New old Braun SK61

[larryvee]

Hi everyone,

By means of introduction, I'm Laurence and I've recently come into possession of a Braun SK61. It was Dachbodenfund which I believe translates into an "attic find".

As a sentimental endeavour I want to bring it back to glory myself - with one important caveat: I have absolutely no idea what I'm doing. My Dad died recently and he would have had no problem rehabilitating this old girl.

Still, I'm prepared to put in the hours and I've already starting a basic electrical course online.

Question is - where do I start?
I'm somewhat hesitant to plug it in in case I blow everything but I've opened it up to have a look in and it seems fairly clean and undisturbed inside.

I've attached some photos

['LIVEWIRE?']

You would be wise not to plug it in until it has been checked. In the first place, that's continental 'schuko' mains plug, which almost certainly set for 220v AC, not 230/240v ( I assume that Ireland uses the 13Amp 3-pin plug the same as in the UK, and a nominal 230v Mains supply) Secondly, as it's a valve set, certain components, including two referred to on this forum as 'That Capacitor' connected between the anode of the preamp. valve (ECC83?) and the control grid of the output valve, EL84 (of which there are two - hence two 'That capacitors') (Edit; I've just noticed that the mains transformer has on it a label showing voltages from 110 to 240v, even so, check that it's set to the correct mains voltage, and change the mains plug for a 13 Amp 3-pin one, fitted with a 3 Amp Fuse.

[larryvee]

Thanks Livewire.

Yes - we're almost as civilised over here - we're on the the 230v Mains and we use 13Amp 3 pin plugs.
I've read Darren's sticky post, "intro to reviving your old record player" (a few times).
I'm going to spend a bit of time identifying all the components first and get a bit more comfortable with electronics.

Lar

[1955APREN]

HI Laurence
Welcome to the forum . I have not come across this unit, but basic tests can be carried out. Do you have any test equipment like a test meter.
As the valves are ''e type'' the chassis should be isolated from the mains but be very careful as the HT voltage is about 200 volts +.
What is the number of the valve to the left of the EL84 is it another EL84.
Before plugging the unit into the mains the capacitor that is connected to pin 2 of the EL84 MUST replaced and inspect all the metal capacitors for leakage. You could now connect to the mains, but it would good to use limiter lamp at first.
The gram deck will require all the old grease removed as this might gone hard.
Hope his will help as a starter, feel free ask for further advice as there are lots of helpful people on this forum.
regards Derrick

PS. Crossed with Livewire while typing

[larryvee]

Thanks Derek. Going to get some supplies tomorrow - a new multimeter and a limiter lamp.
The valve to the left of the EL84 is an EL95 - posted a photo of the valve schematics in last reply to Livewire.
Is it worth taking the entire chassis out to inspect everything for damage or leakage?

Lar

And sorry to be a pest - what does the capacitor look like?

['LIVEWIRE?']

From that valve lineup it looks a fairly standard set for it's day (1950s or early 60s) The ECC85 is the VHF Mixer/Oscillator, ECH81 the AM Mixer/Osc. & possibly the 1st. IF Amp, EBF89 AM/FM IF Amp. & Detector. The only slightly puzzling thing, to me at any rate is the use of an EL95 and EL84. Both are audio output valves, the '95 having a B7G base, and the '84 a B9A base. Provided you bear in mind the relatively high DC voltages in mind, it should be safe to work on, certainly safer than a 'live chassis' AC/DC Radio, but if in doubt, seek advice from someone local to you who has experience of working with valved equipment (BTW I hope my comments regarding the mains supply & plugs weren't misconstrued. I thought, but wasn't sure, that ROI used the same mains wiring system as the UK)

[Chiltern]

I have had a couple of these Braun sets over the years, one being the stereo version with a matching seperate speaker, that one IIRC used an EL84 for one channel and strangely an EL95 for the other.

Is there any reference to connecting a 2nd stereo speaker on the rear cover?

Alan

['LIVEWIRE?']

Just wondeed why my use of the term 'Eire' in post #6 was changed to 'ROI'?

[Station X]

See post #3 and #5 here:-

https://www.vintage-radio.net/forum/...101#post555101

No more discussion about this please.

[larryvee]

Originally Posted by Alan SP15

Is there any reference to connecting a 2nd stereo speaker on the rear cover?

Thanks Alan,

yes there is indeed an audio out to what's called an L11 speaker.

No misconstrue take, I was just being self-deprecating!

[Chiltern]

The L11 is indeed the Stereo extra speaker, so it looks like you have the stereo version.

Assuming that you do not have this speaker then you should ensure that either a dummy load or another suitable speaker is connected to this output.

Alan

[Radio Wrangler]

That's good. It means you have a stereo cartridge (the lump at the end of the arm that the stylus fits into) and you can play stereo records.

If you'd had a mono cartridge, it would have damaged stereo records played with it.

Now you've got to hope the cartridge is in working order. Some of them absorb water from the air and their active elements dissolve! There's a good chance yours is a later ceramic type which should be OK.

One of the photos shows the mains selector switch set to 220v, so that needs moving round to the 240v position. It's the little tarnished brass contact held in place with the blue thumbscrew, under the fuse, near where the mains cable enters.

Oh, and welcome!

Snow White's Coffins are highly sought after.

David

['LIVEWIRE?']

Might it not be a good idea to replace that mains lead with a modern colour-coded one? As this unit has a mains transformer, possibly a 3-core lead could be fitted, with the earth lead (green/yellow) being taken to a convenient point on the chassis near where the mains lead enters the set.

[SteveCG]

I thought the ROI used to use 220V - before all this Harmonisation...

An AC voltmeter could confirm.

[AC/HL]

If they did, they still do.
Harmonisation was only on paper, increasing permitted tolerances for new equipment. This has been thoroughly discussed here.

[larryvee]

Building my lamp limiter today, will report back later, once it's built and I've changed the plug and fired it up.

@Radio_Wrangler - I have a stereo cartridge - (the red thingamabob attached) but it doesn't sit snugly into the over arm - slips out, but I can see all the connections line up with it.

[larryvee]

Quick update - I looked at changing the plug - but there's no colour coding on either plug or cables which scares me a little. I know they were non polarised so I think I'll put the new 3 core cable and 3 pin plug on.

Newbie question: what's the best way to fix the earth to the chassis?

['LIVEWIRE?']

I usually solder either a spade or eylet tag of suitable dimensions, than secure it under a convenient screw, preferably one of the transformer mounting bolts. Otherwise, if there is achassis tag close to where the mains lead enters, the earth lead can be soldered directly to that point.

[TonyDuell]

I thought that a safety earth tag had to be secured by its own screw and couldn't be fitted under (say) a transformer fixing screw. The idea being that if somebody replaces the transformer they might forget the earth tag if its under a mounting screw but if it's held on by its own screw then the repairer would notice an apparently useless screw and investigate.

[Herald1360]

It should be, and there should also be an external toothed washer between the tag and the chassis. Also any accessible metalwork should be bonded to the main chassis properly too.

However, since the whole process would constitute a design change, one is back in the legal grey area again. Fitting an RCD plug to a replacement two core lead would be legally less problematic in the event of an accident and would provide a greater degree of safety than the original design.