Re: [time-nuts] 5370B / TimeLab question

Hi Skip, You are exactly right. And, surprisingly, this is correct and normal for most TI counters. The short answer is -- for your use case, a *zero deadtime* time interval counter (TIC) or a timestamping counter (TSC), is what you want. The long answer is -- your problems is due to

Re: [time-nuts] HP5065a cfield issue

> To make any sense at all out of the synthesizer settings, you need the magic > table in > the manual. They are very random and not all settings actually work ( = > produce a > stable output). A few of the entries have very much longer moduli than the rest, and those will probably be less

[time-nuts] 5370B / TimeLab question

Hello Time-Nuts, I have been having fun playing with the DMTD, but have a question regarding data collection. Obviously with a 10Hz offset oscillator I am feeding square waves with a 100ms period to the START and STOP of the 5370B. The trigger lights are happily blinking away at 10Hz. However,

Re: [time-nuts] HP5065a cfield issue

Hi To make any sense at all out of the synthesizer settings, you need the magic table in the manual. They are very random and not all settings actually work ( = produce a stable output). Bob > On Dec 1, 2020, at 3:20 PM, paul swed wrote: > > A quick update. Several people have made very

Re: [time-nuts] HP5065a cfield issue

paul swed writes: >Bob mentioned flipping the synthesizer switch. Heck they have been sitting >at 8714 (Also on the tube label) for 30 years. I did and it did not fix >the problem. But I went through the switch seeing how each section behaved. >By dropping to 8614 [...] Please notice

Re: [time-nuts] HP5065a cfield issue

paul swed writes: > > Also you can kludge in an HP 3325A/B in place of the A1 synthesizer to > > see if that's the problem. 3336 or even 33120 works fine too. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer

Re: [time-nuts] HP5065a cfield issue

A quick update. Several people have made very good comments. Some online and offline. Bob mentioned flipping the synthesizer switch. Heck they have been sitting at 8714 (Also on the tube label) for 30 years. I did and it did not fix the problem. But I went through the switch seeing how each

Re: [time-nuts] HP5065a cfield issue

Hi …… the synth output comes right out of the BNC on the front panel. Pretty easy to hook a counter to. Also a good place to feed in an external synth. Bob > On Dec 1, 2020, at 2:11 PM, paul swed wrote: > > Corby I like the 3325 suggestion. I have a 3335 that I can lock together > with

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

>One (as yet unmentioned) solution is to equip the device with an air inlet >*and* a small bleed >hole. You feed cleaned / dried air ( or nitrogen if you are picky) under >modest pressure down >the air line. Works fine right up to the point somebody cuts costs by not >doing proper support >for

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Hi You are going to fabricate the “base” as a solid piece. Getting a coax style connector into that is just a matter of your credit limit. The larger issue on the device is making the “cover” out of metal. That probably isn’t going to work very well :) Now you are off into a glass cover of

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

On 12/1/20 11:03 AM, Hal Murray wrote: kb...@n1k.org said: Yes, there’s more to it if you want to get connections in and out. Forget about “hermetic� connectors, they aren’t up to the task. You need glass to metal seals embedded in the structure. Now you have even more constraints

Re: [time-nuts] HP5065a cfield issue

Corby I like the 3325 suggestion. I have a 3335 that I can lock together with everything. That will help identify a synth issue. Thanks Paul. On Tue, Dec 1, 2020 at 12:24 PM wrote: > Paul, > > C-field current is adjustable from 2.5 to 6ma. > > I use a clip on milliammeter. > > Also you can

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

kb...@n1k.org said: > Yes, there’s more to it if you want to get connections in and out. Forget > about “hermetic” connectors, they aren’t up to the task. You need > glass to > metal seals embedded in the structure. Now you have even more constraints on > the package. What's

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Hi The gotcha with the device in question is that roughly 90% of the volume is in the microwave path to the antenna. Most of the remaining 10% if filled with electronics …. One (as yet unmentioned) solution is to equip the device with an air inlet *and* a small bleed hole. You

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Yes, without true hermetic enclosure, eventually enough moisture and other stuff will leak around or diffuse through the seals and materials. Depending on climate conditions and maintenance schedules, you could try try an old-school remedy, which is to stuff as much desiccant (like silica gel)

[time-nuts] HP5065a cfield issue

Paul, C-field current is adjustable from 2.5 to 6ma. I use a clip on milliammeter. Also you can kludge in an HP 3325A/B in place of the A1 synthesizer to see if that's the problem. Cheers, Corby ___ time-nuts mailing list --

[time-nuts] Early Christmas - DMTD up and running

Skip, Nice! Now you can go down another rabbit hole!!! Nothing fancy is needed for noise floor DMTD tests! Here is a PIX of what I use. - A passive SMA power splitter - a couple short SMA cables - an assortment of sma M to SMA F adaptors (elbows work nice) - A variable phase shifter from an HP

Re: [time-nuts] HP5065a cfield issue

Hi Well that puts it at 5/3 = 1.3 ppb low. The C field *should*adjust over a 2 ppb-ish range. Assuming you were near center, that puts the shift in the “couple of ppb” range. Very much the sort of thing the synth could do. Bob > On Dec 1, 2020, at 9:44 AM, paul swed wrote: > > Bob > I did

Re: [time-nuts] HP5065a cfield issue

Bob I did not see your response before responding to Poul. This morning I did flip those switches and agree that I may have something going on in the synthesizer. The offset that showed up is a drift of 5ns in 3 seconds and its running slow. I do have the offsets from past measurements. Will have

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Hi > On Nov 30, 2020, at 6:08 PM, jimlux wrote: > > On 11/30/20 1:22 PM, Art Sepin wrote: >>> To me it looks more like water ingress through micro-cracks in the >>> plastic-dome, and the O-ring did its job and kept that water in. >> Interesting. That's the first we've heard about micro-cracks

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Breathable vents such as https://www.hylec-apl.com/venting-elements-breather-plugs can be useful. On 30/11/2020 22:08, Lester Veenstra via time-nuts wrote: > This brings up a point I have made frequently, in my professional life. > Do

Re: [time-nuts] HP5065a cfield issue

Hi The C field coil resistance is low enough that you have something in the vicinity of 10mv across it. If you want to check the C field regulator, I’d just pop a wire and put a meter in series with the coil. My bet: your synthesizer has slipped a bit somewhere. I’d check it’s output against