Hi You could always set up a Beckman EPUT meter to do period and get effectively the same sort of result. No solid state in them at all. Full of warm glowing stuff (some of it glowed yellow, some of it glowed purple).
Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, June 10, 2010 11:13 AM To: [email protected] Subject: [time-nuts] Reciprocal Counters Hi Jim, You're showing your age (you young whippersnapper!). ?? "They've been around at least since the 80s,..." Well, my General Radio 1159 Recipromatic Counters are from 1968 - built using those new transistor thingies and with the warm glow of Nixie tube readout. Best, Jerry Message: 2 Date: Thu, 10 Jun 2010 06:55:15 -0700 From: jimlux <[email protected]> Subject: Re: [time-nuts] TPLL secret reveled To: Discussion of precise time and frequency measurement <[email protected]> Message-ID: <[email protected]> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Ulrich Bangert wrote: > > > > The next improvement to the old fashioned pure counter was the invention of > subclock interpolation schemes. A counter using this works so: After the > beginning of the gate time it waits of the next zero crossing and then > measures the time up to the last zero crossing within the gate time with a > fixed resolution of say 1 ns (like the well known Racal Dana > 1992/1996/1998). The frequency value is then the result of a computation. If > you consider this working principle you notice that this is even more a > phase meter like thing than the original counter only thing. For that reason > frequency measurements with a counter like that are suited as well for ADEV > calculation. > I've always referred to these style counters as "reciprocal" counters.. (because the frequency is calculated as the reciprocal of the length of N periods of the input signal). They've been around at least since the 80s, especially for applications where you need short gate time, but measurement precision greater than 1/gate time. It was very popular for applications like intercept receivers in the signals intelligence area before straight digital processing (ADC and FFT) was practical. ------------------------------ _______________________________________________ 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. _______________________________________________ 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.
