The voltage was significantly higher. I am fairly sure it went from around 5-10KV to 15-25KV.
heter on te cathode, massive anode voltage applied to plates through which the electrons shot, deflected electrostatically by further plates (CRT) or by magnetic coils (TC tube) before biffing a phosphor screen on the nose. The colored phosphors needed a bigger biff.
Well took off is a relative term. The first B & W TVS had a screen about the size of a modern phone I think it was towards the late 1950s that many affluent middle class households got a TV . Not being affluent it wasn't until the early 60s that we rented one
You and your paraphrasing! It was actually "volts jolt, mills kill" - a bit pithier but meaning the same thing.
Cue chicken/egg egg/chicken themed discussion. :-)
The earliest sets used a mains transformer to produce EHT directly. This could kill, unlike later LOPT derived EHT. They did sometimes have a bulb in series as a fire prevention measure, but the EHT was still lethal.
Colour TVs did use more volts, but I don't know of any lethal colour tv EHT supplies. B&W TV began decades earlier with deadly EHT setups. By the 50s I think they were all LOPTF derived.
Voltage & current were both higher in colour. Barely 1/3 of the EHT current ever made it to the phosphors, and they weren't selected for maximum light output, colour choice came first. But the EHT still wasn't lethal. Colour sets were significantly more complex, so significantly less reliable. FWIW we didn't see colour here until the 60s.
For reference, in 1966 I started as a development engineer in colour TV. The LOPT-derived EHT was 25kV. The CRT had an inner and outer metallic coating, making a capacitor that stored the charge, which could be a danger if not discharged before working on it.
The only shock I got while at the lab came from the mains isolating transformer at every seat. They had a neon between each pole and earth, so that the one connected to the live chassis would go out when the chassis was earthed. Unfortunately the neons took about 3mA each, so if you touched an unearthed live chassis you would get a 6mA shock.
NT will believe that you would use a permanent magnet to induce this field. And he calls himself an engineer!
Maybe I don't, but that's infinitely more than you know.
You'd lose.
Most publications say the human body has a higher impedance to DC than AC and his was known during the current wars. DC was considered safer, AC had many other positive attributes.
At higher frequencies still, ie kHz, you get a burn, as I can attest to from the back of a TV.
I had two bad experiences, one was picking up a selenium stack rectifier that was live that I couldn't let go. My hand went into spasm holding it even tighter.
The other was a US radio that used a resistance wire dropper in the flex, that had confusing cable colours. I had hold of the chassis obviously live, whilst holding a metal clad socket with the other hand. I might add that experience frightened me. Of course before we had RCDs.
Yes, one example of earthing exposed metal surfaces can make matters far worse! Having been prodding around with these kind of voltages now for the best part of 50 years it's been long ingrained into me to keep my left hand behind my back at all times when exposed EHT is around.
Coronation was 1953.
Many guitarists would disagree. There's still a strong demand which some manufacturers are only too happy to service (and charge accordingly).
And that means you can still get cool T-shirts. I am at this moment wearing a T-shirt with the circiit symbol for an 807 on it!
newshound formulated the question :
From memory - both current and voltage was quick a bit higher, voltages ranged up to 30Kv, depending on the tube size. Still not generally fatal, the bigger danger was from X-rays.
I used to be able to strike up and hold a spark from the EHT, with a finger tip, creating a finger tip burn.
The early valve colour sets were so much more complex than the B&W ones, so they needed much more attention from the repairers - hence one good reason to rent, rather than buy. There were repairers on many street corners. Things improved dramatically once valve were replaced with more stable transistors, then improved once again with more integration.
Now they so rarely need attention during their entire working life, there are almost no repairers to be found.
Oh I know - in niche areas. I have tow guitar amps, one cost $85 - less than the cost of one of the two loudspeaker in it - second hand. The other cost back in the 90s around £450 and is worth over £700 simply because its got rubbishy red glowy things inside. It cost me more to replace bad valves than buy the second hand transistor one...
...by the way, you would be surprised how much of a belt you can get from a 400W transistor power amplifier if you touch the output with one hand an the input with the other output voltages up to 400V p to p are getting close to normal.
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