Showing posts with label Murphy Radio. Show all posts
Showing posts with label Murphy Radio. Show all posts

Monday, March 24, 2014

Wartime Civilian Receiver - Part 5: Finishing touches

With the set working again, the final part of the restoration entailed making replicas of the top panel and rear panel labels, and sticking these onto the cabinet.

Top label in place

The design for the top panel label was available on the web; all I had to do was download the image and print it full size. I did consider using the water-slide transfer paper for this, but I finally decided to use a colour laser printer and ordinary paper.  After sticking it in place I gave the label a couple of coats of spray lacquer to protect it.

Th rear panel label required a bit more effort. Once again a scanned image was available on the internet, but it required a lot of cleaning up with Paintshop to remove odd marks and artifacts. After cleaning up the image I tried to give it an aged look. I wasn't completely happy with the colour though, as on the computer it looked more like somebody had spilled tea on it!

Rear label, cleaned up (click to enlarge)

With the label glued in place and the rear panel re-fitted, the colour doesn't look too bad really.

Rear view, with vintage Bakelite plug fitted

It would have been nice to have repaired the original speaker, or at least fitted a replacement of similar age. For now though I will enjoy it as it is, and perhaps another speaker will turn up at some time in the future.

Since completing the restoration I have determined that my WCR was probably built by Murphy Radio, which means that it would originally have been identified with the code 'U7' somewhere on the rear of the chassis.

Blogging my restoration of this wonderful old set has turned out to be a bigger task than I had originally planned, but I hope that the information in all five parts will have been of interest, and perhaps even useful to anybody who wants get one of these sets working again.

Keep listening!

Saturday, March 01, 2014

Wartime Civilian Receiver - Part 1: Introduction

During the latter half of World War 2, the British government determined that there were a million or more UK households without a working radio.  The manufacturers had stopped producing consumer sets in order to concentrate on war work, so no more new sets were available. Faulty sets often didn't get repaired, as many radio technicians and engineers had been called up for military service.

A family gather around their wireless set during WWII (photo: BBC)

Recognising that the wireless was an important source of information and propaganda, the government created a scheme to produce domestic sets cheaply and in bulk, but using the minimum of materials.  The task of designing this radio was assigned to Dr G.D. Reynolds of Murphy Radio Ltd. The final design was then given to 42 different manufacturers, who were contracted to produce identical looking sets. Whilst this seems strange today, the government were concerned that customers might prefer one manufacturer over another, presumably leading to supply difficulties, and making them anonymous avoided this. Manufacturers were therefore not allowed to put their name or any identifying marks on the finished set, although they were allowed to make small changes to the design in order to use stocks of components that they had. Most of these differences appear to have been things like loudspeakers and transformers, but there were a few minor circuit changes as well.  Each manufacturer was allocated a code (A1 to A42) from which a technician could determine who the the manufacturer was when carrying out warranty repairs.

Wartime Civilian Receiver - AC Version

The cabinets were very basic, made from soft pine wood, with two vertical  pieces of hardwood on the front for decoration.  The tuning was also extremely basic with no reduction drive or glass scale, and instead of the exotic-sounding names found on pre-war sets, the WCR tuning dial has only 'HOME' or 'FORCES' stations. The set was medium wave only , as the long wave broadcast service was closed down during the conflict to prevent German aircraft from using it for navigation. A few sets were produced as MW/LW after the war (using a design produced, I believe, by Bush Radio) and these are now quite rare. Many more were converted by radio shops or by the owners themselves.

The WCR was produced in battery only and AC mains only versions, and went into production in June 1944. It was priced at £12 3s 6d and 175,000 AC versions were sold in the first year.

Electronically the set is a four valve 'short' superhet, but with the traditional detector valve replaced by a 'Westector ' metal oxide rectifier.

Wartime Civilian Receiver - Battery Version

Although some cost savings were obviously made, having restored my AC set I'm not convinced that the WCR was actually as cheap to build as the  'utility' design implied. The mains transformer for one seems to be rather larger than it needs to be, and could have been avoided altogether if a transformerless AC/DC design had been adopted, as was very common in post-war sets. There would have been other advantages in doing this as DC mains was still widely used in the UK during the forties.

Given its simplicity, the WCR seems to work surprisingly well. Mine is working nicely on the workbench as I write, but needs a bit more 'soak' testing before I'll be happy to call it completed. I'll then be taking lots of photos before putting it back together.

Details of the restoration will appear on here soon, so come back if you are interested.

Keep listening!