1951 Philips BS311AN AC mains 5 valve MW/LW/SW midget radio

[howard]

Hello again,

I hope everyone had a good Christmas and has a Happy New Year !

I didn't do much restoring over Christmas nor acquire any sets, apart from this little Philips wooden cased set which caught my eye on eBay and I won it for £6.50 and collected it locally from Croydon. This is a Swedish market/built Philips and was brought over to the UK many years ago by its original Swedish owner so all its markings and the station names on its dial are in Swedish, but luckily it has a 240 volt mains voltage setting. I have searched everywhere for information about it but very little exists, no schematics on offer, just one pic of it on a Spanish collector's website and its 1951 year of manufacture listed on a Dutch Philips website. It's an AC mains set and came complete with all its original Philips ECH42, EAF42, EF41, EL41 and AZ41 valves all marked "Fabrike in Hollandie". It was not working and very grubby and its 13A fuse had blown ....

The first thing to do was to check the mains transformer and to sort out its mains lead which had been joined in two places (almost certainly the cause of its blown fuse). I checked the transformer for leakage with my 500 volt Megger and it was perfect so I proceeded to replace its dangerous lead with a new 3 core cable and a new plug fitted with a 3A fuse. It had 7 large wax capacitors inside all bearing the "Farad" brand name - the voltage ratings marked on these were unusually high, the coupling capacitor lowest at 500 volts, the highest on the output transformer at 3750 volts and the others all 1500v. I replaced the coupling capacitor with a new Vishay 630v cap, cleaned the switched volume pot, waveband switch, the tone switch on the back and all the valve pins and bases with Servisol 10, switched it on and away it went, working quite well on all wave bands. The only thing not working was its SW fine tuning control. I then replaced all its wax capacitors and used 1600v orange dip and 1500 volt LCR capacitors.....except for one as its value had worn away. All the old capacitors leaked badly. The set was now working really well, and sounding rather good through its 6 inch loudspeaker, which is unusually large for a set this size.

I dismantled the case, scrubbed the wood with white spirit and revived its original colour with some Danish oil. The white urea formaldhyde front panel and the perspex dial were gently cleaned with upholstery cleaner and finally the whole case was polished with Mr. Sheen wax polish.

The only thing left to do now was to replace the unidentifiable wax capacitor and sort out the SW fine tuning so I took the set over to Ron Bryan for help. The remaining capacitor was removed and on Ron's bridge its capacitance measured at around 0.0084uF so I plumped for a new 1600v 0.01uF orange dip and that was duly fitted. The SW fine tuning failure was due to a perished rubber sleeve on the spindle end of the knob - when the knob is turned it moves a rod pressed into the sleeve by a phosphor bronze spring and this operates a coil (see pic). The perished rubber sleeve was removed, the knob pulled out and Ron had some suitable rubber tubing which was cut to size, pushed over the spindle and the knob replaced and it then worked perfectly.

Western European radios built in the early 1950s can look a bit austere in their dark bakelite or wooden cases but this pretty little set is very different in its light wooden case and ivory trim. It sounds very good with its very generously sized loudspeaker and its sensitivity especially on SW with an aerial attached is amongst the best I've encountered on a set of its period. I really like this set and it's in excellent condition.

Howard

[paulsherwin]

An interesting set Howard, and a good restoration as usual.

You sometimes find radios fitted with very high voltage caps. I think manufacturers sometimes had access to these at good prices so used them, even though the voltage ratings were way in excess of what was actually needed.

You would probably have been fine using 400V caps in all positions apart from the tone correction cap, which should either be 1kV or X2. It obviously does no harm to use higher ratings of course.

Paul

[Steve_P]

Interesting set there Howard. A nice addition to your collection and no doubt sounds as good as it looks.

Cheers,

Steve P.

[howard]

Originally Posted by paulsherwin

......
You would probably have been fine using 400V caps in all positions apart from the tone correction cap, which should either be 1kV or X2. It obviously does no harm to use higher ratings of course. Paul

Ron thought my use of 1600v capacitors was overkill as well ...

Originally Posted by Steve_P

Interesting set there Howard. A nice addition to your collection and no doubt sounds as good as it looks. Cheers,
Steve P.

I can safely state that there aren't many of these Scandinavian sets in the UK ! It's a very attractive little set and considering its modest size sounds brilliant.

Howard

[Brian R Pateman]

This must be one of the most attractive sets of the period I think.

And a stunning restoration (as usual).

I get a tremendous amount of pleasure out of finding things to listen to on the broadcast SW bands especially on a period set.

Regards,