Re: [time-nuts] 60kHz Loop antenna
Date: Mon, 04 Oct 2010 11:53:10 -0400 From: Chuck Harris Subject: Re: [time-nuts] 60kHz Loop antenna The coil with 50T and 5 foot diameter is 11.5mH. It would take about 220pf of self capacitance to make it resonate at 100KHz. Anyway, if the capacitance is too much, it's all in the way you splice the ends together in the conduit box. If you want, you can make the loop a single turn with 50 parallel conductors. -Chuck Harris paul swed wrote: I have used 25 pair telco cable. The issue that can happen is the inter pair and strand capacitance can exceed the resonance frequency of the loop. Or resonates below 60 KC. Just a heads up. Using a 3 foot loop was not a problem. Regards There is a number of software applications at http://www.zerobeat.net/G4FGQ/page3.html#S301, written by a silent key Reg Edwards, G4FGQ from the UK. In particular, the program titled RJELOOP3 is of particular interest in the design and analysis of loop antennae in the VLF region. I've used several of Reg's programs and have never found an error (doesn't mean there aren't any, but he was a very knowledgeable engineer). This program is based on a square loop, but will certainly get in the ballpark with the circular and other shapes. It calculates inductance, self-resonant frequency, capacitance needed for resonance, receiving sensitivity, impedances, etc. A nice program. David dgminala at mediacombb dot net ___ 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] 60kHz Loop antenna
Understood. I have gotten better with the loops over the years. Someone mentioned 1000 strand phone cable. On Mon, Oct 4, 2010 at 12:52 PM, J. Forster wrote: > 220 pF is about 8' of coax. > > -John > > = > > > The coil with 50T and 5 foot diameter is 11.5mH. It would take about > > 220pf > > of self capacitance to make it resonate at 100KHz. > > > > Anyway, if the capacitance is too much, it's all in the way you splice > the > > ends together in the conduit box. If you want, you can make the loop a > > single > > turn with 50 parallel conductors. > > > > -Chuck Harris > > > > paul swed wrote: > >> I have used 25 pair telco cable. > >> The issue that can happen is the inter pair and strand capacitance can > >> exceed the resonance frequency of the loop. Or resonates below 60 KC. > >> Just a > >> heads up. > >> Using a 3 foot loop was not a problem. > >> Regards > > > > ___ > > 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.
Re: [time-nuts] 60kHz Loop antenna
220 pF is about 8' of coax. -John = > The coil with 50T and 5 foot diameter is 11.5mH. It would take about > 220pf > of self capacitance to make it resonate at 100KHz. > > Anyway, if the capacitance is too much, it's all in the way you splice the > ends together in the conduit box. If you want, you can make the loop a > single > turn with 50 parallel conductors. > > -Chuck Harris > > paul swed wrote: >> I have used 25 pair telco cable. >> The issue that can happen is the inter pair and strand capacitance can >> exceed the resonance frequency of the loop. Or resonates below 60 KC. >> Just a >> heads up. >> Using a 3 foot loop was not a problem. >> Regards > > ___ > 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.
Re: [time-nuts] 60kHz Loop antenna
The coil with 50T and 5 foot diameter is 11.5mH. It would take about 220pf of self capacitance to make it resonate at 100KHz. Anyway, if the capacitance is too much, it's all in the way you splice the ends together in the conduit box. If you want, you can make the loop a single turn with 50 parallel conductors. -Chuck Harris paul swed wrote: I have used 25 pair telco cable. The issue that can happen is the inter pair and strand capacitance can exceed the resonance frequency of the loop. Or resonates below 60 KC. Just a heads up. Using a 3 foot loop was not a problem. Regards ___ 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] 60kHz Loop antenna
I have used 25 pair telco cable. The issue that can happen is the inter pair and strand capacitance can exceed the resonance frequency of the loop. Or resonates below 60 KC. Just a heads up. Using a 3 foot loop was not a problem. Regards On Mon, Oct 4, 2010 at 9:51 AM, Chuck Harris wrote: > Austron uses an 8 conductor piece of ribbon type antenna rotor cable. They > connected all 8 strands together so the loop was a single turn. They used > a pot core transformer to help match impedance. > > When I made my general purpose loop, I made an octagon shaped loop out of > 3/4 inch copper pipe, and 45 degree elbows. I used a cast conduit box for > the terminations, and a plastic PVC coupler to break continuity at the top > of the loop. For the winding, I took a single piece of 25 pair CAT3 cable > and soldered the wires to form a 50T loop. I put a toroid balun in the box > to convert from 50 ohm unbalanced to 50 ohm balanced... I think? > > It works pretty nicely as an antenna for my HP3586C. > > -Chuck Harris > > > J. Forster wrote: > >> When I designed mine maybe 20 years ago, I did consider using something >> like phone cable and ribbon cable, but there was a good performance reason >> for using the heavier wire. Sadly I can't recall why right now. >> > > ___ > 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.
Re: [time-nuts] 60kHz Loop antenna
In message <61314.12.6.201.2.1286146064.squir...@popaccts.quikus.com>, "J. Fors ter" writes: >Before I got the cannonical antenna for my Austron LORAN Rx, I used a >roughly 30" square of 3/4" Cu tubing threaded with a bunch of #18 >insulated hookup wire. The slick glop electricians use helped a lot. What >a mess though. Telephone cable i neat for big loop-antennas: You get the shield, and up to 1000 colorcoded and patchable wires all ready to go, all you need to do is patch them together with an offset of one. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] 60kHz Loop antenna
Austron uses an 8 conductor piece of ribbon type antenna rotor cable. They connected all 8 strands together so the loop was a single turn. They used a pot core transformer to help match impedance. When I made my general purpose loop, I made an octagon shaped loop out of 3/4 inch copper pipe, and 45 degree elbows. I used a cast conduit box for the terminations, and a plastic PVC coupler to break continuity at the top of the loop. For the winding, I took a single piece of 25 pair CAT3 cable and soldered the wires to form a 50T loop. I put a toroid balun in the box to convert from 50 ohm unbalanced to 50 ohm balanced... I think? It works pretty nicely as an antenna for my HP3586C. -Chuck Harris J. Forster wrote: When I designed mine maybe 20 years ago, I did consider using something like phone cable and ribbon cable, but there was a good performance reason for using the heavier wire. Sadly I can't recall why right now. ___ 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] 60kHz Loop antenna
When I designed mine maybe 20 years ago, I did consider using something like phone cable and ribbon cable, but there was a good performance reason for using the heavier wire. Sadly I can't recall why right now. FWIW, -John === > In message <61314.12.6.201.2.1286146064.squir...@popaccts.quikus.com>, "J. > Fors > ter" writes: > >>Before I got the cannonical antenna for my Austron LORAN Rx, I used a >>roughly 30" square of 3/4" Cu tubing threaded with a bunch of #18 >>insulated hookup wire. The slick glop electricians use helped a lot. What >>a mess though. > > Telephone cable i neat for big loop-antennas: You get the shield, > and up to 1000 colorcoded and patchable wires all ready to go, all > you need to do is patch them together with an offset of one. > > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by > incompetence. > > ___ 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] 60kHz Loop antenna
I'd think the capacitance of the coax would present problems. Before I got the cannonical antenna for my Austron LORAN Rx, I used a roughly 30" square of 3/4" Cu tubing threaded with a bunch of #18 insulated hookup wire. The slick glop electricians use helped a lot. What a mess though. -John === > I have been very superficially following this topic and looked at some > links about 60 KHz Loop antennas, including one on Tom's site (I think?) > describing building one out of 100 feet of RG58 coax. > > Could CAT 5 cable be used? It is 4 twisted pairs and you can get it > shielded. Any issue with 'twisted pairs'? > > Joe > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of J. Forster > Sent: Sunday, October 03, 2010 1:48 PM > To: b Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] 60kHz Loop antenna > > > I observed a diurnal phase shift with my 117A system. I never investigated > whether this was due to loop phase shifts with temperature or propagation, > but it was likely a combination. > > These phase shifts matter less if you are doing long term (multi-day) > measurements, but, to be valid, your system has to maintain phase lock for > the entire time. In my experience, that rarely happens in my location. > Remember a 1 cycle hop is about 16-17 usecond. > > Phase shilt with temperature becomes a real worry if you are trying to > adjust a local standard in a few hours or a day. > > FWIW, > > -John > > > > >> John,-"My concern with tuning the loop is that as the tuned circuit >> drifts with temperature, or other things, an extraneous phase shift >> will be intoduced to the received signal. Remember, the phase of a >> complex pole pair tuned circuit goes from +90 to -90 degrees as you >> sweepo through resonance. The higher the Q, the steeper this effect >> would be." >> + >> Don Lancaster addresses this concern in his article where he states: >> ââ¬ÅTune this coil to 60 kHz with high quality polystyrene capacitors >> or the more expensive >> silver micas. Any other capacitor type is unsuitable. The coil Q should >> be >> around >> 25 to 40. More will cause temperature and tuning problems, less will let >> in too >> much noise.ââ¬Â >> >> To tell the truth, I really haven't given this much thought for the >> 30+ years my loop has been working. >> >> à à à à à à à à -Arthur >> >> >> >> >> ___ >> 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.
Re: [time-nuts] 60kHz Loop antenna
I have been very superficially following this topic and looked at some links about 60 KHz Loop antennas, including one on Tom's site (I think?) describing building one out of 100 feet of RG58 coax. Could CAT 5 cable be used? It is 4 twisted pairs and you can get it shielded. Any issue with 'twisted pairs'? Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Sunday, October 03, 2010 1:48 PM To: b Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 60kHz Loop antenna I observed a diurnal phase shift with my 117A system. I never investigated whether this was due to loop phase shifts with temperature or propagation, but it was likely a combination. These phase shifts matter less if you are doing long term (multi-day) measurements, but, to be valid, your system has to maintain phase lock for the entire time. In my experience, that rarely happens in my location. Remember a 1 cycle hop is about 16-17 usecond. Phase shilt with temperature becomes a real worry if you are trying to adjust a local standard in a few hours or a day. FWIW, -John > John,-"My concern with tuning the loop is that as the tuned circuit > drifts with temperature, or other things, an extraneous phase shift > will be intoduced to the received signal. Remember, the phase of a > complex pole pair tuned circuit goes from +90 to -90 degrees as you > sweepo through resonance. The higher the Q, the steeper this effect > would be." > + > Don Lancaster addresses this concern in his article where he states: > “Tune this coil to 60 kHz with high quality polystyrene capacitors > or the more expensive > silver micas. Any other capacitor type is unsuitable. The coil Q should be > around > 25 to 40. More will cause temperature and tuning problems, less will let > in too > much noise.†> > To tell the truth, I really haven't given this much thought for the > 30+ years my loop has been working. > >         -Arthur > > > > > ___ > 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.
Re: [time-nuts] 60kHz Loop antenna
I observed a diurnal phase shift with my 117A system. I never investigated whether this was due to loop phase shifts with temperature or propagation, but it was likely a combination. These phase shifts matter less if you are doing long term (multi-day) measurements, but, to be valid, your system has to maintain phase lock for the entire time. In my experience, that rarely happens in my location. Remember a 1 cycle hop is about 16-17 usecond. Phase shilt with temperature becomes a real worry if you are trying to adjust a local standard in a few hours or a day. FWIW, -John > John,-"My concern with tuning the loop is that as the tuned circuit drifts > with > temperature, or other things, an extraneous phase shift will be intoduced > to the received signal. Remember, the phase of a complex pole pair tuned > circuit goes from +90 to -90 degrees as you sweepo through resonance. The > higher the Q, the steeper this effect would be." > + > Don Lancaster addresses this concern in his article where he states: > âTune > this coil to 60 kHz with high quality polystyrene capacitors or the more > expensive > silver micas. Any other capacitor type is unsuitable. The coil Q should be > around > 25 to 40. More will cause temperature and tuning problems, less will let > in too > much noise.â > > To tell the truth, I really haven't given this much thought for the 30+ > years my loop > has been working. > > Â Â Â Â Â Â Â Â -Arthur > > > > > ___ > 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] 60kHz Loop antenna
John,-"My concern with tuning the loop is that as the tuned circuit drifts with temperature, or other things, an extraneous phase shift will be intoduced to the received signal. Remember, the phase of a complex pole pair tuned circuit goes from +90 to -90 degrees as you sweepo through resonance. The higher the Q, the steeper this effect would be." + Don Lancaster addresses this concern in his article where he states: “Tune this coil to 60 kHz with high quality polystyrene capacitors or the more expensive silver micas. Any other capacitor type is unsuitable. The coil Q should be around 25 to 40. More will cause temperature and tuning problems, less will let in too much noise.” To tell the truth, I really haven't given this much thought for the 30+ years my loop has been working. -Arthur ___ 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] 60kHz Loop antenna
The air core loop may well be suggested because the incremental permeability of the ferrite, hence the inductance, varies with temperature. -John = [snip] Interestingly a lot of the modern LF and > VLF > Off-air Standards use ferrite rod antennas and there are known problems > with > those, Quartzlock advise a air loop for critical requirements. > > Alan G3NYK ___ 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] 60kHz Loop antenna
As I remember, the WWVB waveform is a 60 KHz sine wave, slowly AM modulated, <100%, for a digital time code. Every hour there is a 45 degree phase shift between xx:10 and xx:15. If you plot the phase out from a receiver, the trace will look like a straight line with 1/12 duty cycle pulse. The slope of the line give the difference between your local standard and the WWVB one. My concern with tuning the loop is that as the tuned circuit drifts with temperature, or other things, an extraneous phase shift will be intoduced to the received signal. Remember, the phase of a complex pole pair tuned circuit goes from +90 to -90 degrees as you sweepo through resonance. The higher the Q, the steeper this effect would be. I expect, but am not certain, that the HP and similar amps would be double tuned for a "rabbit ears" bandpass response that has flat phase through the bandpass. FWIW, -John = > John - It has been a while since I have seen the waveform. What is the > rate > of change of phase per unit time? Or, the occupied BW? Thanks - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > > > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of J. Forster > Sent: Sunday, October 03, 2010 11:29 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] 60kHz Loop antenna > > Since WWVB is a phase tracking system, I'm not convnced a high-Q loop is > such a good idea. HP's loop for the 117A is not tuned, as I rember, but it > is followed with a narrow band amp. > > FWIW > > -John > > === > > >> Thanks Dick, Ok with interference that close it would help. Shielding >> doesnt >> always provide much at these frequencies and can reduce the Q of the >> loop. >> >> Best Wishes >> Alan G3NYK >> >> - Original Message - >> From: "Dick Moore" >> To: >> Sent: Sunday, October 03, 2010 6:56 AM >> Subject: Re: [time-nuts] 60kHz Loop antenna >> >> >>> Alan, I did try a real half-a$$ed pile of wire and a tuning cap. My >>> shop >> has fluorescent lights and I got a lot of noise. Once I built the >> shielded >> loop and got it lined up with east and a little south (I'm in Washington >> State), WWVB came in gang-busters. This was before I built a GPSDO or >> two >> and then got a TBolt. >>> >>> The shielded loop has just been sitting for years. >>> >>> Dick >>> >>> >>> On Oct 2, 2010, at 3:42 PM, time-nuts-requ...@febo.com wrote: >>> > >>> > Message: 5 >>> > Date: Sat, 2 Oct 2010 23:40:52 +0100 >>> > From: "Alan Melia" >>> > Subject: Re: [time-nuts] HP/Dymek DY-5842 >>> > To: "Discussion of precise time and frequency measurement" >>> > >>> > Message-ID: <015501cb6283$10071ad0$4001a...@lark> >>> > Content-Type: text/plain; charset="iso-8859-1" >>> > >>> > Dick did you ever try an unscreened loop ?? they should be just as >>> good >> if >>> > not better at 60kHz. >>> > Alan G3NYK >>> > >>> > - Original Message - >>> > From: "Dick Moore" >>> > To: >>> > Sent: Saturday, October 02, 2010 11:22 PM >>> > Subject: Re: [time-nuts] HP/Dymek DY-5842 >>> > >>> > >>> >> I used to have one of these marvelous receivers and sold it. I still >> have >>> > the WWVB/60kHz shielded loop antenna that I made for it and although >>> it >> is >>> > big, at about 30" x 30" x 2" or so, I believe it will ship FedEx or >>> UPS >> OK. >>> > It's free to anyone who'll pay the shipping. It's made out of copper >> pipe >>> > and works quite well, and is tuned for the 5842 at 60kHz. >>> >> >>> >> Best, >>> >> Dick Moore >>> >> >>> >> >>> >> On Oct 1, 2010, at 3:50 PM, time-nuts-requ...@febo.com wrote: >>> >> >>> >> >>> >>> Message: 5 >>> >>> Date: Fri, 01 Oct 2010 16:34:57 -0600 >>> >>> From: ziggy9 >>> >>> Subject: [time-nuts] Possibly OT - Any interest in a vintage >>> HP/Dymec >>> >>> DY-5842 VLF receiver? >>> >>> To: >>> >>> Message-ID: <990bd60b3c5d084910c10c8855912...@pu
Re: [time-nuts] 60kHz Loop antenna
There are some interesting VLF antenna/amplifier designs on vlf.it I used one of them as inspiration and built my own AD797 based indoor loop antenna: http://phk.freebsd.dk/loran-c/Antenna/ -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] 60kHz Loop antenna
The loop will be tuned (!) but hopefully to a freqency much above 60kHz by the inter-turn and turn to screen capacitance. Also hopefully this will be a low Q resonance and the phase frequency response at 60kHz should then be stable with ambient conditions. Interestingly a lot of the modern LF and VLF Off-air Standards use ferrite rod antennas and there are known problems with those, Quartzlock advise a air loop for critical requirements. Alan G3NYK - Original Message - From: "Arthur Dent" To: Sent: Sunday, October 03, 2010 5:09 PM Subject: [time-nuts] 60kHz Loop antenna > John-…”HP's loop for the 117A is not tuned, as I rember, but it > is followed with a narrow band amp.“ > > Both the nuvistor and FET versions of the loop show capacitors across the loop winding to tune it. > http://www.leapsecond.com/museum/10509a/ > > -Arthur > > > > > ___ > 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] 60kHz Loop antenna
John-…”HP's loop for the 117A is not tuned, as I rember, but it is followed with a narrow band amp.“ Both the nuvistor and FET versions of the loop show capacitors across the loop winding to tune it. http://www.leapsecond.com/museum/10509a/ -Arthur ___ 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] 60kHz Loop antenna
John - It has been a while since I have seen the waveform. What is the rate of change of phase per unit time? Or, the occupied BW? Thanks - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Sunday, October 03, 2010 11:29 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 60kHz Loop antenna Since WWVB is a phase tracking system, I'm not convnced a high-Q loop is such a good idea. HP's loop for the 117A is not tuned, as I rember, but it is followed with a narrow band amp. FWIW -John === > Thanks Dick, Ok with interference that close it would help. Shielding > doesnt > always provide much at these frequencies and can reduce the Q of the loop. > > Best Wishes > Alan G3NYK > > - Original Message - > From: "Dick Moore" > To: > Sent: Sunday, October 03, 2010 6:56 AM > Subject: Re: [time-nuts] 60kHz Loop antenna > > >> Alan, I did try a real half-a$$ed pile of wire and a tuning cap. My shop > has fluorescent lights and I got a lot of noise. Once I built the shielded > loop and got it lined up with east and a little south (I'm in Washington > State), WWVB came in gang-busters. This was before I built a GPSDO or two > and then got a TBolt. >> >> The shielded loop has just been sitting for years. >> >> Dick >> >> >> On Oct 2, 2010, at 3:42 PM, time-nuts-requ...@febo.com wrote: >> > >> > Message: 5 >> > Date: Sat, 2 Oct 2010 23:40:52 +0100 >> > From: "Alan Melia" >> > Subject: Re: [time-nuts] HP/Dymek DY-5842 >> > To: "Discussion of precise time and frequency measurement" >> > >> > Message-ID: <015501cb6283$10071ad0$4001a...@lark> >> > Content-Type: text/plain; charset="iso-8859-1" >> > >> > Dick did you ever try an unscreened loop ?? they should be just as >> good > if >> > not better at 60kHz. >> > Alan G3NYK >> > >> > - Original Message - >> > From: "Dick Moore" >> > To: >> > Sent: Saturday, October 02, 2010 11:22 PM >> > Subject: Re: [time-nuts] HP/Dymek DY-5842 >> > >> > >> >> I used to have one of these marvelous receivers and sold it. I still > have >> > the WWVB/60kHz shielded loop antenna that I made for it and although >> it > is >> > big, at about 30" x 30" x 2" or so, I believe it will ship FedEx or >> UPS > OK. >> > It's free to anyone who'll pay the shipping. It's made out of copper > pipe >> > and works quite well, and is tuned for the 5842 at 60kHz. >> >> >> >> Best, >> >> Dick Moore >> >> >> >> >> >> On Oct 1, 2010, at 3:50 PM, time-nuts-requ...@febo.com wrote: >> >> >> >> >> >>> Message: 5 >> >>> Date: Fri, 01 Oct 2010 16:34:57 -0600 >> >>> From: ziggy9 >> >>> Subject: [time-nuts] Possibly OT - Any interest in a vintage >> HP/Dymec >> >>> DY-5842 VLF receiver? >> >>> To: >> >>> Message-ID: <990bd60b3c5d084910c10c8855912...@pumpkinbrook.com> >> >>> Content-Type: text/plain; charset=UTF-8 >> >>> >> >>> >> >>> Fellow time-nuts: >> >>> I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated >> in >> >>> conjunction with an external time interval counter to make a >> frequency >> >>> comparison. So you would select WWVL for example, and use that as >> your >> >>> primary standard for comparison to your local standard. It's got 5 >> > crystals >> >>> in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, >> > WWVB). >> >>> It works and I have the manual. The thing is, the interest in > something >> >>> like this is bound to be a bit narrow, so I thought I'd mention it > here. >> >>> >> >>> So if there are any collectors, equipment museums, etc. that might >> be >> >>> interested in this, please let me know. I'm a bit sentimental about > this >> >>> thing, it's sort of a bit of history, and from what I can tell, > somewhat >> >>> rare (doesnt make it worth anything though :). Since it's a bit of a >> >>> curiosity, I'd like to pass it to someone th
Re: [time-nuts] 60kHz Loop antenna
Since WWVB is a phase tracking system, I'm not convnced a high-Q loop is such a good idea. HP's loop for the 117A is not tuned, as I rember, but it is followed with a narrow band amp. FWIW -John === > Thanks Dick, Ok with interference that close it would help. Shielding > doesnt > always provide much at these frequencies and can reduce the Q of the loop. > > Best Wishes > Alan G3NYK > > - Original Message - > From: "Dick Moore" > To: > Sent: Sunday, October 03, 2010 6:56 AM > Subject: Re: [time-nuts] 60kHz Loop antenna > > >> Alan, I did try a real half-a$$ed pile of wire and a tuning cap. My shop > has fluorescent lights and I got a lot of noise. Once I built the shielded > loop and got it lined up with east and a little south (I'm in Washington > State), WWVB came in gang-busters. This was before I built a GPSDO or two > and then got a TBolt. >> >> The shielded loop has just been sitting for years. >> >> Dick >> >> >> On Oct 2, 2010, at 3:42 PM, time-nuts-requ...@febo.com wrote: >> > >> > Message: 5 >> > Date: Sat, 2 Oct 2010 23:40:52 +0100 >> > From: "Alan Melia" >> > Subject: Re: [time-nuts] HP/Dymek DY-5842 >> > To: "Discussion of precise time and frequency measurement" >> > >> > Message-ID: <015501cb6283$10071ad0$4001a...@lark> >> > Content-Type: text/plain; charset="iso-8859-1" >> > >> > Dick did you ever try an unscreened loop ?? they should be just as >> good > if >> > not better at 60kHz. >> > Alan G3NYK >> > >> > - Original Message - >> > From: "Dick Moore" >> > To: >> > Sent: Saturday, October 02, 2010 11:22 PM >> > Subject: Re: [time-nuts] HP/Dymek DY-5842 >> > >> > >> >> I used to have one of these marvelous receivers and sold it. I still > have >> > the WWVB/60kHz shielded loop antenna that I made for it and although >> it > is >> > big, at about 30" x 30" x 2" or so, I believe it will ship FedEx or >> UPS > OK. >> > It's free to anyone who'll pay the shipping. It's made out of copper > pipe >> > and works quite well, and is tuned for the 5842 at 60kHz. >> >> >> >> Best, >> >> Dick Moore >> >> >> >> >> >> On Oct 1, 2010, at 3:50 PM, time-nuts-requ...@febo.com wrote: >> >> >> >> >> >>> Message: 5 >> >>> Date: Fri, 01 Oct 2010 16:34:57 -0600 >> >>> From: ziggy9 >> >>> Subject: [time-nuts] Possibly OT - Any interest in a vintage >> HP/Dymec >> >>> DY-5842 VLF receiver? >> >>> To: >> >>> Message-ID: <990bd60b3c5d084910c10c8855912...@pumpkinbrook.com> >> >>> Content-Type: text/plain; charset=UTF-8 >> >>> >> >>> >> >>> Fellow time-nuts: >> >>> I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated >> in >> >>> conjunction with an external time interval counter to make a >> frequency >> >>> comparison. So you would select WWVL for example, and use that as >> your >> >>> primary standard for comparison to your local standard. It's got 5 >> > crystals >> >>> in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, >> > WWVB). >> >>> It works and I have the manual. The thing is, the interest in > something >> >>> like this is bound to be a bit narrow, so I thought I'd mention it > here. >> >>> >> >>> So if there are any collectors, equipment museums, etc. that might >> be >> >>> interested in this, please let me know. I'm a bit sentimental about > this >> >>> thing, it's sort of a bit of history, and from what I can tell, > somewhat >> >>> rare (doesnt make it worth anything though :). Since it's a bit of a >> >>> curiosity, I'd like to pass it to someone that might be interested >> in > it >> >>> rather than just tossing it. I can always provide more details to > anyone >> >>> that wants them. >> >>> >> >>> Best regards, >> >>> Paul Davis - K9MR >> >>> >> >>> >> >>> >> >>> >> >>> -- >> >>> >> >>> Message: 6 >&g
Re: [time-nuts] 60kHz Loop antenna
On 10/03/2010 03:33 PM, Arthur Dent wrote: Years ago I built a modification of the double shielded WWVB loop antenna described by Don Lancaster in a 1973 magazine. http://www.swtpc.com/mholley/RadioElectronics/Aug1973/RE_Aug1973.htm I have been using that same antenna ever since with good results in NH where the signal is pretty weak and can always get a strong signal. I have used it with both a Tracor 599J and an older modified RMS Engineering receiver that was originally designed for WWVL. I did have to rebuild the amp and circuit board in the base of the loop a few years ago when it failed because the seals had started to let water in and the whole amp was a total loss. Thanks for the link. Always nice to get some input. Have anybody cared to tune the isolating loop for better noise-suppression? It will interact with the H-field due to stray capacitance over the isolation gap, so by tuning it suitably it could be made to short out a strong interference of higher frequency. Thus, it can act as a null in addition to the normal resonance of the antenna. Cheers, Magnus ___ 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] 60kHz Loop antenna
Years ago I built a modification of the double shielded WWVB loop antenna described by Don Lancaster in a 1973 magazine. http://www.swtpc.com/mholley/RadioElectronics/Aug1973/RE_Aug1973.htm I have been using that same antenna ever since with good results in NH where the signal is pretty weak and can always get a strong signal. I have used it with both a Tracor 599J and an older modified RMS Engineering receiver that was originally designed for WWVL. I did have to rebuild the amp and circuit board in the base of the loop a few years ago when it failed because the seals had started to let water in and the whole amp was a total loss. ___ 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] 60kHz Loop antenna
On 10/03/2010 11:43 AM, Alan Melia wrote: Yes Magnus, a break to avoid the shorted turn effect As I suspected, it's a peculiar detail otherwise easilly missed. Cheers, Magnus Alan - Original Message - From: "Magnus Danielson" To: Sent: Sunday, October 03, 2010 10:36 AM Subject: Re: [time-nuts] 60kHz Loop antenna On 10/03/2010 11:03 AM, Alan Melia wrote: Thanks Dick, Ok with interference that close it would help. Shielding doesnt always provide much at these frequencies and can reduce the Q of the loop. I would be careful not to close the shield into a loop, so it only acts on E-field and not H-field. I'd assume this goes for this loop as well, right? Cheers, Magnus ___ 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.
Re: [time-nuts] 60kHz Loop antenna
Yes Magnus, a break to avoid the shorted turn effect Alan - Original Message - From: "Magnus Danielson" To: Sent: Sunday, October 03, 2010 10:36 AM Subject: Re: [time-nuts] 60kHz Loop antenna > On 10/03/2010 11:03 AM, Alan Melia wrote: > > Thanks Dick, Ok with interference that close it would help. Shielding doesnt > > always provide much at these frequencies and can reduce the Q of the loop. > > I would be careful not to close the shield into a loop, so it only acts > on E-field and not H-field. I'd assume this goes for this loop as well, > right? > > Cheers, > Magnus > > ___ > 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.
Re: [time-nuts] 60kHz Loop antenna
On 10/03/2010 11:03 AM, Alan Melia wrote: Thanks Dick, Ok with interference that close it would help. Shielding doesnt always provide much at these frequencies and can reduce the Q of the loop. I would be careful not to close the shield into a loop, so it only acts on E-field and not H-field. I'd assume this goes for this loop as well, right? Cheers, Magnus ___ 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] 60kHz Loop antenna
Thanks Dick, Ok with interference that close it would help. Shielding doesnt always provide much at these frequencies and can reduce the Q of the loop. Best Wishes Alan G3NYK - Original Message - From: "Dick Moore" To: Sent: Sunday, October 03, 2010 6:56 AM Subject: Re: [time-nuts] 60kHz Loop antenna > Alan, I did try a real half-a$$ed pile of wire and a tuning cap. My shop has fluorescent lights and I got a lot of noise. Once I built the shielded loop and got it lined up with east and a little south (I'm in Washington State), WWVB came in gang-busters. This was before I built a GPSDO or two and then got a TBolt. > > The shielded loop has just been sitting for years. > > Dick > > > On Oct 2, 2010, at 3:42 PM, time-nuts-requ...@febo.com wrote: > > > > Message: 5 > > Date: Sat, 2 Oct 2010 23:40:52 +0100 > > From: "Alan Melia" > > Subject: Re: [time-nuts] HP/Dymek DY-5842 > > To: "Discussion of precise time and frequency measurement" > > > > Message-ID: <015501cb6283$10071ad0$4001a...@lark> > > Content-Type: text/plain; charset="iso-8859-1" > > > > Dick did you ever try an unscreened loop ?? they should be just as good if > > not better at 60kHz. > > Alan G3NYK > > > > - Original Message - > > From: "Dick Moore" > > To: > > Sent: Saturday, October 02, 2010 11:22 PM > > Subject: Re: [time-nuts] HP/Dymek DY-5842 > > > > > >> I used to have one of these marvelous receivers and sold it. I still have > > the WWVB/60kHz shielded loop antenna that I made for it and although it is > > big, at about 30" x 30" x 2" or so, I believe it will ship FedEx or UPS OK. > > It's free to anyone who'll pay the shipping. It's made out of copper pipe > > and works quite well, and is tuned for the 5842 at 60kHz. > >> > >> Best, > >> Dick Moore > >> > >> > >> On Oct 1, 2010, at 3:50 PM, time-nuts-requ...@febo.com wrote: > >> > >> > >>> Message: 5 > >>> Date: Fri, 01 Oct 2010 16:34:57 -0600 > >>> From: ziggy9 > >>> Subject: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec > >>> DY-5842 VLF receiver? > >>> To: > >>> Message-ID: <990bd60b3c5d084910c10c8855912...@pumpkinbrook.com> > >>> Content-Type: text/plain; charset=UTF-8 > >>> > >>> > >>> Fellow time-nuts: > >>> I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in > >>> conjunction with an external time interval counter to make a frequency > >>> comparison. So you would select WWVL for example, and use that as your > >>> primary standard for comparison to your local standard. It's got 5 > > crystals > >>> in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, > > WWVB). > >>> It works and I have the manual. The thing is, the interest in something > >>> like this is bound to be a bit narrow, so I thought I'd mention it here. > >>> > >>> So if there are any collectors, equipment museums, etc. that might be > >>> interested in this, please let me know. I'm a bit sentimental about this > >>> thing, it's sort of a bit of history, and from what I can tell, somewhat > >>> rare (doesnt make it worth anything though :). Since it's a bit of a > >>> curiosity, I'd like to pass it to someone that might be interested in it > >>> rather than just tossing it. I can always provide more details to anyone > >>> that wants them. > >>> > >>> Best regards, > >>> Paul Davis - K9MR > >>> > >>> > >>> > >>> > >>> -- > >>> > >>> Message: 6 > >>> Date: Fri, 1 Oct 2010 18:42:16 -0400 > >>> From: "jmfranke" > >>> Subject: Re: [time-nuts] Possibly OT - Any interest in a vintage > >>> HP/Dymec DY-5842 VLF receiver? > >>> To: "Discussion of precise time and frequency measurement" > >>> > >>> Message-ID: > >>> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > >>> reply-type=original > >>> > >>> I am very interested. Do you have any images? > >>> > >>> John Franke WA4WDL > >>> Portsmouth, VA 23703 > >>> > >>> -- &g
Re: [time-nuts] 60kHz Loop antenna
Alan, I did try a real half-a$$ed pile of wire and a tuning cap. My shop has fluorescent lights and I got a lot of noise. Once I built the shielded loop and got it lined up with east and a little south (I'm in Washington State), WWVB came in gang-busters. This was before I built a GPSDO or two and then got a TBolt. The shielded loop has just been sitting for years. Dick On Oct 2, 2010, at 3:42 PM, time-nuts-requ...@febo.com wrote: > > Message: 5 > Date: Sat, 2 Oct 2010 23:40:52 +0100 > From: "Alan Melia" > Subject: Re: [time-nuts] HP/Dymek DY-5842 > To: "Discussion of precise time and frequency measurement" > > Message-ID: <015501cb6283$10071ad0$4001a...@lark> > Content-Type: text/plain; charset="iso-8859-1" > > Dick did you ever try an unscreened loop ?? they should be just as good if > not better at 60kHz. > Alan G3NYK > > - Original Message - > From: "Dick Moore" > To: > Sent: Saturday, October 02, 2010 11:22 PM > Subject: Re: [time-nuts] HP/Dymek DY-5842 > > >> I used to have one of these marvelous receivers and sold it. I still have > the WWVB/60kHz shielded loop antenna that I made for it and although it is > big, at about 30" x 30" x 2" or so, I believe it will ship FedEx or UPS OK. > It's free to anyone who'll pay the shipping. It's made out of copper pipe > and works quite well, and is tuned for the 5842 at 60kHz. >> >> Best, >> Dick Moore >> >> >> On Oct 1, 2010, at 3:50 PM, time-nuts-requ...@febo.com wrote: >> >> >>> Message: 5 >>> Date: Fri, 01 Oct 2010 16:34:57 -0600 >>> From: ziggy9 >>> Subject: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec >>> DY-5842 VLF receiver? >>> To: >>> Message-ID: <990bd60b3c5d084910c10c8855912...@pumpkinbrook.com> >>> Content-Type: text/plain; charset=UTF-8 >>> >>> >>> Fellow time-nuts: >>> I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in >>> conjunction with an external time interval counter to make a frequency >>> comparison. So you would select WWVL for example, and use that as your >>> primary standard for comparison to your local standard. It's got 5 > crystals >>> in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, > WWVB). >>> It works and I have the manual. The thing is, the interest in something >>> like this is bound to be a bit narrow, so I thought I'd mention it here. >>> >>> So if there are any collectors, equipment museums, etc. that might be >>> interested in this, please let me know. I'm a bit sentimental about this >>> thing, it's sort of a bit of history, and from what I can tell, somewhat >>> rare (doesnt make it worth anything though :). Since it's a bit of a >>> curiosity, I'd like to pass it to someone that might be interested in it >>> rather than just tossing it. I can always provide more details to anyone >>> that wants them. >>> >>> Best regards, >>> Paul Davis - K9MR >>> >>> >>> >>> >>> -- >>> >>> Message: 6 >>> Date: Fri, 1 Oct 2010 18:42:16 -0400 >>> From: "jmfranke" >>> Subject: Re: [time-nuts] Possibly OT - Any interest in a vintage >>> HP/Dymec DY-5842 VLF receiver? >>> To: "Discussion of precise time and frequency measurement" >>> >>> Message-ID: >>> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; >>> reply-type=original >>> >>> I am very interested. Do you have any images? >>> >>> John Franke WA4WDL >>> Portsmouth, VA 23703 >>> >>> -- >>> From: "ziggy9" >>> Sent: Friday, October 01, 2010 6:34 PM >>> To: >>> Subject: [time-nuts] Possibly OT - Any interest in a vintage HP/Dymec >>> DY-5842 VLF receiver? >>> Fellow time-nuts: I've got a circa 1964 DY-5842 VLF receiver. This is (was) operated in conjunction with an external time interval counter to make a frequency comparison. So you would select WWVL for example, and use that as your primary standard for comparison to your local standard. It's got 5 crystals in it: 16, 18, 19.8, 20, and 60 kHz (listed as GBR, NBA, NPM, WWVL, > WWVB). It works and I have the manual. The thing is, the interest in something like this is bound to be a bit narrow, so I thought I'd mention it > here. So if there are any collectors, equipment museums, etc. that might be interested in this, please let me know. I'm a bit sentimental about > this thing, it's sort of a bit of history, and from what I can tell, > somewhat rare (doesnt make it worth anything though :). Since it's a bit of a curiosity, I'd like to pass it to someone that might be interested in > it rather than just tossing it. I can always provide more details to > anyone that wants them. Best regards, Paul Davis - K9MR ___ 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 in
