[time-nuts] IF output buffer amplifier
Somewhat off-topic, some months ago someone posted info about a kit for a general purpose IF output buffer amplifier for receivers without such a facility. Foolishly, I did not save it. Was it on this list? Could someone please point me to the article or website? Thanks for any help. 73, ... MartinVE3OAT ___ 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] Hat Creek observatory
Hi, Pat, Oh boy, sounds like quite the place! A tour would be wonderful, but I live even further away than most of you (eastern Ontario, Canada). Hobbies are time-frequency, astronomy and ham radio. Hat Creek sounds like heaven so I hope you get lots of takers. Good luck with the tour. Post more pictures! 73, ... MartinVE3OAT ___ 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] Better quartz crystals with single isotope ?
I always thought crystals with dislocations were used to mark the band edge frequencies. ... MartinVE3OAT - - - - - - - - - - - - - - - - - - On Sun, 22 Apr 2018 11:34:30 -0600 djl wrote : > > Darn. maybe not grain boundaries, but dislocations? or both? > Don > - - - - - - - - - - - - - - - - - - - ___ 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] WWVB information
Hi, Doug, How is your 8161 doing now? Still synced properly? Should I bring my 8164 up from the basement? I was so disappointed when WWVB changed their modulation. Thanks for any encouragement. 73, ... MartinVE3OAT On Wed, 11 Apr 2018 16:28:41 Doug Millar wrote : > Hi, My Spectracom 8161 comparator and 8171A clock are chugging > right along in sync with the proper time. I have only looked at > the digital LED output and it is within one second of my other > WWVB clocks. Seems like magic. It came in synch about two > weeks ago and stayed there. I haven't changed anything in my > lab or moved the units. Antenna is still the same. > Pictures available. Doug K6JEY ___ 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] TV Signals as a frequency reference
I grew up in the 50s and 60s watching the lines at the top of the TV screen change in black and white segments according to their coded information. My Dad had adjusted our set so he could see those lines. (He was a field service specialist for Canadian General Electric.) I think the network timing information was in "line 6", though I might not remember accurately. There was all kinds of other information in those lines at the top, although only technical people knew about it because most TV sets were adjusted so you couldn't see them. 73, ... Martin VE3OAT ___ 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] Outdoor GPS Antenna Selection
Hi, Duane, I am actually using a small commercial GPS antenna with the small (lossy!!) coax and getting good results. It is either a Garmin or Gilsson "puck" style antenna with 15 feet of that terrible coax, mounted on a 3 foot wooden pole at the peak of the roof. The antenna sits on a cast-off 10 inch aluminum pizza plate (turned upside down for drainage) for ground-plane, covered by a large plastic funnel to keep off some of the snow. The coax is just long enough to reach my Thunderbolt receiver in the room below the peak. Lady Heather shows that there are almost always at least 7 birds in view at any time and the setup seems to work fine. You can engineer your solution for optimum results but I would guess that, as long as you are above a certain minimum level of signal for the receiver, you will get reasonably good performance. ... MartinVE3OAT - - - - - - - - - - - - - - - - Duane Wheaton wrote : I'm selecting an outdoors antenna for a Jupiter Pico T Timing GPS (TU36-D400-020) but don't clearly understand what "dB" rating of amplified antenna to use. From web references, it looks like the degree of amplification required is dependent on 1.) The length of run of coax lead-in, combined with the characteristic loss of the type of coax used 2.) The amount of amplification needed to increase the very weak GPS signal to the range the receiver requires it. If I'm running 20 feet of RG-58, would a 26dB antenna be sufficient? The datasheet for the receiver family states, "1575.42 MHz at a level between –115 dBm and –133 dBm into a 50 Ω impedance." So the receiver needs at max a -115 dBm signal. The typical received signal power from a GPS satellite is −127.5 dBm. So it looks like I need to amplify the RF signal for the GPS receiver requirements + compensate for the high loss of the GHz signal traveling through ordinary RG-58 coax. Am I on track, here? Recommendations? - - - - - - - - - - - - - - - - - ___ 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] Time-nut going England!
Attila, Have you thought of visiting the Greenwich observatory just south of London? I don't know if they have tours or when they might be open, but it is the birthplace of GMT. I would join you if I could but I am in Canada. Have a good visit there! ... MartinVE3OAT On Wed, 26 Apr 2017 15:05:52 +0200, Attila wrote : Hi I'll be in the UK for three weeks and will have a "free" week between 13th and 20th of May. I will most probably be around the London area and maybe spend a day or two in Southampton. If someone wants to meet for a beer or cup of hot chocolate, or knows of time-nutty things to do, please let me know. I would also appreciate if someone knows an affordable place to stay at in London, so that it doesn't strain the purse of this poor student too much. Attila Kinali ___ 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] The ultraAtomic clock for home
Bob, if you had your watch set to European time, could the fact that Europe changes to daylight time about two weeks after we do in North America have anything to do with it? ... Martin VE3OAT Bob (KB8TW) wrote : On a side note, my Citizen WWVB watch missed the change to DST this year. I still had it set to European time and it was not able to figure out which system to update to. I suppose it also may have been looking for DCF77 rather than WWVB. ___ 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] Lavoie WWV Frequency Comparator available
Hi, Bill, Thanks for adding the extra detail about how this receiver works. Maybe it will tweak the interest of someone who wasn't already aware of what it does. I had known of them for years before I found one I could afford, but that was many years ago. Spent many hours watching the ellipse and marvelling at the sudden changes of direction as the phase of the received signal changed. It was my introduction to Doppler shifting of ionospherically propagated HF signals. 73, ... Martin VE3OAT On 08/01/2017 01:36, Bill Hawkins wrote: Had one of those before downsizing. Very clever circuit, if you are describing the vacuum tube unit. The small CRT does a circular sweep based on the reference standard with brightness modulated by the strength of the received signal, so that no rotation of the half bright half dark pattern proves a match. From Minnesota, under good conditions, I could see the pattern change phase between Colorado and Hawaii as propagation conditions changed. No room for one now, but it was the most interesting WWV receiver I ever owned. Disclaimer: Absolutely no relation to Martin - thought you should know more about its capabilities. Bill Hawkins -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Martin VE3OAT Sent: Saturday, January 07, 2017 3:40 PM To: time-nuts@febo.com Subject: [time-nuts] Lavoie WWV Frequency Comparator available I have a Lavoie Labs WWV Frequency Comparator that is surplus to my needs. It is s/n 450 but is not marked with the model number, although I believe it is an LA-800D. I also have a photocopy of the operation and service manual, including schematic and parts list. The device gives an oscilloscopic display of the phase difference between your local frequency standard and the received WWV signal on either 5 or 15 MHz. The beast still works although the electrolytics need replacing (symptom -- one of the power transformers gets very warm after a few hours of operation). And it could probably benefit from a proper RF/IF alignment (I have never bothered to do this). The unit is too big and heavy to ship by any normal means, so "local pick up only". However, I could meet you "half-way", provided it is within 200 km of Ottawa, Ontario. Free to a good home. ... Martin VE3OAT (near Ottawa, Canada) ___ 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] Lavoie WWV Frequency Comparator available
I have a Lavoie Labs WWV Frequency Comparator that is surplus to my needs. It is s/n 450 but is not marked with the model number, although I believe it is an LA-800D. I also have a photocopy of the operation and service manual, including schematic and parts list. The device gives an oscilloscopic display of the phase difference between your local frequency standard and the received WWV signal on either 5 or 15 MHz. The beast still works although the electrolytics need replacing (symptom -- one of the power transformers gets very warm after a few hours of operation). And it could probably benefit from a proper RF/IF alignment (I have never bothered to do this). The unit is too big and heavy to ship by any normal means, so "local pick up only". However, I could meet you "half-way", provided it is within 200 km of Ottawa, Ontario. Free to a good home. ... Martin VE3OAT (near Ottawa, Canada) ___ 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] Cable length calibration (Brooke Clarke)
Hi, Brooke, Very interesting stuff. Thanks for the link. Question - Is any of the older chirp sounder equipment now available on the surplus market?? Thanks. ... MartinVE3OAT On 02/07/2016 12:00, time-nuts-requ...@febo.com wrote: Hi Mike: For quite a while I was heavily into "chirp" transmissions. These are HF ionosphere radio transmissions that sweep from 2 to 30 MHz at 100 kHz/sec. ... (snipped) ___ 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] KS-24361 NO GPS - again
Ulli, Sorry that I haven't been following your correspondence so I am coming into the middle of this. The fact that you receive so few satellites says to me that there is a problem at the front end. You said you had changed the cable to the antenna and the antenna itself so those parts seem OK at least. Are you using an active antenna and does the unit provide the required voltage for it? Sorry if you have already checked that. ... MartinVE3OAT Ulli wrote : At least, i saw 1 or 2 satellites from time to time. ___ 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] VLF Phase-tracking receivers.
As I recall (it was a long time ago), it was called Minimum Shift Keying and used the minimum frequency shift (FSK) that would permit reliable detection of a bit (mark or space) at the given information rate. Something like 25 Hz shift at 50 baud keying. But it was necessary to control the instantaneous phase of the signal very carefully. As a result the spectrum of an MSK signal is quite distinct from that of an ordinary FSK signal. As I recall. 73, ... MartinVE3OAT Ken W7EKB wrote : As I understand it from back in the 1970s when I was first working on this sort of thing, the modulation is not FSK, but MSK (whatever that is) at something like 25 to 50 Hz, ... (snip) ___ 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] Dephasing WWVB
John Reed wrote : By the way, my 5 section synchronous filter is an LC with op-amps between each stage to bring the gain up for the squaring chip. It has a 2 KHz -6 dB bandwidth at 60 KHz. John, have you thought of using a single 60.0 kHz crystal as a bandpass filter? I can't remember which receiver it was, but I think one of the old commercial WWVB receivers used a crystal as the tuning element. ... Martin VE3OAT ___ 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] Weather/units question for European members
Here in Canada, for many years we have officially used km/hr and kilopascals (kPa) for all reporting (both civil and aviation). These units are now easily understood by the general population. Personally, for pressure I preferred hectopascals but over the years even I have adapted to the official unit. Sounds like you have a really neat project. ... Martin VE3OAT ___ 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] Phase noise and geomagnetism
Hi, Antonio, I regularly note the geomagnetic Kp value when I take part in an FMT but most of the discussion of this takes place on K5CM's FMT-nuts mail list (as far as I know). Fortunately, most FMTs have not coincided with a major storm but there have been a few where some really weird effects were noted, probably due to minor disturbed geomagnetic conditions. 73, ... Martin VE3OAT Antonio I8IOV wrote : Hi all,thanks for your replies.Geomagnetic storms are known to produce easily detectable effects at earth, sometimes dramatic ( http://en.wikipedia.org/wiki/Solar_storm_of_1859 , http://www.youtube.com/watch?v=7ukQhycKOFw ), sometimes serious (compasses get crazy), sometimes minor (only aurorae boreales and other minor effects). I think that time-nuts should be aware whether these fenomena might affect their measurements or not. Geomagnetic activity data are easily available at the NOAA website http://www.swpc.noaa.gov/ , so checks would be easy. I hope to see some reports here sooner or later.Antonio I8IOV ___ 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] Rb vs.Crystal OCXO
Bert Kehren wrote : The thunderbolt is one of the best timing devices but not for frequency, if you want high resolution. Bert, Would my old HP Z3801A be better for frequency than the Thunderbolt? Could you put some quantitative difference to it? Thanks, ... MartinVE3OAT ___ 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] GPS antenna in silicon/RTV encapsulation
Bert, I don't know about 1.6 GHz but I can tell you with some authority that before RTV/silicone is fully cured it is highly conductive to energy at 60 Hz. ... Martin VE3OAT Bert wrote : Am experimenting with small low cost GPS antennas and am considering as an alternative RTV/silicon. Any information on RF attenuation of RTV/silicon at 1.6 GHz ? Bert Kehren ___ 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.
