EEVblog #1256 - Most Gorgeous Test Gear Teardown Ever!

[Bud]

It is called "gimmick capacitor"

https://en.m.wikipedia.org/wiki/Gimmick_capacitor

[rf-messkopf]

https://www.wg-foundation.de/fileadmin/templates/pdf/Fert_Prog.pdf
PSM-19 is on page 11. The price tag on page 4 says: 34.650 DM. I would agree around 45k$ today.

The PSM-19 was actually intended to be part of a combo of three instruments. The other two were the PS-19 "Pegelsender" (level transmitter) and the SG-4 "Sichtgerät" (display unit). Together these three instruments make up a very nice and high dynamic range low frequency scalar network analyzer that can even measure frequency converting DUTs.

But even alone the PSM-19 is still a very useful and capable instrument today, and is definitely worth fixing. It also makes good VLF, LF and short wave receiver, and could be used as a measuring receiver.

The coaxial connectors on these units are Wandel & Goltermann Versacon convertible connectors. The outer part of them can be detached and changed to another connector standard. There is a special wrench for them with a stud that fits in the holes in the connector body. A very nice system that unfortunately is extinct today (no idea if the W&G successor companies still make them).

By the way: There is a small Wandel & Goltermann museum near Reutlingen, where the company was headquartered. No idea if it's worthwhile, I haven't gotten round to visit it. Anybody been there? Link (German only):

https://www.wg-museum.de/

W&G also manufactured emergency vehicle lighting, sirens, and destination displays for trains, hence the police car in there. 

[schmitt trigger]

Unfortunately the museum, based on my scant German language abililities, it is only open to the public for a few hours every two months or so.

[szymon019]

Thank you: rf-messkopf about mentioning story about their Versacon connectors. I though to replace front connectors on my W&G SNA-2 (VNA) to something standard but since I saw how it is made I decided don't to touch this.

Maybe someone have 2pcs of 50Ohm BNC Wandel Goltermann Connectors and would like to share/ sell them in some normal price to Poland?

Kindly Regards
Simon

[rf-messkopf]

Maybe someone have 2pcs of 50Ohm BNC Wandel Goltermann Connectors and would like to share/ sell them in some normal price to Poland?

Sometimes they pop up on ebay, for example auction 223660316714 for a lot of five (I'm not affiliated with that auction):
https://www.ebay.com/itm/Wandel-Goltermann-Versacon-Einsatz-BNC-5Stk/223660316714?hash=item341331982a:g:nckAAOSws0JaYguJ
No idea if they are 50 Ohms and will fit on the SNA-2. Another idea might be to ask some German used equipment dealers.

Unfortunately the museum, based on my scant German language abililities, it is only open to the public for a few hours every two months or so.

True. And you have to register in advance. But according to the website it's free, includes a guided tour and a talk, and a light meal will be served. Plus Reutlingen has a beautiful historical center and is located in a very pleasant area.

[BrianHG]

Is it just me, or, does it appear that they deliberately scratched off the part numbers on these 3 transistors I circled in red?



2 of them appear to have 3 pins while the third is a four pin transistor/fet.  Must be some kind of secret sauce...

[langwadt]

Is it just me, or, does it appear that they deliberately scratched off the part numbers on these 3 transistors I circled in red?

(Attachment Link)

2 of them appear to have 3 pins while the third is a four pin transistor/fet.  Must be some kind of secret sauce...

might have the print on the side instead of the top

[langwadt]

I wonder what such a thing might have cost when it was new

[BrianHG]

Is it just me, or, does it appear that they deliberately scratched off the part numbers on these 3 transistors I circled in red?

(Attachment Link)

2 of them appear to have 3 pins while the third is a four pin transistor/fet.  Must be some kind of secret sauce...

might have the print on the side instead of the top

A closeup of the top-right transistor looks like it still shows a little of the part-number ink at the edge of the scratch/sanding marks.
The other 2 also have a rough scratched appearance on top of them.
Without better photographs or side view, we cant be sure.

[mengfei]

I wonder what such a thing might have cost when it was new

I wonder why parts are soldered on the copper/ trace side, more prone to shorts

[Kleinstein]

Is it just me, or, does it appear that they deliberately scratched off the part numbers on these 3 transistors I circled in red?

(Attachment Link)

2 of them appear to have 3 pins while the third is a four pin transistor/fet.  Must be some kind of secret sauce...

might have the print on the side instead of the top

A closeup of the top-right transistor looks like it still shows a little of the part-number ink at the edge of the scratch/sanding marks.
The other 2 also have a rough scratched appearance on top of them.
Without better photographs or side view, we cant be sure.

Some of the To18 case transistors have there marking on the side.  There are some RF transistors with an extra 4 th pin for the case.
There are even service manuals available - so not much secrecy.

It is a complicated, high end instrument, but still the parts on itself don't really need very special performance. It is more about really keeping things isolated - thus the large number of separate shielded boxes. Though the input signal is only up to 25 MHz, there seem to be an internal 40 MHz IF. The main concept is likely more like a low frequency spectrum analyzer in the old way - so the similarity to an SA in not such a surprise. It is low frequency, but high accuracy.

[EEVblog]

I wonder what such a thing might have cost when it was new

Someone said US$45k in todays dollars

[EEVblog]

C'mon Dave, we gotta see inside that power supply!
I can't believe it's that difficult to access in a design like that. 

Maybe not, but I knew the video was already way too long.
I have to do a part two because apparently I missed an entire side of cans! 
I might clear some bench space to set it up for a semi-permanent repair series.

[langwadt]

I wonder what such a thing might have cost when it was new

I wonder why parts are soldered on the copper/ trace side, more prone to shorts

several components go to single pads so it must be a dual sided pcb

[JeanF]

back in 2016 when I was collecting stuff for a GPSDO (in the end this project never started, but I'm still thinking about it from time to time) I bought the oscillator that can be seen at the 20 minute mark on ebay for cheap.

Do some of you have documentation about this oscillator ? I wasn't able to find any datasheet, I think I managed to find Vcc and GND and the output pin, but I didn't find what the 4th pin is. It seems to be not connected to anything but I can't be sure and I don't want to open the can. I thought it could be VCO control pin but I wasn't sure about how to check that without risking damaging anything. And there is a screw for adjustment showing through a hole in the can, is it possible to have at the same time a mechanical adjust screw AND a VCO control pin?

Unfortunately I don't have the PCB anymore, only the blurry picture (not mine, from ebay listing) attached.

The fact that I don't have the datasheet nor the full pinout is a serious limitation to using it for anything too serious, but what do you think I could still use this XO for ?

[rf-messkopf]

Do some of you have documentation about this oscillator ?

Sorry, I don't have a datasheet. But the manufacturer is Quarzkeramik GmbH. They were bought by Kristallverarbeitung Neckarbischofsheim in 1997. You can try to ask there, but I wouldn't have too much hope. Link to their homepage: https://www.kvg-gmbh.de/.

[Fungus]

Is it just me, or, does it appear that they deliberately scratched off the part numbers on these 3 transistors I circled in red?

It's just you.




Think: Those things come with full schematics...

[wn1fju]

As rf-messkopf alluded to in the earlier post, one can make a very nice scalar network analyzer with the PS-19 generator, SPM-19 receiver and SG-4 display unit.  Here's a picture of my setup measuring the frequency response of a 7.15 MHz center frequency bandpass filter (not shown).  Enjoy!

(and it took a while to make up all the cables one needs to get these three things to play nice)

[xi00]

As rf-messkopf alluded to in the earlier post, one can make a very nice scalar network analyzer with the PS-19 generator, SPM-19 receiver and SG-4 display unit.  Here's a picture of my setup measuring the frequency response of a 7.15 MHz center frequency bandpass filter (not shown).  Enjoy!

(and it took a while to make up all the cables one needs to get these three things to play nice)

Hi. Does anyone know if it is possible to use the SG-4 display unit without the SPM-16/19, ie providing the x and y deflection voltages on the 14pos connector(i think using cable K145) manually and not interfacing with the IEEE-488 bus at all? I am asking because i couldn't get my hands on a manual for the SG-4, but according to the SPM-16/19 manuals it is possible, at least for the SG-2/3, and i only have the SG-4 and none of the other instruments.
Thank you in advance

[wn1fju]

There might be a work-around if only we had the manual.  I never found one, although I haven't searched again in quite a while.

On my SG-4, if I power it up without hooking it up to the other equipment, all I get is the message "SPM ?" on the screen and the unit is otherwise
totally unresponsive to the front panel.

If I recall (it has been a few years since I had everything running), it wants to see both the 14-pin analog and the 24-pin GPIB cables hooked up.
And if the GPIB settings aren't right on the SPM-19, it will pass by the "SPM ?" message and the screen will say "GP-IB?". 

Not that it can't theoretically be done, but it looks as though W&G really intended the SG-4 to work only with the SPM-16/19 receivers.

[rf-messkopf]

There might be a work-around if only we had the manual.  I never found one, although I haven't searched again in quite a while.

You can order photocopies of the SG-4 manuals from Rainer Förtig in Germany. See his price list at http://rainer-foertig.de/unterlagen/WG-9_2009.htm.

Translation:
"Service-Unterlage ohne Schaltbilder" = service manual without schematics
"Beschreibung + Bedienung" = operations manual
"Schaltbilder" = schematics

The manuals I got from Rainer Förtig in the past were all of excellent quality.

Edit: I forgot to mention that the manuals might be in German. You should ask before ordering.
Edit 2: The price list actually says that they are in German.

[xi00]

The language shouldn't be a problem as I'm from Austria, and thanks a lot so far.

Maybe it is possible to "hardcode" some required GPIB init messages and then it works without more GPIB, i will see what can be achieved with the manuals...

[Syntax Error]

Dave, indeed a master class in construction.

How many drawings do you think it took to make this? I suspect the designer's other jobs were in avionics and space systems, as there's very little waste of anything. Hardware like this kept a lot of skilled people in work. And if you find any youngsters complaining that FPGAs are "a bit difficult", show them how it was done... analogue style.

[thinkfat]

Look what I found in an old EEVblog video:

https://youtu.be/3yTL06ZU5SU?t=249

Hint: Top shelf on the left side.

[German_EE]

Good spot!