[time-nuts] Racal 2201 Frequency Counter
GandalfG8 at aol.com
GandalfG8 at aol.com
Thu Sep 10 16:07:26 UTC 2009
Following recent discussions about the merits, or otherwise, of the Racal
1991/92 counters, is anybody familiar with the 225MHz two channel 2201
which was marketed as being the 1991 replacement?
With an optional 1.3GHz third channel fitted it was also offered as the
replacement for the 1992.
Although a search throws up plenty of sites with the data sheet I get the
impression it's no longer a current model but could be wrong on that.
I'd never even heard of it until very recently but I've just bought one
that seems to be unused and am currently running it alongside a 1991.
Aside from a different panel layout it does seem functionally very similar
to the 1991, complete with the usual drifting TCXO, but one immediately
noticeable omission compared to the 1991 is the ability to shift the display
one place left to up the resolution.
That, plus an inconvenient arrangement that requires setting an internal
link to switch between internal and external frequency standards, has
dampened my initial enthusiasm a bit.
Another really odd quirk for something that seems to be no more than 4 or
5 years old is the use of a lithium battery backed memory module for "non
volatile" storage of user settings.
An optional D to A converter, that would provide a DC output directly
proportional to frequency for driving chart recorders etc, seems like it could
be useful but unfortunately it isn't just a plug in option that can be
added later.
The necessary components are mssing from the motherboard on this one:-(
I've downloaded a user manual so no problems with using it but would be
interested to hear from anyone who might be aware of any other potential
quirks or problems.
If anyone has a pdf copy of the service manual that would also be much
appreciated.
regards
Nigel
GM8PZR
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