[AMRadio] Re: Need ID Help for 1930's Transmitter

A.R.S. - W5AMI ars.w5ami at gmail.com
Wed Sep 13 13:15:52 EDT 2006

On 9/12/06, Don Merz <n3rht at yahoo.com> wrote:
> The final deck has a socket for a single tube with the
> large, twist-lock base and 2 plate-cap-size
> connections for plate and grid caps. Not many tubes
> fit that description, so I am thinking maybe an 810
> goes there? The Eimac tubes are out because they used
> a pin for the grid--not a full-size plate cap. The
> final deck has a filament transformer (I haven't


Determine the filament voltage.  Also, was the bias supply for the
final in the power supply section that's missing?  If not, what does
the voltage appear to be on it?  This would help narrow down a final
tube.  The Eimac tubes above the 250T (450 up) used the standard .5"
grid and plate caps.  The 450T had both the pin and a .5" cap on the
grid.  GE also made some Eimac like triodes such as the GE806 which
was a close cousin to the 250T only it had .5" caps on the grid and
plate.  Of course there are other possibilities like Taylor, etc.

Brian / w5ami

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