Re: [time-nuts] Counter display resolution
Hi Mike, Thanks for the explanation. As I do not own a "reciprocal" counter, I was unfamilar or had forgotten the issue you described. "Reciprocal" was the missing link ! BillWB6BNQ Mike Feher wrote: > Bill - > > Sorry if I was vague. I am assuming that the frequency read out is the > frequency in the display, and, not one over the bus. Regardless of the fact > that the counter is auto scaling or not, they can only display a fixed > number of digits. I am also assuming that these are reciprocal type of > counters. So, given a fixed time base, and a fixed number of digits, if the > delta f measured is above 10 MHz, then with a 11 digit display, you would > read 10,000,000.000 Hz plus the offset from that number. So, the observable > delta f would be at best in the 0.000 Hz range. Now, if the frequency > measured was slightly below 10 MHz, you would be able to display up to > 9,999,999. Hz. I am not considering any averaging at this time, just > what is displayed. So, in this case you should be able to measure down to > 0. Hz delta f. Hence my statement of the extra LSD being shown. This has > been my experience. Regards - Mike > > > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of WB6BNQ > Sent: Saturday, December 22, 2007 7:00 AM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Counter display resolution > > Mike, > > Your statement about "counters" is rather general and misleading. You need > to > explain your comment better. > > For instance, are your referring to the input signal or did you mean having > the > internal reference frequency offset from a standard value ? All the > counters I > have do not "auto-scale" which is what it sounds like your counter is doing. > However, you do not mention the word "scaling" or "auto" in your statement. > > In all of my counters the digits displayed is what you get no matter what > frequency is being observed. There is no gain in resolution by being > slightly > lower then or any loss by being higher then some arbitrary point. > > For the sake of the less skilled that might be on the list -server, could > you > explain in more clear detail what you were eluding to ? > > Thank you ... BillWB6BNQ > > Mike Feher wrote: > > > Bob - > > > > With most counters, I have found that running them at slightly less than > 10 > > MHz gives you an extra displayed digit of resolution. If the "1" out of 10 > > MHz were to be displayed, it would take up one more digit in the MSD > > position, leaving you one less in the LSD position. Since the numbers are > so > > close anyway, if measuring for stability, I personally would prefer that > > extra digit in the LSD position. Regards - Mike > > > > > > > > Mike B. Feher, N4FS > > 89 Arnold Blvd. > > Howell, NJ, 07731 > > 732-886-5960 > > > > > > -Original Message- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > > Behalf Of Robert E. Martinson > > Sent: Saturday, December 22, 2007 1:57 AM > > To: 'Discussion of precise time and frequency measurement' > > Subject: Re: [time-nuts] HP 5370B question > > > > I ran my 5370B for one hour, counting its own reference with a one second > > gate. The summary of the results are: > > > > min 999.99650 Hz > > max 999.99963 Hz > > avg 999.99796 Hz > > median 999.99787 Hz > > > > Per the manual's Performance Test 5 (page 4-12) the spec is +/- 0.005 Hz. > > It would be nice if my average was 10,000,000.000 HZ but?? From a > Time-nuts > > thread of several months ago, the adjustment for this result is very > touchy > > and it's likely you will make the result worse rather then better. Since > > mine is in spec, I'll leave it alone. > > > > I have sent the graphical & raw data to Corby, if anybody else is > interested > > please advise me of your email address. > > > > Regards, > > Bob Martinson, N1VQR > > > > -Original Message- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > > Behalf Of corby d dawson > > Sent: Wednesday, December 19, 2007 2:15 PM > > To: time-nuts@febo.com > > Subject: [time-nuts] HP 5370B question > > > > Hi, > > > > Could a few of the 5370B owners connect the counters reference output to > > its counting input jack and with a 1 second gate let me know what the > > last 2 digits are doing? > > > > An earlier post implied that the last couple digits will wander around > > due to the way its designed. > > > > I'd like to know what a couple different counters show to see if that is > > indeed true! > > > > Thanks, > > > > Corby Dawson > > > > ___ > > 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 maili
Re: [time-nuts] Counter display resolution
> Mike , this is correct. if you display just under 10Mhz , you have a > digit better resolution. My counter does the same > > The same applies to 1Mhz , 100Mhz , etc . When the counter just has to > go to the next higher digit, it will loose one digit resolution. Not if the counter can roll-over (i.e. exceed the maximum count for the number of digits displayed). Typically, you know the frequency is, say, close to 10 MHz so displaying the LEADING digits is just a waste of precision. ___ 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.
Re: [time-nuts] Counter display resolution
Mike , this is correct. if you display just under 10Mhz , you have a digit better resolution. My counter does the same The same applies to 1Mhz , 100Mhz , etc . When the counter just has to go to the next higher digit, it will loose one digit resolution. Regards, Horst Mike Feher wrote: > Bill - > > Sorry if I was vague. I am assuming that the frequency read out is the > frequency in the display, and, not one over the bus. Regardless of the fact > that the counter is auto scaling or not, they can only display a fixed > number of digits. I am also assuming that these are reciprocal type of > counters. So, given a fixed time base, and a fixed number of digits, if the > delta f measured is above 10 MHz, then with a 11 digit display, you would > read 10,000,000.000 Hz plus the offset from that number. So, the observable > delta f would be at best in the 0.000 Hz range. Now, if the frequency > measured was slightly below 10 MHz, you would be able to display up to > 9,999,999. Hz. I am not considering any averaging at this time, just > what is displayed. So, in this case you should be able to measure down to > 0. Hz delta f. Hence my statement of the extra LSD being shown. This has > been my experience. Regards - Mike > > > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of WB6BNQ > Sent: Saturday, December 22, 2007 7:00 AM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Counter display resolution > > Mike, > > Your statement about "counters" is rather general and misleading. You need > to > explain your comment better. > > For instance, are your referring to the input signal or did you mean having > the > internal reference frequency offset from a standard value ? All the > counters I > have do not "auto-scale" which is what it sounds like your counter is doing. > However, you do not mention the word "scaling" or "auto" in your statement. > > In all of my counters the digits displayed is what you get no matter what > frequency is being observed. There is no gain in resolution by being > slightly > lower then or any loss by being higher then some arbitrary point. > > For the sake of the less skilled that might be on the list -server, could > you > explain in more clear detail what you were eluding to ? > > Thank you ... BillWB6BNQ > > Mike Feher wrote: > > >> Bob - >> >> With most counters, I have found that running them at slightly less than >> > 10 > >> MHz gives you an extra displayed digit of resolution. If the "1" out of 10 >> MHz were to be displayed, it would take up one more digit in the MSD >> position, leaving you one less in the LSD position. Since the numbers are >> > so > >> close anyway, if measuring for stability, I personally would prefer that >> extra digit in the LSD position. Regards - Mike >> >> >> >> Mike B. Feher, N4FS >> 89 Arnold Blvd. >> Howell, NJ, 07731 >> 732-886-5960 >> >> >> -Original Message- >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On >> Behalf Of Robert E. Martinson >> Sent: Saturday, December 22, 2007 1:57 AM >> To: 'Discussion of precise time and frequency measurement' >> Subject: Re: [time-nuts] HP 5370B question >> >> I ran my 5370B for one hour, counting its own reference with a one second >> gate. The summary of the results are: >> >> min 999.99650 Hz >> max 999.99963 Hz >> avg 999.99796 Hz >> median 999.99787 Hz >> >> Per the manual's Performance Test 5 (page 4-12) the spec is +/- 0.005 Hz. >> It would be nice if my average was 10,000,000.000 HZ but?? From a >> > Time-nuts > >> thread of several months ago, the adjustment for this result is very >> > touchy > >> and it's likely you will make the result worse rather then better. Since >> mine is in spec, I'll leave it alone. >> >> I have sent the graphical & raw data to Corby, if anybody else is >> > interested > >> please advise me of your email address. >> >> Regards, >> Bob Martinson, N1VQR >> >> -Original Message- >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On >> Behalf Of corby d dawson >> Sent: Wednesday, December 19, 2007 2:15 PM >> To: time-nuts@febo.com >> Subject: [time-nuts] HP 5370B question >> >> Hi, >> >> Could a few of the 5370B owners connect the counters reference output to >> its counting input jack and with a 1 second gate let me know what the >> last 2 digits are doing? >> >> An earlier post implied that the last couple digits will wander around >> due to the way its designed. >> >> I'd like to know what a couple different counters show to see if that is >> indeed true! >> >> Thanks, >> >> Corby Dawson >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow th
Re: [time-nuts] Counter display resolution
Bill - Sorry if I was vague. I am assuming that the frequency read out is the frequency in the display, and, not one over the bus. Regardless of the fact that the counter is auto scaling or not, they can only display a fixed number of digits. I am also assuming that these are reciprocal type of counters. So, given a fixed time base, and a fixed number of digits, if the delta f measured is above 10 MHz, then with a 11 digit display, you would read 10,000,000.000 Hz plus the offset from that number. So, the observable delta f would be at best in the 0.000 Hz range. Now, if the frequency measured was slightly below 10 MHz, you would be able to display up to 9,999,999. Hz. I am not considering any averaging at this time, just what is displayed. So, in this case you should be able to measure down to 0. Hz delta f. Hence my statement of the extra LSD being shown. This has been my experience. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of WB6BNQ Sent: Saturday, December 22, 2007 7:00 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Counter display resolution Mike, Your statement about "counters" is rather general and misleading. You need to explain your comment better. For instance, are your referring to the input signal or did you mean having the internal reference frequency offset from a standard value ? All the counters I have do not "auto-scale" which is what it sounds like your counter is doing. However, you do not mention the word "scaling" or "auto" in your statement. In all of my counters the digits displayed is what you get no matter what frequency is being observed. There is no gain in resolution by being slightly lower then or any loss by being higher then some arbitrary point. For the sake of the less skilled that might be on the list -server, could you explain in more clear detail what you were eluding to ? Thank you ... BillWB6BNQ Mike Feher wrote: > Bob - > > With most counters, I have found that running them at slightly less than 10 > MHz gives you an extra displayed digit of resolution. If the "1" out of 10 > MHz were to be displayed, it would take up one more digit in the MSD > position, leaving you one less in the LSD position. Since the numbers are so > close anyway, if measuring for stability, I personally would prefer that > extra digit in the LSD position. Regards - Mike > > > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Robert E. Martinson > Sent: Saturday, December 22, 2007 1:57 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] HP 5370B question > > I ran my 5370B for one hour, counting its own reference with a one second > gate. The summary of the results are: > > min 999.99650 Hz > max 999.99963 Hz > avg 999.99796 Hz > median 999.99787 Hz > > Per the manual's Performance Test 5 (page 4-12) the spec is +/- 0.005 Hz. > It would be nice if my average was 10,000,000.000 HZ but?? From a Time-nuts > thread of several months ago, the adjustment for this result is very touchy > and it's likely you will make the result worse rather then better. Since > mine is in spec, I'll leave it alone. > > I have sent the graphical & raw data to Corby, if anybody else is interested > please advise me of your email address. > > Regards, > Bob Martinson, N1VQR > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of corby d dawson > Sent: Wednesday, December 19, 2007 2:15 PM > To: time-nuts@febo.com > Subject: [time-nuts] HP 5370B question > > Hi, > > Could a few of the 5370B owners connect the counters reference output to > its counting input jack and with a 1 second gate let me know what the > last 2 digits are doing? > > An earlier post implied that the last couple digits will wander around > due to the way its designed. > > I'd like to know what a couple different counters show to see if that is > indeed true! > > Thanks, > > Corby Dawson > > ___ > 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. ___ 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.