[time-nuts] What signals if any are on the unpopulated SMC pads on the 58503A motherboard?

Roy Phillips phill.r1 at btinternet.com
Mon Jan 9 18:12:03 EST 2017

Many thanks for your help, I have downloaded all three items, my 58503 is an 
A,  I had no idea that a B model existed !   Mine has the front panel 
display, which is very bright suggesting that it had not been used for very 
long periods. The unit was in overall VG condition when I received it (costa 
plenty!) , and I have reason to believe it was used as a portable survey 
tool. Internally there is a panel to the rear that has a number of SMC 
connectors, and just one is used to provide the 1 pps jumper lead to a BNC 
at the rear (external) panel. It would be interesting to know what the other 
SMC connectors where for ??
Am I to assume that no Service/Technical manual is available ?  Mine has the 
HP SmartClock Technology sticker on the front panel - what exactly does this 
mean ?

-----Original Message----- 
From: Dr. David Kirkby (Kirkby Microwave Ltd)
Sent: Monday, January 09, 2017 11:42 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] What signals if any are on the unpopulated SMC pads 
onthe 58503A motherboard?

On 9 January 2017 at 10:44, Roy Phillips <phill.r1 at btinternet.com> wrote:

> I would be grateful for an answer to this question, as I also have a an HP
> 58503  - is the manual for the instrument available for download ?
> Thank you
> Roy

I know its a bit unlikely to use SMC in such a case, but I believe there
are some versions of the 58503A which have a clock, and perhaps some
buttons on the front. I would have expected them to be via a multi-way
cable, but maybe not.

There are at least two relevant manuals on Tom's website


I also have another one - not sure where I got that from. It might have
been on Tom's site too, but if not, I put a copy here.

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