Bodgery...in the interests of getting our sets going!

[Sideband]

Q: What do you do on a Friday night when trying to get more life out of a radio that should work a lot better than it does? You find that the 7C6 has virtually no emmision and the one in your spares box is no better and barely scrapes past the .2 mark on the valve tester where it should be nearer 1.

A: You cobble together a temporary substitute in the form of a 6AT6 (EBC91), a B7G valveholder and seven shortish lengths of wire. In less than half an hour you have soldered them to the B7G valveholder and plugged them in one by one to the respective pins on the Loctal valveholder previously occupied by the dud 7C6. You then switch on and are rewarded by a working radio.

The bodgery shown in the picture actually works very well even though the leads are rather long. At least it enables me to assess the rest of the radio which is rather tatty to say the least and decide whether to repair the other faults and invest in a new 7C6 or use it for spares. I will only do this if the set really is past it. This particular one had been got-at and 'realigned'. It's took a while to get it something like correct, involving dismantling the I.F transformers and replacing the parallel capacitors so that they actually tuned. Anyway that's all for another thread if successful.

Just thought I'd share the bodgery with you and perhaps ask others what they have done in the past to get things going.


SB

[paulsherwin]

Much better than junking the set.

If you don't want to buy a new valve you could always convert the socket. If you drill out the rivets and use some long bolts you can mount an octal socket above the existing one leaving the original in place, and wire it for something like an EBC33 or 6Q7. This mod is easily reversible.

With a bit more fiddling you could fit a B7G, B8A or B9A socket and use whatever valve you have to hand (including your 6AT6.)

Repairmen in the 60s would just rip out the original socket and fit the new one in the space, but we wouldn't dream of doing an irreversible mod like that

[Lucien Nunes]

Projection demonstration at a trade show using Kalee 21 / President arc / Nevelin mercury arc.

First snag - Mercury arc won't start up because ignition dipper ballast resistor has gone O/C.
Solution - 2x 100W light bulbs nicked from nearby light fittings, soldered to a bit of wire and hung inside rectifier cabinet.

Second snag - Soundhead exciter lamp PSU (4V 1A DC) wasn't packed with projector, due to arrive 1/2 hr before kick off but didn't make it.
Solution - Got battery from van as source of smooth DC. Could not find 8R 8W resistor but 12 qty 100R 1/4W found in odds & ends pack in toolbox wired in parallel. Power rating increased by liquid cooling i.e. suspended in coffee mug. Contents of mug turned green due to electrolysis by end of show.

Lucien

[Billy T]

Bodgery is much overstated and unnecessarily maligned. Valve extensions are simply a temporary expedient, and an excellent one at that! I have similar arrangements for B7, B9, octal & loctal valves, but with clips to allow reconfiguring the donor 'plug' and the 'substitute' valve socket connections to suit any valve type. With these devices I can check valve functionality (if the tester gives ambiguous results) in any working radio I have handy, or substitute a suitable valve in a current repair job as you have done to get on with it while you obtain the correct repalcement. It doesn't always work out, and instability is occasionally an issue but they are a useful adjunct to the normal workshop test jigs.

Old radios are rarely 100% original anyway unless they have lived a charmed life, in fact post- WWII Philips New Zealand published a valve substitution guide for the use of their valves as substitutes for hard to obtain US types. The data covered direct equivalents, 'practical replacements" that required minor base wiring or component changes, and 'emergency substitutes' that required socket changes, pin connection rewiring and circuit alterations as well.

Cheers

Billy

[HG MICKE]

We used to call it Works modification,ie we modified it now it works.
What now is called bodgery was accepted practice in the past, when the customer wanted the item repaired like yesterday but did not want to pay much there was little choice but to get it going any way possible [safely of course].
One common bodge was to hang dropper sections on a faulty dropper,some units came into the workshop looking like a Christmas tree.These days this would be frowned apon and considered to be dangerous but was not at the time,even RS supplied dropper sections.

Colin

[kalee20]

Sideband - that looks like a Cossor chassis - 500/501 perhaps? It's a good, quick mod - the sort of bodge that's intended to last until the correct valve turns up, and soldiers on for 30 years.

Lucien Nunes - like the bodges, "The show must go on". Surprised the quarter watt resistors didn't burn out even with liquid cooling, sometimes the protective paint is just too thermally insulating - but well done! Another possibility might have been taking the battery AND an indicator bulb from the van and taping the 12V lamp in place of the original exciter lamp.

[wireful3]

I have often wondered what constitutes a "bodge". Colin has illustrated some points that have often made me ponder. Anything that differs from the original spec is a bodge in some eyes. This could include using a modern component that does not look like the original. Personally I would not be so harsh. Many sets must have experienced this for the reason Colin explains. At the other extreme twisted wires in place of a soldered joint and chassis mounted components hanging by wires is definitely a bodge even if the joint is hidden by a sleeve. I am not too sure of my feeling about obviously sound soldered joints that did not show the skill of the original expert wiremen.

There must be occasions where an individual set is different for other reasons and I would be interested in opinions as to whether others would think this a bodge.

When the original set was designed, before the circuit was fully understood some components may not be optimum and a repairer did a later redesign and put in the more appropriate values.

[Leon Crampin]

Sometimes bodges come back to bite...

I once had a Bush PB22 which I had rescued from a tip. With the usual replacement capacitors and very few other parts it became the kitchen radio in my student flat. It always had a bit of a crackle however, which grew steadily worse with use.

To cut a fairly long story short, a very convincing looking soldered joint on the primary of the output transformer (mounted up on the baffle board) was in fact candle wax. The connecting wire had been pushed through the hole in the tag and wrapped around in usual Bush style and "secured". With a layer of dust, it looked like any other soldered joint - quite a neat one in fact.

The give away was that the joint simply "disappeared" as I approached it with a soldering iron.

I've absolutely no idea how it got like that - the bodge was as neat as all the other joints...

Leon.

[Sideband]

Originally Posted by kalee20

Sideband - that looks like a Cossor chassis - 500/501 perhaps?

Well done that man! It's a 500. I didn't mention the model number as the thread is not supposed to be model specific. This sort of bodge could, of course, be used with any set.

It's still working by the way.


SB

[Tractorfan]

Hi,
Thought I'd show you my contribution to "What Bodger" magazine .
It's a French Reela table radiogram that was missing its EZ90. The "Law of S*d" then came in to effect and stated that I'd have loads of EZ80s and no means of enlarging the 'ole in the chassis . I was worried about restricted headroom under the deck, but all was OK. If not I'd have bodged a right angle adapter.
Cheers, Pete

PS Living in an ancient French house bodging come with the territory.

[Lucien Nunes]

"The show must go on"

is indeed one of the driving factors and many of my bodges are show-related hence not all on vintage gear. But a few more come to mind.

Another daft liquid/resistor trick...
Location - folk music event
Device - Guitar amp. I recall it as a Selmer T&B 50 but that can't be right as it has fixed bias and the amp in question was cathode biased
Fault - distortion when hot, discovered 3 numbers into the first set
Cause - suspected leaking coupling cap, one (EL34? 6L6?) sweating
Solution - 1 pint lager + 2 pieces hookup wire
Time to effect bodge - approx 30 seconds

I'll let you work out the details. It involved temporarily pulling out the hot valve but not accessing under the chassis - there wasn't time for that. TBH I can't remember if it was truly successful, it felt like the best we could do in the middle of a set though. Perhaps it was as I don't remember pulling it apart and changing the cap at half time.

Emergency filament lamp surgery...
Location - Small theatre, about 1 hour before doors on 1st night
Device - Vintage followspot using rare 2kW A-class non-prefocus lamp
Fault - Spare lamp in box on shelf does not work when put into lantern
Cause - It's a used, dud one with one end of the filament dangling loose
Solution - 415V supply, 2x 5A plug fuse, length of flex, gaffer tape
Method - shake carefully so that end of filament hits support square-on, arcs heavily and embeds (tungsten won't weld but it can be captured by the molten nickel support). Fuse blows when weld successful.

Surprisingly, given that the lamp is waggled around in use, it lasted until replaced after the end of the second night, by which time some strenuous searching had turned up some spares.

Lucien

[Jason Pero]

I've done few bodges too. Swap out STR3130 for STR30130 with flying wires. Both works in same circuits since I checked in datasheets for both.

STR3130 types held on with two screws were NLA for long time.

Unfortunately another STR730 series just joined the NLA few years ago and cannot be subbed with later ones. Hot brighter too.

I had one TV using a op amp in inline IC fail so I used a zener and resistor to drive the same transistor for 5V standby.

Cheers, Wizard

Cheers, Wizard

[raditechman]

You would go to a TV service call for "poor sound" having spares with you for an electronic fault only to find the loudspeaker cone rubbing on magnet. Ah! No spare speaker, so a bit of rag or a piece of cotton wall (even a folded piece of valve carton cardboard) wedged at the right spot between the speaker casing and the cone would shift it enough to clear it, and keep the customer happy, until a new loudspeaker could be fitted.

John

[glowinganode]

Whilst setting up a pair of synchronised generators on the Isle of Wight for a festival, I decided to check behind the panel...
I also ended up rebuilding an injector pump in the pi**ing rain that weekend, like Lucien says "the show must go on".
As for the bodge - it lasted the weekend, and the customer didn't even 'twig'.
Rob.

[Tractorfan]

Hi, Just remembered another valve bodge. Valve mono amp started making 'orrible noises and diagnosed a duff 6SN7 phase splitter. Found an ECC40 plus holder plus octal plug. Sounds great!
Cheers, Pete

[Sean Williams]

Rob, that picture is going to cost me 6 months in counselling.... fancy showing that shade of green off in public!

[Peter.N.]

It was the order of the day in the '50s, TVs and radios were very expensive and all sorts of ingenious bodges were done to make the repair affordable to the customer. Failure of the mains EHT transformer on early TVs was a dreaded event, the transformer itself was about £5.00 or a weeks wages, so, we used cut off the u/s winding with a hammer and cold chisel and then make up a doubler circuit on a piece of Paxolin with K3-40, I think they were, selenium rectifier sticks and a couple of TCC Visconel EHT capacitors, we fed the input from the line output valve anode. It didn't give as good a picture as the transformer but you could see it, even if you had to draw the curtains.

Peter

Peter

[Lucien Nunes]

behind the panel...

...lies a special type of uninterruptable contactor that will remain closed reliably even in the event of loss of coil power. A great feature for ensuring continuity of supply and/or motoring of the alternator.

Look out for our matching range of uninterruptable fuses and circuit breakers!

Lucien

[robjkmannering]

Yes I will remember to 'log' that one for future reference!
Lucien, do your uninterruptable fuses come as 'time delay' or are they quick no blow?
Made me laugh.
Rob

[Lucien Nunes]

I can't imagine what wood cause those tree-phase contactors to stick...

I made some of those special solid brass fuses. One day I actually used one to deal (safely) with a peculiar scenario on a show in Ireland. There were delays on the journey home due to ferry cancellations and I got separated from the truckload of kit from my show, which ended up going on somewhere else complete with my brass slug fitted in one of the cables. It was quite difficult, making discreet enquiries about the possible location of a particular cable, without arousing suspicions that I might have done something naughty to it. I did eventually catch up with it in the warehouse but I never used the slugs again because of the risk of them getting out into the wild.

Lucien