HMV 1410G valve hybrid MW+LW radio 1957

Well I brought this to use the insides for another radio repair because the cabinet was a write-off due to fire damage to the rear. (see below) It's quite unusual as it's a hybrid portable 3 valves and 2 transistors with very low battery consumption.So worth saving.

But when it arrived I was so taken by the cuteness and clever use of 2 x OC 81 transistors, I had to save it. So I marked the damaged area in felt tip pen and with a coping saw cut out the melted section, but after I folded back the inside instructions with an elastic band and re-glued later. I then cut a piece of black plastic and glued inside the removed section of the back.

Damaged area removed with Coping saw

Plastic section cut and fitted inside hole

Not too many of this model turn up so it was worth saving. The next problem was the dead radio. I fitted 3 x 1.5 volt heater (4.5v)  LT supply into original springs and fixed 5 PP3's in series behind an elastic band held between to hooks that were fitted for just this job in 1957.

It turns out that the Marconiphone P60B also used the same circuit diagram as the HMV, so I included it here. After cleaning volume control and band switch I ed a RF signal into grid 1 of  the V2 valve and had lots of signal, but none from the grid of V1, voltages checked-out fine around here, so I substituted a good Oscillator valve from another set to check it, and bingo ! that was the doggy valve, I found a used one on line for just 99p + £3 postage and she was a worker again. Very nice sensitivity due to ferrite aerial and low noise output transistors.

I managed to save the rear inside labels before I cut out the fire damage

The chassis inside removes quite easily, held in place by one centre screw that also holds the battery wires. Gently pull off the front knob, held by a spring arched around spindle with two pins, if tight press pins outward.

A pure joy to repair and I recommend this to anybody that sees another come up for sale, well worth restoring back to life.

All the electrolytic capacitors I checked were fine, a wire fell of the AM coil while fixing, but other than that she must have been scraped when the oscillator valve failed to work proberbly in the 1960's when the batteries were also hard to find. I always include lots of photo's as they can say 1000 words, but if anybody has any questions don't be afraid to ask.