Strange question about magic eye tubes

[clintrubber]

Can't help that the following came to mind: do magic eye tubes generate nasty stuff
that should better be filtered out before it reaches you ?

I mean, for CRTs (using kVolts) you see this this 'adequately screened' statement.
Would expect that the mechanism is the same but on such a smaller scale (250Vdc)
that no additional precautions are required ?
Or did the front panel glass of radios provide additional protection ?

Thanks,

Peter

 

[gyraf]

If you're thinking of xray-related hazards, then no - those takes voltages of many-KV to generate..

Jakob E.

 

[clintrubber]

Thanks Jakob, that's reassuring. :thumb:
IIRIC the 'nasty stuff' for CRTs is indeed just that, Xrays, right ?
Ah, so as long as we don't need to increase the HT-supply to get some more light out of that old stuff then we're safe ! :grin:
I thought a EM4/34 allows up to 300V when in action, so that's not kV-area yet.

Thanks,

Peter

 

[pucho812]

Magic eye tubes are no more harmfull then your standard tube, not dangerious in terms of x-ray fields. but swapping them while completeing a circuit and you might get an electrical bite but thats like any other tube

 

[PRR]

What Jakob said. Unless you are highly allergic to faint green light, an eye-tube is about as dangrous as a 6V6. You might get X-rays if you crank an eye-tube to 5,000 volts, but you would also kill it quick.

Even common oscilloscope CRTs are harmless.

TV CRTs are expected to be MUCH brighter over a much wider area. Because the electron spot touches each area of the screen for a very short time, they have to crank the voltage WAY up.

I'm pretty sure there is a threshold voltage. If an electron is below that voltage, no X-ray or other ionizing radiation is possible. While actual electron velocities scatter around the average voltage, hi-energy electrons are rare, low-energy electrons are common.

 

[BYacey]

If I recall correctly, somewhere around 28KV and up is where Xrays start to occur.

 

[CJ]

I noticed a real heavy tube in the last batch from Andy's garage. It was coated in lead! A high voltage rectifier for a TV.
Don't think you could get away with lead tubes today. Especially in Europe.

 

[clintrubber]

Thanks goes to all, reassuring info :thumb:

That protective glass (for halogen bulbs against UV) & old pre-nuclear-bomb technology like those magic eyes made me wonder whether there would be something going on that could better use some precautions with todays insights. But all fine, I dreamt up some relation that's simply not there ! :grin:

[quote author="CJ"]I noticed a real heavy tube in the last batch from Andy's garage. It was coated in lead! A high voltage rectifier for a TV.
Don't think you could get away with lead tubes today. Especially in Europe.[/quote]
Point taken :wink: (just let's ignore Kioto for now, OK ? :evil: )

RoHS
In an effort to reduce the use of hazardous material in electronic equipment as well as allow for additional recycling opportunities for these products, the European Union has initiated a Restriction on Hazardous Substances (RoHS) and a directive on Waste Electrical and Electronic Equipment (WEEE). RoHS bans the use of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated biphenyl ethers (PBDE).

I wasn't sure who initiated RoHS, but it's those d&mn Europeans again ! Funny thing is, the release of an IC we finished at work is delayed because of that RoHS-thing. And it's for an US-customer...

Enough on lead, back to magic eyes: good to know that I can add a gimmick-eye to a box and watch it without having to worry :thumb:

Bye,

Peter

 

[pucho812]

there is more to the magic eyes then gimmic's.

(schemo with 1629 as line amp)

 

[Svart]

Hey pucho that's pretty cool.

 

[clintrubber]

[quote author="pucho812"]there is more to the magic eyes then gimmic's.
[/quote]
You're right, nice idea to use that triode twice, thanks for the info.
It'll obviously require more input signal as I understand it, because of the way lower plate-resistor.
I'll be adding an EM4 to a G-Pultec now there's a HT-supply in the box anyway.
The EM4 has two triode-sections for dual sensitivities, let's see if I find a use for additional amplification stages.

Bye,

Peter

 

[cannikin]

Here's another schematic