Technical competence of the "Repair Shop"?

[N_Cook]

Last night an "arctic " thermometer, so how does a thermocouple power a bordon tube gauge? Looked to me much like a capilliary tube standard old style fridge or boiler thermostat system with Bordon tube rather than switch mechamnism. So loosing any calibration" with reconfiguring the connecting tube, I've no idea what liquid inside the tube for Arctic temperatures though. Then last week an old Russian pocket radio, IF/RF? Ge transistor swapped out with a so-called equivalent heatsinked AF output Ge trannie

[Roland Perry]

In message <u0p83c$rd62$ [e-mail], at 15:07:44 on Fri, 7 Apr

2023, N_Cook [e-mail]> remarked:

I can't watch the electronics chap, I end up shouting at the TV.

[alan_m]

Despite the sob stories, I get the impression that the junk the electronics guy fixes is destined for landfill soon after the program finishes.

[N_Cook]

I end up laughing in amazement at the electonics guy. A few weeks ago he and Dom both farting about around replacing one miniature circlip to a shaft. Anyone familiar with VCR/cassette mechanisms knows you tie a piece of cotton to the circlip and the other end to something convenient, so it can fly off if it wants to.

[Tim+]

Yep, I was shouting at the TV too.

Tim

[Dave W]

I didn't shout, just sighed as per usual.

[Adrian Caspersz]

It's all crap reality TV. Patronisingly focused on the people and their background rather than anything of real technical worth.

YouTube / Odysee has much better content.

[John J]

[Brian Gaff]

I sometimes wonder on series like those if re filming goes on and use of the wrong take etc occurs. I know according to some facts and procedures on shows about canals and railways are often incorrect. Of course on transistors, almost anything will work in a non exacting circuit as long as the gain and type, ie pnp or npn is correct. I had an oc 45go duff on an old IF strip, and I found a pnp silicon transistor placed in the same position worked fine. In theory the gain should have been too great and the difference in the conducting volts should have spelled trouble, but it did not. If anyone was interested, it was the old Heathkit Mohican. The one with the front panel doubling as a microphone because the speaker was in the box. I am being sarcastic here. I think it eventually died because the transistors in the coil pack went short circuit due to the problems with Mullards encapsulation inside the cans. Well known apparently, but it would have been tedious to find suitable replacements, considering the age and how primitive the ssb detection was. Brian

[Brian Gaff]

I had a Russian radio for a while, and it was interesting to note that at the time, it was mostly germanium, the Oscillator did have a habit of popping off. I eventually found 1 half of a silicon complimentary pair that fixed it. Not much room for it though, and it looked a little like overkill as it was one of those flat ones with a hole through the middle.. That radio also died eventually due to crackles and intermittencies. Its funny, but here we are all these years later trying to bring back to life old junk we threw in the bin when they became unserviceable. What next, the repair of a Sinclair Z12 power amp perhaps? Brian

[Brian Gaff]

I would not attempt to fix a thermostat switch of the type mentioned. Outside my skill set.

Back in the 80s, Clive Sinclair sold his Spectrum Computer. The ram chips needed plus and minus 5 v. He only had one of those so a tiny wee coil and a transistor were used to generate the other half. Thing was that this transistor tended to go a bit weird. Indeed you could trash it and at least one other simply by plugging in a peripheral with the power on. We regularly replaced these transistors on any pcb that needed repairing as many add ons used quite a high current on both rails and the transistors did not like it much. Brian

[alan_m]

Old junk that been left in the loft or leaky shed for decades so it's never been a treasured family heirloom to pass on to the next generation, or if passed on will be binned.

[N_Cook]

And the QL pc fault lying in wait, of leaving a "microdrive" tape in its slot while switching off the power and an induced spike would corrupt the tape contents.

[N_Cook]

Then the Fools and Horses Trigger concept of his favourite broo mwith 3 new rush heads and 2 new handles, the "Repair" Shop use of "donor" kit to replace most of the original "heirloom"

[Roland Perry]

In message <u0r900$16v2i$ [e-mail], at 09:35:17 on Sat, 8 Apr

2023, N_Cook [e-mail]> remarked:

Yes, it's the over-use of "donors" (sometimes complete chassis) to do the electronics repairs which is one of my peeves.

[Roland Perry]

In message <u0r52a$16eok$ [e-mail], at 08:28:04 on Sat, 8 Apr

2023, Brian Gaff [e-mail] remarked:

Oddly, I was reminded earlier today that 7th April (1986) was when he sold his entire computer empire.

[Roland Perry]

In message <u0r4b9$16bt0$ [e-mail], at 08:15:47 on Sat, 8 Apr

2023, Brian Gaff [e-mail] remarked:

Something I find irritating is the "one camera" technique (very common on this sort of show) where you see the guest talking to the presenter who is stood alone. Then swaps to the second half of the sentence shot over the presenter's shoulder at the guest (who is now standing alone).

It means every sequence is shot at least twice, then spliced back together. So pretty much very expression of surprise/glee is at least half from a re-take.

[Max Demian]

Some versions of the Sinclair Spectrum had an IC upside down on top of another IC with connections soldered between them. Known as the "dead cockroach" version.

[The Natural Philosopher]

I did see a better than average repair video where the gut said 'yep. what's gone is an unobtainable custom chip. and this is not a repairable unit'

I occasionally fix guitar amplifiers, and there is a dead band where they started to use for example audio chips that are simply no longer available.

Now they have gone full DSP with equally unobtainable custom digital chips.

Unless you want to part such an amplifier out, its worthless if something complex has gone. .

[The Natural Philosopher]

And it vanished into the history books where it always belonged