Soldering an art (Yes there is art in technology!)

I bet you are thinking about stained glass now, all held together by solder beaded up all nice and pretty. But that is not what I am talking about.

Back in the day when equipment with tube chassis filled with wires soldered from one tube socket to a resistor or capacitor were giving away to transistor based equipment a new thing came along; printed circuit boards (PCB). PCBs electrically connect electronic or electrical components using conductive tracks, pads and other features etched on layers of copper laminated plastic. That old rat’s nest of wires went away. That made life a great deal easier.

Image courtesy of talkingelectronics.com Except for one thing; you did not have to be a soldering wizard to solder a wire to a tab on a tube socket but you had to be pretty careful when soldering to a circuit board. Also with transistors, you had to be pretty careful about heat. If you heat up a transistor too much you ruin it. So in the late 60’s and early 70’s a plethora of soldering aids came along to help out.

They were legion; “third hands” to hold your work at the best angle to work on, “third hands with sponge” to wipe your soldering iron tip, “third hands with sponge and magnifying glass so you could better see your work. “Solder suckers” were one of the best things to come along; heat the old connection until the solder liquefied and then with a click and a puff and the solder was cleared and you could easily remove the bad component and replace it with a new one.

Now here is where the art meets the technology; if you did it right, you could not tell the new solder joint from the one made by original manufacturer. That was the holy grail of the electronic technician back in the day. The early manufacturers had rows and rows of technicians all dressed in white lab coats soldering the components on the PCBs. Later that gave way to wave soldering machines where the circuit board is passed over a pan of molten solder in which a pump produces an upwelling of solder that looks like a standing wave. As the PCB with the components glued to it made contact with the wave of solder, the components become soldered to the board and the glue was vaporized by the heat.

There was nothing more satisfying back in those days to have your boss pick up a circuit board that you worked on and ask; “Where is the transistor you replaced?” I remember having to replace the decoupling transistors on some Ampex videotape machines (VTR) over and over because of voltage spikes from lightning or manmade causes. This often happened in pressure situations.

My worst pressure related soldering situation occurred on November 21, 1971, a Sunday morning. I was the engineer in charge of Master Control at WIS-TV in Columbia SC. The demolition of the Columbia Hotel was scheduled for 10AM. We were in the middle of our usual local religious programming. A crowd gathered near the demolition site less than two blocks from the station to watch the building demolition. I had loaded the next show on the left hand VTR. The show that was on the air was on the film projector. Bill Roehl one of our most experienced “switchers” was ready to run the station break on the video control board. I had basically nothing to do for the next few minutes so I told him I was going to watch the demolition from the base of our 400 foot tall downtown tower. There was a small door that led from the control room to the roof of the studio that was under the tower.

Fortunately, I left the door open so I could give Bill a “blow by blow” description of the demolition.

Sure enough, right after “H” hour, there was a large boom and the building came down ALMOST perfectly.

Bill interrupted my description, yelling to me that VTR 2 had lost lock and it didn’t look like it was coming back. Boom! I went back through the small door and on the control room floor without touching the three stairs that led to the door. He threw up the “Technical Difficulties” slide as I tried to get the machine to sync up. I quickly realized that was not going to happen, so I rewound the tape and loaded it onto the other VTR machine. Yikes! It would not lock up either. At that time, Bill loaded the next film show on the projector and started it.

I called Tom our “Studio Supervisor” to let him know that we had just lost both tape machines at the same time and began work troubleshooting the first one. I had just determined that the pair of decoupling transistors on the Servo module were blown when Tom blew into the control room. He said, “It’s the decouplers, right?“ as he came through the door. “Yup!” I answered as I broke out the screwdrivers and heat conducting paste. There were 12 modules each containing two of the decoupling transistors in each VTR machine. It took us a little over two hours to change out those 48 transistors. Not too shabby, around 5 minutes per transistor per person. That including un-mounting module from the machine, putting it on the bench and then remounting it after the repairs were made. While it was true that those transistors were mounted on sockets, there was one solder joint that had to be made on each one of them. All the sponsored shows got on that morning, just not in their normal time slots.

After the dust settled and Tom and I had retired to the canteen on the first floor, I asked Tom how he knew it was the decouplers before he even saw the machines and he told me that he was listening to our sister station, WIS Radio on the way in and they reported that some power lines were taken down by debris from the building that fell outside the expected footprint for the demolition. That’s why I said that the building came down ALMOST perfectly.

These days, I can no longer solder like I used to. For one thing with the advent of PCBs with three or more conductive layers laminated together, component level repairs became very difficult in the field. That ushered in the area when board swapping became the way to repair broken equipment. These days, with integrated circuits and onboard processors inside almost every piece of equipment in the studio; the entire piece of equipment is normally replaced instead of repaired. The other impediment to soldering is that I just can’t see the components like I used to. So another small joy is relegated to the past; sitting at the bench and admiring the beauty of a well executed solder joint. Oh MY!