Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Shitty interpolation o clock?

[Mr. Scram]

Shitty interpolation o clock?

Maybe? It doesn't really sound like it and they don't seem to be beating around the bush.

"Real time sampling: In this mode the system makes full acquisition to fill the memory. Maximum real time sampling rate is 1GS/s. At a setting of 50ns or faster, the oscilloscope will automatically carry out interpolation, i.e. inserting a sampling point between other sampling points."

[Cubdriver]

Excellent. The 5325B is a nice unit.  It's more than likely got the old PS-163 oval power connector.  It's got a switchable mains input, so it's happy on 120 or 230, and I'd be unsurprised if it just works if you get power to it.

This is one I got a few years ago; I haven't yet fully wrung it out, but it seems to work at least partially based on some very limited testing.  The push button switch array mechanics may need some lubrication.


More pics at
https://pmanning.smugmug.com/Electronics/HP-5325B-Universal-Counter

-Pat

Thanks for the encouragement. IIRC, my HP 140A oscilloscope had the same power jack. First thing I did was to replace it with a IEC C14 standard connector, even it involved filing. The Nordmende counter came with a C10 jack, which I likewise exchanged with a C14 that fit quite well. And I still have quite a few of them. 

That's weird - I don't see the image I inserted in my original post, but it is showing up in your quote.   

-Pat

[mnementh]

SMDs are awesome for a lot of things in prototyping/one-offs... especially the smaller passives which lend themselves to being installed deadbug-style directly between pins of semis.

I had a Tek 485 with a faulty hybrid. Tacking an SMD resistor in the right place "repaired" it to the extent that its risetime was 1.25ns rather than 1ns. I pointed that out to the person that bought it; he was happy, so was I.

"Necessity is the mother of invention; being skint is the father."

In short; well and properly MacGyver-fied! 

Every time you take something to bits you have to do it twice; it's the rules.

The other kind of TEA...

A few pages back I had a "fuck it" moment and decided to build a voltmeter because I missed my old HP 427A for poking around in RF circuits with an RF probe. Now I can't replicate that to any standard but I can get some of the way there.

Quick update ... enclosure sorted.

Gubbins:



Outside:



Todo: legend and divider (awaiting resistor delivery mid-next-week). Linearity is crazy good and it doesn't need zeroing regularly so slightly better than the average

Nice & tidy, no-nonsense modular meter frontend. I like that; reminds me of my collection of "Fieldpiece" MV meter and modular heads to go on it.

Excellent. The 5325B is a nice unit.  It's more than likely got the old PS-163 oval power connector.  It's got a switchable mains input, so it's happy on 120 or 230, and I'd be unsurprised if it just works if you get power to it.

This is one I got a few years ago; I haven't yet fully wrung it out, but it seems to work at least partially based on some very limited testing.  The push button switch array mechanics may need some lubrication.


More pics at
https://pmanning.smugmug.com/Electronics/HP-5325B-Universal-Counter

-Pat

Thanks for the encouragement. IIRC, my HP 140A oscilloscope had the same power jack. First thing I did was to replace it with a IEC C14 standard connector, even it involved filing. The Nordmende counter came with a C10 jack, which I likewise exchanged with a C14 that fit quite well. And I still have quite a few of them. 

That's weird - I don't see the image I inserted in my original post, but it is showing up in your quote.   

-Pat

You know, seeing all these counters made me just think of a new arduino project... Well, probably not new; SOMEBODY must have come up with it already. Program it to output a square wave in MHz that increments every second, so you can use any counter (or collection of counters) as a "Display" for the clock.


mnem
*TV time with the kiddles*

This is one of my favorite Nixie Clocks so far:

[bitseeker]

I 'need' a Nixie testgear something but just what IDK 

 

The nixie variety generally tend towards boat anchorishness, though, unless you go for smaller units like the Fluke 8100/8120/8200 for meters, and HP 5221/5321 or GenRad 1192 types for counters.  I'm sure there are other ones too, those are what I'm familiar with.

 

For more digits without crossing without entering boat-anchor territory, there's also the HP 5216A (seven choobs). It's only 12.5 MHz, but you could make 10x pre-scaler for it.

[bitseeker]

You know, seeing all these counters made me just think of a new arduino project... Well, probably not new; SOMEBODY must have come up with it already. Program it to output a square wave in MHz that increments every second, so you can use any counter (or collection of counters) as a "Display" for the clock.

Yep! It's on my to-do list for the aforementioned HP 5216A. Since I haven't tried it yet, I wonder how useful the last digit will be. It might turn out to be quite jittery, which could add some character to the "clock."

[beanflying]

This for here is most appropriate  Spotted last night on evilbay for sale.

[beanflying]

I have a few divider and multiplier chips due tomorrow from Mouser. The plan is to take one of my aged 3.2Meg OXCO Polytrons and multiply it up then divide it back down referenced back to a GPS.

I was going to go old school hex/binary rotary encoder switches for control but a 4 or 5 way switch for the multiplier and a rotary encoder/display handled by an Arduino is making more sense due to the 64 steps.

Multiplier https://au.mouser.com/productdetail/863-nb3n501dg

Divider 64 step https://au.mouser.com/productdetail/595-sn7497n

To give 4 main range 50, 100, 200 & 400kHz increments to a bit over 20Meg.

[HalFET]

Whats the input impedance of this then?

10M. The divider, that doesn't exist yet, is responsible for setting the impedance between the terminals which is always less than the measurement amplifier. It's hacked up to measure direct without the divider at the moment so it's 10Tohm or the insulation resistance or leakage somewhere at the moment. If you put your hand near it, it pegs at the moment unless you stick a low impedance source on it.

Why 10M? Can use it with the RF probe I made for my VTVM then (if I chop the 1/4" jack off it):

Nice construction, my only remark is that you can make it even better by using old tungsten wafer probe needles. 

[tggzzz]

Nixies are boring.

Has anybody found any test equipment using NIMO tubes for a display?

[bd139]

Yes those tubes are rather nice.

I have a mostly abandoned project in my ideas notebook which consists of going one step further and building an "overkill clock" using 4x VCR139A tubes (because they're easy to drive) and use one per digit. I have designed and prototyped the power supply for it already, well lifted the design from the Philips PM2524 anyway and bodged it. It was the experimental base for me playing around with E-core ferrite transformers. So far I made a very loud voice coil by accident which immediately makes people cover their ears 

Also I don't have a VCR139A tube yet. I have a 3JP1 but that requires stupid 2KV acceleration which is a total PITA to wind a transformer for that doesn't arc out. An hour winding it and "phut" straight away

Back to the drawing board

Nice construction, my only remark is that you can make it even better by using old tungsten wafer probe needles. 

Those would be nice. Nice and sharp!

[beanflying]

I'm Excited 

Something Aussies will understand The front panel on the HP was covered in LED baked glue residue and curved from the heat too. Nothing was shifting it until Big Kev came to the rescue followed by some careful heat from my rework gun with no nozzle at 180C.

[BU508A]

Nixies are boring.

Has anybody found any test equipment using NIMO tubes for a display?

If you found Nixies boring, why not trying seven little thyratrons (per tube)?



These tubes are called ITS1A or ITS1B and in opposite to the NIMO ones, you can get them on ebay.
But they aren't cheap as well.

[Specmaster]

I'm Excited 

Something Aussies will understand The front panel on the HP was covered in LED baked glue residue and curved from the heat too. Nothing was shifting it until Big Kev came to the rescue followed by some careful heat from my rework gun with no nozzle at 180C.

WTF LED baked glue residue??

[neo]

Just curious, but does anyone here have experience with the 8500A? What are my chances of getting one that isn't screwed is my question 

[beanflying]

The stock LED's have run so hot over time the faceplate had bowed 4-8mm out. Evidence of stickers being removed and that leftover glue had baked hard and didn't want to soften with the usual.


https://youtu.be/4cl5MWyM78Q

[bd139]

OMG it's an Aussie Barry Scott:

[Specmaster]

OMG it's an Aussie Barry Scott:

Whats the betting the products are identical, just given different names and made by the same company?

[mnementh]

Nixies are boring.

Has anybody found any test equipment using NIMO tubes for a display?

If you found Nixies boring, why not trying seven little thyratrons (per tube)?



These tubes are called ITS1A or ITS1B and in opposite to the NIMO ones, you can get them on ebay.
But they aren't cheap as well.

Ooooh... those would be very nice in a project that incorporates a 6E5C "Tuning Eye" and maybe one of the smaller electro CRTs like a 2AP1 or 3BP1 used in Jon Stanley's CRT clock.

Speaking of tubes... has anybody seen a useful project for the Russian-made 1J17B/1J24B/1J29B battery-op micro pentodes that are flooding eBay right now? They're SO cheap... you just wanna make some kind of steampunk gimcrackery out of a handful of 'em.


mnem
*Feeling warmed by the cathode's glow*

[tggzzz]

Nixies are boring.

Has anybody found any test equipment using NIMO tubes for a display?

If you found Nixies boring, why not trying seven little thyratrons (per tube)?



These tubes are called ITS1A or ITS1B and in opposite to the NIMO ones, you can get them on ebay.
But they aren't cheap as well.

Strange; never heard of those! But they look too much like green LEDs ;(

[bd139]

Green 7 segment displays are cheaper too 

[Specmaster]

Green 7 segment displays are cheaper too 

I like them.

[bd139]

On the subject of green LED displays I saw these the other day: https://uk.rs-online.com/web/p/led-displays/8770779/

3x5mm sized characters.

LED wrist watch anyone?

(yes I know you'd need to disable the display if not in use )

[mnementh]

Nixies are boring.

Has anybody found any test equipment using NIMO tubes for a display?

If you found Nixies boring, why not trying seven little thyratrons (per tube)?



These tubes are called ITS1A or ITS1B and in opposite to the NIMO ones, you can get them on ebay.
But they aren't cheap as well.

Strange; never heard of those! But they look too much like green LEDs ;(

Naaahhh... I can see a distinctive difference in the richness of the color that you rarely see from LED. I get it... not willing to pay the price for it, but I get it.

I think this might be more to your taste.


50 Pc Grab Bag LED Modules $US20 at Jameco



mnem
*Lit*

[SeanB]

Got a really nice Medelec display in the list for Xmas teardown. GE CRT's in there, and i just tried powering this up and it still works, though with one having a P37 ultra slow phosphor, and the other CRT being a flat face brilliant white fast tube, designed to be used as a photo printer onto some self developing paper ( Weird stuff, looks like regular thermal paper, but responds to bright light by darkening, though as it is now around 30 years old it really is poor contrast now, but does respond to the blue laser pointer quite quickly) as a semi permanent recording method. was some physiological recorder, but all i have left is the CRT display section, that has a 4 channel display, and some assorted controls for the 4 chopped traces.

Still got to see if I can get the Domino A200 printer in some sort of running mode, or at least get the passcode for the service or maintenance menus, or even any manual.