Okay, my first mistake here was not having a terminator when looking at it on the scope, but it was terminated at 50ohms when attached to the counter. This looks much nicer:
http://www.nerdhouse.org/frsc.jpg Turning off the 20MHz bandwidth filter cleaned it up to what you see there. When I gate the frequency counter with the 1PPS signal from the Lassen iQ, I'm getting 10,000,000 +/- 1Hz counts. This seems reasonable, as that fits the spec of the counter (HP 5335A). When counting using the internal TCXO which may be way off, I'm getting 9,999,975.55 Hz +/- 0.06Hz give or take). When I first powered it on I did see the frequency swing to either side of 10MHz and settle down a bit, then settle down some more. The last digit moves a bit, sometimes moving the one before it (0.xx Hz). Maybe this thing IS working and is measuring the stability of the oscillator in the counter. I still see nothing on the lock line but it may need a pull up resistor. I'll play around with it some more. I'm getting dragged to dinner so I can't play anymore tonight. Thank you all for the help and suggestions. I'm very green but am learning. -Bob On Fri, Oct 17, 2008 at 5:24 PM, Hal Murray <[EMAIL PROTECTED]> wrote: > > > The unit that I received does not show TTL after the frequency and the > > scope output looks like a cross between a sinewave and a ringing > > square wave. I have about 13 feet of RG174 between the FRS and the > > measurement equipment so who knows. > > Do you have a terminator at the far end of the coax? > > What does it look like with a scope directly at the unit without any coax? > > > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
