Restoring a Field Switchboard

So I was scrolling on eBay and found an old Bundeswehr field telephony switchboard with 10 slots and a dial-out addon. The whole offer included:

• The switchboard itself
• Dial-out addon
• ~50m of ab wire
• 3x single lightning protectors (Natobrötchen)
• Quante junction for lightning protection?
• and a fire extinguisher (for some reason lol)

And all that for about ~330€. I managed to convince a financially responsible friend from the Eigenbaukombinat to purchase it together, because I don’t have that much money just laying around.

After it finally arrived at home I brought it to the EBK to unbox and try it out. After unboxing we noticed a strange smell and tasty battery crystals everywhere. Turns out that the seller shipped it with the original batteries from around ~1963, which had unfortunally leaked everywhere.

After removing the batteries and disposing them in our munitions crate (we use it to store dead batteries) we started to clean everything by brushing it off. We also disassembled the battery holder / phone connector and completely soaked it in water. During the whole procedure a wire got loose which I quickly resoldered.

Then I used a sandpaper to get rid of the more stubborn residue. After we managed to clean the whole switchboard, we wanted to test it but didn’t have the correct batteries on hand. So we decided to just use standard AA batteries and kinda jammed them in there with some nuts and screws to make contact.

After that it was basically fully functional and we started doing some shenanigans with a field telephone from the NVA, which also had batteries from like ~1960. I was suprised to find out that those still worked!

We also had some fun with SSTV

To prepare everything for the HaGeWe'26 (Geekend at Eigenbaukombinat) we ran ab wire throughout the whole building and set up 5 field telephones + the switchboard in the hackspace. We started by trying to get the wire from the hackspace to the “new rooms” by spanning the wire over the court yard. Our plan was to attach a screw and some nuts to a string and use a sling shot to shoot it to the other balcony. After 30 combined tries of me & my friend, I managed to successfully land the screw in the rain gutter.

All that was left to do is to pull the ab wire

Then we also ran an ab wire to the backyard and placed a field telephone there.