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Old 18th Jul 2012, 7:53 pm   #1
howard
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Default 1949 Masteradio D120 Sandown AC/DC 5 valve MW/LW midget radio

Hello again,

And yet another of these Masteradio Sandown D120 midget radios, this time the early 1949 model with 5 octal valves (12K8GT, 12K7GT, 12Q7GT, 35L6GT and 35Z4GT) and a line cord dropper. This one was acquired at the last Harpenden swap meet for just £5 in good original condition and complete, even its line cord was still attached. Even though the resistive wire in the line cord was intact there was no way the cord could be used as the sheathing on the other wires had all but disintegrated so I decided to replace it with a dropper capacitor, a 4uF Ducati Motor Start capacitor obtained from Farnells for £3.27 + VAT.....

http://uk.farnell.com/ducati/4-16-10...vac/dp/1219037 .

Trader sheet 943 covers this model, available here ....

http://www.service-data.com/section.php/4731/1

First job after cleaning off 60 years of crud from the chassis with pure turpentine (very effective and smells nice too) was replacement of its tubular capacitors and one electrolytic which were in poor condition. The values of three of the capacitors differed to those in the Trader sheet (C15, C16 and C21 were 0.01uf rather than 0.05uF) so I replaced them with values as found in the set. Next resistors were checked and three were found which were more than 10% out of spec and were replaced. The line cord dropper and one dead wirewound resistor attached to the end of the dropper resistance wire were removed, a new mains lead fitted (blue wire to the single pole switch, brown wire to an unused tag on the rectifier socket) and an 8mm hold drilled in the chassis and the dropper capacitor fitted (blue wire to the stand off vacated by the line cord resistive wire, red wire to the same tag as the mains lead brown wire on the rectifier socket). A 100 ohm 4 watt wirewound resistor to act a surge resistor to help protect the bulb was then fitted where vacated by the duff wirewound resistor above. Finally all valve sockets, waveband switch and the volume potentiometer were cleaned with DeoxiT and the chassis taken over to Ron Bryan for its initial powering up on his Variac.

The set was powered up at 120 volts for a few minutes to allow the smoothing capacitor to reform and then up to 240 volts, HT and LT were checked and both were surprisingly close to spec but the set wasn't working. A few more checks were performed and it was evident that the 12K8GT frequency changer wasn't working so when I got home a NOS W76 Osram equivalent was fitted and away she went, working well. RF realignment was performed and the chassis was then finished. The cabinet just needed a clean and polish with Brasso and beeswax polish and the set was reassembled.

This little set with its throw out aerial works surprsingly well with decent enough sensitivity and it doesn't take up a lot of room either.

Howard
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Old 18th Jul 2012, 8:08 pm   #2
Norman Raeburn
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Default Re: 1949 Masteradio D120 Sandown AC/DC 5 valve MW/LW midget radio

Hi Howard, What a lovely set and a good write up as usual. I really need to complete some restorations myself, I am a great starter but when hit a spares problem or similar the radio gets put aside. I look forward to the next one. Kind regards, Norman.
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Old 18th Jul 2012, 8:46 pm   #3
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Default Re: 1949 Masteradio D120 Sandown AC/DC 5 valve MW/LW midget radio

Quote:
Originally Posted by Norman Raeburn View Post
Hi Howard, What a lovely set and a good write up as usual. I really need to complete some restorations myself, I am a great starter but when hit a spares problem or similar the radio gets put aside. I look forward to the next one. Kind regards, Norman.
Hello Norman,

I bought four of these for a total of £20 from Graham Terry who is/was a collector of Masteradio radios and TVs and he did have a website 'www.masteradio.co.uk' (now sadly closed) with the history of Masteradio and examples of the models. I've managed to build nice examples of three different D120s, and one with a cracked cabinet I've kept for spares. I wish I'd bought more cos they're rather good little radios and didn't take that much effort to restore. This one cost a little more than the other two to restore, but still cost me a total of just £17 including the set. This one in a brown bakelite cabinet rather than a white cabinet is the nicest one.

Regards ....... Howard

PS: Don't forget to stick some insulating tape or rubber feet over the four chassis screws underneath. These sets are still live when switched off !
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Old 19th Jul 2012, 7:45 pm   #4
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Default Re: 1949 Masteradio D120 Sandown AC/DC 5 valve MW/LW midget radio

And here's a video of it working which lasts one minute. I must get a tripod .....

http://www.youtube.com/watch?v=26p49D0-XSc

Howard
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Old 19th Jul 2012, 8:01 pm   #5
Norman Raeburn
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Default Re: 1949 Masteradio D120 Sandown AC/DC 5 valve MW/LW midget radio

Hi Howard, The radio looks even better in the flesh and the restoration costs were fine. I like bakelite radios as my cabinet skills are non existant, unfortunately they don't survive well in transit. I can't get anything up here and have to rely on ebay etc, car boot sales seem to have nothing these days. I must admit you are inspiring me to get something off the shelf and have a go. Regards, Norman.
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Old 19th Jul 2012, 8:08 pm   #6
MALC SCOTT
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Default Re: 1949 Masteradio D120 Sandown AC/DC 5 valve MW/LW midget radio

Very nice job Howard
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