[time-nuts] Anyone Have Plug/Jumper Information on the 87-601 board in a TrueTime XL-DC?

Jim Lux jimlux at earthlink.net
Sat Jul 2 23:42:43 UTC 2011


On 7/2/11 4:12 PM, Shane Justice wrote:
> Hi All,
>
> I have an "ebay special" TrueTime XL-DC that seems to work fine, only
> thing is, I pulled the lid and found one of the BNC's was not connected
> on the 87-601 board, and would like to know what the jumper/plug
> arrangement is. (some BNCs have a black and white wire in one two-pin
> push-on plug, others have a single wire (black or white) per push-on
> (two-pin) plug, and I am at a loss to understand why one might use one
> in one place, and the others in another). I am seeking a 10 MHz output
> specifically, but would like to know more about what each pin is, and if
> there are pins with voltage-bias, etc, in the unused pins. If someone
> has either a pin-out list to share, or a pictorial of the pin arrays
> with descriptive nomenclature, that would be most appreciated.
> Otherwise, I'll poke around in there with an oscilloscope to ferret-out
> the details.
>
> Thank you, in advance, for any assistance you can offer!!!
>

WHat you really want is a service manual, I suspect..

Be aware that the XL-DC has tons and tons of options.. you could get 
them with a Rb or with a OCXO with low phase noise, a whole raft of 
output options, as well.   And then, there were programmable timer and 
counter option card.  We had a couple with the low phase noise 10 MHz 
option, which came out on 3 BNCs, and some extra 1pps as well.  (Those I 
remember, because I was using them)

there were also a variety of parallel time code interfaces (in addition 
to the usual IRIG in various forms, NASA-36, ...)

Basically, the XL-DC was a sort of base unit into which they'd put a 
variety of option cards. A lot of the pins might have no function 
without a particular option installed.

True-Time is now Symmetricom, so when you go hunting for documents, that 
might help.




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