[Boatanchors] Suppressor grid modulation

[Carl]

----- Original Message ----- 
From: <w8au at sssnet.com>
To: <boatanchors at mailman.qth.net>
Sent: Wednesday, January 27, 2010 11:51 PM
Subject: Re: [Boatanchors] Suppressor grid modulation


> At 11:03 PM 1/27/2010, Jim Haynes wrote:
>>On Wed, 27 Jan 2010, Al Klase wrote:
>>
>> > In addition, you need a pentode with the suppressor grid brought out to
>> > a separate pin, as opposed to being internally connected to the 
>> > cathode.
>> >
>>This ticked a faint memory of some article about tubes, 807 or 1625,
>>and in some brands there was something connected internally, but in
>>others there were two separate wires going to the same pin on the base.
>
> This discussion accounts for the efficiency modulation techniques used by
> Navy WW2 gear where the TDE and earlier xmtrs using 803 tubes used 
> suppressor
> grid modulation, and the later TCK, using a pair of 813's, used 
> control-grid
> modulation.  Although the 813 was the successor to the 803, the suppressor
> grid vs. beam forming plates was a definite change and required a change
> in the modulation arrangement.
>
> Perry  w8au

The larger TBL/TBK used screen grid modulation on the 861 final. I was 
surprised how well it sounded. The TDE was in Emergency Radio on one of the 
ships I was on in the 60's and the TBK in Radio Central.

Carl
KM1H



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