schneider: Romance FM 1961: Repair

I call this a "repair" rather than restoration as I have no circuit, no back, no speaker, most tubes missing, Model and Tube line up unknown. The case is a little rough. It was part of a Lot I bid on for the Ultra "Twin 50", so in a way it was "free". No extra postage as it was an Auction in Ireland.

Stage 1

Schneider “Romance FM”

Yes, that's what is on the front! The “stages” are roughly different days, some days might have more stages though.

But.. the valve line up is a problem ( ) means missing

VHF( ) Noval
Mixer/Osc: ECH81 / 6AJ8 (but plugged into the IF position)
IF ( ) Noval
?? ( ) B7G
O/P EL84 (yes it's connected to audio transformer)

Magic Eye EM81

Rectifier ( ) (on top of transformer)
Chassis is stamped 1961 below the switch unit at the front.

That’s an ECH81 between the two IFT cans. Can’t be right!

The main elliptical speaker is missing.

I thought it was the Schneider Romance FM 1958
 
But impossible
Valves / Tubes 8: ECC85 ECH81 EBF89 EB91 EM81 6AU6 6AQ5 EZ80

The main chassis has only 4 sockets, one is B7G. There are 3 other valves Magic Eye, Rectifier and FM head. Intriguingly there is a punch out for a 5th base, but it definitely never had one.

It's got a pair of OA something maybe for FM discriminator. Maybe the b7G is an EBC91?

Maybe it's the case and chassis of two different sets? The speaker is missing.

Any ideas what schematic and what missing tubes? Underneath looks original

They do seem to use the 6AU6 RF/IF as an audio pentode on some Romance sets

It's B7G = EF94

So then there needs to be a 3rd diode somewhere else.. EAF80, EBC80, EBF85 for IF?

The Romance FM (1958)
8: ECC85 ECH81 EBF89 EB91 EM81 6AU6 6AQ5 EZ80
So the two OAxxx diodes replace the EB91 (hence tag strip with them is under unused socket hole)
The higher power EL84 replaces the 6AQ5 = EL90

So my best guess
7: (ECC85) ECH81 (EBF89) EM81 6AU6 EL84 EZ80 (maybe EZ81)
The two OA somethings definitely replace EB91.
There is a French thread discussing EL84 vs 6AQ5 (plus de puissance = More Power!) in relation to Schneider Romance but no schematics or other tubes mentioned

There are two 1958 Schneider models on Radiomuseum with
9: ECC85 EF89 ECH81 EBF89 EM81 EB91 6AU6 EL84 EZ80
The 6AU6 = EF94 is used only as Audio preamp. The EF89 is RF preamp, a deluxe feature... So take out the EF89 and the EB91 is logical for my model.

There is a Romance (1959) with no FM on Radio Museum. But no Romance FM (1959) though a picture of one on a French site doesn't look like mine.

I wonder is mine a later Romance FM in the 1958 cabinet?

Anyway what you think of the screened turning Loop Aerial Drum? I never saw that before!

Stage 2

After studying as many Schneider schematics as I could find:
The missing IF is certainly EBF89
Some (many?) Schneider sets did use 6AU6 (EF94) RF Pentode as audio preamp driving an EL84. A 6AU6 does make gram input work.

The missing VHF "head" might conceivably be an ECF82 and not the common ECC85

I decide the line up is either

ECC85, ECH81, EBF85, 6AU6(EF94), EL84, EM81 and EZ80

or

ECF82, ECH81, EBF85, 6AU6(EF94), EL84, EM81 and EZ80

Eventually after "Raiding" my friend's valve stock and borrowing the VCM162 to test them I get very weak LW from signal generator (Thanks Albert Lahoud).
 

Stage 3

Three smaller "hunts" style caps cracking up so replaced as is 2nd HT capacitor and EL84 cathode decoupling. RTE1 on LW and hiss on VHF. Swap the ECC85 for ECF82 and Local FM stations... But it fades away.

Find two more dodgy HT Electrolytic capacitors and radio bursts LOUDLY to life!

See the photo at the model of replaced capacitors

Capacitors replaced

So differences with 1958 Schneider "Romance FM" identical case
EB91 --> 2 x OA79 makes sense
6AQ5 --> EL84 makes sense
But why swap from ECC85 to ECF82?

The giant funky drum does work on LW as rotatable directional aerial. Presumably MW too (try at night).
 

Stage 4

I had to redo the AM drive cord which is a pig.

Fortunately it's virtually identical to 1958 Romance FM. (The Chassis has a "1961" stamped on it)

The Radio has separate AM & FM drive knobs and scale pointers.

Amazingly the entire VHF-FM scale is a + & - 50 (KHz?) "band spread" on SW.
The LW & MW both have piano key positions for External Aerial and internal loop (Cadre = lit. framework)

GO = LW
PO = MW
OC = SW

FM scale marked also "OC Loupe" lit. "Magnifying"

Now to figure out alignment with no service info. Too many coils and the schematics for Schneider sets show simply a dotted box for the switches and coils.

Now I need a new EM81 (not a glimmer) and an Elliptical speaker. The alignment first as it's badly out.

Stage 5

Repairing the VHF Head

The performance on VHF-FM was strange. A strong station was beautiful. But a weak station would have a fistling and whistling with distortion.

The IF on this set is marked on one can as 6.75MHz (I've seen 6MHz, 6.5MHz, 68MHz and 44MHz as well as the "normal" 10.7MHz).

I started with the IFT on the VHF head (carefully) and it suddenly went dead. Swapped ECF82 and just the same. LW/SW/MW ok. I peered at the lurking VHF head and pondered what to do. I could see two of the litz wires on the IFT to tags for o/p coax to main set from "open" side of the unit. They looked OK but I resoldered.

Still dead.

Examination suggested the screws on the valve base/screening can base + three solder joints held cover on. Indeed the screws are on pillars on top of a valve socket under chassis.

I scored solder joints with knife blade and a slight twist of screwdriver blade in joint and the joints one after another spring free.

The reason for the silence was immediately obvious. The Primary winding between an Anode on the ECF82 (no idea which, but likely the triode is oscillator and Pentode is mexer/IF out) and the HT was missing about 5mm of Litz wire at the HT side.

I'd guess it was rubbing against the underside of the cover, or was damaged originally and gradually disintegrated.

I added a fine piece of solid wire putting one turn on the "peg" of the coil former using fine nipper nose pliers.

Then with a hook made of the wire and very pointy tweezers I put 3 turns of the end of the Litz wire going to coil around it and "dressed" the remaining Litz wire along the solid wire. I soldered then till I could smell the coil former starting to protest.

The VHF is now nearly perfect (helped by a piece of Lidl coffee tine replacing the missing valve screening can.

I gave the IF chain a quick check by unplugging the ECF82 and connecting the Signal generator to the tags on the VHF Head IF out at 6.75MHz.
 

Stage 6

The case is missing the elliptical speaker so I cut off two edges on an old 8" Speaker, the remaining one from a pair on an "Amstrad" not-really-HiFi system dumped 30 years ago and someone gave me the remaining speaker about 12 years ago. It fits now in space for the elliptical on the Romance FM. I used the cutting wheel on the Dremel. Minimal dust as it "burns" away the steel. This is just temporary till I pick up a cheap elliptical speaker to fit properly so I slipped heavy corrugated card under the speaker to block the two spaces on either side.

Stage 7

Repairing the On/Off switch.Faulty On/off Switch

The on/off mechanism is just too poor quality. The pillar with the actuator is loose and thus the the spring pushes the actuator past the stop and the switch opens again.

So since it's a strange dual gang pot with a long shaft I decided to put a microswitch. The NC contacts which open when the lever is depressed is used.

Here is the spindle about to turn off

Here the switch is pressed, i.e. off

The edge of the case cut open and hole at "pot" enlarged. The microswitch lever was bent to poke thorough the hole and engage with the plate on rear of pot and put in place with rapid epoxy.

 

My espresso maker failed because the microswitch fell to bits. I'd bought a pack of 10 decent ones not long previous for not much different to one in Maplin and they were same size. The Espresso maker working now 3 years. So likely it will be reliable on the radio. Of course I forgot to refit the insulation ring and end stop so the back has to come off the pot. Fortunately I think I can do this without disturbing the nicely working microswitch or the wiring. I have a little "dinge" in case for shaft lever to catch on so it stays in off position.

 

Here is the "repaired" Dual gang 1M Ohm log volume control

Arrow points at Microswitch epoxy glued on rear of volume control. Note dual gang 1M Ohm even though a Mono set!

 

The replaced parts

The one in a plastic tube with tar like ends was across the mains.
The 25uF 30V was on EL84 cathode. Replaced with Military grade 22uF 25V Metal can Tantalum. The other three electrolytic were HT decoupling.

Top view of chassis

Performance
It sounds fine with my "chopped" 8" speaker (original elliptical missing) and the original electrostatic tweeter. The Bass and Treble controls work well

The unusual "Cadre" (Rotating drum with LW and MW loops at right angles X and Y and 3rd sceen loop on outside in Z direction) works very well for R4 LW (day & night) and R.Scotland MW (night).

The VHF is prone to a "whistle" when not tuned to a station and doesn't seem very sensitive. I'll check the ECF82 later. But with medium strength stations seems fine.

The Shortwave is awesome on just 2.5m of wire over curtain rail. The entire VHF dial is about +/- 50KHz bandspread (100KHz) (A Yaesu FT101 does about 500KHz per band), so you have "full" bandspread no matter what part of SW band the main AM dial is set (FM labelled also "OC loupe" = SW magnifier). SW reception seems very good and stable.

Considering this set came with only EM81 (dead), EL84 (tests good) and a faulty ECH81 incorrectly plugged into the IF tube socket, I'm very chuffed to have got this "thrown in" the lot I bid in a local auction to get the "Ultra Twin 50" I'm even more pleased to get it working without any documentation of valve lineup or an accurate schematic. The EBF89, 6AU6, replacement ECH81 and ECF82 (along with ECC85 to try) came from Member Albert Lahoud.

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The Chinese 6E1 came in just over a week from Tiawan to Ireland (Under €8 including shipping) and works perfectly as the Magic Eye with no modifications. There is a very short period of drift on VHF-FM while the set warms up (under 2min?) and the FM tuning is much easier with the "eye" fitted. The original spring holding the tube to the window was very rusted so a I used a spring in my spares box that could even have been from a large ballpoint pen, or anything.

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