1956 Stella ST236A AC mains 7 valve MW/LW/VHF table radio

[howard]

Hello again,

I've had a couple of these Stella 236A AM/FM sets in the past and they both worked well but both were sold on. It is of course a Philips built set and is a clone of their B3G63A model (of which I have three) but in a different shaped red bakelite case. I won this one on ebay last week and collected it locally yesterday and it only took a few hours to restore it. Cosmetically it was in virtually mint condition, with hardly any dust inside, no tarnished brass trim, no scratches, no chips, no cracks, none of its gold paint worn away and its red case is as glossy as new, it just has a couple of faint marks on its grille cloth. It was sold as working although it didn't when demonstrated on collection. Trader sheet 1374 covers the Philips B3G63A / Stella ST236A and is available here .....

http://www.service-data.com/section.php/7685/1

These Philips AM/FM sets are usually a cinch to restore and they are easy to work on. They have only six of those Philips black pitch tubular capacitors to replace and sometimes they're still OK so on this occasion to retain originality I replaced only the ones that can be seen with the cover off, the 0.015uF AF coupling capacitor (C60), the 0.015uF tone control capacitor (C59) attached to it and the 0.001uF 1kv capacitor (C66) across the output transformer. The first two are hidden under a paper strap and the other is behind the case. The waveband switches, valve pins/sockets and volume/tone potentiometers were cleaned with DeoxIT, a new 3 core mains lead fitted as the original 2 core cable had been cut short, the set was switched on and away she went working well on all 3 wavebands. Not all was well though, the VHF dial pointer vanished off the scale and a spring on its cord then caught on the diffuser frame - I took the bottom cover off the FM tuner and discovered that the pulley on the end of the FM tuning capacitor had come loose, so the VHF pointer was realigned and the pulley grub screw tightened up. I meggered the transformer, no leakage, and checked the HT and it was fine.

The chassis was dusted off and the case cleaned inside with upholstery cleaner and the outside with white spirit followed by a quick polish with car polish, it didn't need an abrasive polish. The sponges around the dial glass aperture had disintegrated so I scraped all that off and replaced it with brown draught excluder. I made no attempt to clean off the faint marks on the grille cloth, I've tried that before on one of these and it looked worse afterwards.

I haven't seen many 55 year old radios in this sort of original condition, it obviously hasn't seen much use. It works perfectly with no hum and no drift, and with excellent sensitivity on all bands, and on VHF with its original dipole aerial it manages to pick up Classic FM, which is a weak station here, loud and clear. It sounds very good and it's a most attractive looking 1950s radio set in an unusual colour. And all for under £20.

Howard

[vinrads]

What a beauty and in such good condition this is an every day radio,i bet it sounds good too, another nice restoration job , Mick.

[Tim]

Nice one Howard.
You're right about it being in good nick. I have seen plenty of these(and Phiips B3G63A) with a faded tuning scale. You were also lucky the tuning didn't need re cording! Nice to have seperate tuning knobs for VHF and AM.
Another thing to watch is the speaker leads burning through on the hot EL84. I recall I tied mine back out of the way after one broke and the EL84 nearly took off!

[Radioboy Angus]

Well done Howard, another excelent restoration, you've no idea how jealous I am! I want one! would go in our dining room beautifully and it's red too! I have a B3g63A and it's a fantastic radio, but I think the cabinet on the Stella is much more interesting, so I guess it's a winning combination. Well done again.
Angus.

[Andrewausfa]

An excellent bit of sprucing up Howard. Lovely looking radio!

Andrew

[Hybrid tellies]

Nice one Howard,really attractive looking little set but bet it sounds good though.

[howard]

Thanks all,

Yes I am pleased with this Stella which is a much nicer looking set than the Philips B3G63A version. Its burgundy red cabinet is really eye catching.

Howard

[JoshWard]

Looks very nice, and virtually immaculate to boot!

I will stick my head out and say I prefer the B3G63A but I do like the colours of that a lot.
Sadly my 63A is well past it, the dial has faded, the cloth is stained, the transformer is literally falling apart (windings now exposed) and one of the FM tuning cables has snapped. It does work well, just needs a cable for the FM and maybe a new transformer (unless I can reseal the old one in pitch or something). Luckily these seem to be fairly common sets.

As an aside isn't it really nice to find a set in such clean smart condition? I'd be thrilled with something looking that smart.

Josh.

[howard]

Hello again,

Well that's handy, this thread is still open, did the mods here think this set was likely to go wrong so left it open, because it has, and has just undergone quite a lot of work to fix !! Sadly it stopped working properly recently on AM, with crackling noises, instability and poor gain. However it continued to work well on VHF. I had a go first, I tried swapping the ECH81, EF85 and EABC80 valves and cleaned the valve sockets and waveband switches thoroughly with switch cleaner and that made no difference at all. So Ron Bryan offered to take a look at it.

As FM was working OK, the problem probably existed in the ECH81 mixer oscillator or IF stages so resistors and ceramic capacitors in that part of the circuit were checked and one or two were out of spec so were replaced and that didn't make any difference. So maybe the ECH81 valve socket was faulty, nope that was replaced and that made no difference either. So next the two AM IF transformers were removed and checked. All four capacitors in these two IFTs were found to be very leaky (3 x 195pf and 1 x 110pf) but fortunately the coils tested fine on a Q meter. The next problem was finding replacement precision capacitors of those values and rated at 250v +. It's amazing what one can find on Ebay USA, and I won 20 X 195pf and 25 x 110pf Cornell Dubilier high voltage silver mica capacitors and at considerable expense had them shipped over here.
While they were in transit, two IFTs from a scrap B4X23A were fitted and they worked surprisingly well in the Stella, but there was still a hint of crackling which turned out to be a noisy ECH81 after all so that was replaced with another. Then a couple of days later that suddenly expired so in went another NOS Mullard ECH81. The capacitors eventually arrived from the USA and were fitted into the original IFTs which then peaked perfectly in the set and the ST236A was once again working well on AM.

This is the first Philips radio with this fault that we have encountered, indeed it's an unusual problem to find in any post-war set. But then a week later the same problem was found in a Hacker Hunter transformer.

This Stella is one of my favorite radios, it is in mint condition (it's bakelite cabinet is still glossy red) and these Philips sets do perform very well. My thanks to Ron for sorting it out.

Howard

PS: I have a few spare Cornell Dubilier silver mica caps in 110pf, 195pf and 200pf +/- 1% and 3% 300v-500v available at cost if anyone wants any, they are almost impossible to find in Europe.

[Tazman1966]

It really is in beautiful condition Howard. Nice one!

I wonder how much more common as the years roll by that this type of capacitor problem will be?

[howard]

Hello Taz,

This set is a beauty, so it was well worth spending some more time and money on it.

The original capacitors were ceramics and they don't often give much trouble. I've had several Philips B3G63As pass through my hands and all worked very well. The silver mica IFT capacitors in US built 1940s-1950s radios are known to be troublesome though. Definitely worth checking these caps when a set is lacking gain.

Howard

[Meat Pye]

Nice set! I have a Convair 10 which is a little lacking in gain but the audio section seems OK. I know this is a transistorised radio but would the fault be similarly attributable to leaky caps in the IF section? I will have to investigate!

[Station X]

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