Test Equipment Anonymous (TEA) group therapy thread

[TERRA Operative]

Something arrived today. 

[pdenisowski]

Yep. For entertainment sake: wiggle a BNC cable on a VNA in 'thru' mode and watch the plot on the screen...

You can fix that if you use a BNC torque wrench    

[TERRA Operative]

Yep. For entertainment sake: wiggle a BNC cable on a VNA in 'thru' mode and watch the plot on the screen...

You can fix that if you use a BNC torque wrench    

I'll check aliexpress for one of those. lol

[PA0PBZ]

Here you go: https://www.mathews-engineering.com/store/p3/BNC_Tool_-_Connector_Tightening_Wrench.html

[Vince]

Micropross ROM 3000U EPROM Programmer

Season #2 has already started it seems !

You can find the latest episode by clicking here --> > >

https://www.eevblog.com/forum/repair/vintage-chip-programmer-micropross-rom-3000u/msg4609888/#msg4609888

Today we scoped the serial link between the MS-DOS S/W on the computer, and the programmer.

... because the S/W doesn't tell you what the settings are. It only tells you how to set the DIP switches at the back of the programmer but you don't know what these switches mean at all either.

Well now that we know the data format, we can configure a terminal and talk to the programmer directly ourselves ! 

.. but there is just one little problem left before we can do that.... read on 

[TERRA Operative]

Here you go: https://www.mathews-engineering.com/store/p3/BNC_Tool_-_Connector_Tightening_Wrench.html

I got this one!

https://www.tomoca.co.jp/brand/tomoca/tom_rec_63p/bnc-box-wrench/

(I didn't pay that much for it!)

[McBryce]

Picked up 5 of these for a bit over a tenner to fix the Fluke 80K-40. The connections aren't exactly what I had hoped for, but they are from Pomona and should do the trick.

McBryce.

[DC1MC]

Dear TEA members, I have decided that before I'll get too old to care, to have nice discussion over GPIB with my TE, so I've ordered 10 PCBs for the buffered version of the AR488 design of WaveyDipole and Jay_Diddy_B, I have assembled two of them and I still have two full kits and a number of PCBs.
The buffered version should be WAY better than Prologix and NI interfaces, ca. 10-15 times cheaper, if not more, and easy to do (it took me 10min to solder them). Also the software was extensively tested and it can fully emulate well known commercial devices.
I want to spread the boards and kits at cost, mostly in Germany (not sure if it makes sense anywhere in EU, but feel free to ask if you have good cheap shipping options, if not, DHL it is).
I can also solder them for you, because my Metcal begs for some action .

Pictures are here: https://www.eevblog.com/forum/projects/ar488-arduino-based-gpib-adapter/msg4610047/#msg4610047

Anyone interested, PM me.

 Cheers,
 DC1MC

[Vince]

Micropross 3000U EPROM Programmer


MAJOR UPDATE.... there ---- > > > >

https://www.eevblog.com/forum/repair/vintage-chip-programmer-micropross-rom-3000u/msg4610500/#msg4610500

As of a few minutes ago.... we successfully managed to interact with the programmer manually, using a terminal...

All the serial commands are documented so in theory I can do anything and everything with that programmer now... it basically works !

Now it's only a matter of time before I can program an EPROM with this thing.... that will be the core of Season #2 in 2023.

Please don't forget to renew your subscription to The ElectroFrog channel so you don't miss the next season !!! 

[Neomys Sapiens]

Micropross 3000U EPROM Programmer


MAJOR UPDATE.... there ---- > > > >

https://www.eevblog.com/forum/repair/vintage-chip-programmer-micropross-rom-3000u/msg4610500/#msg4610500

As of a few minutes ago.... we successfully managed to interact with the programmer manually, using a terminal...

All the serial commands are documented so in theory I can do anything and everything with that programmer now... it basically works !

Now it's only a matter of time before I can program an EPROM with this thing.... that will be the core of Season #2 in 2023.

Please don't forget to renew your subscription to The ElectroFrog channel so you don't miss the next season !!! 

..Tossing some EPROMS on the 'for Vince' heap..

Are you sure that 'The ElectroFrog' is not taken by a certain Mr. Volta?

[Neomys Sapiens]

And here we have rescued a Siemens VD35 (VD = Verdrahtungstester = Wiring tester) from the scrap heap by exchange of the badly corroded battery clip.
It is exactly what it looks like - a 'squeaky box' with three ranges. The variation of the tone within a range is much more useful and precise than the instrument. Note that it does have a 'zero adjust', but none for volume. The tone it makes is squeaky and not very pleasant indeed, so that I will continue to prefer my Unitest Ohmvariant (which can also by varying the contact pressure by one#s fingers used superbly to irritate a cat or simulate he presence of one).

Nevertheless, I might even refit a 'Volume' pot and maybe renew the barely readable lettering for the ranges. I think I even know where those bloody transfer letters are. One has to remind oneself that this device was sold with a typical Siemens price tag of several hundred DM. Should I become annoyed by it's presence in some box, it will find a taker.

[factory]

Picked up 5 of these for a bit over a tenner to fix the Fluke 80K-40. The connections aren't exactly what I had hoped for, but they are from Pomona and should do the trick.

McBryce.

They do a version with a cable guide that might be better for the Fluke probe.

Datasheet https://www.pomonaelectronics.com/sites/default/files/d_MDP-4892-4898_102_10.pdf



David

[Neomys Sapiens]

Here you go: https://www.mathews-engineering.com/store/p3/BNC_Tool_-_Connector_Tightening_Wrench.html

WTF? They let you enter all the data and it is possible to select 'Germany' as the destination country only to tell you 'that this shop does not ship to this destination' after you have completed the form.
 

[Andy Watson]

P.S. Here are some pictures showing the condition of the original custom IC from the DMM2, slight issue with iron oxide, mixed with corroded copper.

"Custom IC" ! Advance certainly liked to get their own logo on the main chips, however, I suspect these are starndard GIM chips that have been labelled with Advance's in-house number. The GIM AY-5-4057 looks pretty close in function - not sure about the pin-out though.
  AY-5-4057.pdf (48.67 kB - downloaded 72 times.)

I have been resuscitating an Advance Alpha II DVM. The main chip claims to be a GIM T4. It's suspiciously identical to an AY-5-3500 in both pin-out and function! This DVM has been worked-on before it came into my hands - I can tell - the main chip was in backwards!

[factory]

Yes I suspect it's a custom version of that, pinout is different of course, there might be differences in functionality, logic levels, etc.
The AY-5-4057 is not an easy to obtain part these days, not sure I would want to pay a lot for something ancient, that might be just as broken as the original part. 

This was mentioned in another thread on this forum, it's where I found the logic analyzer data, that has been helping with this project.

David

[factory]

Here you go: https://www.mathews-engineering.com/store/p3/BNC_Tool_-_Connector_Tightening_Wrench.html

WTF? They let you enter all the data and it is possible to select 'Germany' as the destination country only to tell you 'that this shop does not ship to this destination' after you have completed the form.
 

As bad as this webshop then, no shipping to the EU since July 2021, they think Scotland is part of the EU  (wonder if they got confused with Ireland), but shipping to UK is apparently fine. 

https://talonelectronics.com/shop/custom.aspx?recid=1

David

[Robert763]

I have HP 1250-0780 N-to-BNC adapters, so pretty decent ones I guess.

Thing is, most measurements are on the far end of some cable and generally not hanging on the adapter so we need to measure just the DUT not the cabling and adapters to it so our Cal kits need be in a form that suits our DUT and/or cabling.
Cal kit gender and form should drive your needs otherwise you'll end up with a selection of different type Cal kits.

When I looked at this a while back not wanting to throw a fortune at it SMA was selected as all manner of reasonably priced cabling and connectors were readily available and in reality you Cal any influence they have on measurements out anyways.
You just need a reasonable SOLT collection and for the quality of measurements the novice does the don't need be super flash to obtain real world results.

Go have a look here for the result I got with just a bit of mucking around and not a Cal kit in sight and only a N-BNC adapter uncertainty as the feedline coax was an integral part of the DUT.
https://www.eevblog.com/forum/rf-microwave/antenna-project-log/

No cal kit means your amplitude (and phase) measurements are meaningless. That does not stop you tuning the antenna though. The same could be done with a signal generator coupler and detector.
Also the "SVA1015X in VNA mode Log Mag"  and "VNA SWR"  plots are electrically identical they just have different amplitude presentation. A 1.014 SWR = -43 dB return loss so the two are well withing measurement error.  The -40 dB return loss seems rather good. Better in fact than a Keysight 909A 50 Ohm load (-32 dB spec).

I'm not knocking your post, just saying that you could have done this 10 years ago with basic TE and pretty pictures from modern TE don't mean better measurements. Yes the VNA makes it easier on the face of it. However it does not do much for understanding.  If you used a 315 MHz AM modulated from a sig gen, a coupler (can be home made) and a diode detector feeding a audio amplifier and "tuned" the antenna for minimum audio level the end result would be the same for the antenna. You would not have any values (but without cal kit the ones from the VNA are just numbers) but would probably have a better understanding of what was going on.

Robert G8RPI.

[McBryce]

Picked up 5 of these for a bit over a tenner to fix the Fluke 80K-40. The connections aren't exactly what I had hoped for, but they are from Pomona and should do the trick.

McBryce.

They do a version with a cable guide that might be better for the Fluke probe.

Datasheet https://www.pomonaelectronics.com/sites/default/files/d_MDP-4892-4898_102_10.pdf



David

That would have been useful, but I think the cable of the 80K-40 is thin enough that I could drill a hole in the top surface and feed the cable through for a slimmer version.

McBryce.

[Mortymore]

Have a great 2023 

[Neomys Sapiens]

A most successful, enjoyable and fully instrumented new year to all denizens!

[Vincent]

Came across one of these on fle@bay:



A unit sold for parts or repair, minus the test probes (alligator clips leads seem to be included though) for $CAD45 shipped to my door. I'll challenge myself to repair it. Wish me bad luck!

[DC1MC]

Came across one of these on fle@bay:



A unit sold for parts or repair, minus the test probes (alligator clips leads seem to be included though) for $CAD45 shipped to my door. I'll challenge myself to repair it. Wish me bad luck!

Break a leg 

[TERRA Operative]

Paralleled vregs? My skin crawls....

[AVGresponding]

Came across one of these on fle@bay:



A unit sold for parts or repair, minus the test probes (alligator clips leads seem to be included though) for $CAD45 shipped to my door. I'll challenge myself to repair it. Wish me bad luck!

In this case, having good luck means not being able to repair it...

[Wolfgang]

No reason for a skin problem. A lot of appnotes show how to do it for all kinds of linear chips. The simple trick is a small equalization resistor.