[time-nuts] No 1 PPS output on a Tbolt

[Bruce Griffiths]

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.)
>
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> ________________________________
> From: Bruce Griffiths<bruce.griffiths at xtra.co.nz>
> To: Discussion of precise time and frequency measurement<time-nuts at 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 Juges<didier at cox.net>
>>> To: Time-Nuts<time-nuts at 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<salccor at rogers.com>
>>> Date: Sun, 7 Feb 2010 08:42:49
>>> To: Discussion of precise time and frequency measurement<time-nuts at 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<lists at cq.nu>
>>> To: Discussion of precise time and frequency measurement<time-nuts at 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"<salccor at rogers.com>
>>> Sent: Sunday, February 07, 2010 11:06 AM
>>> To: "Discussion of precise time and frequency measurement"
>>> <time-nuts at 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"<stanw1le at verizon.net>
>>>> To: Discussion of precise time and frequency measurement
>>>> <time-nuts at 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
>>>>
>>>>
>>>>
>>>>          
>>>        
>>      
>