[Boatanchors] simple transmitter using the 1625 tube

[Ken]

Hi Al & Group,

True, the suppressor grid is brought out of the glass envelope
but is connected into the same tube pin as the cathode on
SOME BRANDS OF TUBES. The RCA and one or more
others have the suppressor grid connected to the cathode
within, repeat, within the glass envelope.
On the brands that bring out the suppressor grid from the
glass envelope separately it is connected into the same
tube pin as the cathode.
Fortunately, there is a blank pin right next to the cathode
pin. So, by unsoldering the two leads from the cathode
pin, finding out which one is the suppressor grid and
connecting it to the blank pin, the 1625's can be used
in a grounded grid configuration which I used for many
years in a linear I built up with 4 1625's grounded grid
driven by one 1625 grounded grid. My "exciter" was
the Central Electronics 10B only rated at 10 watts
output so I had to boost up the drive to the linear.
Way back when, new 1625's were 25 cents apiece!
FWIW.

Ken   N5CM



----- Original Message ----- 
From: "Al Klase" <al at ar88.net>
To: "n0alo" <n0alo at kans.com>
Cc: "boatanchor" <boatanchors at mailman.qth.net>; "Homebuilt"
<homebuilttuberadios at yahoogroups.com>; "Hallicrafters"
<hallicrafters at mailman.qth.net>; "Regenrec" <regenrx at yahoogroups.com>
Sent: Sunday, November 16, 2008 7:09 PM
Subject: Re: [Boatanchors] simple transmitter using the 1625 tube


> Keep in mine this is fundamentally an 807 with a 12-volt heater and the
> suppressor grid brought out separately rather than being tied to the
> cathode.
>
> Al





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