[R-1051] Frequency standard module

[James A. (Andy) Moorer]

Boy, no kidding. I hadn't looked at it closely, but that schematic is mixed
up in a number of ways. You are correct - the 1N3026 is an 18-V zener.
Combined with the 0.6 V drop of the B-E junction, that would be about 17.4V.
Close enough. But the real problem with that diagram is that the transistor
is drawn upside-down! The way it is shown, the emitter is connected to the
+28 rail! Besides not regulating anything, it would probably hit the 6V
reverse breakdown voltage of the B-E junction!

Given also that that regulator is drawn in a different style than the rest
of the schematic, it had to be a late add-on, and a rather careless one as
well.

I have the 1964 version of the manual as well, but I haven't scanned it. The
schematic for the frequency standard has the slug-tuned transformers (and no
voltage regulator). I'll scan just that page and send it to you (and anybody
else that wants it).

James A. (Andy) Moorer
www.jamminpower.com

----- Original Message ----- 
From: "Steve Hobensack" <stevehobensack at yahoo.com>
To: "r1051 radio" <r-1051 at mailman.qth.net>
Sent: Sunday, September 14, 2003 5:49 PM
Subject: [R-1051] Frequency standard module


> Look at the schematic diagram of the frequency
> standard module. There is a small voltage regulator
> board that drops voltage and sends it to the oven
> circuit. It is marked as "27 volt regulator". Could
> this be a misprint ? The voltage on my unit measures
> 17v. The zener diode references out to near 17v in my
> parts books. I have found a couple modules where this
> regulator board has been removed and the oven wired
> straight to the 28v source. Should the temperature
> circuit fail, it will really cook the crystal circuit
> board.
>
> Also , I am still looking for a schematic diagram for
> the frequency standard module that uses slug tuned
> transformers instead of trimmer caps. Thanks
>
> Steve......KJ8L
>