Month: May 2020

This Philco is a small cheap table top radio. It’s very simple in design, has quite a low component count and actually works really well. The only down-side to it’s design is that it uses a dropper-resistor to step down mains voltage to power the heaters in the valves. This is really inefficient, of the 43 Watts consumed by the radio, about 30 is burned up in that resistor! I guess it doubles as a nice personal heater for those cold winter nights! The cabinet wasn’t too bad, just needed […]

Roberts Radio was a very successful manufacturer of portable radios in the UK. This RT1 was their first ever transistorised model, from 1958. I was fortunate to find this one on an auction site for small money but it needed a lot of love, missing strap, broken logo, terrible knobs, broken clasp and really really grubby leather. On the up side, the electronics seemed to look nice an clean, with only moderate damage to the aerial coil. These early transistor sets have quite rare and delicate components that can be […]

This is an old cabinet speaker dating from the 1920s. I was unable to find any details about it on the internet, other than a similar looking Model 140, dated 1929. It took a while to get the cabinet open as storage and time had rusted some of the screws. Stress on the front and back panels also caused the plywood to delaminate! On investigating, there was an internal transformer (high impedance to low) and a smaller than standard vintage speaker driver that had been fitted. The transformer had been […]

I was never really happy with the appearance of the 471, after spending only minimal time on the cabinet. So, the other day I decided to strip it down and do some work on it. The other things I want to do, re-wire the speaker connector and investigate why the volume output is so low. Update on this, I’ve managed to redo the speaker wiring and also found some small problems around the amplifier section (EL33 valve) I had substituted a 0.1uF cap in place of the old 0.2uF. Fixed […]