[time-nuts] Trimble T Lassen 2 - suitableantenna....advice.....questions

Tom Miller tmiller at skylinenet.net
Mon Aug 20 06:44:25 UTC 2012

You can see it easily with any 50+ MHz analog scope that has a working DC 
trigger function.

If it is a 1 us pulse width TTL output or close, set the H sweep to 1 
us/div, The vertical to 1 volt/div, the triggering to normal, and the 
trigger input to DC. Then adjust the trigger point to +1 volt. You should 
see a sweep every second. If you turn up the intensity and dim the room 
lighting, the pulse should be visible.

If you are using a Tek scope and need help setting it up, just ping me and 
I'll assist. Others on this list can also give good advise in seeing this 


----- Original Message ----- 
From: "Chris Albertson" <albertson.chris at gmail.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Monday, August 20, 2012 1:52 AM
Subject: Re: [time-nuts] Trimble T Lassen 2 - 

On Sun, Aug 19, 2012 at 9:27 PM, Robert Darlington 
<rdarlington at gmail.com>wrote:

> It's a pain to capture on any scope, but really easy to see with an
> LED across the output.  it's not bright, but definitely easy to see on
> my tbolt.

That is true.  One must have very good eyes to see a one microsecond pulse
that only happens one per second.  Blink and you miss it.

The LED might work but the "for sure" way is to send the PPS to a flip flop
so you can see the state change at 1Hz.  Use a solderless bread board and
5V power supply.


Chris Albertson
Redondo Beach, California
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to 
and follow the instructions there. 

More information about the Time-nuts_lists.febo.com mailing list