Anyone for a group restoration project?

[YC-156]

Fellow vintage radio enthusiasts,

Today I received my latest acquisition, a Loewe-Opta Bella Record. This family of sets was suggested to me by Paul Sherwin in a recent thread.

Upon giving it the initial inspection, it dawned on me that this might be the perfect excuse for starting a project I have been thinking about for a while: That of making an illustrated vintage radio restorer's guide for the newcomer to the hobby.

In the last few years I have had the good fortune to start in some new hobby activities. One thing that always struck me was how the old hands took many things for granted, which often went completely over my head as a newcomer. Additionally, being new to a group, it often felt a bit awkward or embarassing often having to ask about 'self evident' solutions and knowledge. Many newcomers to the vintage radio hobby may have a background knowledge about electronics, but would you know what a paper capacitor looks like? And what is a ferrite antenna?

We can and do provide textual descriptions when needed, but I wonder if it wouldn't often be of interest to newcomers if we had an 'illustrated encyclopedia' of valve set restoration to point to when needed, complete with detailed descriptions of the issues at hand.

Maybe such a set of texts and photos already exist on the 'net somewhere, but if that is the case, then I haven't been able to find them. Many sites provides a virtual walkthrough of a circuit, but nowhere that I can see is the walkthrough accompagnied by photos of the actual set, identifying key components and subassemblies etc.

So my idea is to give the little Loewe-Opta the deluxe treatment, carefully documenting and photographing each step along the way. To that end it would be great if some of the experienced hands would be interested in providing suggestions, proofreading and background technical insight as they see fit. I have many ideas of what to show and how I want to do this, but realistically I cannot hope not to forget something crucial.

If some of you are interested in helping out, then my suggestion for how to proceed is that the restoration is split up into distinct phases.
Each phase is named ahead of time ('Initial disassembly and inspection', 'Identifying the main components', 'First sanity checks without power', ...) and I will list what I intend to do and how.
The 'Inspectors' will then chime in with their suggestions and additions.
I will go and do as suggested, making the photos and writing a raw web page for that section for all to see. People provide feedback and suggest additions I missed the first time around.
Once we all are reasonably happy with the results, we proceed to the next phase.

My reasons for choosing the little Loewe are as follows:

• These sets are plentiful (inexpensive!) and available in many case styles from early fifties lookalikes to late sixties 'Scandinavian style' blocky exterior. All of them share more or less the same chassis/circuit with only minor differences. My 'Bella Record' looks neither quite like Paul Sherwin's Junior, nor like Paul Stenning's Jubilar, but technically they are quite similar. (Paul Stenning's page has a photo of the chassis).
• They are very small and lightweight, 38(W) x 24(H) x 17(D).
• They were apparently sold in the UK.
• They are non-universal sets with a genuine mains transformer, allowing for fitting a three lead mains wire. (Keyword: Ground fault interrupter.)
• Valve lineup is as standard as they come: ECC85, ECH81, EF89, EABC80, EL84 and optionally a magic eye, EM84, and the circuits are just as standard.
• Build quality is quite good, and the chassis sports pretty much all components and circuits found in much larger sets, up to and including the ferrite rod antenna.
• My set looks like it has a few fun problems to solve, which are typical of many sets we buy from auction sites etc.
• Late valve set with VHF tuner, which goes to 104MHz.
• VHF tuner uses coils made from PCB traces, which are hard to mess up beyond repair.
• Set has simple tone controls to ponder.

But before I get ahead of myself, I want to hear the opinions of the group. Is this a great idea, or did I miss an obvious objection or two? Anyone feel like participating?

Best regards

Frank N.

PS: I intend to post photos of my set in the near future. Read: Once I get the chance to be home with it during the daytime for photography.

[paulsherwin]

This is a good idea Frank, and would certainly help beginners. I would make 2 comments (and these are comments, not criticisms ):

1. There is some danger that such a project will document every single thing that forum members can think of relating to radio restoration. This will be very discouraging for beginners, who typically simply want to make their radios work without exploding;

2. I don't believe Loewe-Opta radios were ever officially marketed in the UK. Both mine and Paul's seem to be German 220V sets without a 240V transformer tap, and the brand is quite rare here. The construction techniques used in German radios of the 1950s are somewhat different to those used by domestic British manufacturers. Loewes are also quite cramped under the chassis which may make life difficult for a beginner. One of the 'simple' Grundigs may be a better choice as these *were* imported into the UK (and North America). The trouble with this is that even the 'simple' Grundigs are quite complex

Best regards, Paul

[Paul Stenning]

For choice of set it would have to be something that is fairly common, reasonably easy to work on and once it's working would be useful (so should have FM) and sound reasonably good.

I guess nobody will be very surprised if I suggest the Bush VHF80. The only drawback is that it's AC/DC.

[YC-156]

Originally Posted by paulsherwin

This is a good idea Frank, and would certainly help beginners. I would make 2 comments (and these are comments, not criticisms ):

Don't mind criticism at all, that is why I posted about my idea befor diving in.

Originally Posted by paulsherwin

1. There is some danger that such a project will document every single thing that forum members can think of relating to radio restoration. This will be very discouraging for beginners, who typically simply want to make their radios work without exploding;

Yes, I have been thinking about that one as well. So far my best solution is to divide the 'encyclopedia' into a number of pages, each adressing a single issue, like replacing paper capacitors. Another page will deal with electrolytics etc.

Then, as time progresses, these pages should be sorted into two categories: One group are those items, which must be adressed before the set is used. The other are those details, which you are free to postpone to a later date if chomping at the bit to get the set running again.

Ie. if Group One is completed, then the set shouldn't explode, though performance is not guaranteed. (Paper and 'lytics replaced, voltages checked, contacts cleaned, obvious faults to look out for found and corrected etc.)

The second group of subjects can adress more advanced(?) subjects like cleaning/restoration of both interior and exterior, tuning, checking valve operating points in more detail and whatnot.

Originally Posted by paulsherwin

2. I don't believe Loewe-Opta radios were ever officially marketed in the UK. Both mine and Paul's seem to be German 220V sets without a 240V transformer tap, and the brand is quite rare here. The construction techniques used in German radios of the 1950s are somewhat different to those used by domestic British manufacturers. Loewes are also quite cramped under the chassis which may make life difficult for a beginner. One of the 'simple' Grundigs may be a better choice as these *were* imported into the UK (and North America). The trouble with this is that even the 'simple' Grundigs are quite complex

Hmm, drats, thought I had it nailed there...

You are right about the cramped conditions below the chassis, had wondered about that one myself.

The Loewe Bella models are very common in Germany, and I was obviously fooled by two of the well known UK enthusiasts having one each as well. Of course I in particular wouldn't mind an excuse for finding yet another Grundig, but your reservations were also mine, save for the differences in construction. Hadn't thought about that.

Grundig did in fact make fairly largeish sets with a circuit very nearly identical to the Bella models, but I'm not sure how common they are. Would probably take me all of next week to locate one on German eBay.

So this probably calls for a decision:

I could try and find a semi-large Grundig with a similar circuit, even if it isn't too common. Less cramped, high quality construction and point-to-point wiring. This could serve as a guide to that to do and what components looks like, more than being something for others to replicate 1:1. Someone in the UK could then perhaps supply some closeup photographs of the major internal components of a typical UK set by Bush or something similar, with the intention of showing the major differences between German and British construction techniques. This would cover both bases.

- or -

I could find a British set to work on instead, like a Bush VHF something-or-other. I probably need a bit of guidance here.

The Bella could then be saved for some of the more advanced technique pages, like working on old PCBs without ruining them, working in cramped quarters etc.

Comments and critique welcome.

Frank N.

[YC-156]

Originally Posted by Paul Stenning

For choice of set it would have to be something that is fairly common, reasonably easy to work on and once it's working would be useful (so should have FM) and sound reasonably good.

Exactly, but I'm in deep waters when it comes to British sets.

Originally Posted by Paul Stenning

I guess nobody will be very surprised if I suggest the Bush VHF80. The only drawback is that it's AC/DC.

I would really prefer that the set uses a proper mains transformer and 'E' valves.

Best regards

Frank N.

[paulsherwin]

The choice of a set to use as an example will be difficult. Radios in the valve era were largely domestically produced, even in small countries like Ireland. The only manufacturer to export worldwide on a large scale was Grundig, because it produced large expensive sets which were less vulnerable to the import taxes which most countries imposed.

I'm sure a forum member would be prepared to send Frank a British wreck for this project, but this would be less useful to people in continental Europe and (particularly) the US where such sets are very rare.

Murphy did export a lot of sets to Switzerland though, for no obvious reason that I know of, so their radios may be more common in mainland Europe. My A684 has a socket marked 'Swiss LW' for connection to some sort of wired distribution system used there: http://www.******************************/A674.jpg

A Philips set may be a possible choice. Philips made electrically similar designs in many of their factories across the world, with modifications for the local market. The 'Philetta' models common in Europe were never made in the British or Irish factories though.

Good luck Frank!

Best regards, Paul

[Paul Stenning]

Yes, a Philips is a good idea as many were sold (with some minor variations) to much of Europe. We need to avoid one with too many Phlips quirks though...

[G0PKH - Pete]

Hi all.

If a mains transformer and E series valves are preferred, then how about the Bush VHF61 etc.

Pete

[YC-156]

Originally Posted by Paul Stenning

Yes, a Philips is a good idea as many were sold (with some minor variations) to much of Europe. We need to avoid one with too many Phlips quirks though...

Since several forum members have suggested Philips, I investigated this a bit today.

Surprisingly, if we are talking about buying online, then it looks like Grundig is a better bet than Philips, assuming the intention is to find a 'common' starter set. Philips made lots and lots of radios, but unfortunately they also made lots and lots of models.

The number of sets up for sale online seems to be about comparable, strangely enough. So, with the lower number of models, it was fairly easy to locate previously sold specimens of the Grundig model I initially had in mind. Four has been sold alone within the last month on ebay.de, and those were found by only searching for an exact keyword match on the subject line.

In the Philips camp I cannot say that I have even managed to limit the search to a group of models, and much less a particular model. There are of course plenty up for sale, all different...

Also, and Paul Stenning touched the subject, from my investigations it seems to me that Grundig's models have much more in common, technically, than the Philips models do. With a late fifties Grundig, you can be reasonably certain what you will find inside one of the better tabletop models. With Philips ... well...

I'm undecided.

Frank N.

[Paul Stenning]

Bush sets are fairly predictable and straightforward too, but we are back to availability problems outside the UK.

[YC-156]

There are around 27 different Grundig sets within the 1954 to 1963 timeframe with the valve lineup listed above. If we allow an EM85 in place of the EM84, then another 15 can be added. Some of these models probable aren't true transformer sets or a few radiograms may have sneaked through my filter. Even then there should be a fair number to choose from, covering a range of styles, physical sizes and 'extra features'.

Frank N.

PS: One version of the 2035/3D 'Hastings' is on my list.

[XTC]

Why not just pick a set that's available to you, not over complicated or weird and with a sensible set of valves such as E 30 series octals E 40 series B8A valves, or an FM/AM set which means E80 series B9A valves?

Philips or Grundig? I don't know about Grundig but I've turned a Philips set to junk by adjusting the MW coil, so I have a prejudice. Isn't there a Danish set that's sufficiently generic?

The aim of this project is for it to be seen as an illustration of techniques rather than the restoration of a particular example of a particular model, and much of the value to the beginner would depend on the way the project is written up.

Apart from the electronics, the case restoration is interesting. Wood, Bakelite or plastic? And what about the speaker cloth/grill, scale and knobs?

Should it be a demanding restoration, or a needed checking over of a set that's already basically serviceable?

I'd say it had to be a fairly straightforward restoration, to a fairly clean set, done with more attention to detail than normal. Let's assume that the transformers are good and that you don't have to find or reproduce a tuning scale. Let's also assume that it isn't caked in tobacco tar.

Then having asked for ideas, you have to be the editor. e.g. Thermal trips on mains transformers are a good idea, but I don't bother with them myself.

Now, the second part of this project could be someone else writing up how they applied the methods to another set altogether.

Pete.

[Darren-UK]

Something vaguely similar to this suggestion cropped up sometime last year; the idea being, IIRC, to produce an illustrated guide to enable newcomers (to the radio hobby) to identify components and their function. I think the idea died a death though.

However, if someone were to need a guide such as Frank suggests in order to do some radio repairs/restorations - then I'd have thought some sort of component + function guide would be an essential first step. Yes, yes, ok .... so we assume anybody (a beginner ) wishing to undertake repairs and restoration would have some sort of electronic knowledge - but many may not and many more may know nothing about valve technology specifically.

Nonetheless I think the idea (Franks) is basically a good one, but the choice of subject radio is a very difficult one - as others have already said - and not something I'd care to make a decision on. This very problem arose in last years discussion, as I recall, and focussed upon whether the subject radio should be AC-only or AC/DC ........ and so it goes on until you end up with a whole library of different documents covering different types of set.

Regarding Loewe-Opta, I also own one of these and, as someone has already said, they are internally very cramped and far from the easiest sets to work on in many areas. The Aus (off) switch on mine, for example, is knackered and I've left it alone simply because it's such a b d to get at.

As most will be aware, some books already exist, for example those by Chas Miller, going into valve radio repairs, alignment of superhets etc etc and these talk in a very general sense but with a few examples of specific sets mentioned. Perhaps this kind of thing is the best course of action because I really can't see how a guide for beginners which focusses upon just one particular radio would be of any great benefit beyond teaching the absolute basics.

[YC-156]

Originally Posted by XTC

Philips or Grundig? I don't know about Grundig but I've turned a Philips set to junk by adjusting the MW coil, so I have a prejudice. Isn't there a Danish set that's sufficiently generic?

Unless you count B&O, then no, it is just as easy for me to buy a set in Germany, as I have 'connections' down there.

[Snip.]

Originally Posted by XTC

I'd say it had to be a fairly straightforward restoration, to a fairly clean set, done with more attention to detail than normal. Let's assume that the transformers are good and that you don't have to find or reproduce a tuning scale. Let's also assume that it isn't caked in tobacco tar.

That was my intentions, an easy beginner project, which should have a fairly high chance of success. That said, then it seems to me there is always a little something, which sets every restoration project apart. Icing on the cake if you will.

I do not intend to write anything about cabinet restoration, at least not at this point. My experience in that area is very limited, so I tend to stay away from projects, which need major work to the cabinet. Living in an appartment without a dedicated workshop also puts a limit on what I can accomplish in this area.

You are probably right. At some point I will have to put my foot down and decode I will go with *this* set! Initially I didn't even think all that much about choosing a brand, I was more interested in finding a radio with a rather generic and easy to work on circuit, if such a thing can even be said to exist.

Originally Posted by darren-uk

However, if someone were to need a guide such as Frank suggests in order to do some radio repairs/restorations - then I'd have thought some sort of component + function guide would be an essential first step. Yes, yes, ok .... so we assume anybody (a beginner ) wishing to undertake repairs and restoration would have some sort of electronic knowledge - but many may not and many more may know nothing about valve technology specifically.

You are quite right. The ability to follow a valve radio circuit hinges on the ability to understand electronics, of course.

But starting a restoration while assuming the reader have at least some basic experience with electronics was a way for me to initially cut the project down to a mentally manageable size. If I set out with the intentions of writing a full blown book, I might never had gotten out of the starting blocks. I can always add more material at a later date.

Originally Posted by darren-uk

As most will be aware, some books already exist, for example those by Chas Miller, going into valve radio repairs, alignment of superhets etc etc and these talk in a very general sense but with a few examples of specific sets mentioned. Perhaps this kind of thing is the best course of action because I really can't see how a guide for beginners which focusses upon just one particular radio would be of any great benefit beyond teaching the absolute basics.

I will not focus on a particular radio with the intention of getting everyone to work on a particular set. I do intend to be general in my descriptions, and use the set chosen as an example for practicing general techniques.

I think it must be time for me to simply come up with some example text, then let the rest of you comment on that.

Best regards

Frank N.

[mieite]

Hi
A beginners comment
I think this is a great idea and would be very happy with a restoration of any radio with pictures and text explaining what is done and why (between the aerial and speaker )
By getting info of your project I could improvice on another type of radio.
It's like car engines, you understand one then it's easier to learn about another.
Regards
Nisse