In a message dated 04/09/2009 16:32:09 GMT Daylight Time, [email protected] writes:
I must say that much of what you have stated is right, I have a 53131A counter and the basic time-base is a joke, but agreed, we mostly use a common external reference with our instruments. There are some exceptions, as I am finding with a very recently purchased HP 8657A Sig. Gen. that has the option 001 oven oscillator. This is a 1998 production (made in the US), the TCXO would seem to be a very stable device with coarse and fine adjustment - after running for 48 hours its holding 10 Mhz to ^10. In fact it would seem to be somewhat better than the TCXO in my Marconi 2024 Sig. Gen. - - hence my singing the praises of HP. ----------------- Hi Roy I suspect the 8657A option 001 is likely to be a 10811B, which also appears in quite a lot of other HP kit and is also the better of the options for the 53131A and 53132A. They are certainly very nice oscillators. ------------------ The large number of Racal 199# on the UK market in recent times are I would suggest, ex UK military issue and as portable instruments have probably had a rough life, and have frequently been stored for ten years in somewhat poor environments. I would suggest that buying equipment that has come from a commercial origin, and has been part of a rack test set-up, have been better cared for and sometimes have had very little use. What do you others think about this theory ? ---------------- You're quite right that the majority of 199x counters available in recent times are ex-mil but that doesn't always mean a hard life, although I agree there can be an element of risk involved when buying them. My first 1991, bought a few years ago, was ex-mil but had never been issued and was still new in its original box, having been taken out just once since original calibration to check it was still "serviceable". The one just bought is also ex-mil, this one has been used but looks to have been very well treated. It carries a label indicating the warranty ran out in 2001, so I assume it was manufactured in 2000, with last calibration expiring in April 2009. Although it's fitted with the manual pouch for portable use it doesn't show any signs that it's actually been used portable, the case and front and rear panels are unmarked, so I suspect it may have just seen bench use. There's no obvious problems with the front panel switches either, which is another good sign, although, of course, that could change tomorrow:-) It's very likely that there's a lot more of all sorts of test gear, on Ebay at least, that's ex-mil rather than ex-commercial so it's really quite difficult to avoid unless prepared to always buy from dealers who are able to guarantee previous ownership, and also prepared to pay their much higher prices. regards Nigel GM8PZR _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
