Ed I seem to be a bit slow. Had not heard of your project. On the real 3801 the 25 pin connector is actually RS 422. Regards Paul WB8TSL
On Tue, Oct 5, 2021 at 3:11 PM ed breya <[email protected]> wrote: > I've been doing a bit more work on the far from finished Z3801A project, > trying to button things up. It has been sitting for years all opened up > (but running), with temporary pieces and cables and wiring hanging out > every which way. The next piece I want to get going is the 1 PPS > interface, to provide the signal out, and to run the clock. In the > manual it says the 1PPS signals are on the DB-25 connector, in > differential "pseudo-ECL" form, but that's all - no level or common-mode > info is provided. Online searching the term seems to indicate it's just > PECL - Positive ECL running from +5 V, with everything shifted up > accordingly. That's just fine (and easy to implement), as long as I know > what to expect. I figured I'd check here to see if that's correct, or if > it means something else in the Z3801A context. I'll find out eventually > when I start fooling with it, but right now it's buried deep in the guts > of the box, so not easy to scope out yet until I start hooking it up and > designing the interface. > > A related question is, is there any particular generally accepted or > favorite spec or description of the 1PPS signal output from the BNC? > I'll probably make it 0/+5 V out, fairly strong, with the leading > positive edge being the official tick mark. The clock will use a > softened up version. The DF will be whatever the Z3801A puts out. > > Ed > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send > an email to [email protected] > To unsubscribe, go to and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
