1946 Decca Double Decca 46 mains/battery 4 valve MW/LW/SW portable - UK Vintage Radio Repair and Restoration Discussion Forum

howard · 21st Jan 2009, 5:54 pm

Hello again,

This is the second Double Decca 46 in my collection, a slighly later example with all Mullard valves in it, but still an early '46' set with chassis number 19762, suggesting that Decca built a lot of these in 1946. I won it for £22 at one of the BVWS auctions last year and its cosmetic condition is outstanding with no marks on its 'deck chair' hessian cloth cover and just a couple of little chips on its beige painted front panel. The inside was the same condition as the outside, all original and it looked like new and the only things missing from the set were its mains lead and one of its battery plugs.

I gave the case a quick wipe down and touched in the chips in its paint.
I then replaced its 2 core mains lead using some braided cable obtained from PWH here and it matched the short piece remaining in the set perfectly. There were only six wax capacitors in this set, it seemed a shame to replace them as they too looked like new but I did so with new Canadian sourced polyester axials. After cleaning the valve pins, volume pot and waveband switch with Servisol 10 I plugged it in, switched it on and away it went on MW, but it only just worked on LW and SW.

I eventually managed to find an HT battery plug for it (in a scrap Bush BAC31) so I took the set over to Ron Bryan to fit it and to check over the set. The plug was fitted and Ron realigned MW and LW and it peaked up really well. The selenium rectifier was checked and was found to be working 100% and then the voltages to the valves were checked, all were good except to the DK32 where the heater voltage was a bit high at 1.8 volts instead of 1.4 volts. When I got it home I realigned SW and that too peaked up well.

This Decca Double Decca 46 is in exceptionally good condition for a 63 year old radio. It works well, hums a bit on County Sound at 192 metres whose 800 watt transmitter is only half a mile away but apart from that it's fine and picks up loads of stations on all three AM wavebands (it needs a good aerial for SW). It's good to have another nice example of the Double Decca 46 which is a most attractive looking set, but is also one of the most unreliable radios ever built !

Take great care when working on these sets, the battery plugs are live when the set is plugged into the mains and one or two of the adjusters are dangerously close to the selenium rectifier.

Howard

PS: Does anyone know what the characters 'ICST MIN 550' engraved on the front top of this set mean ?

Nickthedentist · 21st Jan 2009, 7:22 pm

Very nice, Howard, and no re-spray required this time

Not sure about ICST, though Google suggests Imperial College of Science and Technology as one possibility. Maybe an acquisition number

Nick.

howard · 21st Jan 2009, 7:56 pm

Quote:

Originally Posted by Nickthedentist

....... Not sure about ICST, though Google suggests Imperial College of Science and Technology as one possibility......... Nick.

Now that's a possibility, if so I wonder if its poor circuit design was ever discovered !

Howard

Tim · 22nd Jan 2009, 3:23 pm

Another great resto Howard. I do like the look of those sets, I think they're cute!.

Tom_I · 22nd Jan 2009, 4:06 pm

Quote:

Originally Posted by howard

PS: Does anyone know what the characters 'ICST MIN 550' engraved on the front top of this set mean ?

Quote:

Originally Posted by Nickthedentist

Not sure about ICST, though Google suggests Imperial College of Science and Technology as one possibility. Maybe an acquisition number

Interesting thought. One of the organisations which came together to form Imperial College was the Royal School of Mines. I wonder if that's got anything to do with it?

howard · 22nd Jan 2009, 4:25 pm

Quote:

Originally Posted by Tom_I

Interesting thought. One of the organisations which came together to form Imperial College was the Royal School of Mines. I wonder if that's got anything to do with it?

Hello Tom,

I think you're right, ICSTmin is an acronym for Imperial College School of Mining. I've just found another item on the web with a similar inscription on it, a chronometer with ICST Min 574. I guess as Nick suggested this was a stock number used by the college.

And to think I was considering respraying the front .....

Howard

ppppenguin · 22nd Jan 2009, 4:43 pm

As an alumnus of Imperial College (EE75-78 in case anyone's interested) I can confirm that ICST was a commonly used abbreviation. Not so sure about the "Min" bit. Although I wasn't in that part of ICST, the standard abbreviation was RSM = Royal School of Mines. The other constituent colleges were Royal College of Science (RCS) and City and Guilds College (C&G). It's possible that "Min" was used to indicate a department within the RSM though I'm not familiar with department names in that constituent college.

If you ever find a Cornish connection with this set it's worth noting that the RSM had a branch in Cambourne, in the heart of tin mining country.

21st Jan 2009, 5:54 pm	#1
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	1946 Decca Double Decca 46 mains/battery 4 valve MW/LW/SW portable Hello again, This is the second Double Decca 46 in my collection, a slighly later example with all Mullard valves in it, but still an early '46' set with chassis number 19762, suggesting that Decca built a lot of these in 1946. I won it for £22 at one of the BVWS auctions last year and its cosmetic condition is outstanding with no marks on its 'deck chair' hessian cloth cover and just a couple of little chips on its beige painted front panel. The inside was the same condition as the outside, all original and it looked like new and the only things missing from the set were its mains lead and one of its battery plugs. I gave the case a quick wipe down and touched in the chips in its paint. I then replaced its 2 core mains lead using some braided cable obtained from PWH here and it matched the short piece remaining in the set perfectly. There were only six wax capacitors in this set, it seemed a shame to replace them as they too looked like new but I did so with new Canadian sourced polyester axials. After cleaning the valve pins, volume pot and waveband switch with Servisol 10 I plugged it in, switched it on and away it went on MW, but it only just worked on LW and SW. I eventually managed to find an HT battery plug for it (in a scrap Bush BAC31) so I took the set over to Ron Bryan to fit it and to check over the set. The plug was fitted and Ron realigned MW and LW and it peaked up really well. The selenium rectifier was checked and was found to be working 100% and then the voltages to the valves were checked, all were good except to the DK32 where the heater voltage was a bit high at 1.8 volts instead of 1.4 volts. When I got it home I realigned SW and that too peaked up well. This Decca Double Decca 46 is in exceptionally good condition for a 63 year old radio. It works well, hums a bit on County Sound at 192 metres whose 800 watt transmitter is only half a mile away but apart from that it's fine and picks up loads of stations on all three AM wavebands (it needs a good aerial for SW). It's good to have another nice example of the Double Decca 46 which is a most attractive looking set, but is also one of the most unreliable radios ever built ! Take great care when working on these sets, the battery plugs are live when the set is plugged into the mains and one or two of the adjusters are dangerously close to the selenium rectifier. Howard PS: Does anyone know what the characters 'ICST MIN 550' engraved on the front top of this set mean ? Attached Thumbnails Last edited by howard; 21st Jan 2009 at 6:00 pm.

21st Jan 2009, 7:22 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,858	Re: 1946 Decca Double Decca 46 mains/battery 4 valve MW/LW/SW portable Very nice, Howard, and no re-spray required this time Not sure about ICST, though Google suggests Imperial College of Science and Technology as one possibility. Maybe an acquisition number Nick.

22nd Jan 2009, 3:23 pm	#4
Tim Dekatron Join Date: Jan 2003 Location: Bradford on Avon, Wiltshire, UK. Posts: 3,310	Re: 1946 Decca Double Decca 46 mains/battery 4 valve MW/LW/SW portable Another great resto Howard. I do like the look of those sets, I think they're cute!. __________________ "Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."

22nd Jan 2009, 4:43 pm	#7
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: 1946 Decca Double Decca 46 mains/battery 4 valve MW/LW/SW portable As an alumnus of Imperial College (EE75-78 in case anyone's interested) I can confirm that ICST was a commonly used abbreviation. Not so sure about the "Min" bit. Although I wasn't in that part of ICST, the standard abbreviation was RSM = Royal School of Mines. The other constituent colleges were Royal College of Science (RCS) and City and Guilds College (C&G). It's possible that "Min" was used to indicate a department within the RSM though I'm not familiar with department names in that constituent college. If you ever find a Cornish connection with this set it's worth noting that the RSM had a branch in Cambourne, in the heart of tin mining country.