RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Another couple ways to calibrate: I use a GPS receiver with an 10 meg output to calibrate my service monitor. Before GPS just find out if you have a TV station that is using a Rubidium Standard for their frequency. Here in Milwaukee Ch4 uses one and we always used it to check calibration in the field, the standard was at 67.24 MHz, a lot better than using 10 megsmuch higher order of precision. Gregg R. Lengling, W9DHI, Retired Administrator http://www.milwaukeehdtv.org K2/100 S#3075 KX1 S# 57 Politics is the art of appearing candid and completely open, while concealing as much as possible. -States: The Bene Gesserit View -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 03, 2003 10:04 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) Ian, you should have time standard frequencies in Australia on 5 10 and 15 MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to the output of the 10 MHz timebase in your service monitor. This has been one of my obsessions for a while now, to find a way of more accurately setting my 10 MHz timebase in my service monitor. Zero beating with our WWV signal will only get you within a cycle or so. (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then there's trying to find a time when the signal is strong and doesn't fade too much. Since I live about 50 miles south of Ft Collins you would think I would have a strong signal all the time, but no. So I figure there must be a way to use a scope to compare two audio signals (X/Y like we do with PL tones) and be able to set it more accurately. I have tried comparing the 1000 cycle audio tone from an external receiver when I generate a signal from the service monitor I kc off frequency from WWV. Then comparing that to the 1kc tone generated from the monitors own PL tone generator (phase locked to the 10 MHz time bases). You should be able to see a slow drift between the two on the oscilloscope but so far no success, too much noise to see much. Does someone have a way of getting closer than 1 cycle? (no I haven't bought a GPS timebase receiver yet but have drooled over them on Ebay. I've always wondered if a tuned RF receiver using 10 MHz crystals for IF filters would give you a strong 10 MHz carrier that could be used for calibration. Hopefully this is still somewhat on topic since we all need to set our repeaters on frequency. Art - KC7GF Golden, CO Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Used to be... In the good old days before frame syncs, you could wait until the local affiliate was in network programming and you had a REAL good 3.58 reference. Not so anymore. 3.579545 was an easy number to remember for some reason... ;^) 73 de N1FNE -Original Message- From: Gregg Lengling [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 03, 2003 11:07 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) Another couple ways to calibrate: I use a GPS receiver with an 10 meg output to calibrate my service monitor. Before GPS just find out if you have a TV station that is using a Rubidium Standard for their frequency. Here in Milwaukee Ch4 uses one and we always used it to check calibration in the field, the standard was at 67.24 MHz, a lot better than using 10 megsmuch higher order of precision. Gregg R. Lengling, W9DHI, Retired Administrator http://www.milwaukeehdtv.org K2/100 S#3075 KX1 S# 57 Politics is the art of appearing candid and completely open, while concealing as much as possible. -States: The Bene Gesserit View -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 03, 2003 10:04 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) Ian, you should have time standard frequencies in Australia on 5 10 and 15 MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to the output of the 10 MHz timebase in your service monitor. This has been one of my obsessions for a while now, to find a way of more accurately setting my 10 MHz timebase in my service monitor. Zero beating with our WWV signal will only get you within a cycle or so. (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then there's trying to find a time when the signal is strong and doesn't fade too much. Since I live about 50 miles south of Ft Collins you would think I would have a strong signal all the time, but no. So I figure there must be a way to use a scope to compare two audio signals (X/Y like we do with PL tones) and be able to set it more accurately. I have tried comparing the 1000 cycle audio tone from an external receiver when I generate a signal from the service monitor I kc off frequency from WWV. Then comparing that to the 1kc tone generated from the monitors own PL tone generator (phase locked to the 10 MHz time bases). You should be able to see a slow drift between the two on the oscilloscope but so far no success, too much noise to see much. Does someone have a way of getting closer than 1 cycle? (no I haven't bought a GPS timebase receiver yet but have drooled over them on Ebay. I've always wondered if a tuned RF receiver using 10 MHz crystals for IF filters would give you a strong 10 MHz carrier that could be used for calibration. Hopefully this is still somewhat on topic since we all need to set our repeaters on frequency. Art - KC7GF Golden, CO Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
I remember an old QST article about the 3.58 Mhz color burst sig on network tv being tracable to NBS. If I remember correctly the sets are phase locked to the incoming sig? Never was much at TV.. Ssb Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
At 11:03 PM 12/3/03 -0500, you wrote: >Ian, you should have time standard frequencies in Australia on 5 10 and 15 >MHz. If you have a secondary receiver, tune in the 10 MHz and compare it >to the >output of the 10 MHz timebase in your service monitor. > >This has been one of my obsessions for a while now, to find a way of more >accurately setting my 10 MHz timebase in my service monitor. > >Zero beating with our WWV signal will only get you within a cycle or so. >(i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then >there's >trying to find a time when the signal is strong and doesn't fade too much. >Since I live about 50 miles south of Ft Collins you would think I would >have a >strong signal all the time, but no. > >So I figure there must be a way to use a scope to compare two audio signals >(X/Y like we do with PL tones) and be able to set it more accurately. I have >tried comparing the 1000 cycle audio tone from an external receiver when I >generate a signal from the service monitor I kc off frequency from WWV. Then >comparing that to the 1kc tone generated from the monitors own PL tone >generator >(phase locked to the 10 MHz time bases). You should be able to see a slow >drift >between the two on the oscilloscope but so far no success, too much noise to >see much. > >Does someone have a way of getting closer than 1 cycle? (no I haven't bought >a GPS timebase receiver yet but have drooled over them on Ebay. > >I've always wondered if a tuned RF receiver using 10 MHz crystals for IF >filters would give you a strong 10 MHz carrier that could be used for >calibration. > >Hopefully this is still somewhat on topic since we all need to set our >repeaters on frequency. > >Art - KC7GF >Golden, CO One technique that I overheard a local NBC engineer discussing was that he took advantage of the fact that the TV transmitter video carrier was phase-locked to a rubidium standard. He first zero-beated 10mhz WWV with his service monitor then switched over to the video carrier of the TV station and fine tweaked the service monitor's time base. If you know any local TV engineers it would be worth asking if any have rubidium- locked transmitters. Just an idea that I overheard, I haven't tried it. Or measure the color burst crystal in a TV set - it has to be dead-on to 3.579-something-or-other mhz or the colors shift. Mike WA6ILQ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Not using the frame syncsusing the actual RF carrier! Gregg R. Lengling, W9DHI, Retired Administrator http://www.milwaukeehdtv.org K2/100 S#3075 KX1 S# 57 Politics is the art of appearing candid and completely open, while concealing as much as possible. -States: The Bene Gesserit View -Original Message- From: Rod Lane [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 03, 2003 10:55 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) Used to be... In the good old days before frame syncs, you could wait until the local affiliate was in network programming and you had a REAL good 3.58 reference. Not so anymore. 3.579545 was an easy number to remember for some reason... ;^) 73 de N1FNE -Original Message- From: Gregg Lengling [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 03, 2003 11:07 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) Another couple ways to calibrate: I use a GPS receiver with an 10 meg output to calibrate my service monitor. Before GPS just find out if you have a TV station that is using a Rubidium Standard for their frequency. Here in Milwaukee Ch4 uses one and we always used it to check calibration in the field, the standard was at 67.24 MHz, a lot better than using 10 megsmuch higher order of precision. Gregg R. Lengling, W9DHI, Retired Administrator http://www.milwaukeehdtv.org K2/100 S#3075 KX1 S# 57 Politics is the art of appearing candid and completely open, while concealing as much as possible. -States: The Bene Gesserit View -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Wednesday, December 03, 2003 10:04 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) Ian, you should have time standard frequencies in Australia on 5 10 and 15 MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to the output of the 10 MHz timebase in your service monitor. This has been one of my obsessions for a while now, to find a way of more accurately setting my 10 MHz timebase in my service monitor. Zero beating with our WWV signal will only get you within a cycle or so. (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then there's trying to find a time when the signal is strong and doesn't fade too much. Since I live about 50 miles south of Ft Collins you would think I would have a strong signal all the time, but no. So I figure there must be a way to use a scope to compare two audio signals (X/Y like we do with PL tones) and be able to set it more accurately. I have tried comparing the 1000 cycle audio tone from an external receiver when I generate a signal from the service monitor I kc off frequency from WWV. Then comparing that to the 1kc tone generated from the monitors own PL tone generator (phase locked to the 10 MHz time bases). You should be able to see a slow drift between the two on the oscilloscope but so far no success, too much noise to see much. Does someone have a way of getting closer than 1 cycle? (no I haven't bought a GPS timebase receiver yet but have drooled over them on Ebay. I've always wondered if a tuned RF receiver using 10 MHz crystals for IF filters would give you a strong 10 MHz carrier that could be used for calibration. Hopefully this is still somewhat on topic since we all need to set our repeaters on frequency. Art - KC7GF Golden, CO Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
>From: Rod Lane [mailto:[EMAIL PROTECTED] >Sent: Wednesday, December 03, 2003 10:55 PM >To: Repeater-Builder@yahoogroups.com >Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is >accurate) > >Used to be... In the good old days before frame syncs, you could wait >until the local affiliate was in network programming and you had a REAL >good 3.58 reference. Not so anymore. 3.579545 was an easy number to >remember for some reason... ;^) Yes it is - 357-9545 is a friend's phone number. Yes, he is a TV broadcast engineer. Yes, he asked for that particular residence number. Mike WA6ILQ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Thank you very much Ian Wells - Original Message - From: "Gregg Lengling" <[EMAIL PROTECTED]> To: Sent: Thursday, December 04, 2003 2:06 PM Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > Another couple ways to calibrate: > > I use a GPS receiver with an 10 meg output to calibrate my service monitor. > > > Before GPS just find out if you have a TV station that is using a Rubidium > Standard for their frequency. Here in Milwaukee Ch4 uses one and we always > used it to check calibration in the field, the standard was at 67.24 MHz, a > lot better than using 10 megsmuch higher order of precision. > > > Gregg R. Lengling, W9DHI, Retired > Administrator http://www.milwaukeehdtv.org > K2/100 S#3075 KX1 S# 57 > Politics is the art of appearing candid and completely open, while > concealing as much as possible. -States: The Bene Gesserit View > > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 03, 2003 10:04 PM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > > Ian, you should have time standard frequencies in Australia on 5 10 and 15 > MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to > the > output of the 10 MHz timebase in your service monitor. > > This has been one of my obsessions for a while now, to find a way of more > accurately setting my 10 MHz timebase in my service monitor. > > Zero beating with our WWV signal will only get you within a cycle or so. > (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then > there's > trying to find a time when the signal is strong and doesn't fade too much. > Since I live about 50 miles south of Ft Collins you would think I would have > a > strong signal all the time, but no. > > So I figure there must be a way to use a scope to compare two audio signals > (X/Y like we do with PL tones) and be able to set it more accurately. I have > > tried comparing the 1000 cycle audio tone from an external receiver when I > generate a signal from the service monitor I kc off frequency from WWV. Then > > comparing that to the 1kc tone generated from the monitors own PL tone > generator > (phase locked to the 10 MHz time bases). You should be able to see a slow > drift > between the two on the oscilloscope but so far no success, too much noise to > > see much. > > Does someone have a way of getting closer than 1 cycle? (no I haven't bought > > a GPS timebase receiver yet but have drooled over them on Ebay. > > I've always wondered if a tuned RF receiver using 10 MHz crystals for IF > filters would give you a strong 10 MHz carrier that could be used for > calibration. > > Hopefully this is still somewhat on topic since we all need to set our > repeaters on frequency. > > Art - KC7GF > Golden, CO > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Thank you very much Ian Wells - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Thursday, December 04, 2003 2:03 PM Subject: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > Ian, you should have time standard frequencies in Australia on 5 10 and 15 > MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to the > output of the 10 MHz timebase in your service monitor. > > This has been one of my obsessions for a while now, to find a way of more > accurately setting my 10 MHz timebase in my service monitor. > > Zero beating with our WWV signal will only get you within a cycle or so. > (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then there's > trying to find a time when the signal is strong and doesn't fade too much. > Since I live about 50 miles south of Ft Collins you would think I would have a > strong signal all the time, but no. > > So I figure there must be a way to use a scope to compare two audio signals > (X/Y like we do with PL tones) and be able to set it more accurately. I have > tried comparing the 1000 cycle audio tone from an external receiver when I > generate a signal from the service monitor I kc off frequency from WWV. Then > comparing that to the 1kc tone generated from the monitors own PL tone generator > (phase locked to the 10 MHz time bases). You should be able to see a slow drift > between the two on the oscilloscope but so far no success, too much noise to > see much. > > Does someone have a way of getting closer than 1 cycle? (no I haven't bought > a GPS timebase receiver yet but have drooled over them on Ebay. > > I've always wondered if a tuned RF receiver using 10 MHz crystals for IF > filters would give you a strong 10 MHz carrier that could be used for calibration. > > Hopefully this is still somewhat on topic since we all need to set our > repeaters on frequency. > > Art - KC7GF > Golden, CO > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
If you are looking at the 3.58 MHz on demodulated video, then you are looking at a framesync. In today's world of broadcasting, the consumer TV's will be much more forgiving of the 3.58 drift and still lock on to it, so its accuracy is not as important as it was back in the day. Knowing what I do about the TV station I work for, I would NOT use that as a reference. I don't think I have ever checked our 3.58 for accuracy. The FCC is MUCH more relaxed about TV standards than they were 20 years ago. If you have a 'top notch' station with a rubidium or GPS based frequency standard, then using the carrier (not demodulated 3.58 video) will get you a good reference. --John - Original Message - From: "Gregg Lengling" <[EMAIL PROTECTED]> To: Sent: Thursday, December 04, 2003 7:02 AM Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > Not using the frame syncsusing the actual RF carrier! > > Gregg R. Lengling, W9DHI, Retired > Administrator http://www.milwaukeehdtv.org > K2/100 S#3075 KX1 S# 57 > Politics is the art of appearing candid and completely open, while > concealing as much as possible. -States: The Bene Gesserit View > > > > -Original Message- > From: Rod Lane [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 03, 2003 10:55 PM > To: Repeater-Builder@yahoogroups.com > Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is > accurate) > > Used to be... In the good old days before frame syncs, you could wait > until the local affiliate was in network programming and you had a REAL > good 3.58 reference. Not so anymore. 3.579545 was an easy number to > remember for some reason... ;^) > > 73 de N1FNE > - Original Message ----- From: "Steve S. Bosshard (NU5D)" <[EMAIL PROTECTED]> To: Sent: Thursday, December 04, 2003 1:16 AM Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > I remember an old QST article about the 3.58 Mhz color burst sig on network > tv being tracable to NBS. If I remember correctly the sets are phase locked > to the incoming sig? > > Never was much at TV.. > -Original Message- > From: Gregg Lengling [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 03, 2003 11:07 PM > To: Repeater-Builder@yahoogroups.com > Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is > accurate) > > Another couple ways to calibrate: > > I use a GPS receiver with an 10 meg output to calibrate my service > monitor. > > > Before GPS just find out if you have a TV station that is using a > Rubidium > Standard for their frequency. Here in Milwaukee Ch4 uses one and we > always > used it to check calibration in the field, the standard was at 67.24 > MHz, a > lot better than using 10 megsmuch higher order of precision. > > > Gregg R. Lengling, W9DHI, Retired > Administrator http://www.milwaukeehdtv.org > K2/100 S#3075 KX1 S# 57 > Politics is the art of appearing candid and completely open, while > concealing as much as possible. -States: The Bene Gesserit View > > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 03, 2003 10:04 PM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Re: crystal alignment (how accurate is > accurate) > > Ian, you should have time standard frequencies in Australia on 5 10 and > 15 > MHz. If you have a secondary receiver, tune in the 10 MHz and compare it > to > the > output of the 10 MHz timebase in your service monitor. > > This has been one of my obsessions for a while now, to find a way of > more > accurately setting my 10 MHz timebase in my service monitor. > > Zero beating with our WWV signal will only get you within a cycle or so. > > (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And > then > there's > trying to find a time when the signal is strong and doesn't fade too > much. > Since I live about 50 miles south of Ft Collins you would think I would > have > a > strong signal all the time, but no. > > So I figure there must be a way to use a scope to compare two audio > signals > (X/Y like we do with PL tones) and be able to set it more accurately. I > have > > tried comparing the 1000 cycle audio tone from an external receiver when > I > generate a signal from the service monitor I kc off frequency from WWV. > Then > > comparing that to the 1kc tone generated from the monitors own PL tone > generator > (phase locked to the 10 MHz time bases). You should be able to see a > slow > drift > between the two o
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Thank you Ian Wells - Original Message - From: "Mike Morris WA6ILQ" <[EMAIL PROTECTED]> To: Sent: Thursday, December 04, 2003 6:25 PM Subject: Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > At 11:03 PM 12/3/03 -0500, you wrote: > > >Ian, you should have time standard frequencies in Australia on 5 10 and 15 > >MHz. If you have a secondary receiver, tune in the 10 MHz and compare it > >to the > >output of the 10 MHz timebase in your service monitor. > > > >This has been one of my obsessions for a while now, to find a way of more > >accurately setting my 10 MHz timebase in my service monitor. > > > >Zero beating with our WWV signal will only get you within a cycle or so. > >(i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then > >there's > >trying to find a time when the signal is strong and doesn't fade too much. > >Since I live about 50 miles south of Ft Collins you would think I would > >have a > >strong signal all the time, but no. > > > >So I figure there must be a way to use a scope to compare two audio signals > >(X/Y like we do with PL tones) and be able to set it more accurately. I have > >tried comparing the 1000 cycle audio tone from an external receiver when I > >generate a signal from the service monitor I kc off frequency from WWV. Then > >comparing that to the 1kc tone generated from the monitors own PL tone > >generator > >(phase locked to the 10 MHz time bases). You should be able to see a slow > >drift > >between the two on the oscilloscope but so far no success, too much noise to > >see much. > > > >Does someone have a way of getting closer than 1 cycle? (no I haven't bought > >a GPS timebase receiver yet but have drooled over them on Ebay. > > > >I've always wondered if a tuned RF receiver using 10 MHz crystals for IF > >filters would give you a strong 10 MHz carrier that could be used for > >calibration. > > > >Hopefully this is still somewhat on topic since we all need to set our > >repeaters on frequency. > > > >Art - KC7GF > >Golden, CO > > One technique that I overheard a local NBC engineer discussing was that he > took advantage of the fact that the TV transmitter video carrier was > phase-locked > to a rubidium standard. He first zero-beated 10mhz WWV with his service > monitor > then switched over to the video carrier of the TV station and fine tweaked the > service monitor's time base. > > If you know any local TV engineers it would be worth asking if any have > rubidium- > locked transmitters. > > Just an idea that I overheard, I haven't tried it. > > Or measure the color burst crystal in a TV set - it has to be dead-on to > 3.579-something-or-other mhz or the colors shift. > > Mike WA6ILQ > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Thank you verymuch Ian Wells - Original Message - From: "Rod Lane" <[EMAIL PROTECTED]> To: Sent: Thursday, December 04, 2003 2:55 PM Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > Used to be... In the good old days before frame syncs, you could wait > until the local affiliate was in network programming and you had a REAL > good 3.58 reference. Not so anymore. 3.579545 was an easy number to > remember for some reason... ;^) > > 73 de N1FNE > > -Original Message- > From: Gregg Lengling [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 03, 2003 11:07 PM > To: Repeater-Builder@yahoogroups.com > Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is > accurate) > > Another couple ways to calibrate: > > I use a GPS receiver with an 10 meg output to calibrate my service > monitor. > > > Before GPS just find out if you have a TV station that is using a > Rubidium > Standard for their frequency. Here in Milwaukee Ch4 uses one and we > always > used it to check calibration in the field, the standard was at 67.24 > MHz, a > lot better than using 10 megsmuch higher order of precision. > > > Gregg R. Lengling, W9DHI, Retired > Administrator http://www.milwaukeehdtv.org > K2/100 S#3075 KX1 S# 57 > Politics is the art of appearing candid and completely open, while > concealing as much as possible. -States: The Bene Gesserit View > > > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Wednesday, December 03, 2003 10:04 PM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] Re: crystal alignment (how accurate is > accurate) > > Ian, you should have time standard frequencies in Australia on 5 10 and > 15 > MHz. If you have a secondary receiver, tune in the 10 MHz and compare it > to > the > output of the 10 MHz timebase in your service monitor. > > This has been one of my obsessions for a while now, to find a way of > more > accurately setting my 10 MHz timebase in my service monitor. > > Zero beating with our WWV signal will only get you within a cycle or so. > > (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And > then > there's > trying to find a time when the signal is strong and doesn't fade too > much. > Since I live about 50 miles south of Ft Collins you would think I would > have > a > strong signal all the time, but no. > > So I figure there must be a way to use a scope to compare two audio > signals > (X/Y like we do with PL tones) and be able to set it more accurately. I > have > > tried comparing the 1000 cycle audio tone from an external receiver when > I > generate a signal from the service monitor I kc off frequency from WWV. > Then > > comparing that to the 1kc tone generated from the monitors own PL tone > generator > (phase locked to the 10 MHz time bases). You should be able to see a > slow > drift > between the two on the oscilloscope but so far no success, too much > noise to > > see much. > > Does someone have a way of getting closer than 1 cycle? (no I haven't > bought > > a GPS timebase receiver yet but have drooled over them on Ebay. > > I've always wondered if a tuned RF receiver using 10 MHz crystals for IF > > filters would give you a strong 10 MHz carrier that could be used for > calibration. > > Hopefully this is still somewhat on topic since we all need to set our > repeaters on frequency. > > Art - KC7GF > Golden, CO > > > > > > Your use of Yahoo! Groups is subject to > http://docs.yahoo.com/info/terms/ > > > > > > > > > Your use of Yahoo! Groups is subject to > http://docs.yahoo.com/info/terms/ > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Thank you verymuch Ian Wells - Original Message - From: "Steve S. Bosshard (NU5D)" <[EMAIL PROTECTED]> To: Sent: Thursday, December 04, 2003 4:16 PM Subject: RE: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > I remember an old QST article about the 3.58 Mhz color burst sig on network > tv being tracable to NBS. If I remember correctly the sets are phase locked > to the incoming sig? > > Never was much at TV.. > > Ssb > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
It never fails - pose a simple question, and you get a series of overly complicated answers involving expensive equipment. To calibrate a local frequency standard, one needs a short wave rx with an s meter (mechanical type), and a means of balancing the local standard signal level with that of WWV at 10 MHz. All you need to do is adjust the local standard while watching the s meter. As it is adjusted, you will notice the s meter flutter at a decreasing rate as you reach 10 Mhz. When you are dead on, the s meter will drift slower and finally stop. You are there. And please, do not argue about doppler, selective fading, etc. Sure you will be able to see these effects, but they will not affect the accuracy of this operation. Just watch for the response when the WWV or whatever signal is steady. I hope this helps Bob - W3TGG [EMAIL PROTECTED] wrote: >Ian, you should have time standard frequencies in Australia on 5 10 and 15 >MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to >the >output of the 10 MHz timebase in your service monitor. > >This has been one of my obsessions for a while now, to find a way of more >accurately setting my 10 MHz timebase in my service monitor. > >Zero beating with our WWV signal will only get you within a cycle or so. >(i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then >there's >trying to find a time when the signal is strong and doesn't fade too much. >Since I live about 50 miles south of Ft Collins you would think I would have a >strong signal all the time, but no. > >So I figure there must be a way to use a scope to compare two audio signals >(X/Y like we do with PL tones) and be able to set it more accurately. I have >tried comparing the 1000 cycle audio tone from an external receiver when I >generate a signal from the service monitor I kc off frequency from WWV. Then >comparing that to the 1kc tone generated from the monitors own PL tone >generator >(phase locked to the 10 MHz time bases). You should be able to see a slow >drift >between the two on the oscilloscope but so far no success, too much noise to >see much. > >Does someone have a way of getting closer than 1 cycle? (no I haven't bought >a GPS timebase receiver yet but have drooled over them on Ebay. > >I've always wondered if a tuned RF receiver using 10 MHz crystals for IF >filters would give you a strong 10 MHz carrier that could be used for >calibration. > >Hopefully this is still somewhat on topic since we all need to set our >repeaters on frequency. > >Art - KC7GF >Golden, CO > > > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
> It never fails - pose a simple question, and you get a series of overly > complicated answers involving > expensive equipment. To calibrate a local frequency standard, one needs > a short wave rx with an > s meter (mechanical type), and a means of balancing the local standard > signal level with that of WWV > at 10 MHz. All you need to do is adjust the local standard while > watching the s meter. As it is > adjusted, you will notice the s meter flutter at a decreasing rate as > you reach 10 Mhz. When you > are dead on, the s meter will drift slower and finally stop. You are I was wondering when someone would post this method. If a service monitor is used and you want to use wwv then all you have to do is hook it up to an outside antenna and tune it to the highest wwv frequency you can hear. Measuer the frequency directly and watch the meter on the monitor and adjust the master oscillator directly. . Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
You don't even need an S-meter. The background noise level will vary inversely with the signal level and as you approach zero beat, the noise will flutter slower until it rises and falls very slowly. It is just as accurate as using an S-meter. I have used that technique many times on my freq counter timebase. Burt VE2BMQ>> "Robert D. Mantell" wrote: > > It never fails - pose a simple question, and you get a series of overly > complicated answers involving > expensive equipment. To calibrate a local frequency standard, one needs > a short wave rx with an > s meter (mechanical type), and a means of balancing the local standard > signal level with that of WWV > at 10 MHz. All you need to do is adjust the local standard while > watching the s meter. As it is > adjusted, you will notice the s meter flutter at a decreasing rate as > you reach 10 Mhz. When you > are dead on, the s meter will drift slower and finally stop. You are > there. And please, do not argue > about doppler, selective fading, etc. Sure you will be able to see > these effects, but they will not affect > the accuracy of this operation. Just watch for the response when the > WWV or whatever signal is steady. > > I hope this helps > > Bob - W3TGG > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
ok thanks bob i will give it a go ian - Original Message - From: "Robert D. Mantell" <[EMAIL PROTECTED]> To: Sent: Saturday, December 06, 2003 11:23 AM Subject: Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > It never fails - pose a simple question, and you get a series of overly > complicated answers involving > expensive equipment. To calibrate a local frequency standard, one needs > a short wave rx with an > s meter (mechanical type), and a means of balancing the local standard > signal level with that of WWV > at 10 MHz. All you need to do is adjust the local standard while > watching the s meter. As it is > adjusted, you will notice the s meter flutter at a decreasing rate as > you reach 10 Mhz. When you > are dead on, the s meter will drift slower and finally stop. You are > there. And please, do not argue > about doppler, selective fading, etc. Sure you will be able to see > these effects, but they will not affect > the accuracy of this operation. Just watch for the response when the > WWV or whatever signal is steady. > > I hope this helps > > Bob - W3TGG > > [EMAIL PROTECTED] wrote: > > >Ian, you should have time standard frequencies in Australia on 5 10 and 15 > >MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to the > >output of the 10 MHz timebase in your service monitor. > > > >This has been one of my obsessions for a while now, to find a way of more > >accurately setting my 10 MHz timebase in my service monitor. > > > >Zero beating with our WWV signal will only get you within a cycle or so. > >(i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then there's > >trying to find a time when the signal is strong and doesn't fade too much. > >Since I live about 50 miles south of Ft Collins you would think I would have a > >strong signal all the time, but no. > > > >So I figure there must be a way to use a scope to compare two audio signals > >(X/Y like we do with PL tones) and be able to set it more accurately. I have > >tried comparing the 1000 cycle audio tone from an external receiver when I > >generate a signal from the service monitor I kc off frequency from WWV. Then > >comparing that to the 1kc tone generated from the monitors own PL tone generator > >(phase locked to the 10 MHz time bases). You should be able to see a slow drift > >between the two on the oscilloscope but so far no success, too much noise to > >see much. > > > >Does someone have a way of getting closer than 1 cycle? (no I haven't bought > >a GPS timebase receiver yet but have drooled over them on Ebay. > > > >I've always wondered if a tuned RF receiver using 10 MHz crystals for IF > >filters would give you a strong 10 MHz carrier that could be used for calibration. > > > >Hopefully this is still somewhat on topic since we all need to set our > >repeaters on frequency. > > > >Art - KC7GF > >Golden, CO > > > > > > > > > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > > > > > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
hi again bob i carnt receive any signal on 10 meg . thansk ian - Original Message - From: "ian wells" <[EMAIL PROTECTED]> To: Sent: Saturday, December 06, 2003 3:33 PM Subject: Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > ok thanks bob i will give it a go > ian > - Original Message - > From: "Robert D. Mantell" <[EMAIL PROTECTED]> > To: > Sent: Saturday, December 06, 2003 11:23 AM > Subject: Re: [Repeater-Builder] Re: crystal alignment (how accurate is > accurate) > > > > It never fails - pose a simple question, and you get a series of overly > > complicated answers involving > > expensive equipment. To calibrate a local frequency standard, one needs > > a short wave rx with an > > s meter (mechanical type), and a means of balancing the local standard > > signal level with that of WWV > > at 10 MHz. All you need to do is adjust the local standard while > > watching the s meter. As it is > > adjusted, you will notice the s meter flutter at a decreasing rate as > > you reach 10 Mhz. When you > > are dead on, the s meter will drift slower and finally stop. You are > > there. And please, do not argue > > about doppler, selective fading, etc. Sure you will be able to see > > these effects, but they will not affect > > the accuracy of this operation. Just watch for the response when the > > WWV or whatever signal is steady. > > > > I hope this helps > > > > Bob - W3TGG > > > > [EMAIL PROTECTED] wrote: > > > > >Ian, you should have time standard frequencies in Australia on 5 10 and > 15 > > >MHz. If you have a secondary receiver, tune in the 10 MHz and compare it > to the > > >output of the 10 MHz timebase in your service monitor. > > > > > >This has been one of my obsessions for a while now, to find a way of > more > > >accurately setting my 10 MHz timebase in my service monitor. > > > > > >Zero beating with our WWV signal will only get you within a cycle or so. > > >(i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then > there's > > >trying to find a time when the signal is strong and doesn't fade too > much. > > >Since I live about 50 miles south of Ft Collins you would think I would > have a > > >strong signal all the time, but no. > > > > > >So I figure there must be a way to use a scope to compare two audio > signals > > >(X/Y like we do with PL tones) and be able to set it more accurately. I > have > > >tried comparing the 1000 cycle audio tone from an external receiver when > I > > >generate a signal from the service monitor I kc off frequency from WWV. > Then > > >comparing that to the 1kc tone generated from the monitors own PL tone > generator > > >(phase locked to the 10 MHz time bases). You should be able to see a slow > drift > > >between the two on the oscilloscope but so far no success, too much noise > to > > >see much. > > > > > >Does someone have a way of getting closer than 1 cycle? (no I haven't > bought > > >a GPS timebase receiver yet but have drooled over them on Ebay. > > > > > >I've always wondered if a tuned RF receiver using 10 MHz crystals for IF > > >filters would give you a strong 10 MHz carrier that could be used for > calibration. > > > > > >Hopefully this is still somewhat on topic since we all need to set our > > >repeaters on frequency. > > > > > >Art - KC7GF > > >Golden, CO > > > > > > > > > > > > > > > > > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > > > > > > > > > > > > > > > > > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Hi Ian, Use any standard frequency transmission on any frequency ( the higher the better). I know Japan has such transmissions, and I think India. Do a google search for standard frequency transmissions. You might even find what you want in VK land. 73 - Bob - W3TGG ian wells wrote: hi again bob i carnt receive any signal on 10 meg . thansk ian - Original Message - From: "ian wells" <[EMAIL PROTECTED]> To: Sent: Saturday, December 06, 2003 3:33 PM Subject: Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) ok thanks bob i will give it a go ian - Original Message - From: "Robert D. Mantell" <[EMAIL PROTECTED]> To: Sent: Saturday, December 06, 2003 11:23 AM Subject: Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) It never fails - pose a simple question, and you get a series of overly complicated answers involving expensive equipment. To calibrate a local frequency standard, one needs a short wave rx with an s meter (mechanical type), and a means of balancing the local standard signal level with that of WWV at 10 MHz. All you need to do is adjust the local standard while watching the s meter. As it is adjusted, you will notice the s meter flutter at a decreasing rate as you reach 10 Mhz. When you are dead on, the s meter will drift slower and finally stop. You are there. And please, do not argue about doppler, selective fading, etc. Sure you will be able to see these effects, but they will not affect the accuracy of this operation. Just watch for the response when the WWV or whatever signal is steady. I hope this helps Bob - W3TGG [EMAIL PROTECTED] wrote: Ian, you should have time standard frequencies in Australia on 5 10 and 15 MHz. If you have a secondary receiver, tune in the 10 MHz and compare it to the output of the 10 MHz timebase in your service monitor. This has been one of my obsessions for a while now, to find a way of more accurately setting my 10 MHz timebase in my service monitor. Zero beating with our WWV signal will only get you within a cycle or so. (i.e., one cycle off at 10 MHz equals 40 hertz error at 400 MHz) And then there's trying to find a time when the signal is strong and doesn't fade too much. Since I live about 50 miles south of Ft Collins you would think I would have a strong signal all the time, but no. So I figure there must be a way to use a scope to compare two audio signals (X/Y like we do with PL tones) and be able to set it more accurately. I have tried comparing the 1000 cycle audio tone from an external receiver when I generate a signal from the service monitor I kc off frequency from WWV. Then comparing that to the 1kc tone generated from the monitors own PL tone generator (phase locked to the 10 MHz time bases). You should be able to see a slow drift between the two on the oscilloscope but so far no success, too much noise to see much. Does someone have a way of getting closer than 1 cycle? (no I haven't bought a GPS timebase receiver yet but have drooled over them on Ebay. I've always wondered if a tuned RF receiver using 10 MHz crystals for IF filters would give you a strong 10 MHz carrier that could be used for calibration. Hopefully this is still somewhat on topic since we all need to set our repeaters on frequency. Art - KC7GF Golden, CO Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
> Someone wrote: > Use any standard frequency transmission on any frequency ( the higher > the better). I thought the higher frequencies were not as reliable for frequency reference due to propagation delays such as multiple hops via the ionosphere. I have seen professional calibration labs use WWVB 60 KHz for a reference. This low frequency signal normally is received via ground wave therefor has much less propagation delays. For many years I had reference to the primary frequency supply signal which the telephone network used for synchronization. I routinely calibrated my service monitor to this signal which was derived from an atomic clock synced with the NBS clock. After loosing access to this reference I built a large loop antenna and tuned it to the WWVB 60 KHz signal. Since I live about 1400 miles from this signal source I had to amplify it about 20 db to see a nice signal directly with an oscilloscope. By triggering the scope with this 60 KHz signal and displaying the test oscillator signal with the scope input the oscillator can be adjusted to synchronize with the 60 KHz reference by watching the sine wave crawl across the screen. When he displayed pattern stops moving it is on frequency. The same can be done with a dual trace scope. Reference signal on one channel with the oscillator to be test on another. Triggering can be off either channel. The displayed patterns will stay still when they are in sync. I recently calibrated an IFR-1200S with this method. I then checked it with a GPS frequency reference signal used for CDMA timing. It was dead on. Dexter, w4dex Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Art, Until I installed one of those GPS-disciplined 10 MHz oscillators on my bench, I used my local cellular telephone site to provide an extremely precise signal for checking my service monitor's time base. Each analog cell site transmits a control channel at about 880 MHz. The exact frequency depends upon whether the cell site is Block A or Block B. This carrier is continuous, and it is modulated with a raspy tone. Since this control channel carries no voice, you are not violating the FCC eavesdropping rules. The control carrier is used by mobile phones to know what power setting to use and to know what other sites are available. It my area, the Verizon Wireless system is Block B, which is GPS synchronized, while AT&T uses Block A, which is not GPS synchronized. I only need to tune in the control channel, and I have a rock-stable carrier that I can zero the service monitor's carrier meter on, to about 0.1 Hz. That's a resolution of about 0.001 parts per million. 73, Eric Lemmon WB6FLY [EMAIL PROTECTED] wrote: > > Perhaps I wasn't clear. I have been using this simple comparison method for > years to align my IFR timebase to WWV. It gets you within 1 cycle or so at the > 10 MHz. (or closer if you compare the second harmonic of the 10 MHz timebase > with the 20 MHz WWV signal when it's strong enough.) What I was asking was, > Is > there anyone out there using another method (short of having your service > monitor locked to the 10 MHz output of a GPS receiver) that gives you a more > accurate measurement. I am looking for a method that would give you a visual > indication similar to using a lissajous figure as in when comparing two audio > frequencies. > > Art - KC7GF > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
hi eric i will try that ian - Original Message - From: "Eric Lemmon" <[EMAIL PROTECTED]> To: ; <[EMAIL PROTECTED]> Sent: Monday, December 08, 2003 6:43 AM Subject: Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate) > Art, > > Until I installed one of those GPS-disciplined 10 MHz oscillators on my > bench, I used my local cellular telephone site to provide an extremely > precise signal for checking my service monitor's time base. > > Each analog cell site transmits a control channel at about 880 MHz. The > exact frequency depends upon whether the cell site is Block A or Block > B. This carrier is continuous, and it is modulated with a raspy tone. > Since this control channel carries no voice, you are not violating the > FCC eavesdropping rules. The control carrier is used by mobile phones > to know what power setting to use and to know what other sites are > available. It my area, the Verizon Wireless system is Block B, which is > GPS synchronized, while AT&T uses Block A, which is not GPS > synchronized. > > I only need to tune in the control channel, and I have a rock-stable > carrier that I can zero the service monitor's carrier meter on, to about > 0.1 Hz. That's a resolution of about 0.001 parts per million. > > 73, Eric Lemmon WB6FLY > > [EMAIL PROTECTED] wrote: > > > > Perhaps I wasn't clear. I have been using this simple comparison method for > > years to align my IFR timebase to WWV. It gets you within 1 cycle or so at the > > 10 MHz. (or closer if you compare the second harmonic of the 10 MHz timebase > > with the 20 MHz WWV signal when it's strong enough.) What I was asking was, Is > > there anyone out there using another method (short of having your service > > monitor locked to the 10 MHz output of a GPS receiver) that gives you a more > > accurate measurement. I am looking for a method that would give you a visual > > indication similar to using a lissajous figure as in when comparing two audio > > frequencies. > > > > Art - KC7GF > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: crystal alignment (how accurate is accurate)
Hi I think that your gps may well be the ideal as I know that our company's(my gsm calibration equipment) Rubidium Standards are calibrated against the GPS. The method is to take that 1 sec pulse and up count to 10Meg ref and compare that by the same method you are currently using. This is how the labs calibrate our standards-should be the same all over the world. Good luck Brad --- [EMAIL PROTECTED] wrote: > Perhaps I wasn't clear. I have been using this > simple comparison method for > years to align my IFR timebase to WWV. It gets you > within 1 cycle or so at the > 10 MHz. (or closer if you compare the second > harmonic of the 10 MHz timebase > with the 20 MHz WWV signal when it's strong enough.) > What I was asking was, Is > there anyone out there using another method (short > of having your service > monitor locked to the 10 MHz output of a GPS > receiver) that gives you a more > accurate measurement. I am looking for a method that > would give you a visual > indication similar to using a lissajous figure as in > when comparing two audio > frequencies. > > Art - KC7GF > > > > > > Your use of Yahoo! Groups is subject to > http://docs.yahoo.com/info/terms/ > > __ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
