1947 Philips 371A /15 5 valve MW/LW/SW AC mains table radio

[howard]

Hello again,

I won this set on eBay for £25 which is about the right price for one of these in unrestored condition. These late 1940s Philips sets IMHO look gorgeous, with strong art deco influence in their design even though they were built post war, so I simply had to have one ! It arrived with its dial glass smashed cos it wasn't packed adequately but in all other respects its condition is remarkable for a 60 year old radio, with no cracks, chips or nasty scratches evident, just two tiny light half inch scratches on the front which are hardly visible and it still had an excellent gloss finish on its brown tortoiseshell bakelite cabinet. Gosh !
Sadly it was missing its little 10mm x 17mm Philips badge and a small bracket from the edge of its bottom cover and looking inside after removing rear and bottom covers it was found to be fitted with a 6V6GT instead of an EL33 output valve. A replacement off/on/volume potentiometer had been fitted at some time but was otherwise totally original and no internal changes to accomodate the 6V6GT output valve were evident, but then these sets do not have a bias resistor connected directly to the output valve. I see there's some doubt on the forum as to the exact years of manufacture of the 371A, this one was built in 1947/8 as one of its original electrolytic capacitors is dated September 1947. Service data for the 371A is available from Paul Stenning's website, link above, both the Philips service manual and the Trader sheet for the Mullard MAS221 model which has the same chassis, but that's housed in nowhere near as nice a looking cabinet.

The first thing to be done was to replace the dial glass which fortunately is flat - I managed to acquire a suitable piece of glass and cut a new one, it's square with a small piece cut out the top for the bulb so straightforward to make. All but one of the white rubber grommets which support the chassis/case brackets had disintegrated so I pulled them all off and fitted new (black) ones. I tested the mains transformer with my Megger which showed some very slight leakage and then brushed the light layer of dust off the rust free chassis, replaced the audio coupling capacitor, cleaned the off/on/volume potentiometer, valve pins, tone control and waveband switches with Servisol 10, fitted a plug with a 3 amp fuse to its excellent original mains lead, powered it up and away she went.... humming like the devil....... but working on all wavebands, just its dial bulb was dead. I replaced its dial bulb (marked 8045 which is 6 volt 0.3 amp), all its wax capacitors, its black pitch capacitors (except one buried deep under a load of other components) and the set worked considerably better, picking up lots more stations. All the original black pitch capacitors were found to be leaky but the mains transformer when retested was found to be fine. One feature I found with this set is that it crackled when moved. I thought I might have soldered a joint badly somewhere, but in fact it turned out to be coming from the internal aerial connection .... the internal aerial is simply a piece of aluminium foil stuck on the interior surface of the case and connection to it from the chassis is via a sprung tab on the left-hand chassis support, so I simply took the latter off, polished the tab, cleaned the surface of the aerial carefully and that sorted that out. But it continued to hum so I tried bridging the two smoothing capacitors with a 32uF electrolytic earthed to the chassis and that made no difference so I took the set over to Ron Bryan for advice.

Ron first checked the voltage to the non original 6V6GT which surprisingly was found to be absolutely fine, even though it's not the same spec as an EL33. Ron then noticed from the circuit diagram that the smoothing capacitors in this set are not earthed to the chassis, and viewing them from the top revealed wires connected to tagged washers sandwiched between rubber insulating washers on the chassis and the capacitor cans. So a new 33uF capacitor was bridged between the positive tag on each of the smoothing capacitors and the ends of the leads from the negative connections on top and the hum disappeared. Just one of the smoothing capacitors was found to be faulty.

So I then started looking for a good original smoothing capacitor and an original EL33 .... cos I'm fussy about originality ... gosh aren't EL33s rare and expensive, NOS examples fetching from £32 - £60 apiece ! I managed to find a scruffy looking one but which tested 100% from Mike Lewis and also a perfectly good 32uF smoothing capacitor and fitted them, and also replaced the last of the black pitch capacitors (just as well as it was leaking badly). I noticed some fluttering distortion after fitting the EL33, so I took it out, polished its pins and as its glass tube was rocking around in its bakelite base, I tipped some superglue down between the two and that held it secure it within 10 seconds. It was refitted and the set then worked perfectly, indeed it now plays rather louder than when the 6V6GT was fitted.

The case was straightforward to restore, as it had been carefully stored it only needed a wipe. Much of the ivory paint on the case and on the knobs was peeling so I scraped it all off and replaced it with PolyVine ivory acrylic enamel which is only £1 a 20 ml pot from Homebase and it's an excellent match, dries quickly and adheres to bakelite extremely well. The technique I use is to brush on two coats of paint, allow to dry, and then to scrape off any excess along the edges. It took me around 4 hours to do that, the coachlines were straightforward but the round knobs were tricky ( I managed to wear away quite a lot of my thumbnail as I use that to scrape off the excess paint ! ). In fact I am not convinced that the round knobs should be decorated, I only found old paint on the waveband knob but Tony Thompson's excellent book has a picture of a 371A with painted front knobs, but all other 371As in pics on the web have plain knobs. Finally I polished the case with Safecut polish.

I've run this set now for over 20 hours and it works well. It's reasonably sensitive with just its internal aerial but does work better especially on SW with an external aerial attached. It sounds rather good and it's a lovely looking radio although I wish it had its badge but I daresay one will eventually turn up....fingers crossed.

This is a very nice radio indeed.

Howard

[Lloyd 1985]

Hi ,
the set looks fantastic! I have one of these, not restored it yet, but it does have all its original bits and the badge! works ok too. could I ask where you get those rubber grommet things from? I need something similar for my Ekco AC86's as they have all turned to goo

regards,
Lloyd.

[Sideband]

Originally Posted by howard

I tipped some superglue down between the two and that held it secure it within 10 seconds. It was refitted and the set then worked perfectly, indeed it now plays rather louder than when the 6V6GT was fitted.

Be carefull when doing this with output valves. I would prefer to use something like Evo-Stik rather than Superglue simply because Superglue doesn't have much 'give' when heated. There may be a danger of cracking the glass because or the heat that can be generated by some output valves.

An excellent job Howard...not dissimilar in style to the 470A shown in my avatar


Rich.

[howard]

Originally Posted by Lloyd 1985

.......... could I ask where you get those rubber grommet things from? I need something similar for my Ekco AC86's as they have all turned to goo regards, Lloyd.

Hello Lloyd,

Here's a pic of the one survivng white grommet alongside a new black one. The hole in the middle of the new one is 8mm in diameter. The new grommets don't look much like the old ones but they fit fine and do the job. I can't remember where I got them from and I don't have that many left, but I think you'll find someone on the forum who has one or two that they could spare. Should anyone know where grommets like the originals can be obtained, do please let us know.

Also in the pic the ivory paint used to decorate the case and knobs.

Howard

[howard]

Originally Posted by Richard_Newman

Be carefull when doing this with output valves. I would prefer to use something like Evo-Stik rather than Superglue simply because Superglue doesn't have much 'give' when heated. There may be a danger of cracking the glass because or the heat that can be generated by some output valves. An excellent job Howard...not dissimilar in style to the 470A shown in my avatar Rich.

Hello Richard,

I think Superglue will be OK, do you know of a case when it caused a valve to crack ?

I think your 1938 470A is even nicer than the 371A, a genuine art deco cased radio and its dial is just stunning. But yes, they are similar designs despite the 9 year gap between them.

Howard

[yestertech]

Another fine job Howard - I love these sets to bits
( I'm on my second one having been persuaded to sell the first ). The one I have here cost just £8 at closing time from 2007's Audiojumble. The only fault is a small piece missing from the bakelite "skirt" at the bottom. I filled that with epoxy putty and painted it with acrylics. Very passable even quite close ..
As with other Philips bakelite mouldings( 206A,462A etc ) , the 371 seems to come in "milk chocolate" and "plain chocolate" colours. Yours looks like the milk version to me - by far the nicest.

EEK ! Is that really the price of EL33's ? Time to lock mine in the safe

Andy

PS anyone for a Mullard version ?

[Sideband]

Originally Posted by howard

I think Superglue will be OK, do you know of a case when it caused a valve to crack ?

I've heard of one instance where this happened. Hopefully yours will be OK.


Rich.

[Nickthedentist]

Hello Howard,

Nice job as usual, on what is also one of my very favourite sets, aesthetically speaking.

Like Andy, I have two of these; a tatty one to be restored when I have time, and one that's nearly as beautiful as yours which sits on the sideboard.

The smoothing electrolytics are notorious on these, and leaky electrolyte sometimes causes electrical leakage between the can and chassis. There is a brief thread somewhere here mentioning this (Zak + me) but I haven't been able to find it yet. I fitted modern replacements under the chassis leaving the originals in place but isolating them electrically which is easier said than done and requires a little re-jigging of the wiring.

Nick.

[howard]

Hello again,

I've removed the paint from the round knobs (a soak in warm detergent for 10 minutes shifted it) and temporarily fitted a later Philips badge (thanks Maitu) just to cover up the hole in the front. Here she is now in daylight ...

https://www.vintage-radio.net/forum/...1&d=1226496017

There's still an original badge, one large spire clip (which holds the loudspeaker baffle in place) and a little bracket on the rear covers yet to find and fit but fingers crossed I'll find those in due course.

Howard

[harvestgold]

Howard, that is a beautiful set and a credit to you!

I buy my rubber grommets from Halfords - they sell a small plastic box full of mixed sizes. They are probably a bit expensive but very useful for both radio and classic car repairs!

Neil.

[howard]

Hello again,

I now have received an original Philips badge of the correct size and a spire clip from Mike Lewis so this gorgeous radio is now good enough to display on my website of vintage valve radios here ....

http://vintagevalveradios.ukgeeks.co.uk/p54899797.html

This restoration was particularly satisfying cos this 60 year old set has come up in such good cosmetic and working condition, and hunting down all the original parts ..... and finding them ..... is what this hobby is all about.

Howard

[batterymaker1]

Is there nothing more lovely than mottled bakelite, polished to a high gloss?

[Tim]

Howard strikes again! Awsome!