Recepteur Type RI 221

[pwdrive]

It's a bit of a sad story how I came by this "radio", won't go into that right now.

So...Found this today in someones old leaking shed, I'll call it a radio for the moment until I investigate further, it was very wet, been in doors now for a few hours so starting to dry out a bit, the first lot of pics were taken after I had moved the set indoors so shown more or less as found ie: not tried to get inside the cabinet yet, cabinet looks like roller front.

First batch of pics:

                   

I'll try and open it up shortly to take some more pics.

Lawrence.

[AlanBeckett]

That looks interesting. Perhaps you'll find rolls of White Fivers in there, or at least a couple of interesting Coils.

Alan

[pwdrive]

Yes, looks interesting Alan, I'll keep my replies short until I can investigate further and take some more pics.

Lawrence.

[pwdrive]

2nd load of pics, not shown yet is the roller slats/bits, they all came out ok all timber, all seem to be there ok and should go again, the backing cloth to the slats is there but seems to have detached long time ago, the cloth looks past it but might do for a pattern or to establish its weave and original colour:

                   

Valves identified so far (left to right) 1st = Mullard PM1 HF....3rd = Mullard PM2.

Hopefully more to come.

Lawrence.

[pwdrive]

Third lot of pics....No ID on the audio transformers just PRI & SEC stamped on, apart from what else is shown no further ID found.

The cabinet is just about shot, to put it back to something like pieces will have to be cut out and replaced or a new cabinet built, it's in a bad state.

Tuning caps, coils, WW pot all seem reasonable and should go again, it all looks French?

The missing chunk off the front panel was found inside and is shown.

The front panel appears in the main to be engraved.

Feel free to Google for ID folks.

The bad news is I have no way to get this going as all my radio kit, receivers, test gear has been flogged off to help pay for a property, all I have left is a Variac and an Avo 8 with a knackered 15 volt battery....Jeeze Hope to get back into it next year.

Anyways I would like to find out more about the radio:

                           

Lawrence.

[Aerodyne]

A fascinating find, Lawrence. RI - that would normally signify a product of Radio Instruments - Ritz - but as you say, there's the French connection shown by the engraved front. Obviously it looks 1920s. The first photos make it look like a converted bread bin... but whatever, hang on to it and I feel sure it will reward you, though much work will be needed.
Tony

[Yorkie]

Yes, 'primaire & secondaire' are clearly French.

I guess the people who cold throw some light on it are the French Vintage Radio Forum:

http://retro-forum.com/

If you've a mind to, you could always join and post some pics there, using google translate for your text, and to make sense of any responses!

You never know, they might go into raptures at the sight of it!  

"C'est magnifique, c'est incroyable, c'est formidable - c'est le Saint Graal de la radio!
Si vous vraiment trouvé ça dans un hangar ? !!

[pwdrive]

I've started to reverse engineer the circuit, from the photo's point of view I'm referring to the 1st pic in post#5.

It doesn't show all the valve sockets because of the two transformers, never the less there's four of them, all B4's, for the purpose of description I'll call them left to right V1, V2, V3 & V4.

V1 is unidentified, V2 is a Mullard PM2, V3 is a Mullard but its ID number is missing, V4 is a Mullard PM1 HF.

Filaments: All 2 volts, fairly certain of that, all the filament pin 3 connections are all connected together and connect via a 6 ohm rheostat to the + 4 V terminal on the front panel, there are no other connections to that terminal.

Both pin 4 filament connections of V3 & V4 are connected together and are connected to the T terminal on the front panel, from there is a connection to the - 4 V terminal, both V3 & V4 pin 4 filament connections also connect to a three position lever switch (leaf type), that switch has four poles, two contacts for each pole, for the purposes of description I'll call that switch S1, later on in this thread I'll try and refer to them as S1a, b, c & d.

V3 & V4 filaments are in circuit at all times irrespective of S1 settings.

With S1 lever in the up position V1 & V2 filaments are in circuit.

With S1 lever in the center position V1 & V2 filaments are not in circuit.

With S1 lever in the down position V1 filament is out of circuit and V2 filament is in circuit.

So....That's the filament circuit sorted...Hopefully.

This subject is also being aired on the UKVRR forum in order to increase the chances of an ID.

More to come.

EDIT: There's a wire connected to pin 4 (filament) of V1, that wire runs to outside the unit, there's no ID tag on that wire.

Lawrence.

[pwdrive]

A bit more on this, it has been suggested on another forum that it might be a bridge due to the number of coils in the unit, not too sure on that yet, I've done some more reverse engineering, don't want to be too specific on the full circuit traced so far as it might come across as a bit complicated, the upshot of this so far is that it might be a multi band TRF regenerative receiver, if so I think it might be a bit of rare beast.

So far the circuit as traced suggests an antenna input to a multi range tuned circuit, there are two separate inductors, you can see them in one of the pics in an earlier post, the left hand one is a single coil, my guess is that one is for the highest band, the one on the right hand side appears to be multi tapped, that coil as a guess covers the other bands down to the lowest band.

The above mentioned tuned circuit (s) appear to be connected via a band change switch to the grid of an RF amp (Mullard PM1 HF) The anode of that valve is also tuned, there are four separate single coils for that, all selected by another band switch, they might be switched individually or in combination, not got that far yet, that tank circuit is capacitively coupled to the grid of a detector which is a Mullard valve of an unknown type (Poss another PM1 HF) The grid has a grid leak resistor from the grid to one side of the filament it's labeled as 3 ohms using the ohms symbol, my guess is that it's supposed to be 3 meg. The anode of that stage is in series with an other RF coil and the primary of an interstage transformer, the RF coil is a single inductor, physically it's in between the two inductors mentioned in para 2, it rotates on shaft that's brought out to the front panel, the scale is numbered 90 through to 0 through to 90 again (180 degree swing in total)

I've seen a regen circuit for that type of arrangement before, feedback from the second stage to the first stage that is, but for the life of me I can't think where at the moment, I'm sure I'll come up with it at some point.

The secondary of the 1st interstage transformer looks as though it connects to a GB battery and looks to be the usual arrangement it feeds a Mullard PM2, that in turn feeds another interstage transformer through to the AF output valve which feeds the 'phones, the make and number of that valve is unknown at the moment.

As it stands it all makes sense to me so far....Except the switchable filament arrangements for the RF and Det valves as mentioned in a previous post.

Any thoughts on this would be most welcome.

Thanks for all comments so far.

Lawrence.

[pwdrive]

Here's the 1st part of what is hopefully a definitive piece of reverse engineering I've carried out on this receiver, I've included a pic of the assembly that the schematic produced refers to, the fixed spring contacts and the turret contacts with the connecting links can be seen.

Also included are pics of the slow motion/fine tune arrangement, the brass shaft goes through the front panel and finishes more or less flush with the front of the panel, that end of the shaft has a slot in it for adjustment, the flat steel spring on the assembly serves to keep the small drive pulley on the end of the shaft in contact with the large disc that's fitted to the end of the capacitors rotor shaft, the slow motion drive is permanently in operation and is not designed to be disengaged.

More to come at some point, eventually I'll try and reverse engineer a full schematic, not sure whether I'll get it all on an A4 sheet though:

                   

Lawrence.