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:

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 <time@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:

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.

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 time-nuts-bounces@lists.febo.com 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 tkamiya9@yahoo.com
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 <time@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:

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.

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

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 kb8tq@n1k.org wrote:

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 k8yumdoober@gmail.com wrote:

Hi,

20us length is a mil standard. Described in ICD-GPS-060.

/Björn

Sent from my iPhone

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

The thing is, the shorter the electrical pulse, the less total energy is
available
(particularly in the audio frequency range), and no amount of "echoing
around"
(which is really just a form of filtering) can fix that.  So there are
limits.

Dana

On Tue, Apr 21, 2020 at 7:49 PM Neville Michie namichie@gmail.com wrote: