Re: [time-nuts] Hyperterminal with variable baud rate
A friend of mine had a need for a round 500Kbit baud rate. What he did was use some FDTI USB/RS232 chip. He could patch the timing values for an existing baud rate (300 baud or something else normally not used). I believe in the Windows registry. This way the (terminal) software can select the patched baud rate and it will in effect behave as the custom baud rate. Cheers, Joop ___ 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] DMTD for different input frequencies
On 11/14/2010 12:08 PM, Magnus Danielson wrote: In the first stage, the input signals is mixed by the average frequency (37 MHz in this case) causing the beat frequencies to become roughly the same (27 MHz in this case). The second stage would then act as as the normal offset local oscillator and beat-frequency mix-down. Magnus, I'm writing you directly because I want to avoid a nitpicking flame war or I agree with your math, but your nomenclature seems a bit confusing. The arithmetic mean or average is 27 Mhz. It seems that for the general case is the local oscillator is the arithmetic mean plus the lower frequency. You want to have high side injection for the low frequency and low side injection for the high frequency. I'd call the average frequency the intermediate frequency and define it as the arithmetic mean of the two frequencies of interest, because it literally is and because it conforms to common use for superheterodyne receivers. Likewise I'd call the injection the first local oscillator or first injection and define it as the intermediate frequency plus or minus the frequencies of interest for comparison. The normal DMTD oscillator could then be called the second local oscillator or second injection One side effect of this approach is that common mode variations on the oscillators being compared will either be enhanced or reduced because those effects are inverted in frequency for the lower frequency. I haven't run the math to prove this, but it looks like it'll be proportional to the ratio of their frequencies. I need to think more about the impact of variations between the first and second LOs. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] DMTD for different input frequencies
On 11/22/2010 7:22 AM, Oz, in DFW wrote: On 11/14/2010 12:08 PM, Magnus Danielson wrote: In the first stage, the input signals is mixed by the Magnus, I'm writing you directly because I want to avoid a nitpicking flame war Well, apparently I screwed up and didn't write you directly. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Hyperterminal with variable baud rate
On 11/18/2010 2:32 PM, Elio Corbolante wrote: From: Hal Murray hmur...@megapathdsl.net Are there any terminal programs out there that allow you to select rates other than the standard values? You can use the wonderful Tera Term (http://ttssh2.sourceforge.jp/): it accepts nonstandard values in the speed parameter. I verified it with an oscilloscope. _ Elio. PuTTY has a serial mode that does this as well. As long as the rate is 115200 divided by an integer, it works. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] FS700 schematic
Gentlemen, I know this one has been asked a few years before but I give it another try: Has anyone of you a Stanford Research FS700 schematic available that he can share with me? Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] FS700 schematic
I have the manual and a working FS700 now. Maybe able to copy several pages. Need to find a scanner for 11X14, and not sure when I can do that. What problem are you having and perhaps we should take this offline. Regards Paul. WB8TSL On Mon, Nov 22, 2010 at 10:00 AM, Ulrich Bangert df...@ulrich-bangert.dewrote: Gentlemen, I know this one has been asked a few years before but I give it another try: Has anyone of you a Stanford Research FS700 schematic available that he can share with me? Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] Changing frequency of an HP 10811 oscillator
Several issues here: 1. Making a precision crystal like the 10811 one is very involved. It cannot simply be rescaled to a different frequency. It represents a whole new design. This is not like ordering custom crystals for your 2 way radio (back in the day). 2. The 10.23 MHz crystals I am going to give away (as time permits :-) were designed under duress by the crystal designers who did not want any part of the operation. That's why I have a box of the crystals, since the project died. Expect a similar welcome from crystal vendors. 3. Many years ago, it may have made sense to have 10.23 MHz GPS time base oscillators. Nowaways, it is much easier to synthesize frequencies and you don't see this any more. Everthing starts with 10 MHz. 4. If you need 20. MHz, then use a doubler as others have noted. If you need some random frequency, use frequency synthesis. 5. The 10811 crystal is in a custom can, and you would have to kluge in any different crystal package. This would probably screw up the oven gain, necessitating rebalancing the heater transistors. Summary: (to use a technical term:) fuggedaboudit Rick Karlquist N6RK On 11/21/2010 10:32 AM, Demian Martin wrote: Having seen the note on alternate crystals for the HP10811 oscillator I was wondering if its realistically possible to re-crystal one to frequencies in the 20 MHz range? Some other components may need to be changed of course but is this worthwhile exploring? Who would be a good vendor for a few custom SC crystals that would work in an HP10811? I have been quoted prices in the $500+ range for finished products and want to explore a more cost effective option before I spend a lot of money. Demian Martin Product Design Services San Leandro, CA 94577 209 613 6990 ___ 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] FS700 schematic
Paul, You can do it in a common scanner in two parts, then using any graphics editor (i.e. Photoshop) rotate one of the files until they match and paste both. I do it routinelly with all my oversize schematics. Or just scan and let someone do the assembly (I can volunteer for some). Regards, Ignacio, EB4APL El 22/11/2010 17:37, paul swed wrote: I have the manual and a working FS700 now. Maybe able to copy several pages. Need to find a scanner for 11X14, and not sure when I can do that. What problem are you having and perhaps we should take this offline. Regards Paul. WB8TSL On Mon, Nov 22, 2010 at 10:00 AM, Ulrich Bangertdf...@ulrich-bangert.dewrote: Gentlemen, I know this one has been asked a few years before but I give it another try: Has anyone of you a Stanford Research FS700 schematic available that he can share with me? Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] Changing frequency of an HP 10811 oscillator
I have a 10.23 MHz 10811 oscillator out of an early GPS simulator somewhere, so, FWIW, HP did make at least one. I remember it because I was disappointed it was not 10.000 or 10.24 MHz. Best, -John = Several issues here: 1. Making a precision crystal like the 10811 one is very involved. It cannot simply be rescaled to a different frequency. It represents a whole new design. This is not like ordering custom crystals for your 2 way radio (back in the day). 2. The 10.23 MHz crystals I am going to give away (as time permits :-) were designed under duress by the crystal designers who did not want any part of the operation. That's why I have a box of the crystals, since the project died. Expect a similar welcome from crystal vendors. 3. Many years ago, it may have made sense to have 10.23 MHz GPS time base oscillators. Nowaways, it is much easier to synthesize frequencies and you don't see this any more. Everthing starts with 10 MHz. 4. If you need 20. MHz, then use a doubler as others have noted. If you need some random frequency, use frequency synthesis. 5. The 10811 crystal is in a custom can, and you would have to kluge in any different crystal package. This would probably screw up the oven gain, necessitating rebalancing the heater transistors. Summary: (to use a technical term:) fuggedaboudit Rick Karlquist N6RK On 11/21/2010 10:32 AM, Demian Martin wrote: Having seen the note on alternate crystals for the HP10811 oscillator I was wondering if its realistically possible to re-crystal one to frequencies in the 20 MHz range? Some other components may need to be changed of course but is this worthwhile exploring? Who would be a good vendor for a few custom SC crystals that would work in an HP10811? I have been quoted prices in the $500+ range for finished products and want to explore a more cost effective option before I spend a lot of money. Demian Martin Product Design Services San Leandro, CA 94577 209 613 6990 ___ 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] FS700 schematic
Paul, I just received an answer fom TVB. Before you engage in any kind of business concerning the copies let us wait whether Tom has the schematics. 73s de Ulrich, DF6JB -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von paul swed Gesendet: Montag, 22. November 2010 17:38 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] FS700 schematic I have the manual and a working FS700 now. Maybe able to copy several pages. Need to find a scanner for 11X14, and not sure when I can do that. What problem are you having and perhaps we should take this offline. Regards Paul. WB8TSL On Mon, Nov 22, 2010 at 10:00 AM, Ulrich Bangert df...@ulrich-bangert.dewrote: Gentlemen, I know this one has been asked a few years before but I give it another try: Has anyone of you a Stanford Research FS700 schematic available that he can share with me? Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] FS700 schematic
It is not just one page. What are you specifically looking for ? Most sheets are B size ( double A size). I got the complete manual from SRS for ~35$ Stan, W1LE On 11/22/2010 10:00 AM, Ulrich Bangert wrote: Gentlemen, I know this one has been asked a few years before but I give it another try: Has anyone of you a Stanford Research FS700 schematic available that he can share with me? Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] GPS jamming susceptibility
Given that this is an extremely sensitive topic and completely illegal also, let me just state at the outset that I have no interest in jamming anyone's GPS. A while back, I was looking at one of those Chinese discount electronics websites, I'm sure we all have, and noticed a GPS jammer for sale. I had been wanting to do some jamming susceptibility testing for quite some time but had never got around to building a generator to test with. The thing was cheap so I ordered it. After it arrived, I opened it up, first thing, to see how it was made. It has a dual 555 oscillator, a couple of analog switches, a 1.9 GHz VCO, a single amplifier. It doesn't look capable of putting out more than 50 milliwatts or so into a 2 inch antenna. I was somewhat dubious that it would do anything, so I took it to the bench where the Z3801 lives and turned it on. Within 2 seconds, the holdover LED lit. I immediately turned it off and within a few more seconds, the holdover LED was back off. The GPS antenna is perhaps 35 feet away with a cinder block wall, a brick wall, and a metal roof in between. I also put a 15 Db attenuator between it and the antenna with almost the same result. I am going to do more testing with it wired into the GPS downfeed an an adjustable attenuator in line just to see how much signal it takes. That way, there will be little danger of messing with anyone's reception. It is just a simple sweeper so it must do its job by brute force. I am amazed that it took so little to shut my Z3801 down. Has anyone here had any actual experience testing GPS receivers for susceptibility? ___ 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] FS700 schematic
My thats a reasonable answer indeed. On Mon, Nov 22, 2010 at 12:24 PM, Stan, W1LE stanw...@verizon.net wrote: It is not just one page. What are you specifically looking for ? Most sheets are B size ( double A size). I got the complete manual from SRS for ~35$ Stan, W1LE On 11/22/2010 10:00 AM, Ulrich Bangert wrote: Gentlemen, I know this one has been asked a few years before but I give it another try: Has anyone of you a Stanford Research FS700 schematic available that he can share with me? Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] FS700 schematic
Looked at the schematics front end is simple. Essentially op amps notch filters and most important electronic selectable attenuators. Any of it could cause issues. But the good news is a amplified loran signal is on the back of the unit so you could look to see whats happening to the signal. Oh other big point. If you are using something different then an active antennathat draws current. You need a 470 ohm resistor to ground at the antenna bnc.The system sense current being drawn both high and low. Regards Paul. On Mon, Nov 22, 2010 at 1:46 PM, paul swed paulsw...@gmail.com wrote: My thats a reasonable answer indeed. On Mon, Nov 22, 2010 at 12:24 PM, Stan, W1LE stanw...@verizon.net wrote: It is not just one page. What are you specifically looking for ? Most sheets are B size ( double A size). I got the complete manual from SRS for ~35$ Stan, W1LE On 11/22/2010 10:00 AM, Ulrich Bangert wrote: Gentlemen, I know this one has been asked a few years before but I give it another try: Has anyone of you a Stanford Research FS700 schematic available that he can share with me? Best regards Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] GPS jamming susceptibility
Hi There is *very* little signal hitting the ground from a normal GPS bird. Even a few mili watts close at hand is going to be an enormous overload. The typical GPS does not use a lot of bits in the front end A/D. I suspect that if you tuned your little gizmo down to the FM broadcast band, it would take out your favorite FM station quite nicely. Same would be true of your cell phone if you tuned it there. Jamming from close by isn't all that hard to figure out, or to implement. There are switching power supplies that make wonderful jammers for low frequency signals. If it's RF, it can be jammed. The real question is can you jam it from a reasonable distance? Bob On Nov 22, 2010, at 12:43 PM, John Green wrote: Given that this is an extremely sensitive topic and completely illegal also, let me just state at the outset that I have no interest in jamming anyone's GPS. A while back, I was looking at one of those Chinese discount electronics websites, I'm sure we all have, and noticed a GPS jammer for sale. I had been wanting to do some jamming susceptibility testing for quite some time but had never got around to building a generator to test with. The thing was cheap so I ordered it. After it arrived, I opened it up, first thing, to see how it was made. It has a dual 555 oscillator, a couple of analog switches, a 1.9 GHz VCO, a single amplifier. It doesn't look capable of putting out more than 50 milliwatts or so into a 2 inch antenna. I was somewhat dubious that it would do anything, so I took it to the bench where the Z3801 lives and turned it on. Within 2 seconds, the holdover LED lit. I immediately turned it off and within a few more seconds, the holdover LED was back off. The GPS antenna is perhaps 35 feet away with a cinder block wall, a brick wall, and a metal roof in between. I also put a 15 Db attenuator between it and the antenna with almost the same result. I am going to do more testing with it wired into the GPS downfeed an an adjustable attenuator in line just to see how much signal it takes. That way, there will be little danger of messing with anyone's reception. It is just a simple sweeper so it must do its job by brute force. I am amazed that it took so little to shut my Z3801 down. Has anyone here had any actual experience testing GPS receivers for susceptibility? ___ 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] GPS jamming susceptibility
On 11/23/2010 12:19 AM, Bob Camp wrote: Hi There is *very* little signal hitting the ground from a normal GPS bird. Even a few mili watts close at hand is going to be an enormous overload. The typical GPS does not use a lot of bits in the front end A/D. I suspect that if you tuned your little gizmo down to the FM broadcast band, it would take out your favorite FM station quite nicely. Same would be true of your cell phone if you tuned it there. Jamming from close by isn't all that hard to figure out, or to implement. There are switching power supplies that make wonderful jammers for low frequency signals. If it's RF, it can be jammed. The real question is can you jam it from a reasonable distance? There are a few reports and articles going into the susceptibility of civilian receivers to jammers. Some public texts have also been written, so the field is not completely covered only on green paper. A CW jammer will basically grab the AGC and as it gains down the CW the GPS reception is gained down with it. In particular 1-bit receivers is susceptable to this effect. 1,5-bit receivers with separate AGC detection was developed and was able to combat the CW jammer situation. The relative time when the code can control the bits quickly becomes just a fraction since a sine spends long times in the extremes far away from detection limits. Next thing to attack is lack of supression in the C/A code, and list of offset-frequencies which is more susceptible can be found. Noise jammers is also possible. Things like these alongside the weak signal makes civilian receivers quite sensitive, so quite a bit of line-of-sight distance can be jammed with a fairly low output. 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] GPS jamming susceptibility
The Phrack article's jammer attacks the offset frequencies. Phrack.org/issues.html?issue=60id=13 This article shows just how vulnerable L1 GPS is Scott Sent from my Verizon Wireless BlackBerry -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Tue, 23 Nov 2010 01:29:56 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] GPS jamming susceptibility On 11/23/2010 12:19 AM, Bob Camp wrote: Hi There is *very* little signal hitting the ground from a normal GPS bird. Even a few mili watts close at hand is going to be an enormous overload. The typical GPS does not use a lot of bits in the front end A/D. I suspect that if you tuned your little gizmo down to the FM broadcast band, it would take out your favorite FM station quite nicely. Same would be true of your cell phone if you tuned it there. Jamming from close by isn't all that hard to figure out, or to implement. There are switching power supplies that make wonderful jammers for low frequency signals. If it's RF, it can be jammed. The real question is can you jam it from a reasonable distance? There are a few reports and articles going into the susceptibility of civilian receivers to jammers. Some public texts have also been written, so the field is not completely covered only on green paper. A CW jammer will basically grab the AGC and as it gains down the CW the GPS reception is gained down with it. In particular 1-bit receivers is susceptable to this effect. 1,5-bit receivers with separate AGC detection was developed and was able to combat the CW jammer situation. The relative time when the code can control the bits quickly becomes just a fraction since a sine spends long times in the extremes far away from detection limits. Next thing to attack is lack of supression in the C/A code, and list of offset-frequencies which is more susceptible can be found. Noise jammers is also possible. Things like these alongside the weak signal makes civilian receivers quite sensitive, so quite a bit of line-of-sight distance can be jammed with a fairly low output. 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] GPS jamming susceptibility
Hi If you run through the article the author claims that he's getting a few hundred feet of range with a few hundred mw of power into a good antenna. Your cell phone and FM broadcast radio are equally susceptible under typical conditions. Bob On Nov 22, 2010, at 8:24 PM, scmcgr...@gmail.com wrote: The Phrack article's jammer attacks the offset frequencies. Phrack.org/issues.html?issue=60id=13 This article shows just how vulnerable L1 GPS is Scott Sent from my Verizon Wireless BlackBerry -Original Message- From: Magnus Danielson mag...@rubidium.dyndns.org Sender: time-nuts-boun...@febo.com Date: Tue, 23 Nov 2010 01:29:56 To: time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] GPS jamming susceptibility On 11/23/2010 12:19 AM, Bob Camp wrote: Hi There is *very* little signal hitting the ground from a normal GPS bird. Even a few mili watts close at hand is going to be an enormous overload. The typical GPS does not use a lot of bits in the front end A/D. I suspect that if you tuned your little gizmo down to the FM broadcast band, it would take out your favorite FM station quite nicely. Same would be true of your cell phone if you tuned it there. Jamming from close by isn't all that hard to figure out, or to implement. There are switching power supplies that make wonderful jammers for low frequency signals. If it's RF, it can be jammed. The real question is can you jam it from a reasonable distance? There are a few reports and articles going into the susceptibility of civilian receivers to jammers. Some public texts have also been written, so the field is not completely covered only on green paper. A CW jammer will basically grab the AGC and as it gains down the CW the GPS reception is gained down with it. In particular 1-bit receivers is susceptable to this effect. 1,5-bit receivers with separate AGC detection was developed and was able to combat the CW jammer situation. The relative time when the code can control the bits quickly becomes just a fraction since a sine spends long times in the extremes far away from detection limits. Next thing to attack is lack of supression in the C/A code, and list of offset-frequencies which is more susceptible can be found. Noise jammers is also possible. Things like these alongside the weak signal makes civilian receivers quite sensitive, so quite a bit of line-of-sight distance can be jammed with a fairly low output. 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] Hyperterminal with variable baud rate
On Thu, Nov 18, 2010 at 11:55 AM, Corby Dawson cdel...@juno.com wrote: Are there any terminal programs out there that allow you to select rates other than the standard values? https://sites.google.com/site/terminalbpp/ Select 'Custom'. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ ___ 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.
