[time-nuts] Racal-Dana 1992 Startup -- GPIB!
lmcdavid at lmceng.com
Wed Nov 16 13:25:16 EST 2011
There are other Racal timebase options as well.
I have a Racal 1999 counter that originally had a 04C timebase option
that was not ovened and had a single adjustment screw. I replaced it
with a 04A ovened ocxo that has a single adjustment screw. I will
shortly install a 04E ocxo as Robert describes below. There is also a
04B ocxo option with two adjustment screws (coarse and fine). All the
specs are slightly different. My manuals do not show a 04T option.
There is also a Rb oscillator option, 04R. I've never seen one of these.
None of these is necessarily on frequency! You must have something like
a GPSDO that outputs 10 MHz to set any of the timebase options
accurately. Accuracy is relative, of course!
I use a HP Z3801A GPSDO and a TAPR distribution amplifier to distribute
the GPS-steered 10 MHz to numerous devices that accept an external
timebase, such as the Racal counter.
It's a very nice counter.
On 11/16/2011 10:02 AM, Robert Atkinson wrote:
> Hi Chuck,
> You need to look at the option sticker on the back of the unit. The 04* is the oscillator option.
> 04T is a TCXO 3x10^7 per month& temp1x10^6 0-40 deg C
> 04A Ovened oscillator 3x10^9 per Day& temp3x10^9 0-45 deg
> 04E High stability ovened oscillator 5x10^10 per day& temp7x10^9 0-50 deg C
> No 04* is basic crystal oscillator. If yours has a mechanical and electrical trim it will be a 04A or 04E.
> From: Chuck Forsberg WA7KGX N2469R<caf at omen.com>
> To: time-nuts<time-nuts at febo.com>
> Sent: Wednesday, 16 November 2011, 16:47
> Subject: [time-nuts] Racal-Dana 1992 Startup -- GPIB!
> I found a use for the GPIB interface on my counter - record
> the frequency drift of its internal timebase during warm up.
> It looks like an oven warming up. I don't know exactly which
> timebase my 1992 has, but I did notice the 5 to 10 MHz doubler
> on the back of the oscillator, The back has separate coarse
> and fine frequency adjustments. Can someone identify which
> timebase is fitted to this counter?
> The link below has the story and plot.
Larry McDavid W6FUB
Anaheim, CA (20 miles southeast of Los Angeles, near Disneyland)
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