burningsuntech
Active member
Hi guys. Been away for awhile but now am back.I was at the local salvage yard and met a guy who was tossing old electronics and I offered to help him unload.
I noticed these 6 blocks of bakelite and asked him if I could have them for the change that was in my pocket.
He agreed and I paid him $1.82 for the six.
When I got home, curiosity got the better of me and I opened one of them by drilling out the corner rivets.
Inside I got an eyeful! There are 70 nubs measuring 1/4 inch diameter by 1/2 inch long which are heavily
plated with a deep yellow gold around the perimeter of the block. Also inside are 35 gold plated strips which
act as contact strips for (plugs?) One side of the block has 300 holes in it to receive plugs and the other side
has 70 holes around the perimeter presumably to act as a connection The blocks are stamped with a Mfg plate
from AMP Incorporated of Harrisburg, PA. USA. Each block bears the "Cat No: 397391-1" and an appropriate
"Ser. No. PB3868" with each having its own serial number.
No amount of internet search turned up what these might be. But based on the color of the gold inside which
is very striking and the layout, I'm guessing that these were used in some sort of military application. Perhaps
cryptography patching blocks for setting keys. Just a guess. They maybe computer patching blocks from the '50s.
I inspected the strips and nubs for clues as to composition. The nubs appear to be made of gold over nickel plate
on copper. To test that, I put 50 of the nubs in Nitric to see what would happen. Gold came off the nubs in foils
and the copper was evident.
The strips were a bit of a puzzle. They appeared to be made of stainless steel. If this is the case, I'm in for a
tough time removing the gold. I tested the strips and nubs with a magnet and neither of them showed that they
were even slightly magnetic. I'm thinking that it must be something other than stainless. The consistency of the
metal acted like beryllium copper so I went back to the Internet and discovered that BeCu is used in contacts like
for its durability. I tested the strips in AP solution and the gold flaked off the BeCu leaving copper pieces
(the BeCu seemed to disintegrate in the AP solution) but besides gold, there is a dark red powder mixed with the
gold. Beryllium is toxic in its dry state so I'm keeping this wet until I can find an appropriate method to remove
the Beryllium.
I have a few questions of you guys.
1. What the heck are these blocks? If you know, please PM me.
2. I think I'm on track for the processing but do you have any suggestions on how to better process the strips and
nubs?
3. Any suggestions on how to identify beryllium and how to remove it from the the final product? AR maybe?
Thanks for your time guys and your expertise. Here are some pics.
