Re: [time-nuts] No 1 PPS output on a Tbolt
Hi Of course the other option is to *finally* break down and buy a digital scope. They've been out there for 20 years now. Yes, I did indeed cross over to the dark side last week Bob On Feb 12, 2010, at 7:24 AM, Peter Vince wrote: Hi Robert, I put a dual-colour (red-green) LED in a BNC plug for just this sort of purpose. No series resistor - the 50-ohm source impedance limits the current nicely. With dual-colour, I can see both positive and negative pulses. 100ms pulses are perfect, 10ms OK, 1ms are very dim, but there is no chance of seeing the 10us pulses from the Thunderbolt. As others have said, I set the (analogue Tek 2445) 'scope to 10us/div, 2 volt/div, 50 ohms, DC positive edge trigger, and waggle the trigger level. The display is dim, but visible. A slightly slower scan would narrow and brighten the pulse on a tired tube. TTFN, Peter On 8 February 2010 15:15, Robert Darlington rdarling...@gmail.com wrote: Try hooking the output to an LED. It's very difficult for me to see the pulse on my analog scopes but there is no arguing with the blinking light. -Bob ___ 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] No 1 PPS output on a Tbolt
An easy way to see the 10 microsecond pulse On the Tbolt is to use a pulse stretcher. I Used this circuit on the 25 microsecond wide Pulse on the HP Z3801 to add a true 1 second pulse indication to the front panel and also output the pulse through a 51 ohm resistor to a BNC on the back panel. Reducing the value of the 1 megohm resistor and/or the .47 mfd capacitor will shorten the output pulsewidth and these values aren’t critical. schematic - http://farm3.static.flickr.com/2679/4351301462_7cd9625a97.jpg ___ 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] No 1 PPS output on a Tbolt
Hi Bob: I have been studying digital scopes for some time and have the Rigol DS1052E on the way. http://www.prc68.com/I/RigolDS1052E.shtml Rigol may make the low end scopes that are sold by Agilent. This model goes for a little over $400 and gets excellent reviews (links on the above web page). Have Fun, Brooke Clarke http://www.PRC68.com Bob Camp wrote: Hi Of course the other option is to *finally* break down and buy a digital scope. They've been out there for 20 years now. Yes, I did indeed cross over to the dark side last week Bob On Feb 12, 2010, at 7:24 AM, Peter Vince wrote: Hi Robert, I put a dual-colour (red-green) LED in a BNC plug for just this sort of purpose. No series resistor - the 50-ohm source impedance limits the current nicely. With dual-colour, I can see both positive and negative pulses. 100ms pulses are perfect, 10ms OK, 1ms are very dim, but there is no chance of seeing the 10us pulses from the Thunderbolt. As others have said, I set the (analogue Tek 2445) 'scope to 10us/div, 2 volt/div, 50 ohms, DC positive edge trigger, and waggle the trigger level. The display is dim, but visible. A slightly slower scan would narrow and brighten the pulse on a tired tube. TTFN, Peter On 8 February 2010 15:15, Robert Darlingtonrdarling...@gmail.com wrote: Try hooking the output to an LED. It's very difficult for me to see the pulse on my analog scopes but there is no arguing with the blinking light. -Bob ___ 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] No 1 PPS output on a Tbolt
I'm using a very bright blue LED and series resistor on the PPS output of my thunderbolt and it's quite visible. It's not bright by any means, but it is distracting to see out of the corner of my eye in the rack some days. I like the dual color LED idea and think I'll make a similar connector for this type of thing. Thanks. -Bob On Fri, Feb 12, 2010 at 5:24 AM, Peter Vince pvi...@theiet.org wrote: Hi Robert, I put a dual-colour (red-green) LED in a BNC plug for just this sort of purpose. No series resistor - the 50-ohm source impedance limits the current nicely. With dual-colour, I can see both positive and negative pulses. 100ms pulses are perfect, 10ms OK, 1ms are very dim, but there is no chance of seeing the 10us pulses from the Thunderbolt. As others have said, I set the (analogue Tek 2445) 'scope to 10us/div, 2 volt/div, 50 ohms, DC positive edge trigger, and waggle the trigger level. The display is dim, but visible. A slightly slower scan would narrow and brighten the pulse on a tired tube. TTFN, Peter On 8 February 2010 15:15, Robert Darlington rdarling...@gmail.com wrote: Try hooking the output to an LED. It's very difficult for me to see the pulse on my analog scopes but there is no arguing with the blinking light. -Bob ___ 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] No 1 PPS output on a Tbolt
I got a DS1052E a few months ago and I'm quite happy with it. It's great for looking at events like this thread has been discussing (although am I the only person who still owns a Radio Shack logic probe from the 70's which would work just fine for detecting 1PPS??). I won't be giving up my three analog Tek scopes anytime soon though. The DS1052E tends to be a bit noisy looking at low level signals, and anything over 50Mhzish pushes me back to the analogs. The user interface isn't always obvious, as it seems most buttons have multiple function and menus abound on this thing. But user interface problems seem to be common on lots of test equipment these days -- I wonder what kind of scope Steve Jobs would design :-) I find myself using it mostly as a kind of 2 channel analog logic analyzer, setting up a single capture from the trigger and studying what happened before and after the trigger. First use was looking at an I2C bus, not only to look at the data, but also the rise time of the signals. For the price it can't be beat, and it fills a diagnostic hole for me that I can't easily fill with the other equipment at my (hobbyist) disposal. Scott Brooke Clarke wrote: Hi Bob: I have been studying digital scopes for some time and have the Rigol DS1052E on the way. http://www.prc68.com/I/RigolDS1052E.shtml Rigol may make the low end scopes that are sold by Agilent. This model goes for a little over $400 and gets excellent reviews (links on the above web page). Have Fun, Brooke Clarke http://www.PRC68.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.
Re: [time-nuts] No 1 PPS output on a Tbolt
I use both a DS1052E and a couple of Tek scopes. I do like the DS1052E and think it offers great value at 25% the price of a comparable Tek. I love the long memory. The Teks still feel more solid (in an accuracy/reliability/usability sense). I noticed some trigger jitter on the DS1052E. Henry On Fri, Feb 12, 2010 at 9:14 AM, Scott Burris slbur...@gmail.com wrote: I got a DS1052E a few months ago and I'm quite happy with it. It's great for looking at events like this thread has been discussing (although am I the only person who still owns a Radio Shack logic probe from the 70's which would work just fine for detecting 1PPS??). I won't be giving up my three analog Tek scopes anytime soon though. The DS1052E tends to be a bit noisy looking at low level signals, and anything over 50Mhzish pushes me back to the analogs. The user interface isn't always obvious, as it seems most buttons have multiple function and menus abound on this thing. But user interface problems seem to be common on lots of test equipment these days -- I wonder what kind of scope Steve Jobs would design :-) I find myself using it mostly as a kind of 2 channel analog logic analyzer, setting up a single capture from the trigger and studying what happened before and after the trigger. First use was looking at an I2C bus, not only to look at the data, but also the rise time of the signals. For the price it can't be beat, and it fills a diagnostic hole for me that I can't easily fill with the other equipment at my (hobbyist) disposal. Scott Brooke Clarke wrote: Hi Bob: I have been studying digital scopes for some time and have the Rigol DS1052E on the way. http://www.prc68.com/I/RigolDS1052E.shtml Rigol may make the low end scopes that are sold by Agilent. This model goes for a little over $400 and gets excellent reviews (links on the above web page). Have Fun, Brooke Clarke http://www.PRC68.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. -- Henry Hallam Sent from my Laptop ___ 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] No 1 PPS output on a Tbolt
Hi I went with a used Tek TDS-380. I still live in a fantasy world where it's not a scope if it doesn't say Tek on it :) For a 15 year old scope the one I found seems to have pretty good performance. I've used them enough at work that I knew anything much under 300 MHz and 2 GS/s would drive me nuts. I must admit that my poor aching back put in a vote for one of the cute little LCD based scopes. Combining the LCD with the samples and bandwidth simply was way outside the budget. The debate went on for a month though . So far no complaints, but I'm not dumping any of the analog scopes quite yet. Bob On Feb 12, 2010, at 11:46 AM, Brooke Clarke wrote: Hi Bob: I have been studying digital scopes for some time and have the Rigol DS1052E on the way. http://www.prc68.com/I/RigolDS1052E.shtml Rigol may make the low end scopes that are sold by Agilent. This model goes for a little over $400 and gets excellent reviews (links on the above web page). Have Fun, Brooke Clarke http://www.PRC68.com Bob Camp wrote: Hi Of course the other option is to *finally* break down and buy a digital scope. They've been out there for 20 years now. Yes, I did indeed cross over to the dark side last week Bob On Feb 12, 2010, at 7:24 AM, Peter Vince wrote: Hi Robert, I put a dual-colour (red-green) LED in a BNC plug for just this sort of purpose. No series resistor - the 50-ohm source impedance limits the current nicely. With dual-colour, I can see both positive and negative pulses. 100ms pulses are perfect, 10ms OK, 1ms are very dim, but there is no chance of seeing the 10us pulses from the Thunderbolt. As others have said, I set the (analogue Tek 2445) 'scope to 10us/div, 2 volt/div, 50 ohms, DC positive edge trigger, and waggle the trigger level. The display is dim, but visible. A slightly slower scan would narrow and brighten the pulse on a tired tube. TTFN, Peter On 8 February 2010 15:15, Robert Darlingtonrdarling...@gmail.com wrote: Try hooking the output to an LED. It's very difficult for me to see the pulse on my analog scopes but there is no arguing with the blinking light. -Bob ___ 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] No 1 PPS output on a Tbolt
Hi Robert, I put a dual-colour (red-green) LED in a BNC plug for just this sort of purpose. No series resistor - the 50-ohm source impedance limits the current nicely. With dual-colour, I can see both positive and negative pulses. 100ms pulses are perfect, 10ms OK, 1ms are very dim, but there is no chance of seeing the 10us pulses from the Thunderbolt. As others have said, I set the (analogue Tek 2445) 'scope to 10us/div, 2 volt/div, 50 ohms, DC positive edge trigger, and waggle the trigger level. The display is dim, but visible. A slightly slower scan would narrow and brighten the pulse on a tired tube. TTFN, Peter On 8 February 2010 15:15, Robert Darlington rdarling...@gmail.com wrote: Try hooking the output to an LED. It's very difficult for me to see the pulse on my analog scopes but there is no arguing with the blinking light. -Bob ___ 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] No 1 PPS output on a Tbolt
Thank You John, I have tried with different sweep speeds both above and below 100 us/div, the problem appears to be no output at all. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: John Ackermann N8UR j...@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 8:45:06 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Sal, what sweep time are you using on the scope? I believe the TBolt PPS is only microseconds wide, so you may need to speed up the sweep time to around 100us/div or faster to see it accurately. And you may need to mess with delaying the sweep to get the pulse on the screen. John SAL CORNACCHIA said the following on 02/07/2010 08:32 PM: I cannot measure anything, with the scope set at max sensitivity, there is only a tiny dot indication every second. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 7:45:26 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox..net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
Try hooking the output to an LED. It's very difficult for me to see the pulse on my analog scopes but there is no arguing with the blinking light. -Bob On Mon, Feb 8, 2010 at 8:05 AM, SAL CORNACCHIA salc...@rogers.com wrote: Thank You John, I have tried with different sweep speeds both above and below 100 us/div, the problem appears to be no output at all. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: John Ackermann N8UR j...@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 8:45:06 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Sal, what sweep time are you using on the scope? I believe the TBolt PPS is only microseconds wide, so you may need to speed up the sweep time to around 100us/div or faster to see it accurately. And you may need to mess with delaying the sweep to get the pulse on the screen. John SAL CORNACCHIA said the following on 02/07/2010 08:32 PM: I cannot measure anything, with the scope set at max sensitivity, there is only a tiny dot indication every second. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 7:45:26 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox..net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo. .com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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
Re: [time-nuts] No 1 PPS output on a Tbolt
Thank You so much for all the great responses for the Tbolt 1 PPS measurements and suggestions how to measure the output of the 1 PPS, unfortunately I am not able to see any output at all, I will contact the seller and make arrangements for an exchange, he is away for about two weeks, I will wait and what he suggests to do. Thank You so much for all Your help, a great group of well informed peoples. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Robert Darlington rdarling...@gmail..com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Mon, February 8, 2010 10:15:32 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Try hooking the output to an LED. It's very difficult for me to see the pulse on my analog scopes but there is no arguing with the blinking light. -Bob On Mon, Feb 8, 2010 at 8:05 AM, SAL CORNACCHIA salc...@rogers.com wrote: Thank You John, I have tried with different sweep speeds both above and below 100 us/div, the problem appears to be no output at all. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: John Ackermann N8UR j...@febo.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 8:45:06 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Sal, what sweep time are you using on the scope? I believe the TBolt PPS is only microseconds wide, so you may need to speed up the sweep time to around 100us/div or faster to see it accurately. And you may need to mess with delaying the sweep to get the pulse on the screen. John SAL CORNACCHIA said the following on 02/07/2010 08:32 PM: I cannot measure anything, with the scope set at max sensitivity, there is only a tiny dot indication every second. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 7:45:26 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox..net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo. .com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE
[time-nuts] No 1 PPS output on a Tbolt
Make sure that the 1 PPS output is enabled... It can be turned off by software and that mode can be set in EEPROM. Also, many scopes have great difficulty showing a 10 uS pulse at a 1 PPS rep rate. Digital scopes might not sample it in normal display modes (envelope or glitch capture mode can help). It can easily get lost on an analog display... _ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. http://clk.atdmt.com/GBL/go/201469229/direct/01/ ___ 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] No 1 PPS output on a Tbolt
The 1PPS signal is actually quite strong. I would hook a telephone receiver or perhaps a little speaker to the 1PPS output and listen. The signal should make an audible click once per second. Joe Gwinn time-nuts-boun...@febo.com wrote on 02/08/2010 12:01:46 PM: From: Mark Sims hol...@hotmail.com To: time-nuts@febo.com Date: 02/08/2010 12:11 PM Subject: [time-nuts] No 1 PPS output on a Tbolt Sent by: time-nuts-boun...@febo.com Make sure that the 1 PPS output is enabled... It can be turned off by software and that mode can be set in EEPROM. Also, many scopes have great difficulty showing a 10 uS pulse at a 1 PPS rep rate. Digital scopes might not sample it in normal display modes (envelope or glitch capture mode can help). It can easily get lost on an analog display... _ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. http://clk.atdmt.com/GBL/go/201469229/direct/01/ ___ 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] No 1 PPS output on a Tbolt
Hi I keep an old fashion logic probe lying around for this sort of thing. If the light flashes, I have a signal. Much easier than a scope. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Joseph M Gwinn Sent: Monday, February 08, 2010 12:21 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The 1PPS signal is actually quite strong. I would hook a telephone receiver or perhaps a little speaker to the 1PPS output and listen. The signal should make an audible click once per second. Joe Gwinn time-nuts-boun...@febo.com wrote on 02/08/2010 12:01:46 PM: From: Mark Sims hol...@hotmail.com To: time-nuts@febo.com Date: 02/08/2010 12:11 PM Subject: [time-nuts] No 1 PPS output on a Tbolt Sent by: time-nuts-boun...@febo.com Make sure that the 1 PPS output is enabled... It can be turned off by software and that mode can be set in EEPROM. Also, many scopes have great difficulty showing a 10 uS pulse at a 1 PPS rep rate. Digital scopes might not sample it in normal display modes (envelope or glitch capture mode can help). It can easily get lost on an analog display... _ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. http://clk.atdmt.com/GBL/go/201469229/direct/01/ ___ 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] No 1 PPS output on a Tbolt
Can someone help with a Tbolt 35757256 built 6/2/05 A002206,G1 Rev E, I have built a power supply and acquired a GPS Antenna and got it assembled and appears to be working properly except for the 1 PPS output, (NO OUTPUT MEASURABLE) I would appreciate any help possible. Thank You, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) sure or other use is strictly prohibited. If you have received this notification in error, please immediately contact the sender and delete the material. From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sat, February 6, 2010 4:16:46 PM Subject: Re: [time-nuts] ADEV vs MDEV The tight PLL method doesn't directly produce the average frequency over Tau. As explained in (see snapshot of relevant section): NIST special Publication 1065 Handbook of Frequency Stability Analysis http://tf.nist.gov/timefreq/general/pdf/2220.pdf the average frequency deviations for averaging time Tau are needed for the calculation. You need to sample at a sufficiently high rate to avoid aliasing and average (ie integrate) the individual EFC samples. If one uses phase measures then the fluctuations in the frequency averages can easily and directly calculated from the difference between the phase measured at time intervals separated by Tau. Bruce WarrenS wrote: Bruce said: Thus NIST and others quietly dropped this method several decades ago. Could it be another reason? I'll bet that was after they wanted to do better than 1e14 resolution AND had unlimited amounts of time and Money, Something most time Nuts are not blessed with. I Never said it was the BEST way. JUST given the goal, which was 1e13 in one second, there is not a simpler and cheaper way to do it. And nothing you said counter that point. The frequency measures need to be integrated (either implicitly or explicitly) to produce phase measures which can then be used to calculate ADEV, MDEV etc. Well ONE of us certainly has something backward. To calculate ADEV, MDEV etc. YOU need Freq Differences. The first thing that happens when phase is used is that it is turned into Freq by taking the difference between each sample. Integrated Freq data, which is what Tight Phase-Lock Loop Method gives you directly (no Phase conversion needed), Need not FIRST turned into Phase so that it can then be turned back into Freq. BUT in any case there is no difference in the noise, for a given bandwidth, If you don't run out of digits and You have enough resolution. The Tight Phase-Lock Loop Method can EASY get sub pS resolution, which is better than most other ways. AND don't need filters and slue rate control and multistage limiters and on on to do it, an RC works fine to replace all the stuff. ws * - Original Message - From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, February 06, 2010 12:11 PM Subject: Re: [time-nuts] ADEV vs MDEV Sounds good but you still haven't found its Achilles heel: The frequency measures need to be integrated (either implicitly or explicitly) to produce phase measures which can then be used to calculate ADEV, MDEV etc. The major problem is that integration amplifies the small errors that are inevitably present.. In practice (except for very noisy sources) the technique isnt particularly useful for Tau more than a few times the inverse PLL bandwidth. Thus NIST and others quietly dropped this method several decades ago. This is alluded to in Steins recent paper availble on the Symmetricom website: *The Allan Variance – Challenges and Opportunities* Bruce WarrenS wrote: Peat said: I would appreciate any comments or observations on the topic of apparatus with demonstrated stability measurements. My motivation is to discover the SIMPLEST scheme for making stability measurements at the 1E-13 in 1s performance level. If you accept that the measurement is going to limited by the Reference Osc, for Low COST and SIMPLE, with the ability to measure ADEVs at that level, Can't beat a simple analog version of NIST's Tight Phase-Lock Loop Method of measuring Freq stability. http://tf.nist.gov/phase/Properties/one.htm#oneone Fig 1.7 By replacing the Voltage to freq converter, Freq counter Printer with a Radio shack type PC data logging DVM, It can be up and running from scratch in under an Hr, with no high end test equipment needed. If you want performance that exceeds the best of most DMTD at low Tau it takes a little more work and a higher speed oversampling ADC data logger and a good offset voltage. I must add this is not a popular solution (Or a general Purpose one) but IF you know analog and have a GOOD osc with EFC to use for the reference, as far as
Re: [time-nuts] No 1 PPS output on a Tbolt
Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
IIRC the pulse on the 1pps output of the TBolt is very narrow, so it is pretty easy to miss. You may need to use a pulse stretcher to see it. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of SAL CORNACCHIA Sent: 07 February 2010 15:45 To: Discussion of precise time and frequency measurement Subject: [time-nuts] No 1 PPS output on a Tbolt Can someone help with a Tbolt 35757256 built 6/2/05 A002206,G1 Rev E, I have built a power supply and acquired a GPS Antenna and got it assembled and appears to be working properly except for the 1 PPS output, (NO OUTPUT MEASURABLE) I would appreciate any help possible. Thank You, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) ___ 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] No 1 PPS output on a Tbolt
It is barely visable on the Tektronix 485. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) The information contained in this e-mail transmission is privileged and/or confidential intended solely for the exclusive use of the individual addressee. If you are not the intended addressee you are hereby notified that any retention, disclosure or other use is strictly prohibited. If you have received this notification in error, please immediately contact the sender and delete the material. From: David C. Partridge david.partri...@dsl.pipex.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:52:03 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt IIRC the pulse on the 1pps output of the TBolt is very narrow, so it is pretty easy to miss. You may need to use a pulse stretcher to see it. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of SAL CORNACCHIA Sent: 07 February 2010 15:45 To: Discussion of precise time and frequency measurement Subject: [time-nuts] No 1 PPS output on a Tbolt Can someone help with a Tbolt 35757256 built 6/2/05 A002206,G1 Rev E, I have built a power supply and acquired a GPS Antenna and got it assembled and appears to be working properly except for the 1 PPS output, (NO OUTPUT MEASURABLE) I would appreciate any help possible. Thank You, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) ___ 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] No 1 PPS output on a Tbolt
Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LE stanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIA salc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LE stanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Camp li...@cq.nu To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIA salc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LE stanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ time-nuts mailing list -- time-n...@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] No 1 PPS output on a Tbolt
The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIA salc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Camp li...@cq.nu To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIA salc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LE stanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ time-nuts mailing list -- time-n...@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] No 1 PPS output on a Tbolt
Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Juges did...@cox.net To: Time-Nuts time-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIA salc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Camp li...@cq.nu To: Discussion of precise time and frequency measurement time-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIA salc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LE stanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ time-nuts mailing list -- time-n...@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. ___ 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] No 1 PPS output on a Tbolt
Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox.net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
The PPS driver appears to use at least 3 inverters from a 74AC04 (U19) connected in parallel with a small series resistor between the parallled inverter outputs and the PPS connector. Open the case and check the waveforms at the 74AC04 inputs and outputs. Check the series resistor for continuity, also check the solder joint between the BNC inner conductor and the PCB. Bruce Bruce Griffiths wrote: Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox.net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
I cannot measure anything, with the scope set at max sensitivity, there is only a tiny dot indication every second. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 7:45:26 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox..net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
What is the best way to measure or to see any display at the 1 PPS BNC connector, unfortunately I don't have a digital oscilloscope. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 8:17:08 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The PPS driver appears to use at least 3 inverters from a 74AC04 (U19) connected in parallel with a small series resistor between the parallled inverter outputs and the PPS connector. Open the case and check the waveforms at the 74AC04 inputs and outputs. Check the series resistor for continuity, also check the solder joint between the BNC inner conductor and the PCB. Bruce Bruce Griffiths wrote: Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C.. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox.net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep.. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
Sal, what sweep time are you using on the scope? I believe the TBolt PPS is only microseconds wide, so you may need to speed up the sweep time to around 100us/div or faster to see it accurately. And you may need to mess with delaying the sweep to get the pulse on the screen. John SAL CORNACCHIA said the following on 02/07/2010 08:32 PM: I cannot measure anything, with the scope set at max sensitivity, there is only a tiny dot indication every second. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 7:45:26 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox..net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
The 10us wide PPS pulse from a thunderbolt shows up just fine on an analog scope. Using a traditional viewing hood (or equivalent) helps considerably if one doesnt have a dark room. Bruce SAL CORNACCHIA wrote: What is the best way to measure or to see any display at the 1 PPS BNC connector, unfortunately I don't have a digital oscilloscope. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bruce Griffithsbruce.griffi...@xtra.co.nz To: Discussion of precise time and frequency measurementtime-nuts@febo.com Sent: Sun, February 7, 2010 8:17:08 PM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The PPS driver appears to use at least 3 inverters from a 74AC04 (U19) connected in parallel with a small series resistor between the parallled inverter outputs and the PPS connector. Open the case and check the waveforms at the 74AC04 inputs and outputs. Check the series resistor for continuity, also check the solder joint between the BNC inner conductor and the PCB. Bruce Bruce Griffiths wrote: Any idea what the pulse shapes you see is with a 1M load and with a 50 ohm load? Bruce SAL CORNACCHIA wrote: Hi Didier, When the 50 ohms termination is switch on the oscilloscope there is a tiny positive dot deflecting every second, it appears to have a very low output. Best regards, Sal C.. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Didier Jugesdid...@cox.net To: Time-Nutstime-nuts@febo.com Sent: Sun, February 7, 2010 11:51:15 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt The pulse is narrow, but it should be a full 5V amplitude. The driver is pretty beefy, the amplitude does dot drop appreciably when loaded with 50 ohms on mine. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: SAL CORNACCHIAsalc...@rogers.com Date: Sun, 7 Feb 2010 08:42:49 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi Bob, The pulse is barely visible on the Tektronix 485 it appears to be a very low output. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Bob Campli...@cq.nu To: Discussion of precise time and frequency measurementtime-n...@febo..com Sent: Sun, February 7, 2010 11:26:16 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hi The 5345 should see it if it's set to 50 ohm termination and DC coupling.. A sweep of the trigger from about 1.5 to 3.5 volts should show it there over most of the sweep.. Bob -- From: SAL CORNACCHIAsalc...@rogers.com Sent: Sunday, February 07, 2010 11:06 AM To: Discussion of precise time and frequency measurement time-n...@febo..com Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Oscilloscope and 5345A Counter, the Tbolt software shows all green. Best regards, Sal C. Cornacchia Electronic RF Microwave Engineer (Ret.) From: Stan, W1LEstanw...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, February 7, 2010 10:47:42 AM Subject: Re: [time-nuts] No 1 PPS output on a Tbolt Hello Sal, What are you monitoring the PPS output with ?? It is a short duration pulse. What does the TboltMON software (available at the trimble website) show ? What does Lady Heather indicate ? (She is just waiting to massage your numbers.) Stan, W1LE ___ 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] No 1 PPS output on a Tbolt
John Ackermann N8UR wrote: Sal, what sweep time are you using on the scope? I believe the TBolt PPS is only microseconds wide, so you may need to speed up the sweep time to around 100us/div or faster to see it accurately. And you may need to mess with delaying the sweep to get the pulse on the screen. John You would need to delay the sweep by 0.99s to get the leading edge on screen if the internal scope vertical delay line is insufficient. With a sweep speed of 2us/div the entire pulse is clearly visible (even without a viewing hood and light from a window (overcast sky) falling directly on the screen) without any delayed sweep. NB trigger on the leading edge which has a positive slope. Bruce ___ 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] No 1 PPS output on a Tbolt
Sal wrote: The [PPS] pulse is barely visible on the Tektronix 485 it appears to be a very low output. The PPS output can be turned off. Are you sure it is turned on? (Check with Tboltmon or Lady Heather.) 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] No 1 PPS output on a Tbolt
HI A lot depends on just how tired the tube in your scope is. Some of these scopes have spent a lot of hours turned on and wearing out the filament The easy thing to do is to vary the trigger point and watch the trigger light. It should tell you if the pulse is there or not. If it's not, then either it's turned off or there's something keeping the electrons from getting to you (like a blown chip). Bob On Feb 7, 2010, at 8:56 PM, Bruce Griffiths wrote: John Ackermann N8UR wrote: Sal, what sweep time are you using on the scope? I believe the TBolt PPS is only microseconds wide, so you may need to speed up the sweep time to around 100us/div or faster to see it accurately. And you may need to mess with delaying the sweep to get the pulse on the screen. John You would need to delay the sweep by 0.99s to get the leading edge on screen if the internal scope vertical delay line is insufficient. With a sweep speed of 2us/div the entire pulse is clearly visible (even without a viewing hood and light from a window (overcast sky) falling directly on the screen) without any delayed sweep. NB trigger on the leading edge which has a positive slope. Bruce ___ 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] No 1 PPS output on a Tbolt
Here is a photo of the Tbolt 1 PPS pulse with 1 megohm load. With a 50 ohm load the output drops from 5.08 volt to 4.68 volt. 1 PPS pulse ___ 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] No 1 PPS output on a Tbolt
Ooops, try this link. 1 PPS pulse http://farm5.static.flickr.com/4013/4339027385_682e78a19e_o.jpg ___ 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] No 1 PPS output on a Tbolt
Sal: I agree with Bob's suggestion below. Set your trigger mode to normal rather than auto and use DC coupling, not AC. Set a slow sweep speed so it's easy to see (maybe 10ms per division). You should see a sweep every second. By varying the trigger level control you can get an idea of the pulse's voltage even if you can't see it. Ed Bob Camp wrote: HI A lot depends on just how tired the tube in your scope is. Some of these scopes have spent a lot of hours turned on and wearing out the filament The easy thing to do is to vary the trigger point and watch the trigger light. It should tell you if the pulse is there or not. If it's not, then either it's turned off or there's something keeping the electrons from getting to you (like a blown chip). Bob On Feb 7, 2010, at 8:56 PM, Bruce Griffiths wrote: John Ackermann N8UR wrote: Sal, what sweep time are you using on the scope? I believe the TBolt PPS is only microseconds wide, so you may need to speed up the sweep time to around 100us/div or faster to see it accurately. And you may need to mess with delaying the sweep to get the pulse on the screen. John You would need to delay the sweep by 0.99s to get the leading edge on screen if the internal scope vertical delay line is insufficient. With a sweep speed of 2us/div the entire pulse is clearly visible (even without a viewing hood and light from a window (overcast sky) falling directly on the screen) without any delayed sweep. NB trigger on the leading edge which has a positive slope. Bruce ___ 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.
