Bush TR82C (1959/1960)

In 2025, I found this radio at the quarterly NVHR swapmeet. I recognised it as the iconical Bush portable radio. But was it real or a replica? It was really dirty. The person selling it said it came right from a shed. I was curious what type it exactly was and took off the back panel. The inside was looking much better than the outside. It was quite clean and undamaged. This turned out to be the original Bush transistor radio. It was really cheap, so I bought it.

This radio has no PCB yet, but an aluminium chassis plate with components soldered on solder posts. The glass-cased germanium transistors are mounted prominently on top. The IF transformers and audio transformers are also mounted on top of the chassis. Apparently, the designers had kept a few habits from their earlier valve radios. It contains 7 germanium transistors, in this version they are:

• OC44 as oscillator and frequency changer,
• 2x OC45 IF stages
• OC71 as AF pre-amplifier
• OC81 as driver for the input transformer
• 2xOC81 as push-pull AF output amplifier

The transistors in this radio are all from Mullard. Four of them come in a glass case, painted black. In later versions, Bush used AF117 metal can transistors, that often develop tin whiskers. The OC81's have a metal case and are mounted with a cooling fin.

This radio first needed a thorough cleaning. For this, I had to take it apart. First I pried off the tuning knob and pointer. Then I unscrewed the chassis. There were only three screws holding it and they were all different. Only one was the original Phillips screw I saw on photographs of other Bush portables on the Web. Apparently, somebody had been working on this radio before who lost most of the original screws.

After this, I cleaned the case with some detergent. That wasn't enough. The radio needed to be polished to remove the dirt and make it shine again. The case consists of a middle part, a front and a back. I removed the 7 screws that held the front. Then I removed the carrying handle by carefully bending the springs that hold its pivots in place. I unscrewed the bezel on top, where the tone and volume controls are. I also removed the chrome-plated circle on the front around the tuning dial.

Then I polished the front and back panels using Brasso polish. The chrome circle received an extra polishing to remove the specks of corrosion coming through the chrome plating. The middle part of the case is covered with a blue linen based artificial leather. After cleaning, I polished it with a bit of furniture wax. This restored the blue color somewhat. The tuning knob, made of perspex, was also polished and was looking better but it remained a bit foggy. After reassembling, the case looked much better, although still yellowed. The layer of yellowed plastic was too thick to simply polish away. But I didn't dare to use a bleaching agent for fear of causing corrosion to the beautiful bright red tuning dial and the metal letters spelling BUSH.

Before trying the radio, I checked a number of components. I had a schematic so that helped. The waxy shell of the paper capacitors was a bit sticky but they didn't look very bad. I decided to keep them as none seemed to be critical regarding leakage current or loss factor. The band switch had blackened contacts. I cleaned them with ammonia first, then with a mild contact cleaner.

There were 3 electrolytic capacitors in a plastic casing. One of them, Plessey 100μF 12V, was leaking and I didn't trust the other two. The leaking one measured bad. I pried it open and hid a modern electrolytic in it. So I did with the identical one. It was harder to open though and the inside was still moist. The third one was smaller, 100μF, 3V. I couldn't open it so I replaced it. I also checked the 500μF emitter decoupling capacitor in the driver stage. It measured ok. As it was large and had an aluminium can, I trusted it was still reliable. The 8μF filter capacitor in the AGC circuit also had an aluminium can. As this is a very small capacitor, it is prone to dry out so I replaced it.

After this, I was confident and connected a power supply. No sound. After increasing the volume, there was noise. I turned the tuning capacitor and heard the familiar sound of radio stations passing by on MW. It was a pleasure to easily find Radio Caroline. The sound was actually quite good.

After this, I mounted the chassis back in its case. I found three acceptable replacements for the lost or misplaced screws. I pushed the pointer and tuning knob back in place and further reassembled the radio. I found a PP9 battery clip and made an adapter for a standard small 9V battery. So I was able to use the radio on batteries, as intended. Maybe it's a good idea to add a larger battery holder for "C" batteries. They will last longer and there is plenty of space for them.