Re: [time-nuts] 5370B stop trigger not working

jim77...@gmail.com said: > I have gone through the troubleshooting process from the manual and it seems > to point to A4U2 (Schmidt trigger) being faulty. I'd put a scope on it to check. > Before I dive into this, does anyone have any advice? Most important being > the Schmidt trigger - where

Re: [time-nuts] modification Lucent RFTG

Joerg, This looks like a very useful mod on a unit that many of us have. I'm not aware of any schematics available for these, so I guess you have reverse-engineered the "black" part of the schematic that you provided. -- Nice work! Having said that, may I offer some minor criticism

Re: [time-nuts] 5370B stop trigger not working

According to the partlist A4U1 and A4U2 seems to be TL072CP opamps. jim77...@gmail.com said: I have gone through the troubleshooting process from the manual and it seems to point to A4U2 (Schmidt trigger) being faulty. I'd put a scope on it to check. Before I dive into this, does anyone

Re: [time-nuts] 5370B stop trigger not working

Yes I've been through the process in the service manual with an oscilloscope and the part number of the Schmitt trigger (apologies for the auto-corrected spelling above) is TL072CP. What I'm after is any "gotchas" or hints before I head down this path. Jim Palfreyman On 13 December 2015 at

Re: [time-nuts] modification Lucent RFTG

Joerg Yes this looks like a nice simple mod. Its difficult to tell from the pictures but in order to use the sma it looks like you cut the trace over by the cap. I ran into the same thing. The lead goes into the board and its end point is unclear. When I released a solution about 9 months ago I

Re: [time-nuts] modification Lucent RFTG

Rex, thank you for your reply! Your "minor criticism" is justified, I wil do the changes immediately (today). If you read your own article for the 20th time you don't see things like these... Thank you very much. vy73 Joerg Am 13.12.2015 um 12:00 schrieb Rex: > Joerg, > > This looks like a very

Re: [time-nuts] Mechanical clock sound pickup circuit

Maybe this can be useful to make the pick-up: http://www.meas-spec.com/downloads/LDT_Series.pdf they can be found also on the usual auction site. On Sat, Dec 12, 2015 at 10:28 PM, Alexander Pummer wrote: > > Once upon the time there was a "Vibrograph", see nice pictures here:

Re: [time-nuts] GPSDO and oscillator steering - EFC vs DDS schemes?

It's been 20 years since I presented that paper in San Francisco at FCS and I had just about forgotten about it. It is flattering to realize that people are still reading it now. It might be useful for the discussion here if I explained why I wrote the paper. We had recently completed the

Re: [time-nuts] 5370B stop trigger not working

Oops yes! I looked up the wrong item. I meant A3U1 which is 5088-7061 Jim On Sunday, 13 December 2015, Cok wrote: > According to the partlist A4U1 and A4U2 seems to be TL072CP opamps. > >> >> jim77...@gmail.com said: >> >>> I have gone through the troubleshooting

Re: [time-nuts] modification Lucent RFTG

Paul, thanks for your reply. I did not cut any trace on the pc board. The separation from the 15MHz signal is done by removing the 10nF capacitor. Yes, the short line leeding to the cap is still there but this little "stub" has no effect. Of course the line can be cut, but I like to "keep all

[time-nuts] when is LH finished with survey?

A couple of years ago Mark Sims wrote concerning how Lady Heather gets the desired precision of stored location even though the Thunderbolt firmware only allows writing the location directly using single precision: "Once the precise position has been calculated, it issues single point survey

[time-nuts] Phase noise from Allan Deviation ?

I've constructed a homebrew setup to measure time intervals using a software defined radio. Basically a single-channel downconversion to about one hertz, then count samples from the SDR clock to time stamp the zero crossings. This is done in gnuradio and saved to a file for post processing. The