Re: [time-nuts] "Q for dummies"

MRI machines use superconducting coils to generate a 1T magnetic field over a volume sufficient for a human body Andy www.g4jnt.com On Tue, 26 Jan 2021 at 21:47, Tom Holmes wrote: > I was told that one of the killers of superconductivity is magnetic > fields. I guess they 'fixed' that. > >

Re: [time-nuts] Need Complete Service Maintenance Manual for HP Agilent 8593EM EMC Analyzer

Hi Based on repairing a couple of the same era analyzers …. It’s a good bet that you have lots / blown the mixer diode in the front end. There are various parts you can replace it with. It’s not brain surgery to do so on the models I have played with ( which does not include the 8593 …). The

[time-nuts] Need Complete Service Maintenance Manual for HP Agilent 8593EM EMC Analyzer

Hello, T-N Gents, I hope someone out there can help me please. I am having some major trouble symptoms on my HP 8593EM EMC/Spectrum Analyzer with Options 004, 010, 027. The S/N is 3649A00197. The display is showing the "LO UNLVL" and "FREQ UNCAL" errors. Also, this analyzer is not able to

Re: [time-nuts] ntp server

I haven't tried one. I didn't see any mention of the software. There are many similar models at similar prices. For roughly that price, you can get a Raspberry Pi and GPS HAT. There are a couple of web pages on how to setup a Pi based NTP server. The downside is that you have to setup and

Re: [time-nuts] "Q for dummies"

I was told that one of the killers of superconductivity is magnetic fields. I guess they 'fixed' that. Tom Holmes, N8ZM -Original Message- From: time-nuts On Behalf Of Mike Feher Sent: Tuesday, January 26, 2021 1:07 PM To: 'Discussion of precise time and frequency measurement'

Re: [time-nuts] "Q for dummies"

Just two sentences is quite a challenge! Maybe one of the two sentences should explain the downsides of a system design that uses filters or networks with high Q. "High-Q filters and matching networks will have circulating currents resulting in poorer efficiency, and higher variation in group and

Re: [time-nuts] "Q for dummies"

I recall back in the late 60’s visiting some friends at BNL. One of them took me through the cryogenic lab. In one they had an LC running at near 0 and it could be heard in a receiver. We know for L, Q in its simplest form is Xl/R. At superconductor temperatures R approaches 0 and therefore Q

Re: [time-nuts] "Q for dummies"

So also, a "bad" Q story may resonate with the audience to reinforce the concepts. There are events like buildings and bridges resonating and collapsing. Ed ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

Re: [time-nuts] "Q for dummies"

But Dana, a high Q can also be a bad thing - depends on the situation. Ed ___ 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] "Q for dummies"

If you have a mechanical tuning fork handy, just ding it and note the gradual decay. Then wrap a small wad of paper towel on one or both arms, with some tape outside (not touching the arms - don't want adhesive residue left on there) to keep in place, and repeat. For using a wine glass or

[time-nuts] FEI FE-5450A manual

Hello; Does anyone have a soft (or hard) copy of the FE-5450A manual that they can share please? I have a part manual that stops at the schematics Thanks! Ken ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

[time-nuts] ntp server

Has anyone tried one of these ebay offerings? opinions? 15ns/1pps 0.5-2ms Network NTP Time Server for GPS Beidou GLONASS Galileo QZSS 124133795048 Don -- The whole world is a straight man. -- Dr. Don Latham AJ7LL PO Box 404, Frenchtown, MT, 59834 VOX:

Re: [time-nuts] "Q for dummies"

If anybody can even approach doing justice to the Q concept, including why it matters, in just two sentences, that person will have definitely earned the "Qulitzer prize" in technical journalism. Here's my entry: "A circuit's Q is closely related to its internal energy losses compared to

Re: [time-nuts] "Q for dummies"

On 1/26/21 5:29 AM, Dave Daniel wrote: That doesn’t really illustrate the fundamental concept of Q. I’ll try and think of something that is still non-mathematical but nonetheless illustrates the concept of Q. DaveD Ultimately, Q is about internal (or external) losses (leaving aside

Re: [time-nuts] "Q for dummies"

That doesn’t really illustrate the fundamental concept of Q. I’ll try and think of something that is still non-mathematical but nonetheless illustrates the concept of Q. DaveD > On Jan 26, 2021, at 07:28, Ole Petter Ronningen wrote: > > Hi, All > > I am going to give a presentation to

Re: [time-nuts] "Q for dummies"

Ole, For a two-sentence summary, I think the wine glass example of Q works fine. The audience typically knows about bells ringing and wine glasses singing, so this factoid resonates with them. But the issue is then: what's the point; why is a long bright ring better than a short dull plink.

Re: [time-nuts] "Q for dummies"

You could mention it is roughly equivalent to the number of swings you get for a weight on a rope before it stops swinging. Or something like that. Andy www.g4jnt.com On Tue, 26 Jan 2021 at 13:14, Ole Petter Ronningen wrote: > Hi, All > > I am going to give a presentation to non-nuts, and

[time-nuts] "Q for dummies"

Hi, All I am going to give a presentation to non-nuts, and in one of the slides I touch on Q - not wanting to spend more than a sentence or two on the subject, I wonder if the following analogy works: "A quality long-stemmed, thin-walled wine glass will ring for a long time after we give it a

Re: [time-nuts] Help with 5370B and Beaglebone replacement board

Hello, Skip, I have one of these, in a 5370A, and have been playing with it lately. I start the 5370d application in the beaglebone with the -hpib-net flag, so HPIB commands can be sent and results get at port 5370. If you send the HPIB command MD4, the 5370 will start sending the results,