[ARC5] OT - the BC-221-D, tube types.

[Richard Knoppow]

     I posted a question to the Tube Collector's list about this. 
Perhaps someone there has more information about the construction of the 
77.
     FWIW, from the RCA RC-14 tube manual the 6C6 and 6J7G have similar 
characteristics to the 77 but the 6C6 has an internal shield connected 
to the cathode pin. The 6J7G is an octal base equivalent to the 6C6 and 
is also available as a metal tube. The Gm of both is slightly higher 
than the 77. Tube base connections and operating voltages for the 6C6 
and 77 are about identical.

On 12/17/2016 1:04 PM, Kenneth G. Gordon wrote:
> On 17 Dec 2016 at 12:47, Richard Knoppow wrote:
>
>>     I can't find any other place where a Type 77 is shown like this. I
>> think its an error that was repeated in the schematics. The 77 was
>> recommended by RCA for use as a plate detector, which is the application
>> in the BC-221. I wonder if there are schematics from other sources.
>
> I think that in order to answer this question adequately one will have to "dismantle" a 77 and
> examine it closely.
>
> I don't have one here at the moment.
>
> Ken W7EKB
>
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-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL