Test Equipment Anonymous (TEA) group therapy thread

[bd139]

I spent the vast majority of my adult life pleasing other people (read: women). Never again. This is MY time. 

Well said 

Talking of which. I spent most of last night pleasing mosquitoes. Bastard things 

[BU508A]

Talking of which. I spent most of last night pleasing mosquitoes. Bastard things 

You need something like this:



Mosquito meets laser. 

[med6753]

I spent the vast majority of my adult life pleasing other people (read: women). Never again. This is MY time. 

Well said 

Talking of which. I spent most of last night pleasing mosquitoes. Bastard things 

Screens on windows do wonders for keeping mosquitoes outside. Don't they have them in the UK? 

[med6753]

Here I am up already and got stuff powered up ready to be time nut calibrated. 

I left the PCOXO powered up all night so it's nice and stable. Just calibrated the first victim. The VC2000. Will let it sit for a while then on to the next victim.

You guys KNEW I would go down this rabbit hole, didn't you?     

[Brumby]

[BU508A]

Here I am up already and got stuff powered up ready to be time nut calibrated. 

I left the PCOXO powered up all night so it's nice and stable. Just calibrated the first victim. The VC2000. Will let it sit for a while then on to the next victim.

You guys KNEW I would go down this rabbit hole, didn't you?     

Please greet the rabbit from me when you meet him.   

[bd139]

Screens on windows do wonders for keeping mosquitoes outside. Don't they have them in the UK? 

Yeah I have actually got them but not on all windows.

Talking of which. I spent most of last night pleasing mosquitoes. Bastard things 

You need something like this:



Mosquito meets laser. 

Sold! 

[tggzzz]

I spent the vast majority of my adult life pleasing other people (read: women). Never again. This is MY time. 

Well said 

Talking of which. I spent most of last night pleasing mosquitoes. Bastard things 

Screens on windows do wonders for keeping mosquitoes outside. Don't they have them in the UK? 

Not normally, but there may be in some places I haven't seen.

When my mother arrived in Pittsburg in the late 50s, she wondered why screens were there, and left it open. She closed it the next day.

[Mr. Scram]

Yeah I have actually got them but not on all windows.

Sold! 

That's like using a condom with just a few holes.

[bd139]

Well not really. The other windows are mostly shut. Apart from when one certain teenager forgets to shut it and turns the light on 

[Specmaster]

Luckily she's not interested in living together as I am not interested. We both strongly agree on that.

I spent the vast majority of my adult life pleasing other people (read: women). Never again. This is MY time. 

Hmm, one thing I have learned is that women very very seldom actually mean what they say, generally meaning the reverse of what they say is their true meaning 

[nixiefreqq]

Here I am up already and got stuff powered up ready to be time nut calibrated. 

I left the PCOXO powered up all night so it's nice and stable. Just calibrated the first victim. The VC2000. Will let it sit for a while then on to the next victim.

You guys KNEW I would go down this rabbit hole, didn't you?     

naaaaaaaaw.  down the rabbit hole is when you stay up all night with your hand on the outer shell to make sure it is staying up to temperature while you log data on the damn thing. 

no doubt you will adjust your other oscillators, stop worrying, and be happy.

unless you make the mistake of using one of your analog scopes in xy mode to make lissajous figure comparisons between your oscillators.  don't do it man!  that can lead to the hard stuff!

 

[Specmaster]

I spent the vast majority of my adult life pleasing other people (read: women). Never again. This is MY time. 

Well said 

Talking of which. I spent most of last night pleasing mosquitoes. Bastard things 

That's the river Thames effect for you, I know its hard but in this heat and with those pests, keep the windows shut, fans on full and have a fully charged and armed electronic bug blasting bat handy, thats what I do.

[med6753]

So......VC2000, 1900A, 1912A, 7260A all calibrated with no issues. Left to do is the 2465DMS which is much more complex as shown in the attached link. But now that I have a more accurate reference I should be able to get closer than the current offset of 25Hz. The IG-4244 does drift somewhat from 1MHz so you have to monitor it just before applying the calibration constant.

https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg1937605/#msg1937605

[Ero-Shan]

I have quite a number of Philips manuals. Well over 400: GM, PE, PM.

Most service manuals.

Feel free to ask.

Frans

I guess everybody in this thread is interested to have user's and (especially) service manuals (in whatever form) of the gear he or she owns. Most definitely I am.

And I have several Philips thingies without them.
Most recent:

PM6603
PM5105  (I found one for PM5106/PM5107, but they have a different output stage on a daughter board)
PM6620
PM6669

and

PM2454  (The one I have is for a different device!?)

For these scopes I have only a user's manual:

PM3265
PM3266

Do you have any of them?

Edit: Of course I meant to thank you for your offer!

[bd139]

Here I am up already and got stuff powered up ready to be time nut calibrated. 

I left the PCOXO powered up all night so it's nice and stable. Just calibrated the first victim. The VC2000. Will let it sit for a while then on to the next victim.

You guys KNEW I would go down this rabbit hole, didn't you?     

naaaaaaaaw.  down the rabbit hole is when you stay up all night with your hand on the outer shell to make sure it is staying up to temperature while you log data on the damn thing. 

no doubt you will adjust your other oscillators, stop worrying, and be happy.

unless you make the mistake of using one of your analog scopes in xy mode to make lissajous figure comparisons between your oscillators.  don't do it man!  that can lead to the hard stuff!

 

That's how I calibrated my OCXO against the GPSDO. Addictive it is indeed.

[battlecoder]

So......VC2000, 1900A, 1912A, 7260A all calibrated with no issues. Left to do is the 2465DMS which is much more complex as shown in the attached link. But now that I have a more accurate reference I should be able to get closer than the current offset of 25Hz. The IG-4244 does drift somewhat from 1MHz so you have to monitor it just before applying the calibration constant.

https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg1937605/#msg1937605

I'm NOT saying that I want to calibrate my newly-acquired frequency counter, or that I'll become a time nut....BUT... if I wanted to do that, would this GPSDO be good enough for that purpose? https://www.aliexpress.com/item/32947070594.html

[tggzzz]

So......VC2000, 1900A, 1912A, 7260A all calibrated with no issues. Left to do is the 2465DMS which is much more complex as shown in the attached link. But now that I have a more accurate reference I should be able to get closer than the current offset of 25Hz. The IG-4244 does drift somewhat from 1MHz so you have to monitor it just before applying the calibration constant.

https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg1937605/#msg1937605

I'm NOT saying that I want to calibrate my newly-acquired frequency counter, or that I'll become a time nut....BUT... if I wanted to do that, would this GPSDO be good enough for that purpose? https://www.aliexpress.com/item/32947070594.html

Welcome to this rathole

You would get a more solid answer if you asked the question in the metrology forum 

I'd search there for the specific device, also for "Allen deviation" and "21ns glitch".

Summary: only you can define "good enough for your purposes.

[battlecoder]

So......VC2000, 1900A, 1912A, 7260A all calibrated with no issues. Left to do is the 2465DMS which is much more complex as shown in the attached link. But now that I have a more accurate reference I should be able to get closer than the current offset of 25Hz. The IG-4244 does drift somewhat from 1MHz so you have to monitor it just before applying the calibration constant.

https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg1937605/#msg1937605

I'm NOT saying that I want to calibrate my newly-acquired frequency counter, or that I'll become a time nut....BUT... if I wanted to do that, would this GPSDO be good enough for that purpose? https://www.aliexpress.com/item/32947070594.html

You would get a more solid answer if you asked the question in the metrology forum 

I'd search there for the specific device, also for "Allen deviation" and "21ns glitch".

Summary: only you can define "good enoughE for your purposes.

I actually searched the forums and the BG7TBL seems to be a popular GPSDO module...but there are several versions and revisions identified by the date, and the ONE almost encyclopedic thread that discussed this module currently does not have information about any of the 2018 revisions (which this one seems to be).

I guess my question was more oriented towards a general usefulness assessment from the time-obsessed crowd.  Is the accuracy of this kind of unit good for calibrating a (200Mhz, 7 digits) frequency counter? Do I need something more precise than this? Is it an overkill?  (The listing says that it's 100 times better than an OCXO, and boy you better believe that, because it's mentioned twice within the same paragraph). Should I invest more (or less) in another type of reference?

.... I mean... assuming I were interested in time accuracy, which I'm OBVIOUSLY not 

[0culus]

OK. I'll be away for work for the next day or so. But...I'll be back!

(Why do I feel like we've just gone head first down a massive rabbit hole? )

No doubt.   

[GreyWoolfe]

A crossover is a station wagon with way less room than a real station wagon. My grandfather drove a Caprice Classic wagon. That thing was likely one of the last American land yachts. It was HUGE!

When I married my ex-wife and her 2 kids, she had a 1974 LTD Country Squire station wagon in red You could see it a mile away and had its own zip code.  I hated changing in the snow tires, they weighted a fuckton.  We had the version that had the hidden storage instead of the fold-away 3rd seat.  400 CID engine, little 2 bbl carb but it could cruise at speed no worries.  Then we downsized to a 1985 Chevy Celebrity wagon.  I still like station wagons-they say it loud and proud.  Not like crossovers that whisper that they want to be station wagons when they grow up.  SUVs with unibody construction instead of body on frame are crossovers, only bigger IMHO.

[mnementh]

Yup... Unibody. Mom's was green, though.


The latter is a careless generalization; full-size cargo vans like the E350 and C3500 have globally been unibody since the 70s (and older even: my 64 Falcon van... about the size of a minivan nowadays... was also unibody) even in the 3/4 and 1-ton sizes. Nothing wrong with unibody in and of itself; it's when you cut corners to shave weight that hull integrity becomes a question.

mnem
4WD Cargo VAN FTW (Fuck The WORLD) !!! 

[tggzzz]

So......VC2000, 1900A, 1912A, 7260A all calibrated with no issues. Left to do is the 2465DMS which is much more complex as shown in the attached link. But now that I have a more accurate reference I should be able to get closer than the current offset of 25Hz. The IG-4244 does drift somewhat from 1MHz so you have to monitor it just before applying the calibration constant.

https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/msg1937605/#msg1937605

I'm NOT saying that I want to calibrate my newly-acquired frequency counter, or that I'll become a time nut....BUT... if I wanted to do that, would this GPSDO be good enough for that purpose? https://www.aliexpress.com/item/32947070594.html

You would get a more solid answer if you asked the question in the metrology forum 

I'd search there for the specific device, also for "Allen deviation" and "21ns glitch".

Summary: only you can define "good enoughE for your purposes.

I actually searched the forums and the BG7TBL seems to be a popular GPSDO module...but there are several versions and revisions identified by the date, and the ONE almost encyclopedic thread that discussed this module currently does not have information about any of the 2018 revisions (which this one seems to be).

I guess my question was more oriented towards a general usefulness assessment from the time-obsessed crowd.  Is the accuracy of this kind of unit good for calibrating a (200Mhz, 7 digits) frequency counter? Do I need something more precise than this? Is it an overkill?  (The listing says that it's 100 times better than an OCXO, and boy you better believe that, because it's mentioned twice within the same paragraph). Should I invest more (or less) in another type of reference?

.... I mean... assuming I were interested in time accuracy, which I'm OBVIOUSLY not 

Looks like my addition of "Welcome to this rathole" may have crossed in the æther, so I'll mention it again

I am far from an expert on such matters, but the timescale over which you measure the frequency/time is important.

In this case GPS is far more accurate at long timescales (less drift, more jitter due to atmospherics and clocks), but crystals, rubidium and caesium are better at short timescales (less phase noise / jitter, but more drift).

That is captured in the Allen deviations of various sources.

[med6753]

What is this? Throw back Thursday? Speaking of old station wagons. And GreyWoolfe mentioned Chevy Celebrity Station Wagon. Well, here was mine. 1986 "Eurosport" option although it was no where near a European inspired vehicle. 2.8 V-6 with a new feature called "Port Fuel Injection". Of course automatic transmission which true to GM form shit the bed at about 80K miles and cost a fortune to fix. The one nice thing it had with the Eurosport option was a free flow exhaust so the V-6 had a nice bark to it.

[med6753]

What the heck.....one more. I consider this my last "fast car". 1993 Chevy Cavalier Z24. Don't laugh mnem....it really would scoot. Why? Well, most Chevy Cavaliers were 4 banger/automatic slow pokes. Not the Z24 option. 3.1 liter V-6 with a Getrag 5 speed stick. Chirp the Goodyear Eagles in 1st and 2nd gear with almost no effort. That car surprised a lot of people....especially the ricer boys with their Civics and Accords.