How far Should you go with electronic restoration?

[Nightcruiser]

We have all heard of drilling out old duff electrolytic capacitors and fitting the new components inside, but what of those sets in which the originals are all apparently good and working well.

Should these be repkaced as a matter of course or left alone for the sake of originality?

And if the set is to be then used on a regular basis, will reforming old capacitors, or using those originals apparently still good be the most suitable and safe solution?

Supposing the capacitor is say of an unusual or unobtainable value or voltage or even a motor start capacitor. ( Im thinking Grundig Papst motor here)

Should an apparently servicable original electrolytic capacitor of the correct specifications be replaced with a modern day near value even IF the original capacitor is still working.

And would that in itself guarentee an equal longevity of service.

These questions recently came up in a group discussion since the modern day equivilents are generally now far smaller and as a consequence have a manufacturers usage guide as to the humber of life hours they will continue to operate, if of course they made to a high standard of manufacture initially which many on the market now are not.

And of the modern day replacements, which manufactures of capacitors do you favour?

[Boater Sam]

It all depends on what you want to achieve. If you want to remanufacture an old set to current standards of reliability and performance, then replace everything possible with new components which are designed to a better standard than say waxy caps. But that is no guarantee that it will last another 50 years.

I tend to consider what the set is. A 30s set I feel should be kept to appear as much as possible as it did when it was in regular use, re-stuffed caps, old style resistors etc.

As far as electrolytic caps in chassis mounted cans I always re-stuff, it looks better and is easy to get new smaller caps in the cans than try to hide them elsewhere.

If its a 50s set I replace what is necessary to restore optimum performance. If this involves a blanket replacement of poor quality parts such as Hunts mold seals then so be it. They can't be re-stuffed but can be disguised by painting the right colour. I would still try to re-stuff waxy caps, its not a lot of work to do and looks good after. I tend to shunt out of tolerance resistors with hidden miniature ones rather than use new 1 watt ones because they are about the same size as original, its less expensive too.

For parts that cannot be directly replaced, eg. loudspeakers, transformers, then the best I can do is all I can do and I have to be happy with that.

Cabinets I prefer to leave as is but clean and polished unless they are too badly damaged. Then its maybe veneer repairs, stripping and refinishing. A non glossy french polished or oiled wood cabinet I think is better than a "brown glacé cherry" in polyurethane varnish.

I must admit to not trying to find matching speaker fret cloth. I use woven table place mats, they are available in many colours and patterns, are usually tough man made fibre and I think look fine.

In the final analysis, it is what you are happy doing. it is a hobby after all.
I think it is a similar situation to the classic car scene. Totally prize winning concours or everyday use?

[Radio Wrangler]

Appearance-wise you can do whatever you like. It's your radio/tv/etc.

But safety rears its ugly head if there are other people involved, even in your own home. Can you make it comply with all current regulations? Probably not, so can you then control the circumstances of its use so that any risks to people other than yourself are controlled?

If you can do this, then fine, but otherwise it may be better to consider the item a non-working showpiece.

Instances of death or injury are very very rare, but balancing this the consequences are very very serious. If something did go wrong, how good a job could you do of convincing a judge that you took all 'reasonable' precautions? Judges and juries considering vintage equipment will still have modern expectations.

I have a vintage lathe (used to make radio parts) which pre-dates safety covers over all the whizzing belts. I'm careful to never run it if there is anyone in the garage who doesn't understand how to avoid the risks.

On the other hand, vintage and classic vehicles go on the road without airbags, seat belts etc etc and often carry passengers. There is legal acceptance that they may be used provided they still meet the standards of their era.
It seems to be accepted that the passenger should know that a lot of modern safety stuff is missing and that by getting in they accept the risks. With radio gear, the risks are invisible and not even understandable by non-technical people. I think that very invisibility may mean such risks are seen differently by those whose business is to apportion blame after an y accident.

David

[paulsherwin]

A lot depends on why you are restoring a set.

People often talk about 'museum grade restoration' (including me) but museums are essentally conservators rather than restorers. They would never change components to make an artifact 'work', as conservation is much more important than functionality. When (say) a smashed vase is reconstructed, the missing bits are reconstructed from obviously different material so that the remaining original parts can be easily identified.

We aren't doing museum stuff. We're playing around with relatively common obsolete technology because we enjoy doing it. Essentially, we're repairing it, just as would have been done throughout the equipment's working life.

['LIVEWIRE?']

As a retired ICE (Car Stereo) Service engineer, I always replace faulty or suspect components with their nearest equivalent modern components, which, as others have said, are smaller than those they replace, and, certainly in the case of polypropylene vs waxed paper capacitors, more reliable. I also fit 'X' & 'Y' tpye capacitors where neccesary. I also replace old wiring with currently available connecting wire, the silicon sleeved type if available. Unless I'm workinh on a very rare or unusual item I don't re-stuff old electrolytics or hide modern components in or under old ones. With my 'service engineer's hat' on I use the maxim that if, say, a polypropylene capacitor of smaller dimensions than the previous paper type had been supplied by one of the setmakers, we would simply remove the old type and fit the new one 'back in the day', so a good many old radios, etc., which have been previously repaired will have more modern components inside already. To me, safety, reliability and functionality come before originality. Under-chassis components, after all, do not alter the outward appearance of a radio. To use the 'old cars' analogy, how many classic cars have modern components, including, e.g., batteries, fitted? Most I would guess!

[HamishBoxer]

Also what depends is how much or rare the set is.The rarer the set I think it needs to be kept as original as possible.
We all I know have different thoughts on the subject and it has been brought up many times before.
At the end of the day it is personal I guess to the owner.

[Leon Crampin]

I would generally agree with the contribution in post #2.

However, I would always take steps to prolong the reliability (and life) of a piece of equipment if there is an obvious design shortcoming which endangers it. This may come about by sheer bad design, or by a poor choice of components - such as Rifa suppressors in Quad preamps.

If experience shows that a set is prone to failure in one area, then steps should in my view, be taken to address this. Sometimes, the measures needed are ridiculously simple - such as oiling the tuning gang bearings in Grundig transistor radios. Generally, these measures do not compromise originality to any great extent.

In future years, an "original" non-worker is more likely to be binned than a functional radio.

I always fit a 1A fuse to BS 1362 in the mains plug where appropriate.

Leon.

[Station X]

Two posts moved to a new thread here:-

https://www.vintage-radio.net/forum/...d.php?t=121634

[wireful3]

I tend to follow Leon's approach. I am interested in 30s woodies and I am aware that many of these would have been treated by repairers in this way during the 1940s. Having different components is a sort of natural feature of these sets.

Whether this can be extended to the tiny resistors and capacitors of today I don't know.

[stevehertz]

In answer to the original question, it's entirely up to the individual, there's no rules!. We're all different. One man's restoration is another's abomination. Personally, I don't restuff caps. I like my sets to look original, clean and smart, but I really don't see the point in spending hours making the underchassis look just as it was when it was new 40, 50, 60 years ago. During that time most sets would have had contemporary repairs anyway, and most of those would have been of the 'capacitors dogged in place' type. My take on it is, if you get too anal about restoration, the fun goes out of it and you become a slave to the 'god of originality'. Fine if you want to do that, I'm more laid back these days and I take an holistic view; I look for satisfaction/fun doing the restoration, appearance and vibe, and of course, performance. To those who want every screw used to affix the back of a set to be 100% oxidised bronze finish and original (like I once did) I have no argument. I just think that I saw the light and lowered my expectations a tad, lowering my heart rate in the process.

[turretslug]

As said, we all have a take on things, and our individual views would themselves be modified by considerations such as rarity or historical significance of individual items. I tend to say to myself, what is it about these vintage things that makes them perform well, have character and be worth saving and pressing into service? Generally, it's the valves (often surprisingly durable and consistent, despite popular wisdom!), the wound components (HT transformers and chokes, O/P transformers, IFTs and coil-packs, developed to a high state of the art in their time and all, if not out of production, then expensive and/or difficult to replace or replicate), metalwork (including tuning drives and VCs) and cabinets (just not made like that any more at any price). It certainly isn't moulded Hunts or noisy, drifty carbon comps! So, I sleep easy with changing these, but I always have "Respect the designer's intention" in the back of my mind. If they'd had access to polyprops and metal films at the prices we're used to 60 or more years ago ago, they'd have been only too pleased.

[G6Tanuki]

My approach is invariably what's described in the custom/classic-car world as "go not show": I'll replace failed/suspect parts with new/modern ones if doing so gives original or better-than-original performance/reliability/function. And I don't worry about preserving 'original' appearance - I'd much rather focus on real-world usability than looks.

There again, my interests are primarily in the area of communications radios/equipment rather than items-of-furniture. I can quite understand how someone might want to cosmetically-restore a 1930s/1940s radio/TV so it *looks* the piece _as furniture_ rather than as something they expect to be able to use safely and reliably on a daily basis for entertainment in the way its original designers intended.

Example: a while back I did some work on what I considered a rather mundane late-1940s 6-valve domestic radio, made by Bush. As a matter of course I summarily ripped out and replaced 25 or so resistors and capacitors with current-production items of better-than-original spec. A few months later I discovered that something like 10 years ago a previous restorer had carefully and expertly "restuffed" the capacitors which I'd looked at, deemed 'time-expired' and replaced by new ones.

We all have different motivations: Mine is performance over appearance.

There's no 'right' answer to the question! Follow the path your heart takes you.

[TonyDuell]

My view is that the interest and beauty (to me) is in the circuit design, and that must be preserved as far as possible.

The appearance to me doesn't really matter.

So I will happily replace components with modern equivalents (a 1k resistor is a 1k resistor, basically). I will not bother to re-stuff capacitors (in fact I am actively against doing it, perhaps it's a justification for lazyness, but to me it's faking. In the future a collector may get very confused by these large cans with tiny capacitors inside...)

But I try not to 'redesign' things apart from trivial safety modifiations (like adding a fuse, please note I do keep voltage selector panels, etc, wired, I know not to touch live metal parts, there is nobody else in the house and Tigger, my cat, is unable to plug things in). I will fit class X or Y capacitors as appropriate. But if there was a design deficiency that doesn't make the set unsafe then I keep it. It is part of the 'character' of the set.

To me, extra features, even if somewhat useless -- a tape recorder socket on a record player, a microphone input on a portable radio, etc -- are part of the design and should be kept and restored.

But in the end it's your set, do what _you_ want.

[Lucien Nunes]

I'm tending towards the same line of thinking as Tony. I used to re-stuff etc, and still would under certain conditions. But increasingly that seems to be an artifical middle ground, that preserves neither, or both, of the functionality and originality, according to viewpoint. For anything pre 1970s the two are almost mutually exclusive, you can't have a set with all original parts that also works as it did originally and vice versa. Rather than compromise, I'm rather keen on duplicating. I have one item as found, telling only a true story of its life and times, and another that I can overhaul to any extent required to bring back the original performance. Look at the first one and listen to the second. Also as per Tony, I don't redesign. I'll change every part if need be, but the moment you change the circuit significantly it's a different thing of your own creation. Alterations that reduce the likelihood of damage to the set itself, such as a thermal fuse slipped inside a vulnerable transformer, are more acceptable as their motivation is actually conservation of the original parts.

What is certain though is that once you start replacing parts on an otherwise original set, you can't turn the clock back. We had a thread that elicited some very interesting viewpoints on this subject about a prewar tabletop TV that was almost untouched inside since new. 'Should it be restored?' was the question. My answer was no, on the grounds that there are multiple working examples that show what the performance was like, but only the one totally original in physical construction to show what that was like, and IIRC this was also the owner's opinion.

The problem arises when there is only one - which aspect do you prioritise, the functionality or the substance? Or is this the time to take the middle ground, restore the functionality while keeping as much of the original appearance as possible even if that involves component fakery?

[TonyDuell]

To tie in a with a thread in the welcome section, I feel that a lot of museums have got it very wrong. They seem to treat everything in the same way as pieces of Fine Art (where visual appearance is the important thing). IMHO that does not apply at all for the sort of things I collect/restore and the things we talk about here.

Having worked on a fair number of devices where the number of surviving examples can be counted on the fingers of one hand (in unary!) I don't hange my views. The important thing is that the device works. The rarer it is, the more important that it works (on the grounds that this might be the only example where you can see how it performed).

If device is rare, but not that rare I still say restore it. If that pre-war TV had been mine I would have done so. Many examples may well be stuck in museums, never to run again. So I would want mine running, so _I_ could enjoy it and investigate it.

And I do much the same thing on that as I do on anything else. If a component has failed, I replace it. Not necessarily with an identical one. If an IC was made by many
manufacturers, then any will do. If I can't get a direct equivalent, then alas I would have to make up a 'kludgeboard' but I would (a) make that fit in place of the original IC and (b) would very carefully document what I had done. In fact for anything even moderately rare I keep a log of what I've done and how. Yes, logs can get lost or separated from the machine, equally they may not be. I can do no harm to document the work.

And no I still won't fake components. To me there is nothing 'wrong' with having to replace a capacitor or whatever. In the case of rare machines I would keep the original parts (labelled) just in case somebody was interested in them.

[Skywave]

This is a tricky - but a fundamental question - that deserves a concise answer. For me, Paul's comments -

Originally Posted by paulsherwin

A lot depends on why you are restoring a set.

We're playing around with relatively common obsolete technology because we enjoy doing it. Essentially, we're repairing it, just as would have been done throughout the equipment's working life.

- provides a good and a condensed answer. I particularly note "because we enjoy doing it".

Al.

[Ted Kendall]

There is an idea from the world of historic motor sport which may be useful here, namely "continuity of identity". It enables an historic racer to fulfil its purpose (racing) without the necessary repairs and replacements affecting the fact of what it is. True, the extreme of this is the headsman's axe - "true, it's had a new handle and perhaps a new head, but it's still a genuine original axe" - but it focuses attention where it should be, that is on the essence of the car (or set) as a whole.

None of the seventeen surviving ERAs is racing with its original engine block or wheels - they are long since life-expired, but the cars continue to give pleasure to their owners and to spectators. So it should be with vintage electronics - preserve function and feel, and original looks as far as reasonably possible, but don't put the cart before the horse. There may be circumstances where component substitution isn't straightforward - "unspecified secondary characteristics", as the ED catalogue used to put it, can sometimes cause problems, but they are seldom beyond the reach of reasonable ingenuity to sort out.

[Sideband]

One other point should be borne in mind, whatever your take on repair/restoration. If you are doing a job for someone else, it's better not to modify it, however much some people might think that it's desirable. The radios' we deal with can never meet modern safety standards so don't try to make them! As they stand in unmodified state, they only have to meet the standards of the time (much like was said about vintage cars and seatbelts above). If you start to modify a set, it then means that it has to comply with modern safety standards since it won't then comply with it's original specs.

Remember if it's your own set for your own use, you can do what you like with it but if after modifying a set you then pass it on to someone else, if anything goes wrong (even if it's not the fault of the set), you will have a very difficult time proving things if it went to court. The safety test lab I work in had to help out in such a case a while ago by examining the modified product.

I recently saw a restorer offering DAC90A's as modified with the speaker grill connected to earth. Effectively it now becomes a class 1 appliance (as it has an earth) but it couldn't pass class 1 testing and probably questionable about passing the flash test (1000V) and leakage requirements so it still wouldn't meet class 1 safety requirements. He could potentially have serious problems if something happened.

[Radio Wrangler]

This isn't a place to discuss vintage cars for the sake of vintage cars, but they can serve as an interesting comparison.

We seem to all accept that if any one safety modification is made to a vintage radio, then every single modern safety requirement falls on it like a ton of bricks. Various formal documents seem to support this view.

But if the owner of a classic car decided to add seat belts (some had mountings but predated compulsory fitment so nothing structural was necessarily involved) and if we assumed the same legal arguments applied, then the owner would be compelled to also fit airbags, dual circuit brakes, catalytic converters, noddy bumpers, etc to make the vehicle compliant with all current requirements.

I don't think this is the case.

Are radio people treated more harshly under law than car people?
Are we making a rod for our own backs?
Or are the car people getting away with it?

David

[Hartley118]

I guess that I follow the Repair rather than Restore philosophy. After taking the usual precautions with electrolytics on first switch-on, I enjoy diagnosing the causes of faults rather than sweating over complete 'recapping', 'reresistoring' or 'revalving'. Occasionally, I've even been known to leave an anode-grid coupling capacitor in place if it's not significantly upsetting the bias of the valve it's feeding.

For me, part of the joy of vintage electronics is getting surprisingly good performance from a bunch of pretty ancient components (a bit like the ageing human condition really ).

Most capacitors that we encounter leak to some extent, but there's a judgement to be made as to whether that matters in their particular circuit position. However I do recall from the 1950s buying brand new ex-WD military spec wax capacitors. They leaked then, just as they do today and may not be due to deteriorate much further over the next half century. By comparison, we thought Hunts Moldseals were sheer perfection so long as the Mold wasn't cracked!

There's a similar need for judgement regarding the usual drifts in resistor values. In critical positions, excessive drift can be nicely corrected by a judiciously positioned modern paralleled resistor, but often it seems to make little difference to performance.

Admittedly, my main interest is in getting radios etc working for my own collection, rather than running a restoration business for customers, but I do try to bear in mind the person who eventually will be the next owner of a vintage radio. Will they want the mystery of trying to work out whether capacitors have been restuffed, or rather will they be reassured by the obvious presence of a modern component where it turned out to be necessary? Sometimes nice to leave the old disconnected defective one in place though if it's a prominent item like a vintage wet electrolytic.

Martin