Radio Tube Mystery: Solving the Buzzing Buzzer

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Discussion Overview

The discussion revolves around the behavior of a radio tube when subjected to a high voltage (1 kV) and its unexpected interaction with a Geiger counter. Participants explore the potential causes of the Geiger counter's response, including the possibility of X-ray emission or interference from static electricity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes the setup involving a 5 cm high radio tube and a Geiger counter, noting the unexpected response of the counter when the tube was energized.
  • Another participant questions the safety and appropriateness of applying 1 kV to unknown components, asking for more details about the voltage source.
  • A participant suggests that UV radiation from the discharge could have ionized the gas in the Geiger counter, leading to its response.
  • One participant speculates that the Geiger counter may have acted as an antenna for static electricity generated by the arcing in the tube.
  • Another participant shares a personal anecdote about safety concerns when working with high voltage and suggests using lower voltages for testing.
  • There are suggestions for using current limiting resistors or fuses when working with high voltage to prevent accidents.
  • Some participants propose alternative methods for generating sparks, such as using an inducer or wire meshes.

Areas of Agreement / Disagreement

Participants express varying hypotheses regarding the Geiger counter's response, with some leaning towards static interference and others considering UV radiation. There is no consensus on the exact cause of the observed phenomenon.

Contextual Notes

Participants discuss the potential risks associated with high voltage experimentation and the need for safety precautions, but there are unresolved questions about the specific mechanisms at play in the interaction between the radio tube and the Geiger counter.

Who May Find This Useful

This discussion may be of interest to hobbyists and professionals working with vintage electronics, high voltage experiments, or radiation detection technologies.

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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  • #11
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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