Greg, I plan on doing the A3/A4 adjustments. I just don't know where I'm going to get a pulse generator or the fancy scope with the 1GHz sampling plugin. Not the type of equipment on your average test bench.
On Sat, Oct 10, 2009 at 5:03 PM, Greg Burnett <[email protected]> wrote: > Joe, > > I think 1 o'clock (instead of 12 o'clock) might still be OK and/or typical? > Maybe some other 5370A users can tell us where their Trigger Level pots are > pointing when centered for triggering on a weak signal. (The pots point to > 12 o'clock on my 5370B, but I can't remember exactly where they might point > on a typical "A".) > > I do know that some of the 5370A A3/A4 Input Amp & Schmitt Trigger I.C.s > developed "I.C. rot" many years after manufacture (due to a contamination > problem during manufacture). For units so afflicted, the symptom was that > "Preset" trigger level was no longer correct, but the trigger level could > still be successfully set manually. For these cases, as the years progressed > (and the "rot" worsened), you had to turn the manual trigger level pot > further and further to one direction to find trigger. As the years of > deterioration continued, there came a point where both trigger level > setability and sensitivity were no longer acceptable. > > If you have only a small trigger level issue in "Preset" mode, my thinking > is that you can still correct for it by doing the A3/A4 input adjustments. > > Best, > Greg > > > ----- Original Message ----- > From: "Joseph Gray" <[email protected]> > To: "Discussion of precise time and frequency measurement" > <[email protected]> > Sent: Saturday, October 10, 2009 2:23 PM > Subject: Re: [time-nuts] 5370A > > > Greg, > > Yes, the trigger levels are near zero when the LEDs are flashing. The > level pots are both at 1 o'clock, instead of 12 o'clock, however. > > There does seem to be a problem with the preset trigger postition. > Although the display shows 0.00V when at preset, I don't think it is. > When I manually set the levels to 0.00V, the TI shows 100nS. At preset > levels, the TI is noticeably higher. > > Joe Gray > KA5ZEC > > > > _______________________________________________ > 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.
