Sunday, March 02, 2014

Wartime Civilian Receiver - Part 2: Chassis and cabinet repair.

I spotted this WCR in 2013 at a 1940s event held in a local village, where it had sat on the stall all weekend getting little or no interest. I had already done a bit of research and had a pretty good idea of what it was, but I wasn't keen on paying the £40 the seller was asking. Late on Sunday afternoon I went back to the stall expecting it to have been sold, but there it was. The seller was keen to get rid of it and quickly offered it to me for £25. Deal done!

Chassis after the initial cleaning

After carrying it home and inspecting it more closely my initial pleasure in getting a bargain began to reduce somewhat. The radio was obviously complete, but the cabinet looked like it had been kicked down the garden path and the chassis was rusty. Wondering if I had taken on too much this time, I put it on the shelf until I could find enough time to work on it properly.

Several months later the fibre back panel broke into two pieces as I removed it; not really a good start! I stuck the bits back together with UHU glue, and then clamped both pieces to the workbench for a few days while the glue did it stuff. I didn't really expect it to work, but the repair seems to have held.

After carefully removing the valves I found that the chassis rust was less extensive than I had first thought. The top of the chassis was only lightly rusted, and a couple of hours scrubbing with a brass brush removed all but a few stubborn patches. The front and  underside of the chassis were pristine, except for the inside bottom rear edge.

Chassis front view, tuning scale removed.

Once all the loose rust and dirt had been removed I treated the metal with a rust converter liquid, taking care not to get it on the aluminum IF cans. After a few hours all the rusty areas had turned a bluish black colour. There were some rusty patches on the steel parts of the tuning capacitor, but a careful work over with the brass brush removed this as well.

The original dust bag around the speaker had lone gone, and I thought that I could see some damage to the paper cone.  After removing the four wood screws, the baffle and speaker were removed from the cabinet.

Here was the first evidence that the Phantom Bodger had been at work on this set! A horrible yellow material had been used to replace the original speaker fabric, it was far too thick and totally unsuitable for the job. This was quickly removed, revealing a very sorry looking speaker.

Just horrible!

The speaker was removed along with the fixing bolts, which had been overtightened so much that they had almost pulled through the wood. To do this I had to remove the two horizontal wooden mouldings. The oversize holes left by the bolts were plugged with wood filler, and the wooden mouldings glued back into place. The replacement speaker would have to be held in with wood screws.

Original speaker before removal

I initially tried to repair the speaker cone, but after some success in gluing the torn edges together, I discovered that the voice coil was out of alignment and was scraping against the magnet. I learned a lesson here, next time I will check the alignment first.

I couldn't find the manufacturer's code anywhere on the chassis and I assume that it may have been obliterated by the rusting.  The speaker was however clearly labelled Plessey;  was this the first clue to my set's origin?

Plessey 6 inch speaker

May 1944 is clearly visible on the cork gasket of the speaker. Since the WCR went into production in June 1944, this suggests that my set may be one of the early ones.

I cut a piece of Tygan speaker cloth to size and carefully fitted it, taking care to keep it taut while fixing with staples. It took a few attempts before I was happy with my work. Purists might argue that the Tygan isn't right for a WCR, but I had plenty in stock and it does look smart.

Turning to the cabinet, there were a few loose joints that had to be glued together. I used Evostick wood glue for this, poking it into the joint with a cocktail stick before clamping it together and leaving it overnight.

The cabinet is made from soft pine and was covered in dents and abrasions. It  also had some form of varnish applied by a previous user.  I decided to take a fairly robust approach, and attacked the cabinet with fine sandpaper.  After a few minutes I thought I had made a mistake, as the lighter areas of the wood were sanding away too easily, whilst the darker, harder areas remained. This gave a textured finish with patterning somewhat like a tiger's stripes. I decided to press on, but kept the sanding to the minimum required to remove most of the dents and marks.

After sanding I gave the wood a coat of Danish Oil. This went on clear but gave the wood a slightly darker finish when dry. This was left to dry overnight before applying a second and final coat. After a good rub down with a beeswax polish I think it looks pretty good!

The finished cabinet

Later on I'll post details of the electronic restoration, so come back for more if you are interested.

Keep listening!

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