Radio Tube Mystery: Solving the Buzzing Buzzer

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SUMMARY

The discussion centers on the unexpected behavior of a radio tube when connected to a 1 kV power supply, specifically the interaction with a GMC-300E plus Geiger counter. The user observed purple eruptions from the tube and a constant display on the Geiger counter, suggesting potential interference or radiation emission. Participants concluded that the Geiger counter may have detected UV radiation or static from the arcing, rather than X-rays. Recommendations included testing with lower voltages and ensuring safety precautions when working with high voltage components.

PREREQUISITES
  • Understanding of radio tube construction and operation
  • Familiarity with Geiger counters and their detection mechanisms
  • Knowledge of high voltage safety protocols
  • Basic principles of ionization and electrical discharge
NEXT STEPS
  • Research the effects of UV radiation on Geiger counters
  • Learn about radio tube types and their applications
  • Investigate safe practices for working with high voltage circuits
  • Explore the use of inductors for generating electrical sparks
USEFUL FOR

Electronics enthusiasts, hobbyists experimenting with vintage radio equipment, and anyone interested in high voltage safety and radiation detection.

eigenmax
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I recently got a 5 cm high radio tube from a old radio in my house. It has 9 pins ,arranged in a C shape at the base, a getter at the top and parallel metal plates inside.

I decided to use my GMC-300E plus ,Geiger counter to check if it had a thoriated cathode. It did not. Just for fun, I two of it's pins to a 1 Kv power supply. I expected a nice show of plasma inside the tube. When I turned on the supply ,purple eruptions came from the plates.

The Geiger counter was still on and sitting beside it. The Geiger counter's display whited out and the light at the side which flashes when the counter registers a click, just glowed constantly, the buzzer did the same.

I instantly moved the counter away and turned off the supply. What made the counter do this? Was the tube interfering with the Geiger counters circuits, which seems unlikely. Or was the tube emitting an amazing amount of X-Rays ? The supply was only 1 Kv so this seems impossible.
 
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1 kV is a lot for a radio tube.
Any descriptive text on the thing ? Is it reddish or is it goldish ?
 
eigenmax said:
I recently got a 5 cm high radio tube from a old radio in my house. It has 9 pins ,arranged in a C shape at the base, a getter at the top and parallel metal plates inside.

I decided to use my GMC-300E plus ,Geiger counter to check if it had a thoriated cathode. It did not. Just for fun, I two of it's pins to a 1 Kv power supply. I expected a nice show of plasma inside the tube. When I turned on the supply ,purple eruptions came from the plates.

The Geiger counter was still on and sitting beside it. The Geiger counter's display whited out and the light at the side which flashes when the counter registers a click, just glowed constantly, the buzzer did the same.

I instantly moved the counter away and turned off the supply. What made the counter do this? Was the tube interfering with the Geiger counters circuits, which seems unlikely. Or was the tube emitting an amazing amount of X-Rays ? The supply was only 1 Kv so this seems impossible.
Do you routinely put 1kV across components and circuits that you don't have a schematic for? Where did you get the 1kV? DC or AC? Source impedance?
 
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A GM tube detects charges freed by the ionisation of the inert gas in the tube. Maybe UV radiation from the 1kV discharge penetrated the GM tube window sufficiently to generate ions within the tube.
 
eigenmax said:
I recently got a 5 cm high radio tube from a old radio in my house. It has 9 pins ,arranged in a C shape at the base, a getter at the top and parallel metal plates inside.

a photo of said tube would be extremely useful
 
Geiger counters make small electrical pulses that get amplified and counted inside the instrument.

I suspect your detector acted as an antenna for old fashioned 'static' from the arcing.

that's specuation, you could check by making some sparks from a lower voltage source like a six volt lantern battery and see if it counts them.

If you do it with a car battery use long jumper cables because you don't want sparks near a car battery The hydrogen inside them can explode and spray acid everyehere.
That happened to me, my glasses saved my eyes but i lost a dress shirt and trousers.
I doggone near got blinded and that's no exaggeration. Stay safe.
 
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Hello,
I am sorry to be so slow getting back, I had some minor account glitches (forgot password :headbang: ) , but I did more research and with your contributions I am now sure of the static/UV interpretation.
Thank you all very much
 
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Thanks for the feedback !
 
jim hardy said:
you could check by making some sparks from a lower voltage source like a six volt lantern battery and see if it counts them.

If you do it with a car battery use long jumper cables because you don't want sparks near a car battery The hydrogen inside them can explode and spray acid everyehere.
Don't use a car battery without a current limiting resistor. A few hundred amps through e.g. a wrist watch strap generates a lot of heat.
 
  • #10
Carrock said:
Don't use a car battery without a current limiting resistor. A few hundred amps through e.g. a wrist watch strap generates a lot of heat.
Yes. Or better yet a fuse, and not slow blow one. Also, eye protection recommended if you go applying 1 KV to a glass component. Remember P = E**2/R.
 
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If you're looking to make sparks, then an inducer would be the thing to use
 
  • #12
Rx7man said:
If you're looking to make sparks, then an inducer would be the thing to use
Wire meshs moved over each other work well too.
 

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