Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
I have found that a piezo sounder, a ceramic disk with two leads for making beepers works quite well for very short pulses. For a very short period charge flows into this device, which is a capacitor, and for that duration its dimensions are changed, and when it reverts to its original state the seismic disturbances echo around the device making a very clear click. cheers, Neville Michie > On 21 Apr 2020, at 12:25, Taka Kamiya via time-nuts > wrote: > > Maybe everyone but I knew, but I just did this and found it useful. > 1 pps signal from some GPS are notoriously narrow and difficult to sync on > and see on scopes. LED will barely light if some kind of stretcher is not > used. If your purpose is ONLY to see if it's there or not, hook up a small > speaker, earphone, amplified or not, and you can hear the tick-tick sound. > > I like DIYing and many times, I wonder if pps distribution circuit is > working. I can tell a very short pulse that will barely register on LED is > clearly audible. > I thought I'd share. > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] What to do with your dead cesium
Well if anyone has the DC-DC converter from PRS50 that they've broken for spares I'd be similarly very interested On Tue, 21 Apr 2020, 22:22 Bob kb8tq, wrote: > Hi > > I figured it wouldn’t hurt to ask. > > Who knows, maybe all this talk has somebody else sending the > innards of one off to oblivion. > > Bob > > > On Apr 21, 2020, at 5:02 PM, ed breya wrote: > > > > Sorry Bob, but in my case, it was long ago, and the few unnecessary > 5065A boards are long gone. The carcass I got had no Rb tube, and a number > of boards/modules were missing. I kept the power supply guts for redesign, > the front panel ass'y, digital clock, mechanical parts, and a few odds and > ends for their reincarnation as a new box. > > > > Ed > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] What to do with your dead cesium
Hi I figured it wouldn’t hurt to ask. Who knows, maybe all this talk has somebody else sending the innards of one off to oblivion. Bob > On Apr 21, 2020, at 5:02 PM, ed breya wrote: > > Sorry Bob, but in my case, it was long ago, and the few unnecessary 5065A > boards are long gone. The carcass I got had no Rb tube, and a number of > boards/modules were missing. I kept the power supply guts for redesign, the > front panel ass'y, digital clock, mechanical parts, and a few odds and ends > for their reincarnation as a new box. > > Ed > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] What to do with your dead cesium
Sorry Bob, but in my case, it was long ago, and the few unnecessary 5065A boards are long gone. The carcass I got had no Rb tube, and a number of boards/modules were missing. I kept the power supply guts for redesign, the front panel ass'y, digital clock, mechanical parts, and a few odds and ends for their reincarnation as a new box. Ed ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] What to do with your dead cesium
Hi If people are scrapping out 5065’s there just *might* be a few of us interested in the various boards and modules that now are surplus to the “new” use. Contact me off list. I’ll gladly pay shipping. Bob > On Apr 21, 2020, at 3:48 PM, ed breya wrote: > > I did a similar thing with an HP5065A carcass, by repackaging the guts of a > Z3801A inside. Actually, I should say doing, rather than did - I started this > over ten years ago, getting only to the point where the Z3801A was functional > again. All the bells and whistles are in various states of (in)completion. > Once a year or so, I get busy on it for a while, advancing it closer to the > end. Maybe only another ten years. Who knows? > > Old equipment carcasses of all sorts make great foundations for building new > stuff. > > Ed > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] What to do with your dead cesium
I did a similar thing with an HP5065A carcass, by repackaging the guts of a Z3801A inside. Actually, I should say doing, rather than did - I started this over ten years ago, getting only to the point where the Z3801A was functional again. All the bells and whistles are in various states of (in)completion. Once a year or so, I get busy on it for a while, advancing it closer to the end. Maybe only another ten years. Who knows? Old equipment carcasses of all sorts make great foundations for building new stuff. Ed ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] What to do with your dead cesium
beautiful. we should create a compendium: '101 uses for a dead cesium' On Mon, Apr 20, 2020 at 9:50 PM Skip Withrow wrote: > Hello Time-Nuts, > Well, with the COVID-19 stay at home order I have been working on a > couple of projects (at home). > > This post shows what I have done with an old FEI FE-5440A cesium > standard. The tube was dead, so I decided to turn it into a GPSDO. I > ripped out the tube, HV supplies, modulator, and OCXO. The battery > was already missing, so it was replaced with a couple of SLA units. I > decided to use a TruePosition GPSDO since it was small (I just wish it > had a LOCK indicator). An SMA antenna connector was added to the rear > panel. > > Basically, the 10MHz from the GPSDO feeds the distribution system in > the FE-5440A. The TruePosition 1pps was brought out to the front > panel, and can be used to synchronize the clock in the unit. An > RS-232 DB-9 was put in place of the C-field control so Lady Heather > can monitor. > > Some of the nice features are: > 10MHz, 1Mhz, 100kHz, 1pps, and 1ppm front panel BNC outputs. > Front panel clock display (that is easily set from the front panel) > 1pps (FE-5440A) can be offset from 0-1 sec in 100ns steps from the > TruePosition 1pps > Battery backup (greater than 2 hours) and DC input, as well as AC input > > I don't know about the phase noise performance, but ADEV is probably > better than the original standard (as long as there is a GPS antenna > connected). > > I have attached a couple of pictures of the unit plus a 5-day TimeLab plot. > > Regards, > Skip Withrow > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > -- Dave Mallery, K5EN (ubuntu linux 19-04) 80018 Lobo CP Grants, NM 87020 linux counter #64628 (since 1997) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
Hi, 20us length is a mil standard. Described in ICD-GPS-060. /Björn Sent from my iPhone > On 21 Apr 2020, at 13:37, Bob kb8tq wrote: > > Hi > > One of the simplest justifications I can think of for a dirt cheap “Chinese” > digital ’scope is to capture short burst stuff like narrow pps pulses. > > 10 us / non-adjustable is a *very* common spec for a 1 PPS. > > Bob > >> On Apr 21, 2020, at 4:56 AM, Chris Burford wrote: >> >> I reached out to SRS several months ago to inquire if the pulse width could >> be configured from the default of 10 micro second. Their responses was no. >> >> Chris >> >> -Original Message- >> From: time-nuts On Behalf Of Taka Kamiya >> via time-nuts >> Sent: Monday, April 20, 2020 22:35 >> To: Discussion of precise time and frequency measurement >> >> Cc: Taka Kamiya >> Subject: Re: [time-nuts] Using speaker / earphone for PPS testing (not a >> question) >> >> Out of all signal source, the shortest 1 pps is PRS-10 at 10 micro second. >> T-bolt is quite short as well but I don't have a definite data. >> For those, speaker method worked just fine. I'm just sharing what I learned >> on happenstance. >> >> --- >> (Mr.) Taka Kamiya >> KB4EMF / ex JF2DKG >> >> >> On Monday, April 20, 2020, 11:05:02 PM EDT, Bill Byrom >> wrote: >> >> It's easy to trigger on short pulses on most oscilloscopes if you follow >> these steps: >> (1) Do NOT use Auto Trigger mode. Instead use Normal trigger mode. >> (2) Set the vertical coupling mode to DC. >> (3) Set the vertical gain (volts/div) and offset so that the baseline (OFF >> voltage between pulses) and pulse ON voltage should both be visible on the >> vertical scale. >> (4) Set the trigger coupling mode to DC and the trigger source to the proper >> channel. >> (5) Set the trigger voltage to the midpoint between the pulse OFF and ON >> voltage. >> (6) Set the trigger slope appropriately, depending on the polarity of the 1 >> PPS pulse. >> (7) Many oscilloscopes have a trigger indicator LED. It should flash visibly >> on each 1 PPS signal. >> (8) If you are using an analog scope which does NOT have a microchannel >> plate (which was used on the Tektronix 2467 family and a few other models), >> the pulse ON signal may be difficult to see at a fast time/div setting, even >> with a high scope intensity setting. But you can slow down the time/div of >> an analog scope to something easy to see, such as 10 ms/div. This will allow >> you to see a bright sweep each time the scope triggers, even if a short >> pulse can't be seen. >> (9) When using a digital oscilloscope, turn on the peak detect display mode. >> This allows the oscilloscope to keep a high sampling rate even if the >> time/div is set for a moderately slow sweep. >> >> If the 1 PPS signal is very short, you won't be able to hear it on a speaker >> with a direct connection as you describe. But you can use a pulse stretcher >> circuit (such as a 555 timer IC) to drive a LED or speaker with a long >> output pulse (such as 10 ms). If you use two 555 IC's (or a 556 dual timer >> IC), you can even configure one section as a one-shot and the other as a >> tone generator so that a beep is produced for each pulse. The 555 and 556 >> may be sold as LM555/LM556 or NE555/NE556. >> -- >> Bill Byrom N5BB >> Retired Tektronix Application Engineer >> >>> On Mon, Apr 20, 2020, at 9:25 PM, Taka Kamiya via time-nuts wrote: >>> Maybe everyone but I knew, but I just did this and found it useful. >>> 1 pps signal from some GPS are notoriously narrow and difficult to sync >>> on and see on scopes. LED will barely light if some kind of stretcher >>> is not used. If your purpose is ONLY to see if it's there or not, hook >>> up a small speaker, earphone, amplified or not, and you can hear the >>> tick-tick sound. >>> >>> I like DIYing and many times, I wonder if pps distribution circuit is >>> working. I can tell a very short pulse that will barely register on >>> LED is clearly audible. >>> I thought I'd share. >>> >>> --- >>> (Mr.) Taka Kamiya >>> KB4EMF / ex JF2DKG >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> <1PPS - 1MΩ.png>___ >> time-nuts mailing
Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
TAPR offers a FatPPS kit to stretch the pulse out, and it looks like they're back in stock. I have one but haven't assembled it yet. https://tapr.org/product/fatpps-pulse-stretcher/ Larry On Tue, Apr 21, 2020 at 8:17 AM Dana Whitlow wrote: > I've seen PPS ticks as short as 100 nsec from some equipment. Didn't think > to try the headphone > trick at the time, but am dubious about hearing pulses that short at > ordinary pulse amplitudes. > > Dana > > > On Tue, Apr 21, 2020 at 6:37 AM Bob kb8tq wrote: > > > Hi > > > > One of the simplest justifications I can think of for a dirt cheap > > “Chinese” > > digital ’scope is to capture short burst stuff like narrow pps pulses. > > > > 10 us / non-adjustable is a *very* common spec for a 1 PPS. > > > > Bob > > > > > On Apr 21, 2020, at 4:56 AM, Chris Burford > > wrote: > > > > > > I reached out to SRS several months ago to inquire if the pulse width > > could be configured from the default of 10 micro second. Their responses > > was no. > > > > > > Chris > > > > > > -Original Message- > > > From: time-nuts On Behalf Of Taka > > Kamiya via time-nuts > > > Sent: Monday, April 20, 2020 22:35 > > > To: Discussion of precise time and frequency measurement < > > time-nuts@lists.febo.com> > > > Cc: Taka Kamiya > > > Subject: Re: [time-nuts] Using speaker / earphone for PPS testing (not > a > > question) > > > > > > Out of all signal source, the shortest 1 pps is PRS-10 at 10 micro > > second. T-bolt is quite short as well but I don't have a definite data. > > > For those, speaker method worked just fine. I'm just sharing what I > > learned on happenstance. > > > > > > --- > > > (Mr.) Taka Kamiya > > > KB4EMF / ex JF2DKG > > > > > > > > >On Monday, April 20, 2020, 11:05:02 PM EDT, Bill Byrom < > > t...@radio.sent.com> wrote: > > > > > > It's easy to trigger on short pulses on most oscilloscopes if you > follow > > these steps: > > > (1) Do NOT use Auto Trigger mode. Instead use Normal trigger mode. > > > (2) Set the vertical coupling mode to DC. > > > (3) Set the vertical gain (volts/div) and offset so that the baseline > > (OFF voltage between pulses) and pulse ON voltage should both be visible > on > > the vertical scale. > > > (4) Set the trigger coupling mode to DC and the trigger source to the > > proper channel. > > > (5) Set the trigger voltage to the midpoint between the pulse OFF and > ON > > voltage. > > > (6) Set the trigger slope appropriately, depending on the polarity of > > the 1 PPS pulse. > > > (7) Many oscilloscopes have a trigger indicator LED. It should flash > > visibly on each 1 PPS signal. > > > (8) If you are using an analog scope which does NOT have a microchannel > > plate (which was used on the Tektronix 2467 family and a few other > models), > > the pulse ON signal may be difficult to see at a fast time/div setting, > > even with a high scope intensity setting. But you can slow down the > > time/div of an analog scope to something easy to see, such as 10 ms/div. > > This will allow you to see a bright sweep each time the scope triggers, > > even if a short pulse can't be seen. > > > (9) When using a digital oscilloscope, turn on the peak detect display > > mode. This allows the oscilloscope to keep a high sampling rate even if > the > > time/div is set for a moderately slow sweep. > > > > > > If the 1 PPS signal is very short, you won't be able to hear it on a > > speaker with a direct connection as you describe. But you can use a pulse > > stretcher circuit (such as a 555 timer IC) to drive a LED or speaker > with a > > long output pulse (such as 10 ms). If you use two 555 IC's (or a 556 dual > > timer IC), you can even configure one section as a one-shot and the other > > as a tone generator so that a beep is produced for each pulse. The 555 > and > > 556 may be sold as LM555/LM556 or NE555/NE556. > > > -- > > > Bill Byrom N5BB > > > Retired Tektronix Application Engineer > > > > > > On Mon, Apr 20, 2020, at 9:25 PM, Taka Kamiya via time-nuts wrote: > > >> Maybe everyone but I knew, but I just did this and found it useful. > > >> 1 pps signal from some GPS are notoriously narrow and difficult to > sync > > >> on and see on scopes. LED will barely light if some kind of stretcher > > >> is not used. If your purpose is ONLY to see if it's there or not, > hook > > >> up a small speaker, earphone, amplified or not, and you can hear the > > >> tick-tick sound. > > >> > > >> I like DIYing and many times, I wonder if pps distribution circuit is > > >> working. I can tell a very short pulse that will barely register on > > >> LED is clearly audible. > > >> I thought I'd share. > > >> > > >> --- > > >> (Mr.) Taka Kamiya > > >> KB4EMF / ex JF2DKG > > >> ___ > > >> time-nuts mailing list -- time-nuts@lists.febo.com > > >> To unsubscribe, go to > > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >
Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
I've seen PPS ticks as short as 100 nsec from some equipment. Didn't think to try the headphone trick at the time, but am dubious about hearing pulses that short at ordinary pulse amplitudes. Dana On Tue, Apr 21, 2020 at 6:37 AM Bob kb8tq wrote: > Hi > > One of the simplest justifications I can think of for a dirt cheap > “Chinese” > digital ’scope is to capture short burst stuff like narrow pps pulses. > > 10 us / non-adjustable is a *very* common spec for a 1 PPS. > > Bob > > > On Apr 21, 2020, at 4:56 AM, Chris Burford > wrote: > > > > I reached out to SRS several months ago to inquire if the pulse width > could be configured from the default of 10 micro second. Their responses > was no. > > > > Chris > > > > -Original Message- > > From: time-nuts On Behalf Of Taka > Kamiya via time-nuts > > Sent: Monday, April 20, 2020 22:35 > > To: Discussion of precise time and frequency measurement < > time-nuts@lists.febo.com> > > Cc: Taka Kamiya > > Subject: Re: [time-nuts] Using speaker / earphone for PPS testing (not a > question) > > > > Out of all signal source, the shortest 1 pps is PRS-10 at 10 micro > second. T-bolt is quite short as well but I don't have a definite data. > > For those, speaker method worked just fine. I'm just sharing what I > learned on happenstance. > > > > --- > > (Mr.) Taka Kamiya > > KB4EMF / ex JF2DKG > > > > > >On Monday, April 20, 2020, 11:05:02 PM EDT, Bill Byrom < > t...@radio.sent.com> wrote: > > > > It's easy to trigger on short pulses on most oscilloscopes if you follow > these steps: > > (1) Do NOT use Auto Trigger mode. Instead use Normal trigger mode. > > (2) Set the vertical coupling mode to DC. > > (3) Set the vertical gain (volts/div) and offset so that the baseline > (OFF voltage between pulses) and pulse ON voltage should both be visible on > the vertical scale. > > (4) Set the trigger coupling mode to DC and the trigger source to the > proper channel. > > (5) Set the trigger voltage to the midpoint between the pulse OFF and ON > voltage. > > (6) Set the trigger slope appropriately, depending on the polarity of > the 1 PPS pulse. > > (7) Many oscilloscopes have a trigger indicator LED. It should flash > visibly on each 1 PPS signal. > > (8) If you are using an analog scope which does NOT have a microchannel > plate (which was used on the Tektronix 2467 family and a few other models), > the pulse ON signal may be difficult to see at a fast time/div setting, > even with a high scope intensity setting. But you can slow down the > time/div of an analog scope to something easy to see, such as 10 ms/div. > This will allow you to see a bright sweep each time the scope triggers, > even if a short pulse can't be seen. > > (9) When using a digital oscilloscope, turn on the peak detect display > mode. This allows the oscilloscope to keep a high sampling rate even if the > time/div is set for a moderately slow sweep. > > > > If the 1 PPS signal is very short, you won't be able to hear it on a > speaker with a direct connection as you describe. But you can use a pulse > stretcher circuit (such as a 555 timer IC) to drive a LED or speaker with a > long output pulse (such as 10 ms). If you use two 555 IC's (or a 556 dual > timer IC), you can even configure one section as a one-shot and the other > as a tone generator so that a beep is produced for each pulse. The 555 and > 556 may be sold as LM555/LM556 or NE555/NE556. > > -- > > Bill Byrom N5BB > > Retired Tektronix Application Engineer > > > > On Mon, Apr 20, 2020, at 9:25 PM, Taka Kamiya via time-nuts wrote: > >> Maybe everyone but I knew, but I just did this and found it useful. > >> 1 pps signal from some GPS are notoriously narrow and difficult to sync > >> on and see on scopes. LED will barely light if some kind of stretcher > >> is not used. If your purpose is ONLY to see if it's there or not, hook > >> up a small speaker, earphone, amplified or not, and you can hear the > >> tick-tick sound. > >> > >> I like DIYing and many times, I wonder if pps distribution circuit is > >> working. I can tell a very short pulse that will barely register on > >> LED is clearly audible. > >> I thought I'd share. > >> > >> --- > >> (Mr.) Taka Kamiya > >> KB4EMF / ex JF2DKG > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com > >> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > >> > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to >
Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
Hi One of the simplest justifications I can think of for a dirt cheap “Chinese” digital ’scope is to capture short burst stuff like narrow pps pulses. 10 us / non-adjustable is a *very* common spec for a 1 PPS. Bob > On Apr 21, 2020, at 4:56 AM, Chris Burford wrote: > > I reached out to SRS several months ago to inquire if the pulse width could > be configured from the default of 10 micro second. Their responses was no. > > Chris > > -Original Message- > From: time-nuts On Behalf Of Taka Kamiya > via time-nuts > Sent: Monday, April 20, 2020 22:35 > To: Discussion of precise time and frequency measurement > > Cc: Taka Kamiya > Subject: Re: [time-nuts] Using speaker / earphone for PPS testing (not a > question) > > Out of all signal source, the shortest 1 pps is PRS-10 at 10 micro second. > T-bolt is quite short as well but I don't have a definite data. > For those, speaker method worked just fine. I'm just sharing what I learned > on happenstance. > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > >On Monday, April 20, 2020, 11:05:02 PM EDT, Bill Byrom > wrote: > > It's easy to trigger on short pulses on most oscilloscopes if you follow > these steps: > (1) Do NOT use Auto Trigger mode. Instead use Normal trigger mode. > (2) Set the vertical coupling mode to DC. > (3) Set the vertical gain (volts/div) and offset so that the baseline (OFF > voltage between pulses) and pulse ON voltage should both be visible on the > vertical scale. > (4) Set the trigger coupling mode to DC and the trigger source to the proper > channel. > (5) Set the trigger voltage to the midpoint between the pulse OFF and ON > voltage. > (6) Set the trigger slope appropriately, depending on the polarity of the 1 > PPS pulse. > (7) Many oscilloscopes have a trigger indicator LED. It should flash visibly > on each 1 PPS signal. > (8) If you are using an analog scope which does NOT have a microchannel plate > (which was used on the Tektronix 2467 family and a few other models), the > pulse ON signal may be difficult to see at a fast time/div setting, even with > a high scope intensity setting. But you can slow down the time/div of an > analog scope to something easy to see, such as 10 ms/div. This will allow you > to see a bright sweep each time the scope triggers, even if a short pulse > can't be seen. > (9) When using a digital oscilloscope, turn on the peak detect display mode. > This allows the oscilloscope to keep a high sampling rate even if the > time/div is set for a moderately slow sweep. > > If the 1 PPS signal is very short, you won't be able to hear it on a speaker > with a direct connection as you describe. But you can use a pulse stretcher > circuit (such as a 555 timer IC) to drive a LED or speaker with a long output > pulse (such as 10 ms). If you use two 555 IC's (or a 556 dual timer IC), you > can even configure one section as a one-shot and the other as a tone > generator so that a beep is produced for each pulse. The 555 and 556 may be > sold as LM555/LM556 or NE555/NE556. > -- > Bill Byrom N5BB > Retired Tektronix Application Engineer > > On Mon, Apr 20, 2020, at 9:25 PM, Taka Kamiya via time-nuts wrote: >> Maybe everyone but I knew, but I just did this and found it useful. >> 1 pps signal from some GPS are notoriously narrow and difficult to sync >> on and see on scopes. LED will barely light if some kind of stretcher >> is not used. If your purpose is ONLY to see if it's there or not, hook >> up a small speaker, earphone, amplified or not, and you can hear the >> tick-tick sound. >> >> I like DIYing and many times, I wonder if pps distribution circuit is >> working. I can tell a very short pulse that will barely register on >> LED is clearly audible. >> I thought I'd share. >> >> --- >> (Mr.) Taka Kamiya >> KB4EMF / ex JF2DKG >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > <1PPS - 1MΩ.png>___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com
Re: [time-nuts] Using speaker / earphone for PPS testing (not a question)
I reached out to SRS several months ago to inquire if the pulse width could be configured from the default of 10 micro second. Their responses was no. Chris -Original Message- From: time-nuts On Behalf Of Taka Kamiya via time-nuts Sent: Monday, April 20, 2020 22:35 To: Discussion of precise time and frequency measurement Cc: Taka Kamiya Subject: Re: [time-nuts] Using speaker / earphone for PPS testing (not a question) Out of all signal source, the shortest 1 pps is PRS-10 at 10 micro second. T-bolt is quite short as well but I don't have a definite data. For those, speaker method worked just fine. I'm just sharing what I learned on happenstance. --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Monday, April 20, 2020, 11:05:02 PM EDT, Bill Byrom wrote: It's easy to trigger on short pulses on most oscilloscopes if you follow these steps: (1) Do NOT use Auto Trigger mode. Instead use Normal trigger mode. (2) Set the vertical coupling mode to DC. (3) Set the vertical gain (volts/div) and offset so that the baseline (OFF voltage between pulses) and pulse ON voltage should both be visible on the vertical scale. (4) Set the trigger coupling mode to DC and the trigger source to the proper channel. (5) Set the trigger voltage to the midpoint between the pulse OFF and ON voltage. (6) Set the trigger slope appropriately, depending on the polarity of the 1 PPS pulse. (7) Many oscilloscopes have a trigger indicator LED. It should flash visibly on each 1 PPS signal. (8) If you are using an analog scope which does NOT have a microchannel plate (which was used on the Tektronix 2467 family and a few other models), the pulse ON signal may be difficult to see at a fast time/div setting, even with a high scope intensity setting. But you can slow down the time/div of an analog scope to something easy to see, such as 10 ms/div. This will allow you to see a bright sweep each time the scope triggers, even if a short pulse can't be seen. (9) When using a digital oscilloscope, turn on the peak detect display mode. This allows the oscilloscope to keep a high sampling rate even if the time/div is set for a moderately slow sweep. If the 1 PPS signal is very short, you won't be able to hear it on a speaker with a direct connection as you describe. But you can use a pulse stretcher circuit (such as a 555 timer IC) to drive a LED or speaker with a long output pulse (such as 10 ms). If you use two 555 IC's (or a 556 dual timer IC), you can even configure one section as a one-shot and the other as a tone generator so that a beep is produced for each pulse. The 555 and 556 may be sold as LM555/LM556 or NE555/NE556. -- Bill Byrom N5BB Retired Tektronix Application Engineer On Mon, Apr 20, 2020, at 9:25 PM, Taka Kamiya via time-nuts wrote: > Maybe everyone but I knew, but I just did this and found it useful. > 1 pps signal from some GPS are notoriously narrow and difficult to sync > on and see on scopes. LED will barely light if some kind of stretcher > is not used. If your purpose is ONLY to see if it's there or not, hook > up a small speaker, earphone, amplified or not, and you can hear the > tick-tick sound. > > I like DIYing and many times, I wonder if pps distribution circuit is > working. I can tell a very short pulse that will barely register on > LED is clearly audible. > I thought I'd share. > > --- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
