Robert, Do you have any information as to where a 9421 stands in this regime, specs etc? It is the same size as the 9420 and has a doubler board attached, but I don't know what equipment it was used in. Regards,
John H. On 16 Nov 2011, at 19:56, Robert Atkinson wrote: > These counters used Racal's own 94xx series OCXO's. The 04A normally had a > 9442, the 04E had the 9420. Easy way to tell which is which is the size. They > are both 51mm (2") square with the 9442 being 51mm tall and the 9420 is 96mm > (3.75") tall. The 9442 is also classed as fast warm-up, 6 minutes to 3x10^7. > > These OCXO's were also used in Racal's frequency standards such as the 9478. > They are very good OCXO's. All of them are 5MHz. Unfortunatly Racal > considered them propriatry and never released any circuits or service > information. > All my information comes from Racal manuals and the 1984/85 catalogue. > > Robert G8RPI. > > > > ________________________________ > From: Larry McDavid <lmcda...@lmceng.com> > To: Robert Atkinson <robert8...@yahoo.co.uk>; Discussion of precise time and > frequency measurement <time-nuts@febo.com> > Sent: Wednesday, 16 November 2011, 18:25 > Subject: Re: [time-nuts] Racal-Dana 1992 Startup -- GPIB! > > 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. > > Larry W6FUB > > > 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<c...@omen.com> >> To: time-nuts<time-nuts@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. >> >> http://www.omen.com/ham/racal.html > ... > -- Best wishes, > > Larry McDavid W6FUB > Anaheim, CA (20 miles southeast of Los Angeles, near Disneyland) > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
