Jon's Dad, Stan, worked at Fry's Metal in Mitcham. Fry's specialty was making all kinds of solder. Stan worked in a team developing solder baths for soldering the new fangled printed circuit boards. Up to then the system was to have a large bath of molten solder an dip the board into it, having first wiped the scum off the top with a scraper. This had lots of difficulties, the board had to be lowered the exact amount so it sat nicely on the surface of the solder, and for the exact time required and then be lifted out. Quite often on lifting long dangly bits of solder were formed on the larger joints which had to be hand worked later. Of course the next board had to be lowered a bit further as some of the solder had been used up. The problems were very much against automationg the prodeedure.

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Someone in the team came up with a brilliant idea. That was to pass the board through the crest of a wave of solder. It solved all the problems. Firstly the board was passing through clean fresh solder, the speed of the board controlled the soldering time and process control kept the wave exactly at the right height. Passinfg through the wave solved the 'dangly bit' problems as well.

At the time I was building a Mullard 5-10 power amplifier on a printed circuit board. When assembled Stan took it to work and soldered it on the prototype machine. To my untrained eye it looked asbsoultely perfect. That board gave us music in The Gap for the next 8 years.