What kind of solder is this? Pictures included.

The back of this board has a very heavy coating of this solder on it. It is to the point of pooling in some places. I am trying to figure out what kind of metal the solder is. Could it be silver solder? Does anyone know the value of this kind of board?

A little background on the boards themselves.

They are GE Radio signal controllers. They come in a rack very similar to a server rack you commonly see.



I have 150ish of these controllers. They are included with a lot of telecom equipment I made reference to in an earlier post. The controllers have a 20+ pound aluminum heat sink. In the pictures I will show the process of them being dismantled, the whole boards and a couple close-ups.

The front and back of the board

1)



2)



3)



4)




Here are some numbers on the board itself

9)



Thank You for any help in grading and identifying the type of metal used on the back of the board.

There were some references to them in an earlier post I had called "big telecom scrapping"

It looks like a high content lead solder. little to no silver. just Pb and Sn.

Eric

Those boards were old enough that they were hand soldered, that's why the different thicknesses. Modern day uses flow soldering (or called wave soldering).

Looks like an early flow and they went back over the components with the solder iron.

Wave soldering - Wikipedia, the free encyclopedia

Originally Posted by happyscraper

That's what I was thinking Mechanic. The boards look like they have a thin layer of metal over the board it self, maybe copper? Looks like they were made in the fifties or early sixties.

It looks like the whole bottom was flow soldered then they touched up the individual solder joints.
Probably copper under the solder.

Originally Posted by happyscraper

That's what I was thinking Mechanic. The boards look like they have a thin layer of metal over the board it self, maybe copper? Looks like they were made in the fifties or early sixties.

I don't think it was made that early the Al cap is from a much later time. Of course it could have been repaired. Also the Ta caps are from the 80-90s. I believe these are from older analog cell towers.


Eric