Re: [time-nuts] Antennas for Symettricom 2500 Time Source
Note that many Antcom antennas are 2.5 to 24VDC... /Björn Sent from my iPhone > On 9 Jun 2018, at 22:31, Dan Rae wrote: > >> On 6/9/2018 12:05 PM, Bruce Hunter via time-nuts wrote: >> Has anyone stumbled across the 12V antennas for Symmetricom 2500 Time Source >> units. > I have a Symmetricom "Replacement GPS Antenna Kit" P/N 142-614-50 which > consists of "one wide range 5-12 VDC L1 antenna" and 50 feet of Belden 9104 > coax terminated with a BNC. Plus the hardware and stub mast to fix it to a > vent pipe or similar. I don't know what system this antenna was designed for > but the 5-12V spec is interesting. > > Dan - ac6ao > ___ > 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] Antennas for Symettricom 2500 Time Source
On 6/9/2018 12:05 PM, Bruce Hunter via time-nuts wrote: Has anyone stumbled across the 12V antennas for Symmetricom 2500 Time Source units. I have a Symmetricom "Replacement GPS Antenna Kit" P/N 142-614-50 which consists of "one wide range 5-12 VDC L1 antenna" and 50 feet of Belden 9104 coax terminated with a BNC. Plus the hardware and stub mast to fix it to a vent pipe or similar. I don't know what system this antenna was designed for but the 5-12V spec is interesting. Dan - ac6ao ___ 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] Antennas for Symettricom 2500 Time Source
I have one, Bruce, do you have questions about it? They are readily available. Search on TELECOM SOLUTIONS TS-3500 090-71010-87 It says TS-3500 but the same part is used on the 2500. Bill On Saturday, June 9, 2018, Bruce Hunter via time-nuts wrote: > > Has anyone stumbled across the 12V antennas for Symmetricom 2500 Time > Source units. The basic 23 dB model was a Symmetricom 112-1-02, > furnished as part of the 093-03110-11 kit. > > > They also offered a 40 dB model, 112-8-02 with the 093-30110-12 kit > and a 50 dB model, 112-8-03 as part of the 093-30110-13 antenna > installation kit. > > > I have never seen noticed any of these offered on eBay, even though the > model 2500 Time Source (with its SRS PRS-10) is now obsolete. It appears > antennas may have been left behind on the roofs when these installations > were upgraded. > > > > Bruce, KG6OJI > > ___ > 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. > -- Patriotism is supporting your country all the time, and your government when it deserves it. --Mark Twain We may be surprised at the people we find in heaven. God has a soft spot for sinners. His standards are quite low. --Desmond Tutu ___ 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] antennas was Re: Common-View GPS Network
If I read the paper correctly you can skip the choke ring if you mount the antenna on top of a 2 meter or longer mast. Iron pipe comes on 10 foot lengths. The choke ring is for portable survey antenna that can't be placed on tall rooftop masts. I think a 2 meter pole on a roof pretty much meets their criteria of multi path difference being over 10 meters. I can see now why surveyers need the choke ring type antenna, because they can not choose the location. They need to place it where they need to measure. But timing is different, we can choose the best location which would be two meters above the tallest object in the area. The cake pan certainly would work. This is not super critical. They are only blocking low elevation signals. and it would give you more option for the location On Wed, Apr 17, 2013 at 8:14 PM, Jim Lux jim...@earthlink.net wrote: Javad has a bunch of choke ring theory.. http://www.javad.com/jns/**index.html?/jns/technology/** Single-Depth%20Low-Multipath%**20Choke%20Ring.htmlhttp://www.javad.com/jns/index.html?/jns/technology/Single-Depth%20Low-Multipath%20Choke%20Ring.html http://www.javad.com/jns/**index.html?/jns/technology/** Choke%20Ring%20Theory.htmlhttp://www.javad.com/jns/index.html?/jns/technology/Choke%20Ring%20Theory.html Their conclusion is you want the depth of the ring to be slightly more than 1/4 lambda. lambda/4 for L1 is 1.87 so a 2 cake pan is just about the right size. -- Chris Albertson Redondo Beach, California ___ 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] antennas was Re: Common-View GPS Network
On 4/18/13 12:01 AM, Chris Albertson wrote: If I read the paper correctly you can skip the choke ring if you mount the antenna on top of a 2 meter or longer mast. Iron pipe comes on 10 foot lengths. The choke ring is for portable survey antenna that can't be placed on tall rooftop masts. I think a 2 meter pole on a roof pretty much meets their criteria of multi path difference being over 10 meters. yes.. multipath that is more than a chip away is generally filtered out by the PN tracking loop, so all you really worry about is multipath signals within a chip. For C/A code at 1 Mchip/sec, the chips are 300 meters long. If you're doing P/Y code, it's a tenth of that. In reality, if the multipath signal is lower, and it's far away (a good fraction of a chip) it doesn't contribute much to the output of the correlator. So their 10 meter thing is probably a good number for a typical receiver they make. ___ 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] antennas was Re: Common-View GPS Network
On 04/18/2013 04:00 PM, Jim Lux wrote: On 4/18/13 12:01 AM, Chris Albertson wrote: If I read the paper correctly you can skip the choke ring if you mount the antenna on top of a 2 meter or longer mast. Iron pipe comes on 10 foot lengths. The choke ring is for portable survey antenna that can't be placed on tall rooftop masts. I think a 2 meter pole on a roof pretty much meets their criteria of multi path difference being over 10 meters. yes.. multipath that is more than a chip away is generally filtered out by the PN tracking loop, so all you really worry about is multipath signals within a chip. For C/A code at 1 Mchip/sec, the chips are 300 meters long. If you're doing P/Y code, it's a tenth of that. In reality, if the multipath signal is lower, and it's far away (a good fraction of a chip) it doesn't contribute much to the output of the correlator. So their 10 meter thing is probably a good number for a typical receiver they make. It's an interesting mix of sample-rate/bandwidth, code you track and distance between early-late detectors (normal distance is one chip) comes in when analyzing and combat the multi-path. I recall there is some subtle points with some of the C/A codes. 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] antennas was Re: Common-View GPS Network
I hope I am not steering the thread to much, I have an Allen Osborne TurboRogue SMR12 RM L1 L2 GPS rec that came from JPL that appears specifically designed for Common View use. Does anyone know the history of these ,I can find almost nothing. Email me directly if you have info, or I can start a new thread. Tom Knox act...@hotmail.com Date: Thu, 18 Apr 2013 19:58:22 +0200 From: mag...@rubidium.dyndns.org To: time-nuts@febo.com Subject: Re: [time-nuts] antennas was Re: Common-View GPS Network On 04/18/2013 04:00 PM, Jim Lux wrote: On 4/18/13 12:01 AM, Chris Albertson wrote: If I read the paper correctly you can skip the choke ring if you mount the antenna on top of a 2 meter or longer mast. Iron pipe comes on 10 foot lengths. The choke ring is for portable survey antenna that can't be placed on tall rooftop masts. I think a 2 meter pole on a roof pretty much meets their criteria of multi path difference being over 10 meters. yes.. multipath that is more than a chip away is generally filtered out by the PN tracking loop, so all you really worry about is multipath signals within a chip. For C/A code at 1 Mchip/sec, the chips are 300 meters long. If you're doing P/Y code, it's a tenth of that. In reality, if the multipath signal is lower, and it's far away (a good fraction of a chip) it doesn't contribute much to the output of the correlator. So their 10 meter thing is probably a good number for a typical receiver they make. It's an interesting mix of sample-rate/bandwidth, code you track and distance between early-late detectors (normal distance is one chip) comes in when analyzing and combat the multi-path. I recall there is some subtle points with some of the C/A codes. 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] antennas was Re: Common-View GPS Network
Tom, Let's do a separate thread on that one. Cheers, Magnus On 04/18/2013 08:07 PM, Tom Knox wrote: I hope I am not steering the thread to much, I have an Allen Osborne TurboRogue SMR12 RM L1 L2 GPS rec that came from JPL that appears specifically designed for Common View use. Does anyone know the history of these ,I can find almost nothing. Email me directly if you have info, or I can start a new thread. Tom Knox act...@hotmail.com Date: Thu, 18 Apr 2013 19:58:22 +0200 From: mag...@rubidium.dyndns.org To: time-nuts@febo.com Subject: Re: [time-nuts] antennas was Re: Common-View GPS Network On 04/18/2013 04:00 PM, Jim Lux wrote: On 4/18/13 12:01 AM, Chris Albertson wrote: If I read the paper correctly you can skip the choke ring if you mount the antenna on top of a 2 meter or longer mast. Iron pipe comes on 10 foot lengths. The choke ring is for portable survey antenna that can't be placed on tall rooftop masts. I think a 2 meter pole on a roof pretty much meets their criteria of multi path difference being over 10 meters. yes.. multipath that is more than a chip away is generally filtered out by the PN tracking loop, so all you really worry about is multipath signals within a chip. For C/A code at 1 Mchip/sec, the chips are 300 meters long. If you're doing P/Y code, it's a tenth of that. In reality, if the multipath signal is lower, and it's far away (a good fraction of a chip) it doesn't contribute much to the output of the correlator. So their 10 meter thing is probably a good number for a typical receiver they make. It's an interesting mix of sample-rate/bandwidth, code you track and distance between early-late detectors (normal distance is one chip) comes in when analyzing and combat the multi-path. I recall there is some subtle points with some of the C/A codes. 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] antennas was Re: Common-View GPS Network
Magnus, Jim, On 04/18/2013 04:00 PM, Jim Lux wrote: On 4/18/13 12:01 AM, Chris Albertson wrote: If I read the paper correctly you can skip the choke ring if you mount the antenna on top of a 2 meter or longer mast. Iron pipe comes on 10 foot lengths. The choke ring is for portable survey antenna that can't be placed on tall rooftop masts. I think a 2 meter pole on a roof pretty much meets their criteria of multi path difference being over 10 meters. yes.. multipath that is more than a chip away is generally filtered out by the PN tracking loop, so all you really worry about is multipath signals within a chip. For C/A code at 1 Mchip/sec, the chips are 300 meters long. If you're doing P/Y code, it's a tenth of that. In reality, if the multipath signal is lower, and it's far away (a good fraction of a chip) it doesn't contribute much to the output of the correlator. So their 10 meter thing is probably a good number for a typical receiver they make. It's an interesting mix of sample-rate/bandwidth, code you track and distance between early-late detectors (normal distance is one chip) comes in when analyzing and combat the multi-path. I recall there is some subtle points with some of the C/A codes. All of the high quality GNSS receiver manufacturers have their own version of correlator that try to mitigate multipath. See for example this Ashtech-document (for a ca 10 year old L1 only receiver (DG14/16)). ftp://ftp.ashtech.com/OEM,%20Sensor%20%20ADU/DG16%20%20DG14/Reference%20Material/Correlator.doc /Björn ___ 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] antennas was Re: Common-View GPS Network
On 4/18/13 1:40 PM, b...@lysator.liu.se wrote: All of the high quality GNSS receiver manufacturers have their own version of correlator that try to mitigate multipath. See for example this Ashtech-document (for a ca 10 year old L1 only receiver (DG14/16)). ftp://ftp.ashtech.com/OEM,%20Sensor%20%20ADU/DG16%20%20DG14/Reference%20Material/Correlator.doc I'm sure.. I wonder, though, if you have a GPS receiver for which you do not know how it works internally, can one come up with a guideline for how much multipath suppression you want. At some level, all those fancy algorithms are trying to build an adaptive equalizer and/or filter for the multipath, helped by the knowledge that the true path is the shortest one. In theory, one should be able to deconvolve arbitrary multipath (if you collect all signals from all directions of the sky, etc.), but I think the idea of the chokering (and other clever antenna designs) is to reduce the work for the back end processing. ___ 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] antennas was Re: Common-View GPS Network
Another way to ask this question is what is the effect of a small deviation form the ideal dimensions? If we assume deviations of about 1/20th of a wavelength are OK then we can allow about 1cm of dimensional error. Almost anyone using simple hand tools can do better. With care using primitive garage equipment we can do much better. The old-school hand method for precision sheet metal work was to make a hardwood form and then bend and cut the metal around the wood form. I think if a cake pan would work is a matter of luck. You'd just have to find one within about 2cm of the correct diameter. If not then you be better off starting with flat sheet and hand shears. On Tue, Apr 16, 2013 at 10:46 PM, David J Taylor david-tay...@blueyonder.co.uk wrote: From: Sarah White I just have to ask though... cake pans? really? I can't imagine it would even be possible to modify a cake pan with enough accuracy to get a usable antenna. -- Chris Albertson Redondo Beach, California ___ 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] antennas was Re: Common-View GPS Network
But the pan is just a ground plane. It isn't a reflector based on the type of antennas I saw in the photograph. Sent via BlackBerry from T-Mobile -Original Message- From: Chris Albertson albertson.ch...@gmail.com Sender: time-nuts-boun...@febo.com Date: Wed, 17 Apr 2013 12:18:00 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] antennas was Re: Common-View GPS Network Another way to ask this question is what is the effect of a small deviation form the ideal dimensions? If we assume deviations of about 1/20th of a wavelength are OK then we can allow about 1cm of dimensional error. Almost anyone using simple hand tools can do better. With care using primitive garage equipment we can do much better. The old-school hand method for precision sheet metal work was to make a hardwood form and then bend and cut the metal around the wood form. I think if a cake pan would work is a matter of luck. You'd just have to find one within about 2cm of the correct diameter. If not then you be better off starting with flat sheet and hand shears. On Tue, Apr 16, 2013 at 10:46 PM, David J Taylor david-tay...@blueyonder.co.uk wrote: From: Sarah White I just have to ask though... cake pans? really? I can't imagine it would even be possible to modify a cake pan with enough accuracy to get a usable antenna. -- Chris Albertson Redondo Beach, California ___ 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] antennas was Re: Common-View GPS Network
On 4/17/13 12:18 PM, Chris Albertson wrote: Another way to ask this question is what is the effect of a small deviation form the ideal dimensions? If we assume deviations of about 1/20th of a wavelength are OK then we can allow about 1cm of dimensional error. Almost anyone using simple hand tools can do better. With care using primitive garage equipment we can do much better. The old-school hand method for precision sheet metal work was to make a hardwood form and then bend and cut the metal around the wood form. I think if a cake pan would work is a matter of luck. You'd just have to find one within about 2cm of the correct diameter. If not then you be better off starting with flat sheet and hand shears. since you can buy cake pans in even inch increments, I think the cake pan will work.. BTW, I've been looking at some choke rings with only 2 rings instead of the usual 3. Apparently, the performance isn't all that much different. When I asked why do all the other ones have 3, it boils down to the first one had 3 and everyone just copied it. Javad has a bunch of choke ring theory.. http://www.javad.com/jns/index.html?/jns/technology/Single-Depth%20Low-Multipath%20Choke%20Ring.html http://www.javad.com/jns/index.html?/jns/technology/Choke%20Ring%20Theory.html Their conclusion is you want the depth of the ring to be slightly more than 1/4 lambda. lambda/4 for L1 is 1.87 so a 2 cake pan is just about the right size. ___ 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] antennas was Re: Common-View GPS Network
From: li...@lazygranch.com But the pan is just a ground plane. It isn't a reflector based on the type of antennas I saw in the photograph. = If you are referring to my antenna farm photo, that's correct. It is also magnetic, so it holds the pucks in place. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] antennas was Re: Common-View GPS Network
On 4/16/2013 1:55 AM, Jim Lux wrote: On 4/15/13 10:22 PM, Jim Lux wrote: On 4/15/13 9:27 PM, Tom Van Baak wrote: NIST SIM GPS common view pinwheel described in one of the NIST reports as an aperture coupled slot fed array that is better than a patch, but not as large and heavy as a choke ring. W. Kunysz, 2000, “High Performance GPS Pinwheel Antenna,” in Proceedings of the 2000 International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GPS 2000), 19-22 September 2000, Salt Lake City, Utah, USA (ION, Alexandria, Virginia), pp. 2506-251 http://www.novatel.com/assets/Documents/Papers/GPS-704xWhitePaper.pdf Patented by Novatel Pinwheel is a trademark Performance is almost as good as a choke ring but a heck of a lot smaller and lighter. of course, cake pans with 2-2.5 inch high walls are readily available. There's a Wilton cakepan set with 6,8 and 10 diameter pans with 3 walls.. hmm, an inch between fins.. Oddly, the package shipping size is 12x12x2... I wonder how they fit a 3 high pan in a 2 thick box.. a real restaurant/pastry supply has a mindboggling variety of pans http://www.fantes.com/cake-pans-round.html every integer inch diameter from 4 to 18 and ditto for heights from 2 to 4... People like those machined or cast choke rings because they're easier to fabricate: Slap a block of aluminum in the lathe or milling machine, push GO on the CNC, and stand back. Or for those with a taste for hot metal.. you could cast it with scrap aluminum you've melted in the forge in your time nuts lab.. Turn those empty beer cans into something useful. If you have a fancy multiaxis mill, you could probably do one of those porcupine looking things. Or, if you have a swimming pool or pond, and some sheet aluminum, and some suitable high explosives.. hydroforming is your friend. If you want true timenuts.. do the explosive hydroforming without a mold/buck, and instead use precision timing of shaped charges. Finally, a use for those krytron switches you found at the surplus place. Thanks for that. The last bit of your post was really cute. I needed a good laugh :) I haven't posted much in a while, partly because I've been kinda bummed out by this list since I got the news about shera... There have been so many constant reminders of his passing and whatnot (multiple thread titles mentioning his legacy) I just have to ask though... cake pans? really? I can't imagine it would even be possible to modify a cake pan with enough accuracy to get a usable antenna. -- Sarah ___ 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] antennas was Re: Common-View GPS Network
On 4/16/13 5:19 PM, Sarah White wrote: I just have to ask though... cake pans? really? I can't imagine it would even be possible to modify a cake pan with enough accuracy to get a usable antenna. Sure.. cake pans, like other stamped goods, are actually pretty high precision, because they're all stamped out of the same die. As long as the dimensions are right (and for choke rings that's not real critical), it works. ___ 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] antennas was Re: Common-View GPS Network
From: Sarah White I just have to ask though... cake pans? really? I can't imagine it would even be possible to modify a cake pan with enough accuracy to get a usable antenna. -- Sarah Well, my GPS antenna farm uses an inverted baking tray http://www.satsignal.eu/ntp/2013-03-31-1226-32-GPS-antenna-farm.jpg Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] antennas
What is the purpose of the temperature sensor chip on the PCB, anyway? Isn't the temperature inside the OCXO much more important? The OCXO isn't perfcet. The frequency will shift slightly with environmental temperature changes. It may have been more important without the high-quality OCXO option that many recent TBolts seem to have. Here is some data: http://www.megapathdsl.net/~hmurray/time-nuts/TBolt-volt-temp-1.gif http://www.megapathdsl.net/~hmurray/time-nuts/TBolt-volt-temp-2.gif It's 24 hours of data in my non air-conditioned spare room. I shifted the DAC voltage to be close to zero. The spikes on the red graph are recovering from holdover. (The antenna isn't very good.) The slight eye openings are hysteresis. Does anybody know if they calibrate it on the fly or do it once at manufacturing checkout? (or just wire a constant into the source code?) Trying to do it do it on the fly seems hard if your system is running in a well air-conditioned place where you don't get much temperature swing. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] antennas
Hi The TBolt firmware does not interact with the ocxo's temperature controller. Bob On Sep 28, 2010, at 1:46 AM, russell rstanph...@austin.rr.com wrote: Isn't the temperature inside the OCXO oven held at a set point (greater than ambient) with it own independent thermostat? The DS1620 thermometer only reads ambient temperature. In this case amibent means inside the Tbolt enclosure. If so, what does the Lady Heather t t command do? It prompts you to enter desired operating temperature. What could it control? Russell (newbie) - Original Message - From: b...@lysator.liu.se To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, September 28, 2010 12:32 AM Subject: Re: [time-nuts] antennas Instead of reacting to a change in the OCXO, the control software can be proactive wrt a change that is heading towards the inside of the oven. -- Björn What is the purpose of the temperature sensor chip on the PCB, anyway? Isn't the temperature inside the OCXO much more important? -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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. ___ 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] antennas
On 09/28/2010 09:38 AM, Hal Murray wrote: What is the purpose of the temperature sensor chip on the PCB, anyway? Isn't the temperature inside the OCXO much more important? The OCXO isn't perfcet. The frequency will shift slightly with environmental temperature changes. Let's consider a thermal gain of 1000, such that 1 K of external temperature difference becomes 1 mK internal. If we want to compensate the remaining error, putting a temperature sensor inside the OCXO, it needs 1 mK resolution for 1 K external temperature shift. Putting the temperature sensor externally will the OCXO thermal gain improvement in resolution. So a 1/32 K resolution external becomes a 1/32 mK resolution internally. This model is oversimplified as the thermal response-time and that of the oven will smooth out temperature shifts, and an external sensor does not experience the same transient response. It may have been more important without the high-quality OCXO option that many recent TBolts seem to have. Here is some data: http://www.megapathdsl.net/~hmurray/time-nuts/TBolt-volt-temp-1.gif http://www.megapathdsl.net/~hmurray/time-nuts/TBolt-volt-temp-2.gif Looks like thermal lag is the reason for the opening between the heat-up and chill-down periods. 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] antennas
Rather than put up two antennas, why not use one, and pick up a HP/Symmetricom GPS splitter? (Mini-Circuits makes a similar unit). You can find them on eBay for various prices. The Symmetricom one, the 58535A, supports 2 GPS receivers. It has a built-in amplifier and filters, so it provides high isolation between the GPS units. It's powered from the GPS units, and passes power to the antenna. The downsides are that it costs more than a pair of cheap antennas, it's heavy (heavier than the Thunderbolt!), and uses type N connectors. But it's low noise, and you only have one antenna and feedline to worry about. 73 bob k6rtm -- Message: 3 Date: Sun, 26 Sep 2010 15:56:47 -0400 From: Heathkid heath...@heathkid.com Subject: Re: [time-nuts] DS1620 Variants in the Thunderbolt To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 795f7aa593814ecb9aa24f0b55cad...@d1x25bd10 Content-Type: text/plain; format=flowed; charset=UTF-8; reply-type=original Thanks for all the information on the DS1620. As it turns out, both of the TBolts (remember I got the from two different sellers and appear identical) have the Trimble OCXO, v3.00 firmware, but the DS1620's are marked as follows: DS1620 0415E2 531AD DS1620 0239D1 690AB Interestingly, the first one appears to have been swapped out at some point (flux residue all over the chip / had to clean it off to read the markings). I've already ordered another D1 to swap out the E2 but really need to get them both up and running (still trying to figure out how to mount the antennas!) and see how much difference there really is. 73 Brice KA8MAV ___ 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] antennas
Last time I checked, the HP/Symmetricom HP58532A GPS antenna was cheaper than a GPS splitter (I paid $50 for my HP58532A, with shipping, and it was brand new). Of course, with two antennas, you will need two feed lines which, depending how long they are, could cost you more than the antenna itself... Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: k6...@comcast.net Sender: time-nuts-boun...@febo.com Date: Mon, 27 Sep 2010 14:50:15 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] antennas Rather than put up two antennas, why not use one, and pick up a HP/Symmetricom GPS splitter? (Mini-Circuits makes a similar unit). You can find them on eBay for various prices. The Symmetricom one, the 58535A, supports 2 GPS receivers. It has a built-in amplifier and filters, so it provides high isolation between the GPS units. It's powered from the GPS units, and passes power to the antenna. The downsides are that it costs more than a pair of cheap antennas, it's heavy (heavier than the Thunderbolt!), and uses type N connectors. But it's low noise, and you only have one antenna and feedline to worry about. 73 bob k6rtm -- Message: 3 Date: Sun, 26 Sep 2010 15:56:47 -0400 From: Heathkid heath...@heathkid.com Subject: Re: [time-nuts] DS1620 Variants in the Thunderbolt To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 795f7aa593814ecb9aa24f0b55cad...@d1x25bd10 Content-Type: text/plain; format=flowed; charset=UTF-8; reply-type=original Thanks for all the information on the DS1620. As it turns out, both of the TBolts (remember I got the from two different sellers and appear identical) have the Trimble OCXO, v3.00 firmware, but the DS1620's are marked as follows: DS1620 0415E2 531AD DS1620 0239D1 690AB Interestingly, the first one appears to have been swapped out at some point (flux residue all over the chip / had to clean it off to read the markings). I've already ordered another D1 to swap out the E2 but really need to get them both up and running (still trying to figure out how to mount the antennas!) and see how much difference there really is. 73 Brice KA8MAV ___ 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] antennas
Great suggestion! I bought two of the Symmetricom 58535A's from Mike Feher. It'll be great only having to deal with *one* antenna and feedline plus I'll have a spare antenna (and a spare splitter - for now)! :) Now... lots of adapters and patch cables to buy (N to F)... I've also bought four (4) DS1620 D1 chips... so that should keep me in business for a while. Since one of my Tbolts has an E2 chip in it... was there an E1? Did the E2 fix anything or should I just go straight back to the D1? Is anyone keeping track of the temp chips and any long term stability data on them? Seems there should be almost a decade of data out there somewhere... Thanks again... 73 Brice KA8MAV - Original Message - From: k6...@comcast.net To: time-nuts@febo.com Sent: Monday, September 27, 2010 10:50 AM Subject: Re: [time-nuts] antennas Rather than put up two antennas, why not use one, and pick up a HP/Symmetricom GPS splitter? (Mini-Circuits makes a similar unit). You can find them on eBay for various prices. The Symmetricom one, the 58535A, supports 2 GPS receivers. It has a built-in amplifier and filters, so it provides high isolation between the GPS units. It's powered from the GPS units, and passes power to the antenna. The downsides are that it costs more than a pair of cheap antennas, it's heavy (heavier than the Thunderbolt!), and uses type N connectors. But it's low noise, and you only have one antenna and feedline to worry about. 73 bob k6rtm -- Message: 3 Date: Sun, 26 Sep 2010 15:56:47 -0400 From: Heathkid heath...@heathkid.com Subject: Re: [time-nuts] DS1620 Variants in the Thunderbolt To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 795f7aa593814ecb9aa24f0b55cad...@d1x25bd10 Content-Type: text/plain; format=flowed; charset=UTF-8; reply-type=original Thanks for all the information on the DS1620. As it turns out, both of the TBolts (remember I got the from two different sellers and appear identical) have the Trimble OCXO, v3.00 firmware, but the DS1620's are marked as follows: DS1620 0415E2 531AD DS1620 0239D1 690AB Interestingly, the first one appears to have been swapped out at some point (flux residue all over the chip / had to clean it off to read the markings). I've already ordered another D1 to swap out the E2 but really need to get them both up and running (still trying to figure out how to mount the antennas!) and see how much difference there really is. 73 Brice KA8MAV ___ 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] antennas
Hi Since few of us have an oil bath to check the thermometer chips with, it's tough to really know what the long term stability is. Those of us that do have sufficiently precise oil baths are a bit reluctant to dunk a TBolt in them on a regular basis Bottom line appears to be - fine for day to day checks. I would not trust any of these chips to be long term stable to sub 10 mK levels. Bob On Sep 27, 2010, at 6:53 PM, Heathkid wrote: Great suggestion! I bought two of the Symmetricom 58535A's from Mike Feher. It'll be great only having to deal with *one* antenna and feedline plus I'll have a spare antenna (and a spare splitter - for now)! :) Now... lots of adapters and patch cables to buy (N to F)... I've also bought four (4) DS1620 D1 chips... so that should keep me in business for a while. Since one of my Tbolts has an E2 chip in it... was there an E1? Did the E2 fix anything or should I just go straight back to the D1? Is anyone keeping track of the temp chips and any long term stability data on them? Seems there should be almost a decade of data out there somewhere... Thanks again... 73 Brice KA8MAV - Original Message - From: k6...@comcast.net To: time-nuts@febo.com Sent: Monday, September 27, 2010 10:50 AM Subject: Re: [time-nuts] antennas Rather than put up two antennas, why not use one, and pick up a HP/Symmetricom GPS splitter? (Mini-Circuits makes a similar unit). You can find them on eBay for various prices. The Symmetricom one, the 58535A, supports 2 GPS receivers. It has a built-in amplifier and filters, so it provides high isolation between the GPS units. It's powered from the GPS units, and passes power to the antenna. The downsides are that it costs more than a pair of cheap antennas, it's heavy (heavier than the Thunderbolt!), and uses type N connectors. But it's low noise, and you only have one antenna and feedline to worry about. 73 bob k6rtm -- Message: 3 Date: Sun, 26 Sep 2010 15:56:47 -0400 From: Heathkid heath...@heathkid.com Subject: Re: [time-nuts] DS1620 Variants in the Thunderbolt To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 795f7aa593814ecb9aa24f0b55cad...@d1x25bd10 Content-Type: text/plain; format=flowed; charset=UTF-8; reply-type=original Thanks for all the information on the DS1620. As it turns out, both of the TBolts (remember I got the from two different sellers and appear identical) have the Trimble OCXO, v3.00 firmware, but the DS1620's are marked as follows: DS1620 0415E2 531AD DS1620 0239D1 690AB Interestingly, the first one appears to have been swapped out at some point (flux residue all over the chip / had to clean it off to read the markings). I've already ordered another D1 to swap out the E2 but really need to get them both up and running (still trying to figure out how to mount the antennas!) and see how much difference there really is. 73 Brice KA8MAV ___ 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] antennas
Hi Based only on the fact that they never fixed the problem with the chip - I don't think they do a lot of fine grain temperature correction. They certainly went on shipping the units as spec compliant. Bob On Sep 27, 2010, at 10:20 PM, Hal Murray hmur...@megapathdsl.net wrote: Bottom line appears to be - fine for day to day checks. I would not trust any of these chips to be long term stable to sub 10 mK levels. I think the temperature correction is only used in holdover. What's the time constant on learning the temperature profile of the OCXO? As long as the aging in the temperature sensor is slow relative to that its (long term) stability shouldn't matter much. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] antennas
What is the purpose of the temperature sensor chip on the PCB, anyway? Isn't the temperature inside the OCXO much more important? -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] antennas
Instead of reacting to a change in the OCXO, the control software can be proactive wrt a change that is heading towards the inside of the oven. -- Björn What is the purpose of the temperature sensor chip on the PCB, anyway? Isn't the temperature inside the OCXO much more important? -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] antennas
Isn't the temperature inside the OCXO oven held at a set point (greater than ambient) with it own independent thermostat? The DS1620 thermometer only reads ambient temperature. In this case amibent means inside the Tbolt enclosure. If so, what does the Lady Heather t t command do? It prompts you to enter desired operating temperature. What could it control? Russell (newbie) - Original Message - From: b...@lysator.liu.se To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, September 28, 2010 12:32 AM Subject: Re: [time-nuts] antennas Instead of reacting to a change in the OCXO, the control software can be proactive wrt a change that is heading towards the inside of the oven. -- Björn What is the purpose of the temperature sensor chip on the PCB, anyway? Isn't the temperature inside the OCXO much more important? -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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] Antennas, roofs
In my case, I have a large number of low angle peaks and valleys (hence the leakage issue); my sky view is really good, and I'm planning on putting a set of parallel horizontal bars about 18 apart between my 4 sewer riser and another point about 15' away. All cables will be going through a 5 roof T vent which happens to be attached to nothing in particular (I had to insert a screen to keep the roof rats out- they were not happy!). The big issue is that I can't get inside the crawl space of the area in question, so I need to wait for drier weather to rip up the existing roof and put everything in place. Sigh... - Original Message - From: Ken Winterling wa2...@frontiernet.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, February 17, 2009 6:33:40 PM GMT -07:00 US/Canada Mountain Subject: Re: [time-nuts] Antennas, roofs Hal, If your new roof will have a ridge vent you can poke the antenna cables through it to the outside leaving enough slack to create a drip loop before continuing to the antenna(s). Since the ridge vent follows the slope of the roof the cable will exit on the down side so water will run off. Ken, WA2LBI On Tue, Feb 17, 2009 at 19:18, Hal Murray hmur...@megapathdsl.net wrote: I really need to put in a feed through to the roof because my Z3801A is struggling with an indoor antenna too; but the roof needs to get replaced first... Speaking of antennas and roofs Currently, my antennas are inside. That's good enough most of the time. It's also good for providing nasty test cases to software. I also need a new roof. I'm scheming to poke a hole in the roof so I can get some antennas in a better position. If I have more than one antenna, does it matter how near eachother they are located? I'm picturing a plastic pipe that sticks up a few feet and a bracket at the base that has the right magic angle to match the pitch of my roof. The pipe would screw or glue into the bracket. The bracket would get screwed to the roof over a hole. The cables would go through the hole and up inside the pipe. I haven't worked out the details for the top of the pipe yet. My (handwave) straw man is a U turn to keep the rain out, and mount the antennas on the main pipe. Maybe a T to get them out to the side. Do brackets like that exist? If so, what term or brand do I google for? I have a typical not-very-steep sloped roof. Is there a standard angle? ... Plan B would be to stick the pipe through the roof and attach it inside to the side of a rafter. I assume the roofers can treat it like a plumbing vent pipe. A slightly crazy idea... Has anybody poked antennas up inside a skylight? I'm thinking of the setup which has a hole in the ceiling of a room, a box from that hole through the attic space up to and through the roof, and a plastic dome on top. A shelf or bracket on the inside of the box would get the antennas almost on the outside. I've seen ads for metal roofs/shingles, the claimed advantage being long life which is attractive to me. I assume they would be a disaster for antennas inside. What about outside, slightly above the roof? I'd expect bad things, but maybe there is some way to turn it into an advantage. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] Antennas, roofs
In message 619502179.1235901234946739463.javamail.r...@sz0108a.emeryville.ca.m ail.comcast.net, d.sei...@comcast.net writes: A slightly crazy idea... Has anybody poked antennas up inside a skylight? Yes, it works, I have a M12T running that way. It is an acrylic or polycarbonate (not sure) dome type skylight. When I replaced the roof on my house, I had three 1/2 wirepipes installed over one of the attic windows and had three irons mounted under the tiles for attachment of antennas: http://phk.freebsd.dk/misc/dscf0180.jpg So now I can just open the window and fiddle with my antennas as much as I like. The wirepipes are wide enough that a BNC can be squeezed through. Poul-Henning -- 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] Antennas, roofs
Hi Hal, A metal roof is generally used for those areas that have heavy snow. Such a roof would be disastrous for the GPS if the antenna is low on top of the roof because of reflections. A metal roof would be harder to seal, I would think, for holes drilled through it. Also a metal roof can be quite slippery and dangerous for someone climbing around on it. The composition roof, at least, provides a less slippery surface and may provide less reflections. Although I would suspect that one would want to mount the antenna at least 10 feet above the roof surface, if not higher based upon surrounding objects like trees and so forth. If there is a header section above the top of the wall line (i.e., in the roof area), you may want to consider passing the pipe horizontally through the header instead of making yet another hole for leakage in your roof. Radio Shack use to carry brackets for side mounting a pole along side the wall. Two such brackets mounted ten feet apart would provide plenty of stability for small antennas, even including small VHF/UHF bean antennas. Radio Shack also use to have metal antenna poles that would stack end to end and give the ability to have any given length (within reason). Just some thoughts. BillWB6BNQ Hal Murray wrote: I really need to put in a feed through to the roof because my Z3801A is struggling with an indoor antenna too; but the roof needs to get replaced first... Speaking of antennas and roofs Currently, my antennas are inside. That's good enough most of the time. It's also good for providing nasty test cases to software. I also need a new roof. I'm scheming to poke a hole in the roof so I can get some antennas in a better position. If I have more than one antenna, does it matter how near eachother they are located? I'm picturing a plastic pipe that sticks up a few feet and a bracket at the base that has the right magic angle to match the pitch of my roof. The pipe would screw or glue into the bracket. The bracket would get screwed to the roof over a hole. The cables would go through the hole and up inside the pipe. I haven't worked out the details for the top of the pipe yet. My (handwave) straw man is a U turn to keep the rain out, and mount the antennas on the main pipe. Maybe a T to get them out to the side. Do brackets like that exist? If so, what term or brand do I google for? I have a typical not-very-steep sloped roof. Is there a standard angle? ... Plan B would be to stick the pipe through the roof and attach it inside to the side of a rafter. I assume the roofers can treat it like a plumbing vent pipe. A slightly crazy idea... Has anybody poked antennas up inside a skylight? I'm thinking of the setup which has a hole in the ceiling of a room, a box from that hole through the attic space up to and through the roof, and a plastic dome on top. A shelf or bracket on the inside of the box would get the antennas almost on the outside. I've seen ads for metal roofs/shingles, the claimed advantage being long life which is attractive to me. I assume they would be a disaster for antennas inside. What about outside, slightly above the roof? I'd expect bad things, but maybe there is some way to turn it into an advantage. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] Antennas, roofs
Yup, running my T-bolt on an indoor patch antenna hoisted to the apex of a skylight. Works fine. My GPS NTP server uses a bullet antenna mounted on a short (~1ft) pole bolted to a block of wood on the side of the house, feedthrough is PVC pipe going through the wall with a 45-degree coupler on the outside pointing down to keep out rain. On Tue, Feb 17, 2009 at 4:18 PM, Hal Murray hmur...@megapathdsl.net wrote: A slightly crazy idea... Has anybody poked antennas up inside a skylight? I'm thinking of the setup which has a hole in the ceiling of a room, a box from that hole through the attic space up to and through the roof, and a plastic dome on top. A shelf or bracket on the inside of the box would get the antennas almost on the outside. ___ 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] Antennas, roofs
Hal, If your new roof will have a ridge vent you can poke the antenna cables through it to the outside leaving enough slack to create a drip loop before continuing to the antenna(s). Since the ridge vent follows the slope of the roof the cable will exit on the down side so water will run off. Ken, WA2LBI On Tue, Feb 17, 2009 at 19:18, Hal Murray hmur...@megapathdsl.net wrote: I really need to put in a feed through to the roof because my Z3801A is struggling with an indoor antenna too; but the roof needs to get replaced first... Speaking of antennas and roofs Currently, my antennas are inside. That's good enough most of the time. It's also good for providing nasty test cases to software. I also need a new roof. I'm scheming to poke a hole in the roof so I can get some antennas in a better position. If I have more than one antenna, does it matter how near eachother they are located? I'm picturing a plastic pipe that sticks up a few feet and a bracket at the base that has the right magic angle to match the pitch of my roof. The pipe would screw or glue into the bracket. The bracket would get screwed to the roof over a hole. The cables would go through the hole and up inside the pipe. I haven't worked out the details for the top of the pipe yet. My (handwave) straw man is a U turn to keep the rain out, and mount the antennas on the main pipe. Maybe a T to get them out to the side. Do brackets like that exist? If so, what term or brand do I google for? I have a typical not-very-steep sloped roof. Is there a standard angle? ... Plan B would be to stick the pipe through the roof and attach it inside to the side of a rafter. I assume the roofers can treat it like a plumbing vent pipe. A slightly crazy idea... Has anybody poked antennas up inside a skylight? I'm thinking of the setup which has a hole in the ceiling of a room, a box from that hole through the attic space up to and through the roof, and a plastic dome on top. A shelf or bracket on the inside of the box would get the antennas almost on the outside. I've seen ads for metal roofs/shingles, the claimed advantage being long life which is attractive to me. I assume they would be a disaster for antennas inside. What about outside, slightly above the roof? I'd expect bad things, but maybe there is some way to turn it into an advantage. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] Antennas, roofs
Depending where you are most homes have sewer vents. I have used this repeatedly in the US and in Germany. This is a PVC pipe going through the roof and normally well sealed by the roofer, but open on the top. In the past Radio Shack had pipe to pipe clamps the pair for less than $10. You choose the pipe closest to your GPS location and drill a hole in the pipe inside the house, above the highest toilet and bring the cable into the house. Seal it with RTV to prevent odor. Water or sewer will never rise to that level, it would overflow the toilet if stopped up. This way you have a solid set up, the pipe you connect to the sewer vent can be long enough to clear the roof! Worked for me. Bert Kehren Miami WB5MZJ **You can't always choose whom you love, but you can choose how to find them. Start with AOL Personals. (http://personals.aol.com/?ncid=emlcntuslove0002) ___ 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] Antennas, roofs
Hello Hal, You can find roof penetrations in the plumbing dept of Home Depot or Lowes. Some will handle from a 4 (ID) PVC pipe used as a drain vent, down to a 1 trade size pipe. I prefer the rubber gland on sheet metal, vs. the rubber gland on plastic. Using the white DWV (drain waste vent) PVC pipe will work but is a bright white eyesore. Conside the toned down, grey electrical conduit, also schedule 40. Galvi pipe works too. These glands are common to a residential roofer. Talk to multiple roofing contractors and get their ideas. My plan is to have the GPS antenna on a metal mast (pipe) slightly higher than the ridge line, penetrating the roof about 1-2' below the ridge line. I will secure the metal mast to the rafter inside and run the coaxial cable thru the mast to the antenna which screws onto the top of the mast. I will use standard roofing shingles, non metal. A metal roof will allow reflections off of the roof into the antenna. Keep the antenna above the highest point of the roof. But, a standing seam metal roof will allow a cost effective way to secure PV solar panels. Model GPS system performance at the exact location with a temporary antenna before any permanent holes are made. Right now I am using a cheap active patch antenna , ~ 5$ on ebay, outside on a temporary tripod at gutter height. Lady Heather shows me with 8 satellites, usually under reception. Try the various inside locations for a GPS antenna. If you can live with the results, avoid the leak potential of a hole in the roof. Ultimately, find the best location with a temporary antenna. make the roof penetration, then add a HP multicoupler inside and feed other GPS receivers. All from a single antenna Your RF electromagnetic environment may be unique. Test at temporary locations. Hopefully, from the final location you can see clean sky from horizon to horizon. I like the radomed (bubble) on the roof, inside installation. Only gotcha is the non standard product and you would have to engineer it. Talk to you roofing contractor for ideas, he does this stuph all day long. What does your Mrs. have to say about the installation ?? Metal roofs are noisey with precipitation, like hale, rain, or snow, as well as creaky with thermal expansion/contraction. I would expect a metal roof, properly installed, to last a lifetime, Can not say that about asphault/fiberglass roofing shingles. Stan, W1LEFN41srCape Cod Hal Murray wrote: I really need to put in a feed through to the roof because my Z3801A is struggling with an indoor antenna too; but the roof needs to get replaced first... Speaking of antennas and roofs Currently, my antennas are inside. That's good enough most of the time. It's also good for providing nasty test cases to software. I also need a new roof. I'm scheming to poke a hole in the roof so I can get some antennas in a better position. If I have more than one antenna, does it matter how near eachother they are located? I'm picturing a plastic pipe that sticks up a few feet and a bracket at the base that has the right magic angle to match the pitch of my roof. The pipe would screw or glue into the bracket. The bracket would get screwed to the roof over a hole. The cables would go through the hole and up inside the pipe. I haven't worked out the details for the top of the pipe yet. My (handwave) straw man is a U turn to keep the rain out, and mount the antennas on the main pipe. Maybe a T to get them out to the side. Do brackets like that exist? If so, what term or brand do I google for? I have a typical not-very-steep sloped roof. Is there a standard angle? ... Plan B would be to stick the pipe through the roof and attach it inside to the side of a rafter. I assume the roofers can treat it like a plumbing vent pipe. A slightly crazy idea... Has anybody poked antennas up inside a skylight? I'm thinking of the setup which has a hole in the ceiling of a room, a box from that hole through the attic space up to and through the roof, and a plastic dome on top. A shelf or bracket on the inside of the box would get the antennas almost on the outside. I've seen ads for metal roofs/shingles, the claimed advantage being long life which is attractive to me. I assume they would be a disaster for antennas inside. What about outside, slightly above the roof? I'd expect bad things, but maybe there is some way to turn it into an advantage. ___ 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] Antennas in apartments
On Sun, 16 Dec 2007 22:57:49 -0800, Hal Murray [EMAIL PROTECTED] wrote: Talk to your building superintendent. Offer to provide NTP service to the whole complex if he will help you setup a GPS antenna. I can see it now. Duh, how's this NTP stuff gonna help me unstop the toilet in 23? :-) What do people who want satellite TV do? Federal law says that landlords cannot prohibit satellite TV dishes. Another one of those best laws money can buy. The implication for a solution to the GPS antenna problem is fairly obvious. John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com -- best little blog on the net! Tellico Plains, Occupied TN If we aren't supposed to eat animals, why are they made with meat? ___ 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] Antennas in apartments
Neon John wrote: On Sun, 16 Dec 2007 22:57:49 -0800, Hal Murray [EMAIL PROTECTED] wrote: Talk to your building superintendent. Offer to provide NTP service to the whole complex if he will help you setup a GPS antenna. I can see it now. Duh, how's this NTP stuff gonna help me unstop the toilet in 23? :-) What do people who want satellite TV do? Federal law says that landlords cannot prohibit satellite TV dishes. Another one of those best laws money can buy. The implication for a solution to the GPS antenna problem is fairly obvious. I think you need to read the law a little bit more carefully! What the law says, as I read it, is that you can put up radio, TV, or satellite antennas on your own property, regardless of covenants, home owners association rules, or zoning ordinances. But, if the property isn't yours, or isn't available for your exclusive use, it is up to the owner (or controlling authority) to decide whether you may or may not. The FCC's website has a QA section where they specifically answer a question about putting up an antenna that extends beyond the apartment/townhouse deck into the air space. They say that the law only controls what is allowed within the confines of the deck, and not what is allowed in the air space beyond the deck. -Chuck ___ 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] Antennas in apartments
On Mon, 17 Dec 2007 13:43:41 -0500, Chuck Harris [EMAIL PROTECTED] wrote: Neon John wrote: Federal law says that landlords cannot prohibit satellite TV dishes. Another one of those best laws money can buy. The implication for a solution to the GPS antenna problem is fairly obvious. I think you need to read the law a little bit more carefully! Should have figured you'd be the one to make that kind of pedantic reply. What the law says, as I read it, is that you can put up radio, TV, or satellite antennas on your own property, regardless of covenants, home owners association rules, or zoning ordinances. But, if the property isn't yours, or isn't available for your exclusive use, it is up to the owner (or controlling authority) to decide whether you may or may not. I'm neither interested in parsing individual sentences in a regulation (I hire a lawyer to do that for me) nor debating this guy's controlling status. As a landlord, I've been told that if I want to avoid a slew of legal fees and hassles, let the tenants put up their dishes as they wish as long as the placement is reasonable. As an observer, I notice that most every apartment complex I've observed follows that same guidance. I'll rephrase. The implication for a solution to the GPS antenna problem is fairly obvious 99.999% of the time. Put the dish up, strap on a GPS receiver and see what happens. Sheesh. John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com -- best little blog on the net! Tellico Plains, Occupied TN I like you ... you remind me of me when I was young and stupid. ___ 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] Antennas in apartments
If you have purchased, leased or rented property and there were CCR's included in the transaction and in those CCR's is buried a prohibition on outside antennas, you are out of luck. You entered into a contract and the CCR's are a part of that contract. In fact, the FCC has stated that in the case of CCR's prohibiting Ham Radio antennae, PRB-1 does NOT apply. That being said, I go for the age old approach that asking forgiveness is better than asking permission. Put up as small an antenna as you can, some are only 2-3 in diameter and tell the landlord, if he asks, the use is classified. 73, Dick, W1KSZ/7 -Original Message- From: Chuck Harris [EMAIL PROTECTED] Sent: Dec 17, 2007 11:43 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Antennas in apartments Neon John wrote: On Sun, 16 Dec 2007 22:57:49 -0800, Hal Murray [EMAIL PROTECTED] wrote: Talk to your building superintendent. Offer to provide NTP service to the whole complex if he will help you setup a GPS antenna. I can see it now. Duh, how's this NTP stuff gonna help me unstop the toilet in 23? :-) What do people who want satellite TV do? Federal law says that landlords cannot prohibit satellite TV dishes. Another one of those best laws money can buy. The implication for a solution to the GPS antenna problem is fairly obvious. I think you need to read the law a little bit more carefully! What the law says, as I read it, is that you can put up radio, TV, or satellite antennas on your own property, regardless of covenants, home owners association rules, or zoning ordinances. But, if the property isn't yours, or isn't available for your exclusive use, it is up to the owner (or controlling authority) to decide whether you may or may not. The FCC's website has a QA section where they specifically answer a question about putting up an antenna that extends beyond the apartment/townhouse deck into the air space. They say that the law only controls what is allowed within the confines of the deck, and not what is allowed in the air space beyond the deck. -Chuck ___ 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] Antennas in apartments
Neon John wrote: On Mon, 17 Dec 2007 13:43:41 -0500, Chuck Harris [EMAIL PROTECTED] wrote: Neon John wrote: Federal law says that landlords cannot prohibit satellite TV dishes. Another one of those best laws money can buy. The implication for a solution to the GPS antenna problem is fairly obvious. I think you need to read the law a little bit more carefully! Should have figured you'd be the one to make that kind of pedantic reply. Really? I wasn't aware that I had a reputation for being a pedant. What the law says, as I read it, is that you can put up radio, TV, or satellite antennas on your own property, regardless of covenants, home owners association rules, or zoning ordinances. But, if the property isn't yours, or isn't available for your exclusive use, it is up to the owner (or controlling authority) to decide whether you may or may not. I'm neither interested in parsing individual sentences in a regulation (I hire a lawyer to do that for me) nor debating this guy's controlling status. As a landlord, I've been told that if I want to avoid a slew of legal fees and hassles, let the tenants put up their dishes as they wish as long as the placement is reasonable. As an observer, I notice that most every apartment complex I've observed follows that same guidance. And I explained the bounds of reasonable. I cannot imagine why that would put you in a huff. I'll rephrase. The implication for a solution to the GPS antenna problem is fairly obvious 99.999% of the time. Put the dish up, strap on a GPS receiver and see what happens. Sheesh. I long ago tired of the petty rules and regulations the city folk foist onto each other. So I bought a farm and do pretty much as I please. -Chuck Harris ___ 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] Antennas in apartments
i thought of tha balcony option. The balcony as an overhang which effectively blots out the other half of ths sky not covered by the building. I cannot hang any antenna over the railing or on it(in my lease and enofrce;I asked), plus there are birds and squirrels which would get into it. Any other suggestions? You said I cannot hang any antenna over the railing or on it. Does that mean you can put things out there as long as they are not visible from the outside? Try it just inside/below the railing. Talk to your building superintendent. Offer to provide NTP service to the whole complex if he will help you setup a GPS antenna. What do people who want satellite TV do? I like the hide-it-in-a-bird-feeder suggestion. Are plants and bird feeders prohibited? -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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.
