Enertec 7150 (not Plus) (Solartron/Schlumberger) repair, upgrade and calibration

[DC1MC]

Hello, I've got a pair of Enertec 7150 and they arrived today.
They look reasonable good, even have some calibration sticker, they both start OK ( I was really afraid that the mains filter will blow in my face  any time ), one just starts normally and one blinks a calibration error but seem to measure something. When trying to see more of what are they capable of I've discovered to my horror that I don't have any un-shrouded probes  .
So I decided to do it properly and upgrade them.
A quick list of questions:

- Good quality shrouded banana sockets, is there any reliable source that delivers in EU, what are the models, sizes and caveats to look for ?

- What actually needs to be stuck in the back panel socket to activate the auto-calibration saving of the constants, a 3.5mm jack, a dumb nail or what, please clarify ?

- Are there any user and service manuals for the original ( not Plus version) ?

- The display LEDs, what diameter, 6mm ?

- Are there any bad caps that needs mandatory replacing ?

- Tips for inspecting and finding eventual issues that affects the calibration, also recommended maintenance ?

- Good quality probes that will help produce at least 4.5 digits of reliable data ?

Each and every answer will be very appreciated.

[kutte]

hi, did you google for SOLARTRON 7150 ?
Manuals are here:
http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=06_Misc_Test_Equipment/Solartron/Solartron_7150

Hints how to repair mains filter and how to replace banana sockets are here:
https://holzleitner.com/el/solartron-7150/filter/index-de.html

and 1st !!! of all replace the filter before it is too late see also here:
http://n4iqt.com/solartron/Solartron.repair.pdf

For cal you need a 2.5mm plug short circuited.
Have fun Kutte

[babysitter]

Did 5mm LED replacement and filter exchange (not cut-away method) after the filter went poof this year. Totally worth the trouble.
Unfortunately, the front/rear switch needed some special methacrylate love, too.

vy 73

Hendrik

[DC1MC]

Thanks to everybody that took the time to answer, sorry that my sickness and the efforts to do my dayjob has been holding me to answer early.
To summarize:
- The manuals for the non-plus variants have been found OK, God bless the kind soul KO4BB that hosts the manuals for these and many others, donated and I'll try to contribute the EEPROM contents for 7150 that seem to be missing, the 7150+ are there already.

- The software part of the calibration procedure is very clear and logic, the hardware plug is described in one manual as 2mm and in the other as 2.5mm, and I still have no clue, it's a stereo or mono jack and how are is the strapping done, but I guess I'll look closer into the schematic.

- The LEDs are confirmed 5mm, I've ordered 10 "milky" and 10 clear to be sanded, I'll see which is more pleasant to the eye.

- Replacing the panel sockets is a whole different  story, I was looking at the pictures of the mod and I've seen the the cuttings that have been done in the surrounding PCB  and thought, hell no, with my luck I may cut some trace in an inner layer, I still hope to find some sockets that are protruding more in the outside, to not have to cut the PCB.

In regard with the calibration, it seem that on fleabay there are available few precision Russian old new stock resistor decades, with 0.02% precision or better, on a very acceptable price, did some one used such things together with http://www.ebay.de/itm/AD584-4-Channel-2-5V-5V-7-5V-10V-High-Precision-Voltage-Reference-Module/221991435819 to build some kind of controlled voltage source, the specialized calibrators are out of my budget  .
Or any suggestion on calibration, I know that I will be faaaar away from the 6.5 digits, but still better then the 20% error now, I'll also measure the relays and surrounding components, barring a catastrophic failure of the calibration EEPROM, it's most likely something on the analogue front end.
Or if there's some one around Mannheim that has some calibration gear, please PM me.

 The fun starts in Christmas/eoy vacation

[kutte]

for calibration take one of these (or similar):
http://www.segor.de/#Q=KLST2%252C5MO-3x&M=1
...dont know the English word for "Klinkenstecker" (:| ... mono phone jack shorted internally by solder bridge.
(btw afaik there are no 2mm Klinkenstecker on the market)
and leave your banana jacks as they are now, I did not replace them. It is not so easy to find good quality replacements and very many people used these instruments without any hazards.

do'nt forget the filter, that's really important.

Kutte

[DC1MC]

Hi Kutte, thanks for the tip, I hope that 2mm is a typo, it could be that I have some obscure phone power supplies with a smaller Klinkenstecker (Jack plug)  I case the need arises, but the store has been bookmarked.
The problem with the panel sockets is that I actually don't have any suitable probes, if anybody knows some good quality probes without security shroud, I will appreciate a hint, sane I will appreciate an advice about some "getto" calibration methods, especially for AC.