Re: [time-nuts] Troubleshooting an HP 58503A
- Original Message - From: "Achim Gratz" To: Sent: Monday, October 15, 2018 2:10 PM Subject: Re: [time-nuts] Troubleshooting an HP 58503A Matthew D'Asaro writes: The concrete block is a generic 1 sqft paver stone which cost all of $1.18. This is to provide a heavy base and avoid tipping. If you want to keep your roof undamaged, you need padding under that concrete block (some geotextile sheet plus perhaps a bit of rubber mat like they use for playgrounds) or it will cut through the roofing sheet over time. Buy your wife a new door mat and use the old one under the block. Kill two birds with one stone. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Troubleshooting an HP 58503A
Matthew D'Asaro writes: > The concrete block is a generic 1 sqft paver stone which cost all > of $1.18. This is to provide a heavy base and avoid tipping. If you want to keep your roof undamaged, you need padding under that concrete block (some geotextile sheet plus perhaps a bit of rubber mat like they use for playgrounds) or it will cut through the roofing sheet over time. > It is sitting on the back railing of the house for now but I > ordered a 40' length of LMR-250 cable with N-connectors on both ends > from http://www.usacoax.com/ and once that comes I can set it up for > real on the roof with the cable running into my lab. Over and out. You'll want to have a good think about lightning protection before you run that cable near anything that enters your house. You should also check that the grounding of your electrical installation is properly done. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ SD adaptations for Waldorf Q V3.00R3 and Q+ V3.54R2: http://Synth.Stromeko.net/Downloads.html#WaldorfSDada ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] RF Isolation Amplifier ...
Thanks for the inputs. Attached is the blurb from the manual on the 5Mhz isolation amps. I don't want to redesign as the 3 amps are matched for delay and temp and run at 45 degrees C. I'll check the output of the amp with a spec-A and select the capacitor as appropriate. Cheers, Corby___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] PRS10 MDEV
I suspect now after your review that the effect is thermally drive, specifically my HVAC. My PRS10 is in a free air environment suspect to the wall thermostat. I'm sure I could parallel the RFS measurements with Lady Heather and find a correlation between RFS case temp and the MDEV. Thanks Tom for the analysis. Chris -From: "Tom Van Baak" To: "Discussion of precise time and frequency measurement" Cc: Sent: Monday October 15 2018 12:31:07AM Subject: Re: [time-nuts] PRS10 MDEV When I see an ADEV or MDEV plot that looks unusual I like to check the phase or frequency plots for clues. Thanks for your .TIM file. Attached are: Burford-6h-adev.png -- TimeLab 'a' command. This is a straight line with slope -1; what you expect for a self-test. Note the ADEV at tau 1 second is right about 7e-11, 70 p/s, which is typical noise for the TICC counter. Burford-6h-mdev.png -- TimeLab 'm' command. As you observed this has, a plateau. Sort of unexpected given you weren't using a GPSDO. Burford-6h-phase.png -- TimeLab 'p' command. Phase difference plot. Notice all those bumps. Burford-6h-phase-100s.png -- TimeLab 'g100' command. Phase difference plot with 100 second averaging makes the variations stand out much clearer. Can you guess what that is? So the smoking gun is that you have quasi-periodic perturbations in phase on the order of about 100 ps. The shape looks thermal to me. Do you have a thermostatically controlled heater in the room or house? I suspect this is causing your MDEV plateau. If so, you've accidentally done a nice experiment -- which is to establish your measurement noise floor and to examine the environmental conditions of your work bench. Ah, the annoying joys of working with precise time! Again, assuming it is due to thermal effects, you can now find out if it's your TICC or your cables or your PRS10. Since TimeLab will display plots in real-time a heat gun or cold spray may help you isolate the culprit quickly. /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
