
> If it is a pentode, there will be no continuity between any of the
> other three pins.
>
> From the pics, they look like 5-500 tubes but the Ohm meter should tell
> you.
>
> 73, Alek
> VK6APK
>
>
> At 12:09 PM 29/11/2010, mike stokes wrote:
>>Hi Guys
>>
>>Someone gave me 2 tubes years ago and said they were 3-500s. Well I am
>>not
>>sure they really knew, and I don't know as the lettering is worn off.
>>Here
>>is a link with some pics.
>>
>>http://picasaweb.google.com/mike9v/Tubes#
>>
>>The one on the left is an Eimac. It end in an A and has S4 7704
>>stamped
>>inside.
>>
>>The one on the right is a Westinghouse and looks like it says 5/5xxA where
>>the x in worn and illegible.
>>
>>Any ideas on what these really are ? Or what is a good way to figure it
>>out
>>?
>>
>>Any help is appreciated.
>>
>>--
>>Mike Stokes
>>KK9V
>>_______________________________________________
>>Amps mailing list
>>Amps@contesting.com
>>http://lists.contesting.com/mailman/listinfo/amps
>
>
> http://www.qrz.com/db/vk6apk
> http://www.qrz.com/db/vk6ap
>
>
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