[time-nuts] fts 4050 performance

Christopher Hoover ch at murgatroid.com
Sun Jul 30 15:33:30 EDT 2006


Brooke wrote:
> If the source of a pulse is 50 Ohms and it's TTL level at 
> open circuit ( 0 to 5 volts) and the load is 50 Ohms, then 
> when  you connect a 50 Ohm load the pulse is 0 to 2.5 volts 
> and so setting the trigger to 2.5 volts is just on the edge 
> of not working.  

Oops.  I mistyped.

The Channel 1 trigger level is set at 0v25 and not 2v5 as I said before.

(What's an order of magnitude between friends?)

The pulse is from my TADD-3 (driven by a Z3801A).

> It's best to put a "T" connector and have a 
> look with a scope.  If the above is the case then a trigger 
> level of 1.25 might work better.

Good idea.  Will do.

-ch




More information about the time-nuts mailing list