[R-1051] Tools, and first assessment (was RE: Intro and WTB: R-1051 cabinet)

[David Wise]

Thanks, Paul, but I want to run it standalone.

My Frequency Standard has an open PTC thermistor.  As far as I can tell from
the archive, nobody, not even Cecil, has ever found a source or a substitute.
If I'm wrong, please tell me the recipe!  In the mean time, I'll take a
whack at it myself.  At least the heater has continuity and doesn't seem
to be shorted to the housing, and the transistor acts like a transistor.

This Standard is a Bendix 4013399-0701, FSN 6625-078-4718.  (By the way, how
do you figure out the FSN?  The module only has the Bendix part number.  I got
the FSN from the archive.)

It is wired like Figure 5-6 in NAVELEX 0967-LP-970-9010, except it has no A4 +27V(sic)
Regulator (actually 17V), and R9 is 820 ohms not 330 ohms.  The board under R9
is discolored.  If anyone has added a 7815 and is satisfied with the result,
I'd like to hear how you mounted it.  I don't see any place to put it.
And did you hack it in like A4, or did you cut into the wire at J1 pin 1?
My idea is to mount it on the mainframe, and bring in +15V on one of the
spare J1 pins.  I'm also thinking of an LED to indicate how much current
the oven is using.

I noticed that S1 is different.  The schematic labels the positions
EXT, INT, and COMP, but my module is INT/COMP, EXT(NORMAL), and EXT(OVEN STBY).
Does anyone have a schematic that matches this?

>-----Original Message-----
>From: r-1051-bounces at mailman.qth.net 
>[mailto:r-1051-bounces at mailman.qth.net] On Behalf Of paul
>Sent: Friday, June 29, 2012 11:14 AM
>To: R-1051 Discussion Group
>Subject: Re: [R-1051] Tools, and first assessment (was RE: 
>Intro and WTB: R-1051 cabinet)
>
>Good news is if there is an issue with the 5mc osc you can run it 
>externally from a 5 mc source.
>I run my 1051 externally with a rb reference compared to GPS
>Regards
>Paul