[time-nuts] Trimble Thunderbolt 1PPS TTL level?

Arnold Tibus Arnold.Tibus at gmx.de
Sat Aug 30 10:12:23 EDT 2008


On Fri, 29 Aug 2008 22:21:43 -0400, Pieter Ibelings wrote:

>Hi All,

>I got a Trimble Thunderbold from Ebay and I am having trouble triggering the 
>HP 53131A. The 1PPS output shows a 10us  pulse of 1 Volt into a high 
>impedance probe. This seems low to me. Should it be 5 volts? Maybe the 
>output 74AC04 is toast?

>Pieter, N4IP

Hi Pieter,
there is nothing to be worried about, I have the same problem with my
53132A, it does not trigger on it with 50 ohms or high impedance load. 
So I tried it with the 5334A - no problem at all ! It does trigger as expected, 
without any signal loss. 
Seem to be a problem of the 53131A/ 53132A series counter.

regards,
Arnold





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