[Amps] Help - anyone in UK with accurate frequency standard?

[David Kirkby]

Sorry this is off-topic, but I'm hoping someone reading this might be 
able to help.

I have (or soon will have) an HP 5370B time/interval/frequency counter, 
like this

http://www.tucker.com/java/jsp/doorway_partnoH-P5370B_invid3074.htm

With shipping and a manual this has cost over $600.   You might question 
the logic of buying a 15 year old 100MHz counter when there are 
brand-new 2.7GHz counters on eBay with a 'buy it now' of about a quarter 
of that.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=40004&item=7509349572&rd=1

But the specs on those 2.7GHz things are pretty poor. In contrast the HP 
is a high-spec device, has 11 digits of resolution, can time single-shot 
events with a resolution of +/-20 ps (accuracy is more like +/-100 ps) 
and sold for over $20,000 in its time.

This was only ever sold with an ovened HP 10811A Quartz Crystal 
Oscillator, which I expect has drifted somewhat since it was last 
calibrated.

Is there anyone in the UK (preferably around London) with either

a) Rubidium (more than adequate, if done over a long time)
b) Cesium
c) GPS locked ovened-crystal/rubidium/cesium or
d) Hydrogen maser (that really would be OTT)

frequency standard that could put the ovened oscillator back on 
frequency for a beer or two? The rubidium would be more than adequate.

Or does anyone have an accurate wrist watch like this one - you really 
need to see this page:

http://www.leapsecond.com/pages/atomic-bill/index.htm

This is for non non-commercial use, so I don't wish to pay NPL to 
calibrate it.

I used to work in a standards lab, and would have had access to a cesium 
standard for doing this, but alas I don't any more.

I intend ultimately locking the crystal to a GPS source, using the 
design from Brooks Shera, W5OJM published in QEX some time back

http://www.rt66.com/%7Eshera/QST_GPS.pdf

More info on this can be found here if interested at:

http://www.rt66.com/%7Eshera/index_fs.htm


-- 
Dr. David Kirkby,
G8WRB

Please check out http://www.g8wrb.org/
of if you live in Essex http://www.southminster-branch-line.org.uk/