Schematic needed - Mullard Z-247 or MAS247

[Nortonics]

Recently acquired a wonderful UK set, all the way over here in Minnesota, USA. How it made its journey all the way over here is a mystery, except to say the seller indicated that his parents received it from a neighbor perhaps 6 years ago. This would be my first foreign set ever. When I saw it on my local Craigslist classifieds I just knew I had to have it - I find this radio to be simply beautiful, and ya gotta' love the greeneye tuning indicators!

The overall radio is in excellent shape and works. Well, at least it worked until the seller's young daughter cranked the tuning knob all the way to one side and ended up breaking the dial cord - Haven't powered it up myself yet - really want to get it out of the cabinet and have a close look at its health, and fix that cord first. I'll likely do a full recapping and the other nominal stuff. The speaker grill has what appears to be a pronounced water stain, but this looks to be completely restorable with the right technique. The cabinet is in excellent condition, but the finish is pretty well crazed throughout - I'll likely look into a refinish job on that as well.

I sure could use a schematic, and/or any other details about this set. It seems these Mullard sets are pretty darn hard to find any information about. Also, is the finish on the cabinet of this radio likely to be lacquer? Any thoughts on the type of wood Mullard likely used on this set?

As I progress on this set I'll be sure to post pics and progress notes... Thank you to the group for any assistance you can provide!

[stitch1]

Hi Tom,
I can't see anything in VRSD but it may well have a Philips equivalent, I'm sure someone here will know.

Any idea what the socket on the back is for? Someone else asked a while ago,
https://www.vintage-radio.net/forum/...ht=mullard+247

Some more detail on Radio Museum but no diagram.

http://www.radiomuseum.org/r/mullard_mas247mas_24.html

Good luck!

[Nortonics]

Originally Posted by stitch1

Hi Tom,
Any idea what the socket on the back is for? Someone else asked a while ago,
https://www.vintage-radio.net/forum/...ht=mullard+247

Some more detail on Radio Museum but no diagram.

http://www.radiomuseum.org/r/mullard_mas247mas_24.html

Good luck!

Hi Stitch,

I saw that post you inquire about. I too believe that connector and switch was simply the ability to power the unit from an external battery pack rather than from the mains. Just like the other reply indicated, that 6 volt DC symbol sure makes it seem like that would be filament voltage for the valves. Hopefully if we can find a schematic for this unit we'll be able to answer that question with a little more authority.

And thanks for the radiomuseum link - found that earlier myself, and that's the ONLY occurrence I could find on this particular set anywhere on the web. Actually took me some time to determine that the set model number could be MAS247 - the only model number on the radio I can find is the little backing cutout window on the rear indicating "Type Z-247", which brings up absolutely nothing with web searches.

[paulsherwin]

It has an early 50s look to it and if so may use the standard Philips chassis used at that time (the control layout would support this). If so, it will use B8A Rimlock valves which are almost unknown outside Europe - ECH42, EF41, EBC41, EL41, EZ40, EM34.

However, the large number of SW bands suggests it may have been made as an export set, in which case it may have been fitted with B9A Noval valves. The Mullard brand was often used for export sets produced by Philips UK.

The first thing to do is to have a look under the chassis. If it is full of large black capacitors that look as if they're covered in tar, get the soldering iron warmed up

[Mr Moose]

Hello,

It does have similarities to the Philips 411A; as Paul says possibly an export version. The case and the wavebands are different and the 411A does not have the Octal socket on the back although the other sockets are similarly placed.
Perhaps we could see a picture with the back removed.

There is a picture of the 411A here https://www.vintage-radio.net/forum/...0&d=1281543450

Yours, Richard

[Nortonics]

Wow, look at that - it sure does have a resemblance to that 411A! Thanks for that detail, Richard.

Hey, thank you for the interest and replies, everybody!

Another interesting point on my set is that Mullard logo on the front - it's a simple, thick piece of paper with the logo printed on it, and attached to the cabinet with two very tiny brad-type nails on each side. It looks like it's been on there like that for the life of the radio as I can see the finish appears different underneath it, and the tiny nails have a patina that would suggest they've been on there since it was manufactured. I'm amazed that it was never torn off and discarded sometime over its 50+ year lifespan. Simply does not have the metallic? trapezoidal style logo that I've seen on many Mullards on the net.

Yes, a picture of the innards - here we go...

[Nortonics]

Originally Posted by Mr Moose

It does have similarities to the Philips 411A

Looking at the Radiomuseum summary detail for the 411A, and seeing the rear shot here:

http://www.radiomuseum.org/r/philips_bf411abf_411.html

I'd have to say the overall build and chassis appears quite different between the two.

[paulsherwin]

It does look like many Philips chassis I've seen from the early 50s though. The horizontal rectifier valve above the chassis is a giveaway. The BF411A on the Radiomuseum site was made by Philips France so maybe they used a different chassis.

See http://www.thevalvepage.com/radios/p.../341A/341a.htm

[Mr Moose]

Hello,

I am attaching a copy of the diagram of the chassis of the Philips 411A taken from the Phillips Service data.
As you can see they are similar, however yours does have an additional rectangular coil and beehive trimmer at the front end presumably because yours has four wavebands rather than the three of the 411A.
Also your output transformer seems to be of a different design possibly related to the extra octal socket you have on the back cover.
I would suspect that the circuits are probably basically similar if you can't find a circuit for yours.
The French BF411A is different; this is the relevant one from the Radiomuseum site http://www.radiomuseum.org/r/philips_411a_411_a.html

Yours, Richard

[paulsherwin]

Yes, that's what I know as the standard Philips UK chassis of the early-mid 50s. They used the same chassis in all sorts of things, from small table radios to radiograms. There is some variation in the tone control arrangements and the gram switching but the design is basically all the same.

It's a good design and works well once those awful Philips black capacitors have been changed.

[val33vo]

I had a look at the site below, they dont list your exact model but maybe if you are really stuck some might be a close equivalent, It's news to me that Mullard manufactured radios I only thought it was valves and transistors

http://www.***********************/manuals.shtml

regards

val33vo