[AMRadio] Ashtabula Bill, 814 tube, Huntsville Hamfest

[Jim Candela]

>
> The 814 has a 5-pin socket, the same as the 807.  It is a pentode,
with a
> separate pin connection for the suppressor grid.  For data on this
tube,
go
> to http://datasheets.electron-tube.net/sheets/049/8/814.pdf
>
> I plan to attend the Huntsville, AL hamfest this coming Saturday, 18
AU.
> Hope to see some of you there.
>
> Don, K4KYV


Don,

   I tried the 814 before in my original Viking I where I used about
1500 volts on the plate modulated by a pair of 8417's. It worked very
well until G1 shorted to the filament. I replaced the tube, and some
months later the same thing happened. I later replaced the tube with an
813, and there were no more failures.

   In looking back I wonder if the failures were due to defective tubes,
improper operating conditions, or maybe a parasitic oscillation.
Whatever the case, the 813 survived when two 814's did not.

   If I had a box of 814's I'd be tempted to use them again.

Regards,
Jim
JKO