To stuff or not to stuff...?

[Panrock]

This comment follows on from another thread about servicing a pre-war television. Mods may wish to move it elsewhere.

Originally Posted by stevehertz

Well found Steve. That's why I always change old caps on sight, electrolytics and waxies. Yank em out like bad teeth, not worth bothering with, it's just buying into future functional problems (hours and hours of faultfinding rework) for the sake of under chassis originality.

Hi Steve. You make a good point and for most sets I would normally agree. Here though, due to rarity and market value, I take the view that this restoration is 'sensitive' and must at least look the part - even if there are sometimes departures from strict originality (like those newly fitted EMI-effect capacitors using a post-war pattern). If there is a penalty to be paid in servicing time, so be it.

In other words, horses for courses!

Steve

[stevehertz]

Yeah, it's just my personal view Steve. I could never perform a refurb to the amazing standards that you do. Mine is a pragmatic approach as in, two vintage televisions sitting aside each other, exactly the same model. One displays a perfect picture and has modern replacement components fitted to a high standard under the chassis. The other set looks totally original under the chassis, but the screen is blank. The latter demanding what could be weeks of work to find a fault caused by not using trustworthy components. The problem it would appear is due to relying on a reformed 1930s electrolytic, not a restuffing issue per se; although that cap could have been restuffed. And there again, depending on how that cap would have been restuffed, the poor connection may well have still been there. When I've restuffed electrolytics in the past (yes I've done it too!) I used to drill through the connection of the original cap and take the new cap's lead through, so that poor contact would have been bypassed. I suspect that some would have made the connection internally, out of sight, thus 'preserving' the bad rivet connection.

We're all different.

[60 oldjohn]

Two points if you do decide to re-stuff the caps.

Make sure there is not the slightest trace of old electrolytic left, as some are highly corrosive and can eat through the new lead in a matter of weeks.

Leave a note inside the set saying the caps are stuffed and the date, save a future owner ripping them all out before their time, if searching for a fault.

John.

[Malcolm G6ANZ]

I'm restuffing some of the caps in the R1155 I'm restoring. Namely the 3x0.1uF in a single can. I've found the easiest way to extract the innards is to remove the mounting end cap and heat the can with a small blowlamp. When the wax starts to melt the complete innards can be pulled out cleanly.
To replace the caps I am using 500v working SMD caps. These are wired together and covered in heatshrink. Untested as yet as the receiver is nowhere near ready for HT to be applied.

[G6Tanuki]

I am not a stuffer; to me, historic repairs and modifications to equipment are perfectly OK; back in the 40s and 50s a repair technician would have replaced failed/suspect parts with new parts then available, and I am happy to continue this approach.

In 50 years time my fitting of currently-available yellow MKT/MKP capacitors and Nichicon/Rubycon electrolytics will themselves be seen as a 'period' repair!

I want my equipment to be fully-functional and as reliable as is reasonably possible; spending time restuffing doesn't improve reliability or functionality - spending that time on doing a *serious* alignment/calibration job so the thing works as well or better than original-spec is to me far better return on my time.

[Equally, I don't obsess over appearance; I'm happy to replace old tuning knobs with modern types, for example, if they result in a better 'feel' to the operation, or LEDs in place of filament-bulbs for indicators/dial/meter-lighting].

[Rich Woods]

In my book “so long as it works” trumps everything. Others have different motivations when repairing / restoring sets.

[lesmw0sec]

I'd reckon that what you do depends upon the categories: Repair, Restore or Re-build. I'm in the middle one as a rule, unless for example all the wiring is perished. I'm not of the "replace every cap. in sight" group. Certain ones e.g. grid couplers are worth doing regardless, but I would rather leave intact reasonable components which have lasted well for 50+ years than make work for myself.

[knobtwiddler]

One neat way of re-stuffing your old cans that I've seen is a small, circular PCB that accommodates new caps. If there are particular common models that we see, then one of us could order a few through JLC PCB or similar. You could get a 2-layer one for pennies.

Oh - and I am in the 'if it works well' camp. Performance is 99% through design, not because you chose an original part (that's probably been on the shelf for decades and will fail in a year or two anyway).

[M0FYA Andy]

Originally Posted by G6Tanuki

I am not a stuffer; to me, historic repairs and modifications to equipment are perfectly OK; back in the 40s and 50s a repair technician would have replaced failed/suspect parts with new parts then available,

I can't agree with this approach. The technician in the 40s and 50s wasn't trying to restore vintage equipment, he was simply repairing his customer's radio so it would work again. The customer probably had no interest in the parts inside his radio, he just wanted to hear his favourite stations.

Move forward seventy years and that radio has now become 'vintage technology', of interest for what it is as a historic object, rather than simply doing a workaday job. Indeed it probably isn't a particularly useful item any more, compared with its modern equivalent.

So disguising the inevitable modern replacement parts inside the old makes sense to me.

Andy

[murphyv310]

I don't re-stuff. I've been bitten in the past when a stuffer got the values wrong and landed up with umpteen faults as he did a blanket job. It was a nightmare to get correct as the circuit diagram had multiple errors which didn't help nor did the araldited caps!

[kalee20]

I don't restuff, though I do try to make repairs look 'right' (silicone rubber sleeved wire in place of original rubber; Vidaflex braided sleeving in place of the sticky cotton braid; the yellow axial polyester capacitors I sleeve with transparent heatshrink sleeving which seems to tone down the newness.

I'd hate to think of someone in a few years time, seeing one of my chassis full of apparent waxies, and them innocently cutting them all out to replace with trouble-free, long-life modern polywhatever capacitors - not knowing that it was all unnecessary because the waxies were all fakes! I don't believe in making something look what it isn't.

[Oldmadham]

Originally Posted by G6Tanuki

I am not a stuffer; to me, historic repairs and modifications to equipment are perfectly OK; back in the 40s and 50s a repair technician would have replaced failed/suspect parts with new parts then available, and I am happy to continue this approach.

In 50 years time my fitting of currently-available yellow MKT/MKP capacitors and Nichicon/Rubycon electrolytics will themselves be seen as a 'period' repair!

I want my equipment to be fully-functional and as reliable as is reasonably possible; spending time restuffing doesn't improve reliability or functionality - spending that time on doing a *serious* alignment/calibration job so the thing works as well or better than original-spec is to me far better return on my time.

[Equally, I don't obsess over appearance; I'm happy to replace old tuning knobs with modern types, for example, if they result in a better 'feel' to the operation, or LEDs in place of filament-bulbs for indicators/dial/meter-lighting].

I agree.
My feeling is that the equipment has a history which is of equal importance to its original configuration.
This applies particularly to gear that was used in the Broadcasting & Comms industries.

Polyester, Polystyrene, & Polycarbonate capacitors arrived in the mid to late 1960s & were quite likely to have been used in everyday repairs over that & the following decades.

At the same time, there were a number of (their manufacturer hoped) "high tech" caps which were widely known to have "problems" & were often replaced with later generation "waxies"!

I would be most likely to "stuff" old cap bodies in a spot where clearances mitigated against just "slotting in" some modern caps.

We sometimes have to be careful with the "technology marches on" idea, though, as I remember having a large Bi-polar Electrolytic fail in an "Electrohome" TV picture monitor.
Looking for a replacement, I was chuffed to see how small BP electros had become, so bought a handful, in case they needed replacement in other monitors of this type.

Up came the monitor, with a nice picture-----for all of 5 seconds, then the "magic smoke" came out of the capacitor!

It transpired that the cap was not only BP, but also low ESR.
As the correct cap was "unobtainium", the monitor went back into service with a "Christmas tree" of "polyester greencaps".

No doubt, if someone in later years was restoring that monitor, they would recoil in horror at the "disgusting bodge", but that unit went back into service for years earning its keep, rather than languishing on the shelf, waiting for the correct capacitors to arrive from Canada.

[ppalped]

I'm also on the pragmatic side of things when it comes to repairing - I just try to make sure the new part meets the specs, but I don't really care much how it looks if it's going to be inside the case. But anything on the outside must match the original look as much as it is practically possible.

Alex

[Ed_Dinning]

Possibly the best route, stuffer or not, is to leave your note inside the set for the next repairer.

Simples, Ed

[Chris55000]

I normally don't bother restuffing – most of the items I look at are 1970s or later and those pieces of equipment I have that employ valves use capacitors past the "waxies" era, but the tip given in an earlier post of covering the AVX/Rodestein yellow cylindrical polyester types in clear heatshrink tubing is a good one tho!

As for electrolytics, I'd rather fit good tested (and "reformed" where appropriate) components of approximately the same age and size to the originals!

Those special odd–value Sprague electrolytics found in HP or Tektronix T & M I prefer to source exact replacements where possible, as these were specified to meet high quality and reliability standards, as well as frequently being an awkward size as well!

Chris Williams

[Panrock]

Originally Posted by 60 oldjohn

Leave a note inside the set saying the caps are stuffed and the date, save a future owner ripping them all out before their time, if searching for a fault.

Originally Posted by Ed_Dinning

Possibly the best route, stuffer or not, is to leave your note inside the set for the next repairer.

Sound advice. Thank you. I shall certainly be doing this on the current pre-war television restoration, which might otherwise be thought to be virtually 'untouched'.

Steve

[Panrock]

My opinion, for what it's worth...

What does 'restoration' mean? It is bringing something back, as much as possible, to how it was when new. In the case of electrical items, for reasons of practicality, safety and reliability, this process can only go so deep. So the capacitors themselves are not rebuilt using the original techniques and materials; they just 'look' as if they have been - or have been left alone. This is called 're-stuffing'.

A less rigorous restoration may often be appropriate, where the bar is set higher. Here, everything still looks original above-chassis but new components will be visible beneath. The newer the set, the less intrusive those components look.

Then we can make it even more superficial. This is where the whole insides are different. An example of this would be recently manufactured sets like the Bush 'retro' transistor sets - sorry, don't know the model number.

But a lot of folk won't want to agonise over all this, and a simple repair may be all that's needed.

Steve

[Ian - G4JQT]

Resistors can't be stuffed (and many develop faults almost as often as capacitors) so what's so special about capacitors? The only time I would consider re-stuffing a capacitor is if it's a large electrolytic visible above the chassis.

[McMurdo]

The only restuffing I've ever done has been on the main reservoir smoothing blocks (as they're usually above chassis, visible and a characteristic part of a set's chassis-look) although on a couple of 30's sets I did restuff the cathode bypass electrolytics as they were under p-clips and I didnt want to disturb the chassis layout, particularly as the service sheets always refer to their position by photo or layout drawing.

I notice on Retro Electro Workshop, Rob H. fitted a little tag strip which I think was in place of restuffing. I've done this where a set has already had its smoothing block removed and replaced with something gruesome.
I admit I'm now saving old capacitor cans in case I need to restuff and replace missing cans.

I don't think I'd tackle a 30's telly, I'm not worthy!

[Panrock]

Originally Posted by McMurdo

I don't think I'd tackle a 30's telly, I'm not worthy!

You won't know unless you give it a try! As for me, it appeals because it has antique restoration aspects (the fabrication of minor parts and the cabinets) and the electronic technology is crude - so I can (just about) cope. But put me in front of miniaturised surface mount, microprocessors and logic and I would run screaming from the room.

Steve