Re: [time-nuts] FMT on October 13

2007-09-26 Thread Tom Van Baak
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY I guess it depends on signal to noise ratio. With reciprocal counters, you only need one period to measure as acurately as you need, but to have good acuracy, you need very good S/N, as there is no filtering possible.

Re: [time-nuts] FMT on October 13

2007-09-26 Thread Hal Murray
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Did mounting it on a block of foam help? That is a rather bad solution. You want much softer material to react to quicker things, such as silicon rubber. Also, that would only be a 12 dB/Oct solution. You would really like

Re: [time-nuts] FMT on October 13

2007-09-26 Thread Magnus Danielson
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY From: Tom Van Baak [EMAIL PROTECTED] Subject: Re: [time-nuts] FMT on October 13 Date: Tue, 25 Sep 2007 23:45:12 -0700 Message-ID: [EMAIL PROTECTED] ); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY I

Re: [time-nuts] FMT on October 13

2007-09-26 Thread Didier Juges
propagation, fading and multipath. Didier KO4BB -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tom Van Baak Sent: Wednesday, September 26, 2007 1:45 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FMT on October 13

Re: [time-nuts] FMT on October 13

2007-09-26 Thread Magnus Danielson
From: Didier Juges [EMAIL PROTECTED] Subject: Re: [time-nuts] FMT on October 13 Date: Wed, 26 Sep 2007 05:57:14 -0500 Message-ID: [EMAIL PROTECTED] Didier, I just wanted to point out that with reciprocal counters, you can get resolution much better than the 1Hz/s you would get

Re: [time-nuts] FMT on October 13

2007-09-25 Thread John Ackermann N8UR
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Tom Van Baak said the following on 09/24/2007 08:57 PM: I would think this is especially true for non-local frequencies, such as one received over the air. I'll leave it to you FMT guys to comment on the magnitude of

Re: [time-nuts] FMT on October 13

2007-09-25 Thread John Ackermann N8UR
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Didier Juges said the following on 09/24/2007 09:40 PM: ); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY I guess it depends on signal to noise ratio. With reciprocal counters, you only need one period

Re: [time-nuts] FMT on October 13

2007-09-25 Thread Tom Van Baak
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY While were at it, in the case mentioned above I'm a curious about their FMT frequency standard -- if it's really accurate to parts in 10^12, as they imply, over 10 minutes. I could believe this if it were an Rb or Cs-based

Re: [time-nuts] FMT on October 13

2007-09-25 Thread Hal Murray
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Make sure not to get near any of the equipment. Free-running oscillators are sensitive to vibration or shock. You've probably heard the story of my best Sulzer oscillator making small phase or jumps which I eventually

[time-nuts] FMT on October 13

2007-09-24 Thread John Ackermann N8UR
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY The Midwest VHF/UHF Society (located in Southwest Ohio) is pleased to announce that the first annual MVUS Frequency Measuring Test will be held on Saturday, October 13, 2007. There will be two transmission periods: the first

Re: [time-nuts] FMT on October 13

2007-09-24 Thread Hal Murray
Plans are to transmit two 10 minute test periods, and a third if the transmitters aren't melting by that point. Our goal is to transmit a signal known in frequency to parts in 10e-12 (i.e., less than 0.0001 Hz error at 10 MHz) and stable to a similar level during the course of the

Re: [time-nuts] FMT on October 13

2007-09-24 Thread Tom Van Baak
Plans are to transmit two 10 minute test periods, and a third if the transmitters aren't melting by that point. Our goal is to transmit a signal known in frequency to parts in 10e-12 (i.e., less than 0.0001 Hz error at 10 MHz) and stable to a similar level during the course of the

Re: [time-nuts] FMT on October 13

2007-09-24 Thread Didier Juges
measurement Subject: Re: [time-nuts] FMT on October 13 Plans are to transmit two 10 minute test periods, and a third if the transmitters aren't melting by that point. Our goal is to transmit a signal known in frequency to parts in 10e-12 (i.e., less than 0.0001 Hz error at 10 MHz

Re: [time-nuts] FMT on October 13

2007-09-24 Thread Bruce Griffiths
Didier Juges wrote: I guess it depends on signal to noise ratio. With reciprocal counters, you only need one period to measure as acurately as you need, but to have good acuracy, you need very good S/N, as there is no filtering possible. For example, the HP 5370 can measure a single period