WTB : Scanner card for 3 Solartron multimeter models: 7061; 7071; 7081

[Djil]

I'm looking for these cards for these three multimeter models: 7061; 7071; 7081.
  - These optional scanner boards provide eight additional input connectors.
  - Please find an example below

Thank you for all your suggestions.
Best regards
Dj

[branadic]

I've only found the pictures provided here:

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg2380377/#msg2380377

With the relays at hand it shouldn't be too hard to replicate the scanner board.

-branadic-

[Kleinstein]

The relay card shown still has quite some extra logic to go with it. It is more than just some  shift registers and drivers and one would need some kind of plan or details description of the interface to buit such a card.

[coromonadalix]

Even duplicating the schematics if they are available into a pcb,  the coto relays must be expensives as hell ??

[Djil]

Hello,

Thank you for the link.

Best regards
Djil

[codaroma]

Apologies for the nostalgia. I worked for Solartron back in the late 80's, early 90's in Farnborough, UK. I was an engineer involved in designing the IMP and Orion product lines. My lab booth was right next door to the DVM guys' booth. They were all in their 50's and really knew their shit. As a youngster I was always a bit intimidated by working along side these geniuses designing equipment capable of accurately measuring nano volts.
https://books.google.com.au/books?id=MUzc2MoLONAC&pg=PA627#v=onepage&q&f=false

[Djil]

Hello,

Thank you for the link.

Best regards
Djil

[meandeev]

I don´t want to sell my card, but I can provide detailed photos if you wish.
The card is only for 7061!

[Djil]

Hello,

I really appreciate these pictures.
Thank you very much.

Best regards
Djil

[Djil]

Hello,

I really appreciate these pictures if you have a moment to do them.
Thank you very much.

Best regards
Djil

[manganin]

I'm looking for these cards for these three multimeter models: 7061; 7071; 7081.

The Solartron 7071 and 7081 have a D25 connector called Minate bus for connecting an external scanner. The bus is simply an 8 bit BCD, so it is easy to make your own scanner. There can be up to 127 channels and also a 5V 100mA supply is available, which is very handy.

The bus pinout can be found here on page 1.4.
http://www.perdrix.co.uk/Solartron7081/Solartron%207081%20User%20Manual.pdf

The bus was originally designed to control the Solartron 7010 Minate which is a 16-way 4-wire scanner from the 7075 era. The 7010 was made of hermetic reed tubes operated by electric magnets on the opposite side of the printed circuit board. That provided low leakage and very long life. I still have two units left, but the 7010 seems to be very rare nowadays. I couldn't even find a photo online.

The 7061 was designed as a system voltmeter and had an option for a built in scanner card as already mentioned.

As far as I remember the original 7061 scanner card was not very good and limited to only 8 inputs. That is why I designed a set of 32-way scanners using a DIN41612 multipole connector for the inputs (best known from Euro card format and provides up to 96 pins of decent quality gold plated contacs in a small space). The connector idea was probably stolen from the Prema scanner multimeters.

The trick was that, even though mechanically different, the 7061 also has a Minate bus. It can found in a DIP IC socket on the main PCB. The socket accepts a DIP flat cable connector which was back then more common than the current IDC connectors.

With a DIP to D25 cable it was even possible to control the 7010 scanner directly.

[Djil]

Hello Mangamin,

Thank you for these details.

Best regards
Djil

[005]

While looking around for the Fischer connectors for my newly aquired 7061, I came across this thread and read you would appeciate some photos.
Here you are!

[Djil]

Hello,

Thank you for these picts.

Best regards
Djil

[hu_lin]

我有一台7010，但状态不太好。

[Kurets]

I am working on a semi-clone of the 70612A scanner card. I guess a lot can be said about other alternatives like: external box controlled by 7061, external box controlled by AVR, etc. But my feel is that this is quite clean.

I don't know if OP is still looking, but thought to share it in case as I will probably end up with spare PCBs.

[Djil]

Hello,

Thank you for this information.
I'm interested in it.

To build one and keep spare PCB also.

Best regards
Djil

[Kurets]

An update.

I have now assembled and integrated the board in myu 7061. The board has some bugs which needed workarounds, nothing major:

• Pinning of DIP16 ribbon cable plug is 16, 1, 15, 2.. etc. I had expected 1, 16, 2, 15.. which means that the cable needs to have every second pair twisted
• A trace needs to be cut between U3 and U4 due to misreading of the schematic
• The OHM V+ and V- labels on the board are flipped, but the TP/DP numbers are correct

Some more general info: I built the board using COTO 3500 and 2300 series relays. This (of course) drives the cost quite a lot, but I found a decent deal on Ebay for the 3500 relays and decided it was worth it. I realize that this might not be ideal if you dont have a source which can give you a discount so the spare PCBs may not be very useful. So I have therefore put all the design files in a Onedrive folder that I can provide a link for to those interested, I am hesitant to share a link in a public forum. The folder contains the Kicad project for the board along with library files and a drawing for the back panel.

Otherwise the schematic is more or less identical to the one found in the service manual with exception to replacing the octal diode package with discrete LL4148s and using an 11V Zener instead of the 30V (!?) which is shown in the parts list. I also added footprints for SMD decoupling capacitors instead of the ceramic disc caps used in the original design.

The back panel and mounting bracket is very improtant for this as the 20+ relays are very heavy and the board is only mounted on two standoffs in the opposite end of the bard from the main mass of relays. I chose to make the mounting bracket from a piece of 15x25mm angle iron just because I had it at home, but given the size of the mini-XLR plugs, I think a 25x25 angle would be better.