Collins 30S-1 (SK) Almost

The Collins 30S-1 amp I acquired from Mac, W6FCS bit the dust a while back. It always had an intermittent problem with dropping off line. At first it seemed that it was a control logic problem. Finally one day it happened... an arcing sound, blown fuses, and a terrific smell. The power transformer was arcing to ground. I tried putting the transformer on a board to lift it above ground. It worked... on the CW position. It was still a no go in the SSB position though. New transformers are available from what used to be Peter Dahl... for $650 plus shipping. Not a happening deal anytime soon. It occured to me that a pair of HV transformers I had bought off ebay might just work. They fit, and the voltage with the secondaries in series was just right. So I set about installing them and a new bridge rectifier in the space occupied by the old transformer and tube sockets.

Here is a shot of my son Isaac who was a big help on the project. Isaac did most of the wiring, and we had a good time together working on the amp.

Here is a shot of the new transformers and rectifiers. I reused as many of the original parts as possible, including the terminals and end insulators from the wires. I used the inner conductor from RG-8 as the new HV wires. The rectifiers are from the old channel 6 analog transmitter.

I had to add a seperate screen transformer. A 120 to 240 isolation transformer from the old channel 6 transmitter was perfect for this application.

 

Here it is ready for testing. The HP meter says it outputs just about 1KW, all it was designed to do. The HV is exactly 3000 just as it originally was, along with 200V on the screen.

The camera flash makes it look like it's on... it's not. I only had the HV up with the cover on.

Well surfs up, so I need to go put on my wet suit and wax my board.

The waves were really beautiful this weekend here in King Salmon.