Hi there everyone.
This radio has significant sentimental value to my friend. I am trying to identify it so I can obtain valve types and schematic.
I have emailed the photos via the instructions so I am hoping I get some help
thank you

One will wait & see but plugging it in / powering it to see if it works is not step one. I see the damage & am expected to fix some of it.

It's a Mullard, manufactured by Philips during the early 1940s. There is a cardboard plaque inside the radio at the back. It may have the model number on it or it may just show valve types and locations and perhaps dial cord information. There may also be a green sticker on the part of the chassis where some wiring comes out (on the side facing the loudspeaker). There is usually a capital letter followed by four or five digits. The letter will give you the year the radio was made. Mullard radios were manufactured by Airzone before WWII so this will most likely be a 40s model.

If the radio is in working order, it should sound quite good. Philips rarely skimped on quality, with one small exception - the markings on the dial glass will be chalky and will rub straight off if touched.

As Marc alluded to, if it hasn't yet been refurbished (and it can be) it is best not to try running it, the power cord is single-insulated and likely to be degraded to the point where electric shock is possible and someone may have tried their own repairs in the past without success, and may have inadvertently left a booby trap.

Rolfred: A list of the valve types is often helpful with identifying the model.


That protruding type of dial glass was beloved of Philips.

That is a MAS1108.
Here is a link to the service manual
https://www.kevinchant.com/uploads/7/1/0/8/7108231/mas1108,_mas1108a.pdf
(the PDFs are stored in a linked array)

I'd run it up on a dim bulb.

6X5 rectifier is a candidate for the classic heater "worm".

Hi Rolfred.

Agree with the others, move very slowly with this one.
Typical of Philps sets was the use of a white coloured hookup wire with 'rubber' covering.
The rubber deteriorates, cracks and falls off. You can get shorts where wires touch each other or metal parts.
Also, they used terrible quality wave change switches where the 'Bakelite' just crumbles with age.
A common horror are the power transformers where they have no cheek insulation and the layer windings spread out and short on the laminations.
These problems I have observed myself first hand.

The safest thing to do is to remove the chassis, get it on the bench and do a careful survey for safeties sake.
Do not ever power one of those !#$ chassis up blind
Safety first with the power wiring, earthing and transformer..
The electrolytics will need forming.
The only good news is the tuning coils and IFT's were always well sealed and never fail.
They have to be good because most of the adjustment 'trimmers' are those wretched ceramic wire wound type that you adjust once.
On the good side I have had several Philips/Mullard sets and the tunings were still as set by the factory and so stable no adjustment was required.

Once any problems are sorted out Philips sets are absolute first class for performance.

Fred.

Thank you to all especially Ian for the link to the schematics. I build valve amps so have experience with do's and donts but I am thankful to all for the hints and cautions..I have not plugged it in and turned it on (I know that much at least).\
Ian you mentioned running a dim bulb- I am not familiar with that term and wondering what it means. I have a variac that I have used to form caps but if there is a better way I again, am grateful.
regards

Dim bulb is commonly light bulbs in series with the transformer in this case. Aimed at soaking up the load & current limiting, should there be a short or overload. Not a believer in the method.

I looked at the AORSM circuit as Adobe Reader corrupted & got removed. The Kevin Chant site wanted to download Adobe and a Virus program I don't want, so that rude & invasive link got trashed.

Beware with the filter caps 16μF. The set is, as is common with Philips, "Back Biased" and neither go negative end to ground, the go negative to the floating centre tap.

Thanks for the tip on the 16μF caps Marcc
I assume when removing the chassis there is a trick to the tuning indicator pulley? i.e. so that I dont lose its calibration so the station indicator
will not approximate to the indicated stations?
Thanks again , I am really impressed by all the knowledge
Regards

Upon checking, I ran into that Adobe link too. I am not sure what the story is with that but it will aggravate anyone that, like me, just uses their web browser to view PDF files. If there was a way to circumvent it, I wouldn't have an issue but it looks like the button has to be pressed first.

On that site my system (Firefox) won't let you view them in the browser, just download them, which I do to a safe file area. No problem.

You can google "dim bulb tester". I use this for everything I do.

Big advantage is, if a fault develops, the bulb will react quicker than a fuse and hundreds of times faster than your reaction time on the variac knob. And it will do so unattended. Important if you suddenly find yourself distracted or occupied elsewhere (my prostate operation is soon lol!)

If a fault occurs, far less damage gets done.

A tungsten filament lamp is actually a very effective PTC thermistor.

I gave my variac away 10 years ago!

But I know some people aren't believers and don't understand the physics.

The Philips mains transformers of that vintage spill their windings out the side. A good soak in oil-based polyester lacquer is a good, permanent solution.

Replace that rubber 2 core flex and suicide plug with a proper 3 core moulded cable and a locking cable gland in the chassis.

Yes the "dim bulb" tester is one of the really best service tools.

They really came to the top of the list when colour TVs came out with their high current switch mode power supplies, in the seventies, but I was using them in the monochrome and valve radio days also.

A short or a failure whilst on the bench was most frightening, fuses just vaporising, and loud bangs.

The "dim bulb" after a while gives many indications of how the repair is progressing.

From electro's charging at startup, excessive current for the type of unit under test, to a dead short. No sweat or bother.

My variac only gets pulled out when doing things like working out transformer ratios etc.

I still do not understand why some people cannot see the huge merits and safety of the "dim bulb".

BTW, it was never called that in my day, in fact I can't recall what it was called at the time.
JJ

That Adobe ambush does them no favours in my book & if I get a pdf file the ABBY Fine Reader can read it. That sort of hijack just totally destroys the usefulness of the site Radio Museum & others are going the same way, obviously they don't want people using their sites.

I had a look at that PDF, and found a way to extract what we want. Firstly I clicked on the link provided by Ian and it downloaded to my hard drive (I have Firefox set up that way). Then I opened the document with Adobe Reader and got a page with F I on it. This indicates that the file contains flash content which is no longer supported by Adobe and they refuse to run it.

So the trick is to extract the original PDF from the supplied package.

Click on View, Portfolio, Preview File - you'll see the document that we're after.

Near the top of the page it will say MAS 1108, A (p1).pdf X followed by Open Document. Click on Open Document - it opens it again as a separate PDF which we need to save.

Click on File, Save As, enter a filename if you want to, and it is saved. The flash stuff will be gone.

You can now dispose of the original that you downloaded.

There's no schematic so I'm not sure that the document ever had any real value anyway.

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As for that radio, I was going to say something, but the photo shows it's in better condition than usual. Of course you'll need to replace all the paper capacitors, the rubber wiring and the things that the others have said. If you do it properly and without mistakes you'll get a good radio.

Also as they said, DO NOT touch or attempt to clean the dial lettering - it will disappear before your eyes.

A light spay of normal "hair spray" is effective in retaining loose lettering.
JJ