Tempo 2020 Zener Question

[Ed Lambert" "K1ZOK]

My Sylvania tube manual shows for RF service a screen voltage of 150
volts.  This is a starting point.  The Heath SB-100/101 run them at 235
volts.  Got to be somewhere in that range.

Ed
K1ZOK

On Tue, 12 Jun 2001 13:18:34 -0400 Marcus Harton
<MHarton at FREEDOMFORUM.ORG> writes:
> Hi guys,
>
> I'm in a pinch with a Henry Radio Tempo 2020 I've got that needs a
> new Zener
> Diode in the screen circuit of the 6146 finals. The diode stabilizes
> the
> tube's screen voltage. The schematic shows the part is actually two
> diodes
> in one case. It has a number on it of DZ750522a. The owners manual
> part
> breakdown also gives it a manufacturer's part number of DDAY038001.
> For the
> record, I have contacted current-day Henry Radio and gotten a
> dust-off from
> them.
> This radio probably has too much silicon in it to rate true BA-hood,
> but I'm
> having a devil of a time finding how to replace the diode, and I
> figured you
> guys might know a trick or two about finding parts for radios whose
> manufacturers no longer exist (or care.)
>
> Neither the operator's manual nor the repair manual give a voltage
> value for
> this zener. Any suggestions on finding the correct value? Was there
> a
> consistent voltage range for radios with 6146 finals?
>
> Thanks for any advice you might offer.
>
> Marcus Harton, nz4e
>