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

[Christopher Hilton-Johnson]

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