[time-nuts] Tracoe 600 rubidium standard - defective?

[paul swed]

Chris,
Good news
The modulation frequency has no great bearing on operation. Yes it should
be in the range that you are seeing and by itself stable. (Reasonably). Its
unfortunate but get good documentations pretty tricky on most of this old
stuff. The internet and time-nuts sure has improved the chance that someone
does have something. I have some 304 information and am very sure its the
same that you have. Obtained from a time-nut. Just in case I stumble across
a 304 some day. Looking thin in that respect.
What other meter readings do you have. Its old so the RB may be finished.
Key is the lamp fires up and is at the right temperature.
Regards
Paul.


On Wed, Jan 29, 2014 at 8:55 AM, Christopher Hilton-Johnson <
chj at pchjhome.com> wrote:

> Hi
> Help needed please
> Bought many years ago, my Tracor 600 has been working fine, remaining on
> lock for months at a time.  It now will not lock at all, the front panel
> lamp flashing rapidly.
> the lamp start process completes OK.
> I have a copy of the operation and service manual, but the manual is very
> light on calibration - actually except for tuning the xtal Oscillator there
> is bugger all (technical term)
> A list member was kind enough to send me an extract from the 304D manual
> which gives so me more information, but that is incomplete.
> I am really looking for a 'how to/what to expect/what to look for'
> calibration manual, complete with some figures/tables showing what to
> expect, so that I can troubleshoot the system.
> I am also after information about what appears to be discrepancies between
> manual and machine.  My Tracor is SN: 203, presumably quite early. In the
> manual the detailed explanation has the AF Oscillator running @330 Hz,
> divided by 2 to 165 Hz, which is compared to a similar frequency coming
> from the lamp unit, the phase difference between the two giving an error
> signal which adjusts the loop towards lock.
> My Manual and the info printed on the machine internals differs For
> example; on A7 (audio) Module, J4 is marked as 310Hz out, yet the schematic
> shows 330Hz.   similarly on A4 (multiplier) , J2 is marked as 155Hz whilst
> the schematic shows 165Hz in. The manual refers to the Circuit Check Meter
> most clockwise position as 330Hz, yet the front panel engraving shows 310
> Hz. All very confusing Is this discrepancy common? Is it relevant?  As a
> matter of interest, someone had previously set the audio oscillator at
> 320Hz, midway between the two!
> what I am looking for is some way to make sense of the detail of what
> should be happening, having settings or values to which I can adjust/tune
> my Tracor, so that I can gain a better understanding of where any problem
> lies
> Do any group members have anything useful I can use, whether skill,
> experience or documents to help me blundering around in search of a
> repair/calibration?
> It would be so useful to know what I should be expecting at any particular
> point!
> All help gratefully received
> Chris HJ
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