What are these boards from? Who can make use of them?

[1audio]

In cleaning a pile of stuff in my shop I saw these boards I had picked up at some swap meet or???

They are out of some IET instrument. Probably an earlier version of a resistance standard. I really don't have use (I have a JRL and an ESI resistance standard box) but they should not go into e-waste, especially with all those relays.

[Vgkid]

Who made the resistors , they look interesting.

[1audio]

They are large and seem to be wirewound. There are no mfr. markings just some numbers and a value. The whole PCB is conformally coated so its not easy to connect to the resistors. The inductors are all marked Dale. The resistors are in a binary sequence 1,2,4,8 to 128 it seems.

if you have the instrument and need one of these boards I'm sure IET would get a bundle for them. I have realized they aren't a lot of use for me.

[cdev]

Are all the yellow boxes relays?

[alm]

Looks like a bunch of inductors / resistors switched by relays to me. Given the binary sequence, likely a variable resistor / inductor, which might be part of an automated bridge. GenRad (and by extension IET) made quite a few of those. This is just speculation; I've never seen the insides of such a bridge.

[Edwin G. Pettis]

Sorry, the resolution is insufficient to 'read' any part numbers, can you do a zoom in on some of them or just write the numbers down.  Even the board numbers are a bit difficult to make out.  Without more information I can't make any identifications.

[umkumiut]

Are all the yellow boxes relays?

They look like Aromat (Panasonic) ones.

[1audio]

A few more details.
The boards are conformally coated and the connectors are eurocard-esque but use hollow sockets, 200 ea, and must be really expensive.

Boards have part numbers and serial numbers Common is a serial number starting with 85350XXX  Pt. No. 002(6404120 1) or similar.

!) Aromat DS2E-ML2-DC24V relays
2) Resistor markings. They all look like wirewound but I can be fooled . Marked for example:
14193
8521 CN
RWR78
S3201
   FR
3) Inductors are Dale marked TE4 or TE5

If someone can make use of these please contact me.

[Edwin G. Pettis]

The resistor is a MIL-PRF-39007 style RWR78, date code is 8521 CN, the part number 14193 is a house number, these are power resistors, not precision.  They are 1% and come in a variety of TCRs, may have been made by Dale as well.  You can find general data sheets on the RWR78 on line, they have commercial versions as well.