Becker Europa LMU car radio

[dcl0]

Way back in the early eighties when I used to prowl around junkyards dreaming of the classic cars I wanted own, I found this Becker Europa LMU radio in a mid-fifties Mercedes 219 sedan. They wouldn't sell me the car but they let me buy the radio. I recently pulled it out of storage and looked it over and found that the wiring in the cable running between the head unit and the power supply/audio output unit had that rubber insulation that falls apart to the touch.

It is a custom cable containing a shielded line for the audio from the head unit back to the audio output tube (6BQ5), two wires for B+ to the head unit, one running ground for the on/off relay through the head unit switch, two tube filiament lines and the whole thing wrapped in shielded mesh to connect the grounds of both units. I managed to reconstruct it.

After replacing all the leaky paper caps (the electrolyics test fine), the unit plays nicely. But what a PITA to work on! Point-to point wiring with everything crammed in. Luckily the leads were not wrapped around the terminals, but instead just inserted about 1 mm and soldered. I see why the switch to printed circuit boards occurred.

LMU (long wave, medium wave (AM) and Ultrakurzwelle (FM). Is there any longwave listening in the US? All I seem to get is a lot of noise.

[Telecolor 3007]

Poor automobile...
L.W. as far as I know isn't used in North America. So that's why you get nothing.
But the F.M. band is 88-100 M.Hz. or 88-108 M.Hz. (M.c.'s)?
What method it uses for transforming D.C. into A.C.?: seminconductors or a vibrator?

[Electronic M]

I've heard reports from people on the coasts that they can DX longwave from other countries at night...I've never experienced it though.

[dcl0]

Hi Telecolor, I think it was originally 88-100 m.Hz. but it must have been tweaked to 88-108 M.Hz. -at least there is a service sticker on top of the head unit from a radio shop indicating that's what was done. To transform DC to AC, it uses a vibrator in the power supply unit which is supposed to mount under the glove box (it doesn't seem to buzz too loudly, unlike some others I've heard). Once the power is converted to AC, the transformer steps it up to the voltage it needs, then it is rectified by a diode pack.

Yeah, I really wanted that car. It was black with red leather seats (real thick coachwork leather-not the thin junk) and it had that scent of old leather and gear oil when you climbed in. The dash fascia and the interior window trim was Bakelite like the radio surround.

[Telecolor 3007]

Any reason that don't gave you the car?
I wanted to get me an tube radio car from a scap yard, but didn't found one when I went. It's outside the city and getting by public transporation there is hard.
When speaking about vibrators, most people think today as to one thing Sorry, but it the truth. Does it uses valves or semiconductor rectifiers.
In Europe I don't know why we initially choose 88-100 M.Hz. band. There where 88-108 M.Hz. radios Made in Europe before the '60's-'70's for the national/international market, but just a few. It's annoying. But having a sticker with the modification made, it's intresting. I guess they didn't changed the dial glass.

[dcl0]

I guess once the paperwork has been turned into to the Department of Motor Vehicles, that's it, done. Rectification is done with semiconductor (selenium. I think) diodes. Interesting thing, there is a needle to indicate position, but there is no scale on the dial glass. I've attached a pdf schematic for the power supply unit, but the pdf for the head unit was too large - so here's a link: https://www.rsp-italy.it/Electronics...-Schematic.pdf Hope it works.

[Telecolor 3007]

Oh, stupid lawa and burecracy.
I wonder how sensivitive is that radio on reciving.

[dcl0]

FM is great. AM is OK, but you have to have the lower clam shell covering attached when doing the AM alignment. Otherwise the alignment will be totally off when you put it back together and AM will be very quiet.

[Jeffhs]

I've always wondered what UKW stood for on European all-band radios; after reading the posts in this thread, now I know. Until now I had no idea UKW on foreign radios is actually the FM broadcast band (88-100 MHz, as opposed to 88-108 MHz in North America).

BTW, I wonder why the European FM band ends at 100 MHz, rather than extending to 108 MHz as in North America? Is there another radio band in Europe (public service, etc.) which starts at 100 MHz and ends at 108 MHz?

Thanks for any info.

[Telecolor 3007]

U.K.W. stands for Ultra Kurz Welle, which means Ultra Short Waves.
As a Europeanen I don't know why the dumbness with 88-100 M.Hz. (M.c.). Probably there where another things above 100 M.Hz., probably they never thought they will going to be so many stations. Well, in the '60's the band started to go to 104. Most Western Countries adopted 88-108 in the '70's... but France, I think in the early '80's.
I've seen radios where the band started at 87.5 M.Hz.

[pgnl]

I remember in the 70s and eighties in the UK all FM radios went to 108, but no channels i think were broadcast above 104 (or less - I cant remember). Then the remainder of the band was used for something else, it was subsequently opened up and 88-108 was eventually used.

Japans FM radio I believe started at 76 not 88..

Now of course we have DAB/DAB+ on Band III in Europe, but in the UK i believe FM radio has been extended until the end of the decade.

There are slight differences between the transmission standard of stereo in the US to Europe, Europe uses 50us deemphasis, the US uses 75us. My old Sony ST3950 had a switch inside….. FM radio to my ears always sounded better in the US, but no doubt it varies with the car radio.

[Telecolor 3007]

In Bucharest they are stations above 104. The 1st one was on 105.3 - the main state owned radio, back in the '90's (I think there was there in 1995-1996). Before that, the 1st station above 100 I think it was Pro F.M. (still broadcasts) on 102.8 in April of 1993.
I don't know why they the state owned station at 2.7 M.Hz. (M.c's) above when 104 is 1.2 * above pro F.M., so they could put it on 103.5.
I wonder if any early '60's cars that runned in Romania in the '90's and early '000's had tube radios. Yes, they where, but after "the increasing of the standard of living" they where

* 1.2 and 2.7 Im borned on 27-12 (December the 27th).
Off-topic: it's pretty annyoing that I had to get accostumed to write 105.3 in stad of 105,3 and so on.