1946 Double Decca 46 MW/LW/SW mains/battery 4 valve portable

[GJR 11L]

A wonderful standard achieved there, Howard, and yes, Steve, I see what you mean about the way in which the set looks like something more modern!

[img]http://farm3.static.***********/2190/1534708744_2235c53924_o.jpg[/img]

[howard]

Originally Posted by Colin

Thanks Robert, I wondered if it was as it should be. I suppose it is and it's a match for the cream coloured front.
rgds Colin

Hello Colin,

The original rear cover and the replacement are both cream in colour, and here's the rear of my set. I may just touch that up too ...... when I repaint the front.

Howard

[af024]

Well done Howard ... another Double Decca 46 saved. I had no end of trouble with mine (which has the same cabinet finish as yours) - well worth the effort though.

One thing I couldn't work out though was that on mine, near the grey ww resistor (near the selenium rectifier), there was a small thermistor. Only one leg was attached with the other going absolutely no-where (dangling in free air). There is no mention of this in the circuit.

Regarding your front, and I know that this sounds a bit wrong for a vintage radio and all, but would plastic coating do the job nicely? Not sure whether it would stand the heat from the oven though. Failing that, I think PlastiKote Antique White is probably the right mach.

What will you do with the speaker grille?

Andy

[Nickthedentist]

Originally Posted by GJR 11L

...I see what you mean about the way in which the set looks like something more modern!

That's exactly the set I was thinking of (as well as it's £20 Chinese imitators).

Nick.

[Colin]

Originally Posted by howard

Hello Colin,

The original rear cover and the replacement are both cream in colour, and here's the rear of my set. I may just touch that up too ...... when I repaint the front.

Howard

Hi Howard,

Thanks for that, I had wondered if mine had been sprayed at some time. Good job I didn't spend ages trying to remove the paint

Here are a few pictures of mine. The front is original but the grille has been re-sprayed, the back's a bit tatty. I think you'll do a great job with yours and it'll look much better

rgds
Colin

[howard]

Originally Posted by af024

Well done Howard ... another Double Decca 46 saved. I had no end of trouble with mine (which has the same cabinet finish as yours) - well worth the effort though.
One thing I couldn't work out though was that on mine, near the grey ww resistor (near the selenium rectifier), there was a small thermistor. Only one leg was attached with the other going absolutely no-where (dangling in free air). There is no mention of this in the circuit.
Regarding your front, and I know that this sounds a bit wrong for a vintage radio and all, but would plastic coating do the job nicely? Not sure whether it would stand the heat from the oven though. Failing that, I think PlastiKote Antique White is probably the right mach.
What will you do with the speaker grille?
Andy

Thanks Andy,

I don't remember seeing any thermistors in this set. I should remove it.

I wouldn't do a plastic coating, but will check out the plastikote antique white to see if it's a suitable colour ..... that's my next challenge, finding suitable paint for aluminium in the right colour. The grille is fine, unmarked, but it'll probably get repainted as well.

Howard

[Nickthedentist]

Originally Posted by Nickthedentist

BTW, have you read the interesting article about these by the late Geoffrey Dixon-Nutall in a back issue of the BVWS Bulletin (on the CD)? I can recommend it highly.

It's in the February 1995 (Volume 20, Number 1) Bulletin, pp. 6-7, on the "BVWS3" CD-ROM.

[howard]

Originally Posted by Colin

Hi Howard,
Thanks for that, I had wondered if mine had been sprayed at some time. Good job I didn't spend ages trying to remove the paint
Here are a few pictures of mine. The front is original but the grille has been re-sprayed, the back's a bit tatty. I think you'll do a great job with yours and it'll look much better rgds Colin

Hello Colin,

It will be resprayed as soon as I find suitable paint. I wish it was white like your later model, no problem finding white paint. I think youre right, it will look a lot better when repainted.

Howard

[howard]

Originally Posted by Nickthedentist

It's in the February 1995 (Volume 20, Number 1) Bulletin, pp. 6-7, on the "BVWS3" CD-ROM.

Thanks Nick.

Howard

[igranic]

If, as I understand it, the front panel of the Double Decca 46 is aluminium, then ordinary aerosol spray paint will not adhere well to the aluminium unless is first treated with 'self etch primer'.

Bare aluminium, exposed to air, rapidly forms a skin of aluminium oxide to which most paint will not successfully adhere. Self etch primer contains a mild acid which eats through the oxide layer allowing the primer to form a firm bond with the underlying aluminium. Etching primer is available in aerosol form from Frosts, or possibly from local motor factors. It also appears on ebay, but often at excessive prices when carriage is included.

Incidentally, caution is required when stripping paint from aluminium; many proprietary paint strippers will attack aluminium - read the label carefully. I recently took a scruffy aluminium cabinet to my friendly local spray shop, who kindly dunked the whole thing in bath of "spray gun cleaner" which stripped it bare ready for a coat of self etch primer.

[howard]

Originally Posted by igranic

If, as I understand it, the front panel of the Double Decca 46 is aluminium, then ordinary aerosol spray paint will not adhere well to the aluminium unless is first treated with 'self etch primer'.

Hello Edward,

Yes, I'm aware of the problems with painting aluminium. PlastiKote do a range of metal primers so I will check them out.

Howard

PS: In fact they do do an aluminium primer

[Alvin]

And here's my 10 quid car boot bargain which came complete with somewhat tatty batteries which I opened up and popped in some pp3s and d cells - it works a treat on all 3 bands. I tried it on mains via the lamp limiter and it behaved itself so left everything well alone as it only gets occasional use on batteries.

Somewhere in this tip I call home I've mislaid the rear panel so I'm grateful for the pics posted here - at least I now know what I'm looking for!

Alvin

[howard]

Hello Alvin,

That can't be bad, finding a working valve radio for a tenner, amazing to find a Double Decca still working !


I've found some suitable paint now for the front, Plasti-Kote aluminium primer and Plasti-Kote vanilla coloured enamel paint. I've just got to locate some now ...

Howard

[af024]

Wilko seem to stock quite a bit and I've seen some in some DIY stores.

I wish you good hunting Howard.

Cheers,

Andy

[howard]

Hello again,

I've got the paint - I didn't go for vanilla as it was too yellow, instead I got some Plasti Kote 'creme de la creme' cream paint which is a good match. I couldn't find any aluminium primer though.

I've read Geoffrey Dixon-Nuttall's article 'The classics: The Double Decca' which certainly highlighted several flaws in its design. In mine, Ron has fitted the shunt resistors to prolong the life of its valves, and there is one more fix to be done to it to prevent the LT smoothing capacitor from exploding should the filament break in the N16 output valve - this work will be done at the same time as the respray of the front panel and I will do a write up on these final pieces of work shortly.

Howard

[igranic]

I downloaded a copy of the Plasti-Kote Safety Data Sheet for their 'Aluminium Primer'. There appears to be no mention of any constituent that would provide 'self etch' properties.

[howard]

Hello again,

I have repainted the front of the Double Decca 46 now. It's quite straightforward get the front off of these, just remove the chassis, the wooden block in the right hand corner, the speaker baffle (4 screws), and the four battens around the edge of the front panel (2 screws each) and it will then come out. I stripped off all the paint with Nitromors, primed it with two coats of Plasti-kote Aluminium primer obtained from here ...

http://www.paintsprays.co.uk

and then two coats of Plasti-kote creme de la creme coloured paint which is a spot-on match. The paint finish is perfect (no runs or blobs !) but I might just compound it down in a few weeks time. Lastly I bought some nice new screws to replace the battens and baffle with.

It does look a lot better now.

Howard

[batterymaker1]

It looks like it came right out of the shipping carton. What a difference!

[Colin]

Great job Howard, much better!

[Nickthedentist]

Ah, that's better Well done, superb workmanship and attention to detail as always, Howard

By the way, do make sure those Rexine squares on the bottom don't fall off or wear thin, as they're an important safety feature to stop anything touching the potentially-live chassis retaining bolts.

Nick.