Re: [time-nuts] Active antennas for a Thunderbolt...
My network analyzer test for the GPS antennae is approximate, of course, but nonetheless you can find out if the antenna is defective. Better to have a known good antenna handy to compare, when using this setup. I'm planning to build a frame (to hold the emitting antenna and the DUT) to find out if this test can give reliable results. On Tue, Jul 31, 2012 at 2:29 AM, Didier Juges shali...@gmail.com wrote: HP58532A The manual is on my web site Www. KO4BB.com/Manuals The Bullet antenna specs are also on my site. Didier Didier Steve stev...@suddenlink.net wrote: Didier, What is the model number of the Symmetricom antenna? Do you happen to know the difference in gain between it and the Trimble Bullet antenna? Steve K8JQ On 7/30/2012 2:46 PM, Didier Juges wrote: Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. ___ 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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] Active antennas for a Thunderbolt...
I already posted a picture of the Trimble antenna a few months back. To get to the active bits, you really have to fillet the antenna. Everything is boxed into tinplate channels. I haven't done that yet. -Chuck Harris Tom Miller wrote: Can you open them up and see how they are made and what they use for the gain device? Take lots of pictures :) ___ 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] Active antennas for a Thunderbolt...
Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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] Active antennas for a Thunderbolt...
Hi Chuck: See: http://www.prc68.com/I/ThunderBolt.shtml#Ant Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Chuck Harris wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. ___ 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] Active antennas for a Thunderbolt...
Hi Brooke, Lots of nice information, but I already have most of it. The question left unanswered is: Is it usually that hard to find a good working active antenna that works with the TB? Thus far, I have several hockey puck antennas that work fine... albeit a bit deafly, as would be expected.. and two bullet antennas that don't work at all. I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. Are a high percentage of the used bullet antennas dead? -Chuck Harris Brooke Clarke wrote: Hi Chuck: See: http://www.prc68.com/I/ThunderBolt.shtml#Ant Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html Chuck Harris wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. ___ 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] Active antennas for a Thunderbolt...
cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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] Active antennas for a Thunderbolt...
Have you any other GPS unit to test your antennae? You can test GPS antennae with a network analyzer or a spectrum analyzer with the tracking generator... yes, first you have to find one. On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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] Active antennas for a Thunderbolt...
On a window sill, my Motorola hockey pucks will get a useable satellite every few minutes, for a few minutes. If the antenna is out in the yard, it does much better, but all satellite signals are really low. The system would like another 10 or 20db of gain... which is what the Trimble bullet antenna would provide if it worked. The 50db Micro Pulse antena should have been ideal... if it worked Sigh! -Chuck Harris Hal Murray wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. ___ 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] Active antennas for a Thunderbolt...
Have you used Lady Heather to automatically set the Default settings? To allow the Tbolt to work with weak signals from any antenna that I've tried, even when indoors, I start by setting the TBolt's AMU level from the default of 4 down to 0. This can be done with the Tbolt S/W or LH. My general AMU setting goal is to make it low enough so that the TB is always using a minimum of three satellites. If the TB ever does goes into holdover, that should be fixed, because that will cause some serious freq offset noise at the TBolt's output, The usual holdover fix is to give the antenna a better view of the sky and/or lower the TBolts AMU setting. It is better to set the AMU too low which will allow it to use weak signals all the time than it is to set it too high and have No signals even for a short time. After lowering the AMU value, if you want to optimize the setting, LH has all kinds of tools to help, such as the sat signal strength plot. ws ** cfharris at erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. ___ 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] Active antennas for a Thunderbolt...
Once, I'd suspect a dead antenna. But twice? I wonder if your cable is bad? Or something else. Did you connect the working puck antenna to the end of the same cable you used for the bullet antennas? Are the bullet antenna designed for 5V (some want a lower voltage.) I'm using a 26dB bullet ant. mount on a long 1 diameter galvanized iron plumbing pipe. It has a 360 degree view of the horizon and works perfectly. But I think the location maters the more then the gain. If you could place your current ant. on a mast it would work better not only because of the beter view of the sky but reflections are deduced. On Mon, Jul 30, 2012 at 6:18 AM, Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. -- 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] Active antennas for a Thunderbolt...
I use one just like auction #180518378555. It is only 26dB but the thing is very reliable. It is a helix antenna inside and the mounting holes on the bottom line up with a standard iron pipe flange so mounting is easy. I filled the flang flat them glued autommotive type gaskit mmaterial to the pipe flange and attached the antenna with four stainless steel machine screws. The N type connector makes it waterproof, The rg-8 style cable is totally inside either the iron pipe or metal conduit so it should last forever. One idea: Possible the ultra-high gain antenna is over loading the GPS receiver. 50dB is very high Another idea: If you want gain buy an in-line ampler of the type made for satelite TV dishes. The specs are close enough that it will work and they are inexpensive. On Mon, Jul 30, 2012 at 8:41 AM, Chuck Harris cfhar...@erols.com wrote: On a window sill, my Motorola hockey pucks will get a useable satellite every few minutes, for a few minutes. If the antenna is out in the yard, it does much better, but all satellite signals are really low. The system would like another 10 or 20db of gain... which is what the Trimble bullet antenna would provide if it worked. The 50db Micro Pulse antena should have been ideal... if it worked Sigh! -Chuck Harris Hal Murray wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. ___ 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. -- 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] Active antennas for a Thunderbolt...
Hi Chris, I agree, once is just anomalous, but twice makes my debugging hat go on... especially when it is two different manufacture antennas. The first antenna is the exact antenna that Trimble recommends for the TB. It is a type 25045-10. Surely it should be compatible? The second antenna is a Micro Pulse 1934NW/C, 50dB model, designed for +3 to +35V, and to test that it was being fed properly, I put a BNC T right at the antenna, and measured +4.5V. In the course of testing I have used cables that came out of my test pool. They are short, and have been proven good. The Motorola hockey puck is about 20db of gain, and as such is a good 8dB less than the minimum recommended by Trimble. It works very well if it is out where it gets a clear view of the sky. It works ok sitting next to my window but nothing stellar. I plan to put it outside on my roof, but I am short of the needed round tuits for the near to immediate future. -Chuck Harris Chris Albertson wrote: Once, I'd suspect a dead antenna. But twice? I wonder if your cable is bad? Or something else. Did you connect the working puck antenna to the end of the same cable you used for the bullet antennas? Are the bullet antenna designed for 5V (some want a lower voltage.) I'm using a 26dB bullet ant. mount on a long 1 diameter galvanized iron plumbing pipe. It has a 360 degree view of the horizon and works perfectly. But I think the location maters the more then the gain. If you could place your current ant. on a mast it would work better not only because of the beter view of the sky but reflections are deduced. On Mon, Jul 30, 2012 at 6:18 AM, Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... ___ 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] Active antennas for a Thunderbolt...
Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] Active antennas for a Thunderbolt...
Hi; Is your coax 50 or 75 ohm? Is it microwave rated? and have you tried changing coax length? None of these should be a major factor but could make a difference. Best Wishes; Thomas Knox From: shali...@gmail.com Date: Mon, 30 Jul 2012 13:46:40 -0500 To: time-nuts@febo.com Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] Active antennas for a Thunderbolt...
My first Thunderbolt related GPS antenna was the mushroom model that came with my first kit from China. It had a length of 50 ohm rg58 attached. I added another 50 feet of rg6 to reach the Thunderbolt in my office. It worked fine but needed an amp to drive two Thunderbolts. I then bought one of the 40bd antennas that appeared on Ebay. I used some rg6 filched from the cable installer so I have enough downlead to raise the GPS antenna higher to get a better sky view. The 40db unit seems to be able to drive two Thunderbolts without an amp. Still need the amp if I want to see anything on a spectrum analyzer. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ 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] Active antennas for a Thunderbolt...
Hi Warren, I am not battling weak signals, I am battling no signals from two mushroom type antennas. -Chuck Harris WarrenS wrote: Have you used Lady Heather to automatically set the Default settings? To allow the Tbolt to work with weak signals from any antenna that I've tried, even when indoors, I start by setting the TBolt's AMU level from the default of 4 down to 0. This can be done with the Tbolt S/W or LH. My general AMU setting goal is to make it low enough so that the TB is always using a minimum of three satellites. If the TB ever does goes into holdover, that should be fixed, because that will cause some serious freq offset noise at the TBolt's output, The usual holdover fix is to give the antenna a better view of the sky and/or lower the TBolts AMU setting. It is better to set the AMU too low which will allow it to use weak signals all the time than it is to set it too high and have No signals even for a short time. After lowering the AMU value, if you want to optimize the setting, LH has all kinds of tools to help, such as the sat signal strength plot. ws ** cfharris at erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. ___ 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] Active antennas for a Thunderbolt...
Hi Azelio, How would you use a network analyzer to test an active antenna like these? I have the ANA, but I am not sure how to couple the input to the antenna effectively. -Chuck Harris Azelio Boriani wrote: Have you any other GPS unit to test your antennae? You can test GPS antennae with a network analyzer or a spectrum analyzer with the tracking generator... yes, first you have to find one. On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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] Active antennas for a Thunderbolt...
Quad RG6, under 10 feet. And RG223 under 10 feet. -Chuck Harris Tom Knox wrote: Hi; Is your coax 50 or 75 ohm? Is it microwave rated? and have you tried changing coax length? None of these should be a major factor but could make a difference. Best Wishes; Thomas Knox ___ 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] Active antennas for a Thunderbolt...
Hi Didier, I don't quite know what to say about that. Trimble seems to think that bullet antenna is the right thing to use. Somehow, I would think they should know. It is possible that they are prone to failure, I guess... It is surprising to me that the only antenna I can get to work is a Motorola puck that is supposed to be too low gain (and is). -Chuck Harris Didier Juges wrote: Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB ___ 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] Active antennas for a Thunderbolt...
On 7/30/2012 6:39 PM, Chris Albertson wrote: I use one just like auction #180518378555. It is only 26dB but the thing is very reliable. It is a helix antenna inside and the mounting holes on the bottom line up with a standard iron pipe flange so mounting is easy. That's exactly the same antenna I use with my Thunderbolt. It is mounted on top of the roof, with a 360 degrees view of the sky and LH reports signal strengths usually in excess of 40 dBc. About 25 meters of TV Sat cable. 73 Alberto I2PHD ___ 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] Active antennas for a Thunderbolt...
I use a small power supply to feed the antenna (use a bias tee) and a DC block for the analyzer input. I have made a quadrifilar helix for the analyzer output. Set a suitable frequency range (1400-1700) and test. Yes, I have (at work) an analyzer with the S-parameter test set, so that no directional coupler and no problems, moreover I have new antennae to test to make comparisons but the results are clearly visible and you can recognize a defective antenna. Usually customers send in questionable antennae and we can tell weather or not they are really unusable: lightning is the killer. On Mon, Jul 30, 2012 at 9:54 PM, Chuck Harris cfhar...@erols.com wrote: Hi Azelio, How would you use a network analyzer to test an active antenna like these? I have the ANA, but I am not sure how to couple the input to the antenna effectively. -Chuck Harris Azelio Boriani wrote: Have you any other GPS unit to test your antennae? You can test GPS antennae with a network analyzer or a spectrum analyzer with the tracking generator... yes, first you have to find one. On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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] Active antennas for a Thunderbolt...
Can you open them up and see how they are made and what they use for the gain device? Take lots of pictures :) - Original Message - From: Chuck Harris cfhar...@erols.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, July 30, 2012 4:07 PM Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Hi Didier, I don't quite know what to say about that. Trimble seems to think that bullet antenna is the right thing to use. Somehow, I would think they should know. It is possible that they are prone to failure, I guess... It is surprising to me that the only antenna I can get to work is a Motorola puck that is supposed to be too low gain (and is). -Chuck Harris Didier Juges wrote: Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB ___ 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] Active antennas for a Thunderbolt...
Chuck, I have seen already intermittent antenna receptacle on the back of the TB, also chk all coax connectors for solid contact. Rgds Ernie. -Original Message- From: Chuck Harris cfhar...@erols.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, Jul 30, 2012 9:52 pm Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Hi Warren, I am not battling weak signals, I am battling no signals from wo mushroom type antennas. -Chuck Harris WarrenS wrote: Have you used Lady Heather to automatically set the Default settings? To allow the Tbolt to work with weak signals from any antenna that I've tried, ven when indoors, I start by setting the TBolt's AMU level from the default of 4 down to 0. This can be done with the Tbolt S/W or LH. My general AMU setting goal is to make it low enough so that the TB is always sing a minimum of three satellites. If the TB ever does goes into holdover, that should be fixed, because that ill cause some serious freq offset noise at the TBolt's output, The usual holdover fix is to give the antenna a better view of the sky and/or ower the TBolts AMU setting. It is better to set the AMU too low which will allow it to use weak signals ll the time than it is to set it too high and have No signals even for a short time. After lowering the AMU value, if you want to optimize the setting, LH has all inds of tools to help, such as the sat signal strength plot. ws ** cfharris at erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. ___ 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. ___ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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] Active antennas for a Thunderbolt...
Chuck wrote: I don't quite know what to say about that. Trimble seems to think that bullet antenna is the right thing to use. Somehow, I would think they should know. I normally use a choke-ring survey antenna, but I also have a Trimble Bullet III, P/N 41556-00 (RoHS version is P/N 57860-10) -- which is the antenna that Trimble recommended for use with the Thunderbolt. IME, at 35-40 north latitude it works OK indoors (with a plaster ceiling and asphalt tile over wood roof between it and the outside), and flawlessly out in the semi-open (some trees closer than you'd like) with 100 feet of good 75-ohm coax (most birds have a c/n of 48 dB or more). A Symmetricom cone timing antenna works pretty much the same, with about 2 dB lower c/n. Best regards, Charles ___ 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] Active antennas for a Thunderbolt...
Hi: What is the GPS bandwidth at 1575.42 MHz? For a band-pass filter / amplifier would a Butterworth response be acceptable? Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Monday, July 30, 2012 1:17 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Active antennas for a Thunderbolt... I use a small power supply to feed the antenna (use a bias tee) and a DC block for the analyzer input. I have made a quadrifilar helix for the analyzer output. Set a suitable frequency range (1400-1700) and test. Yes, I have (at work) an analyzer with the S-parameter test set, so that no directional coupler and no problems, moreover I have new antennae to test to make comparisons but the results are clearly visible and you can recognize a defective antenna. Usually customers send in questionable antennae and we can tell weather or not they are really unusable: lightning is the killer. On Mon, Jul 30, 2012 at 9:54 PM, Chuck Harris cfhar...@erols.com wrote: Hi Azelio, How would you use a network analyzer to test an active antenna like these? I have the ANA, but I am not sure how to couple the input to the antenna effectively. -Chuck Harris Azelio Boriani wrote: Have you any other GPS unit to test your antennae? You can test GPS antennae with a network analyzer or a spectrum analyzer with the tracking generator... yes, first you have to find one. On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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] Active antennas for a Thunderbolt...
Ok, that's about what I thought you would do. Since it isn't in a controlled antenna farm, you get a functionality test, with an approximate example of the gain. Thanks! -Chuck Harris OBTW, any luck fixing bad antennas? Azelio Boriani wrote: I use a small power supply to feed the antenna (use a bias tee) and a DC block for the analyzer input. I have made a quadrifilar helix for the analyzer output. Set a suitable frequency range (1400-1700) and test. Yes, I have (at work) an analyzer with the S-parameter test set, so that no directional coupler and no problems, moreover I have new antennae to test to make comparisons but the results are clearly visible and you can recognize a defective antenna. Usually customers send in questionable antennae and we can tell weather or not they are really unusable: lightning is the killer. On Mon, Jul 30, 2012 at 9:54 PM, Chuck Harris cfhar...@erols.com wrote: ___ 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] Active antennas for a Thunderbolt...
Are you considering lumped components? At that frequency, you really need to be doing a stripline design. There are also COTS SAW filters. I have this US Navy GPS active antenna with integral SAW filter, but never got around to using it due to the 4.3VDC spec. A separate power supply, DC insert and DC block is kind of clumsy. I have considered a series diode to take 5V down to what the active antenna requires, but I don't know how well that would work. -Original Message- From: Ron Ward n6idl...@comcast.net Sender: time-nuts-boun...@febo.com Date: Mon, 30 Jul 2012 16:32:46 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Hi: What is the GPS bandwidth at 1575.42 MHz? For a band-pass filter / amplifier would a Butterworth response be acceptable? Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Monday, July 30, 2012 1:17 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Active antennas for a Thunderbolt... I use a small power supply to feed the antenna (use a bias tee) and a DC block for the analyzer input. I have made a quadrifilar helix for the analyzer output. Set a suitable frequency range (1400-1700) and test. Yes, I have (at work) an analyzer with the S-parameter test set, so that no directional coupler and no problems, moreover I have new antennae to test to make comparisons but the results are clearly visible and you can recognize a defective antenna. Usually customers send in questionable antennae and we can tell weather or not they are really unusable: lightning is the killer. On Mon, Jul 30, 2012 at 9:54 PM, Chuck Harris cfhar...@erols.com wrote: Hi Azelio, How would you use a network analyzer to test an active antenna like these? I have the ANA, but I am not sure how to couple the input to the antenna effectively. -Chuck Harris Azelio Boriani wrote: Have you any other GPS unit to test your antennae? You can test GPS antennae with a network analyzer or a spectrum analyzer with the tracking generator... yes, first you have to find one. On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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. ___ 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] Active antennas for a Thunderbolt...
The coax is actually 50 feet of good quality 75 ohm cable that I bought for this (rated for satellite TV). I have not measured the loss accurately but I did check it at 2GHz when I bought it and it was good. Didier Tom Knox act...@hotmail.com wrote: Hi; Is your coax 50 or 75 ohm? Is it microwave rated? and have you tried changing coax length? None of these should be a major factor but could make a difference. Best Wishes; Thomas Knox From: shali...@gmail.com Date: Mon, 30 Jul 2012 13:46:40 -0500 To: time-nuts@febo.com Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] Active antennas for a Thunderbolt...
Put a capacitor across the diode. 0.01 uF should be fine. - Original Message - From: li...@lazygranch.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, July 30, 2012 7:58 PM Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Are you considering lumped components? At that frequency, you really need to be doing a stripline design. There are also COTS SAW filters. I have this US Navy GPS active antenna with integral SAW filter, but never got around to using it due to the 4.3VDC spec. A separate power supply, DC insert and DC block is kind of clumsy. I have considered a series diode to take 5V down to what the active antenna requires, but I don't know how well that would work. -Original Message- From: Ron Ward n6idl...@comcast.net Sender: time-nuts-boun...@febo.com Date: Mon, 30 Jul 2012 16:32:46 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Hi: What is the GPS bandwidth at 1575.42 MHz? For a band-pass filter / amplifier would a Butterworth response be acceptable? Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Monday, July 30, 2012 1:17 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Active antennas for a Thunderbolt... I use a small power supply to feed the antenna (use a bias tee) and a DC block for the analyzer input. I have made a quadrifilar helix for the analyzer output. Set a suitable frequency range (1400-1700) and test. Yes, I have (at work) an analyzer with the S-parameter test set, so that no directional coupler and no problems, moreover I have new antennae to test to make comparisons but the results are clearly visible and you can recognize a defective antenna. Usually customers send in questionable antennae and we can tell weather or not they are really unusable: lightning is the killer. On Mon, Jul 30, 2012 at 9:54 PM, Chuck Harris cfhar...@erols.com wrote: Hi Azelio, How would you use a network analyzer to test an active antenna like these? I have the ANA, but I am not sure how to couple the input to the antenna effectively. -Chuck Harris Azelio Boriani wrote: Have you any other GPS unit to test your antennae? You can test GPS antennae with a network analyzer or a spectrum analyzer with the tracking generator... yes, first you have to find one. On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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. ___ 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] Active antennas for a Thunderbolt...
Didier, What is the model number of the Symmetricom antenna? Do you happen to know the difference in gain between it and the Trimble Bullet antenna? Steve K8JQ On 7/30/2012 2:46 PM, Didier Juges wrote: Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. ___ 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] Active antennas for a Thunderbolt...
I was wondering if I go for a signal diode (presumably low inductance but also low capacitance) or a beefy power diode with a hunk of capacitance. I suppose a signal diode and chip cap is the best solution. -Original Message- From: Tom Miller tmil...@skylinenet.net Date: Mon, 30 Jul 2012 20:06:01 To: li...@lazygranch.com; Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-to: Tom Miller tmil...@skylinenet.net Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Put a capacitor across the diode. 0.01 uF should be fine. - Original Message - From: li...@lazygranch.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, July 30, 2012 7:58 PM Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Are you considering lumped components? At that frequency, you really need to be doing a stripline design. There are also COTS SAW filters. I have this US Navy GPS active antenna with integral SAW filter, but never got around to using it due to the 4.3VDC spec. A separate power supply, DC insert and DC block is kind of clumsy. I have considered a series diode to take 5V down to what the active antenna requires, but I don't know how well that would work. -Original Message- From: Ron Ward n6idl...@comcast.net Sender: time-nuts-boun...@febo.com Date: Mon, 30 Jul 2012 16:32:46 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Active antennas for a Thunderbolt... Hi: What is the GPS bandwidth at 1575.42 MHz? For a band-pass filter / amplifier would a Butterworth response be acceptable? Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Monday, July 30, 2012 1:17 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Active antennas for a Thunderbolt... I use a small power supply to feed the antenna (use a bias tee) and a DC block for the analyzer input. I have made a quadrifilar helix for the analyzer output. Set a suitable frequency range (1400-1700) and test. Yes, I have (at work) an analyzer with the S-parameter test set, so that no directional coupler and no problems, moreover I have new antennae to test to make comparisons but the results are clearly visible and you can recognize a defective antenna. Usually customers send in questionable antennae and we can tell weather or not they are really unusable: lightning is the killer. On Mon, Jul 30, 2012 at 9:54 PM, Chuck Harris cfhar...@erols.com wrote: Hi Azelio, How would you use a network analyzer to test an active antenna like these? I have the ANA, but I am not sure how to couple the input to the antenna effectively. -Chuck Harris Azelio Boriani wrote: Have you any other GPS unit to test your antennae? You can test GPS antennae with a network analyzer or a spectrum analyzer with the tracking generator... yes, first you have to find one. On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote: cfhar...@erols.com said: I suspect that I have just had the bad luck to buy two bad antennas, but I am naturally curious what happens when the sample set gets larger. I have 2 TBolts using the small Motorola antenna from TAPR in a not-good location. The sheet says 24 dB of gain. I have 6 or 9 or ?? feet of RG-6. They work as expected, that is they work, but not well. The holdover logic gets tested frequently and surveys take a long time. But they do work. -- These are my opinions. 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. ___ 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] Active antennas for a Thunderbolt...
Chuck I have 3 TBs here at the moment. The other two were group buys, therefore more recent than the red box. The two group buys use magnet puck antennas. One is a Trimble (small but heavy, all metal, looks well made) the other a no name Chinese model. Both are inside the house in my upstairs shop and seldom go in holdover but do so on occasion. I have bought a splitter to put everybody on the good Symmetricom but have not gotten roundtuit yet. Didier Chuck Harris cfhar...@erols.com wrote: Hi Didier, I don't quite know what to say about that. Trimble seems to think that bullet antenna is the right thing to use. Somehow, I would think they should know. It is possible that they are prone to failure, I guess... It is surprising to me that the only antenna I can get to work is a Motorola puck that is supposed to be too low gain (and is). -Chuck Harris Didier Juges wrote: Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB ___ 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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] Active antennas for a Thunderbolt...
Looks like my bullet might be bad.. . Didier Charles P. Steinmetz charles_steinm...@lavabit.com wrote: Chuck wrote: I don't quite know what to say about that. Trimble seems to think that bullet antenna is the right thing to use. Somehow, I would think they should know. I normally use a choke-ring survey antenna, but I also have a Trimble Bullet III, P/N 41556-00 (RoHS version is P/N 57860-10) -- which is the antenna that Trimble recommended for use with the Thunderbolt. IME, at 35-40 north latitude it works OK indoors (with a plaster ceiling and asphalt tile over wood roof between it and the outside), and flawlessly out in the semi-open (some trees closer than you'd like) with 100 feet of good 75-ohm coax (most birds have a c/n of 48 dB or more). A Symmetricom cone timing antenna works pretty much the same, with about 2 dB lower c/n. Best regards, Charles ___ 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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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] Active antennas for a Thunderbolt...
HP58532A The manual is on my web site Www. KO4BB.com/Manuals The Bullet antenna specs are also on my site. Didier Didier Steve stev...@suddenlink.net wrote: Didier, What is the model number of the Symmetricom antenna? Do you happen to know the difference in gain between it and the Trimble Bullet antenna? Steve K8JQ On 7/30/2012 2:46 PM, Didier Juges wrote: Chuck, I have one of the original red box TB. It came with the Trimble Bullet antenna that is specified in the TB datasheet. The antenna works but gives extremely poor results. The TB works much better with the Symmetricom antenna that is sometimes available on eBay. The Bullet antenna is usable with other GPS receivers, so I know it is not bad. Its just a poor match for the TB. Didier KO4BB Chuck Harris cfhar...@erols.com wrote: Ok, I'm getting a little puzzled. I have a TB that came from one of the early groups sold by John Ackermann and TVB as part of the TAPR buy. It works nicely, but like all TB's, it is deaf as a post, and needs a high gain antenna When I first got the TB, I tried it with a Motorola hockey puck antenna, with about 17db gain, and if it is outside in the clear, it works nicely... but LH shows the satellites signals are all down in the mud. ...So... I bought the active antenna that the TB data sheet said belonged with the TB, a 24045-10 bullet antenna, and *NO* satellites are visible.. the antenna is dead. I'm no stranger to getting cheated on things I buy, so I chalked it up to bad luck, and put my Motorola hockey puck antenna back on my TB. ...Then A couple of days ago another active antenna became available, a Micro Pulse 1934NW/C 50db antenna from a DATUM INC GPSDO. I checked its data sheet, and it powers off of +5V @ 38ma, so I bought it, hooked it up to my TB, and again *NO* satellites are visible... the antenna is dead. I put a T in the line, and the voltage heading up to the antenna is around +4.5V... The spec sheet says it will work down to +3V. Am I doing something wrong here? Or am I just unlucky? -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. ___ 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. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. ___ 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.
