Voltnut Meetup in Cardiff, Wales this Sunday (June 9) - Page 1
Forum section: electronics / general

author: dkozel
author_rank: Regular Contributor
timestamp: June 03, 2019, 09:27:49 pm
content: Hi folks,Bit of a last minute post. Tggzzz and I are meeting up in Cardiff, at Cardiff University, to compare our references and meters. I'll be bringing two uncalibrated HP 3458As, a Keithley 2000, and three fresh LTZ1000 references (~6 weeks, 1000 hours run time). Tggzzz is bringing a stack of voltage and resistance references as well as some other equipment.If anyone is interested in joining please let me know! There's plenty of room and we'll be there pretty much all day, exact timing TBD.

author: rigrunner
author_rank: Frequent Contributor
timestamp: June 05, 2019, 05:54:30 pm
content: I'm stupid busy with things at the moment, so can't make this.A UK gathering is a great idea.

author: dkozel
author_rank: Regular Contributor
timestamp: June 08, 2019, 12:06:50 am
content: Hey Rigrunner,I'd like to do a better organized meetup sometime in the fall. That'd definitely start planning well in advance so we can collectively pick a good date.I have an interest in precision frequency generation that I'm not going to be able to do much about this weekend as I'm just not yet setup to do precision phase noise measurement. I have an SDR that I want to get setup do to cross correlation based measurements with, but haven't had the time to really do much on it yet. I also have a frequency counter, but need to figure out how to adapt it for use with with ke5fx's TimeLab software. It'd be great to be able to check the two methods against each other.

author: The Soulman
author_rank: Super Contributor
timestamp: June 08, 2019, 12:51:00 am
content: Quote from: dkozel on June 08, 2019, 12:06:50 amHow is dhl doing your country?So you're more of a time-nut? #anotherrabbithole

author: rigrunner
author_rank: Frequent Contributor
timestamp: June 08, 2019, 03:50:50 pm
content: I'll hopefully have a little more free time in the autumn.Time nuttery is a rabbit hole that i've thus yet managed to not step too far into.I've got a loran-c receiver that my counter, sig gens and analayser are locked to, and i have collected some parts to put together a gpsdo. Dr Frank's pcb started me off down the volt nuttery rabbit hole and it's been using up any free time i have had for some while now...

author: tggzzz
author_rank: Super Contributor
timestamp: June 08, 2019, 04:40:42 pm
content: What's the timing and exact location?Is there car parking nearby; I ain't lugging some of my equipment far, nor in the rain!

author: dkozel
author_rank: Regular Contributor
timestamp: June 13, 2019, 08:24:48 pm
content: tggzzz and I had a fun afternoon of comparing our meters. No real conclusions from it other than my Keithley 2000 is in nice agreement with an eye-balled average of the higher grade DMMs and his needs a little tweaking. It was great to see and get to measure against his good collection of resistance standards. The really interesting part will be to repeat all this in 6 months or so and see where things have changed.My technique on a bunch of the measurements and familiarity with the instruments definitely needs to improve before the next meetup. We made things work with the cables on hand but it would have been both easier and probably more repeatable to have more appropriate cables with spade connectors. My LTZ1000s currently only have the buffered diode reference connected to the outside. Next time I'll try and find a way to have both the reference and buffered 10V available. I made some room environment recordings during our measurements, but my script was just not quite primetime ready so it didn't log continuously. It did provide a basic check that the room was only varying by 0.2 C or so over our measurement period. The 3458As weren't logging continuously or their temperatures.I had a good time and it was definitely both educational and reassuring to meet up with a fellow nutter!The Soulman:My background and career are all in the radio realm so it's really frequency that I'm interested in. Absolute global time is a hole that I'm studiously avoiding, though it's looking hazardously necessary for a lot of radio astronomy work where even the changing gravitation field the radio is sitting in as the Earth orbits the sun has an effect... shudder. I've worked on systems that were distributing local time and frequency references over multiple kilometers, a fun experience but a bit more expensive than I'm likely to get at my house soon.