[high_vacuum_house]

This is a bit more of a repair than a full restoration as the cabinet is not too bad with a couple of small knocks but more than presentable.

This came from the recent Radiophile Cowbit event for £6. It looked complete and no signs of any damp. It was also full of dust. In fact it was well crammed with dust and took a lot of hovering with a paintbrush to get rid of it all leaving a very clean chassis.

The UY85 rectifier was very wobbly and loose so the valveholder pins were tightened with a jewellers screwdriver. It is much more firm in its holder now.

The tuning dial would not move. This was down to the small plastic pulleys all being gunged up. They were cleaned and given a very small drop of clock oil. The tuning drive works correctly now.

I decided to cut out the distressed mains filter capacitor and run the set up on the variac. There was no dial lights and only the slightest rustle from the speaker. I decided to tackle the dial lights. One bulb had blown but was rusted solid in the holder. About an hour trying to remove it in pieces failed so I decided to replace the holder. This was no so easy as the MES bulbholder is at near mains potential relative to chassis and therefore a conventional clip on one could not be used. I found an old Maplin plastic surface mounting holder which would suffice and managed to get it to fit with a 4BA nut and bolt. This got the dial lamps working but still not much from the speaker.

I changed out all of the wax capacitors and hunts mouldseals all of which were tested and found very bad. This still did nothing much but was able to pick up 5 live on MW very weakly but with a healthy hum with a finger on the AF triode grid which showed that the AF section was ok.

After checking all of the anode and screen grid resistances were ok I decided to see what the anode and screen voltages were doing when on. I soon found at V2 which is the 2nd IF amplifier a UF89 that there was no voltage drop across the anode load or screen feed resistor. Cleaning the pins did not help and so another UF89 was pinched out of a Ferguson set and immediately the set sprang to life with good volume on all wavebands. The original UF89 had zero emission!! The correct voltages were then observed on the anode and screen pins.

The sound was good but VHF quality was poor. I decided to replace the 5uF capacitor in the ratio detector and the sound is now very good. The original had gone down to 0.1uF!!

Other than a good clean I am very happy with the result and it is a good sounding set. I have been listening to radio 3 all evening at a decent volume and have hardly heard a crackle.