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What is this?

Rayregula

Dec 20, 2016
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what is this? I found it in an old TV and I cant find it anywhere! the glass tube is about 1" long if that helps.

File Dec 19, 7 45 01 PM.jpeg File Dec 19, 7 45 32 PM.jpeg
 

Rayregula

Dec 20, 2016
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I think its a spark gap tube used to excite high voltage for the crt.
Could be. Looking at some picks of them they look somewhat similar. But isn't that a large gap. no printing on the glass either. I would expect some burn marks or something on the terminals. But maybe they cant burn in there?
 

Harald Kapp

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Nov 17, 2011
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I would expect some burn marks or something on the terminals. But maybe they cant burn in there?
This device is called a gas discharge tube. It is used to protect from overvoltages, e.g. when a lightning strikes nearby (it won't protect neither you nor the TV from a direct hit). No burn marks means that this device has seen no or only negligible overvoltages, which is not unusual.
You probably found this at the antenna input of the TV as this is likely the point of entry for overvoltages picked up by the antenna circuit.
 

Rayregula

Dec 20, 2016
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This device is called a gas discharge tube. It is used to protect from overvoltages, e.g. when a lightning strikes nearby (it won't protect neither you nor the TV from a direct hit). No burn marks means that this device has seen no or only negligible overvoltages, which is not unusual.
You probably found this at the antenna input of the TV as this is likely the point of entry for overvoltages picked up by the antenna circuit.
Thanks!
 

debe

Oct 15, 2011
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Those spark gaps are found on CRT type TVs, on the board pluged on the back of the picture tube neck. Usualy to protect from internal flashovers as theres 25KV involved with colour CRTs.
 

cjdelphi

Oct 26, 2011
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I have a "surge" protector it's simply an inductor in a plastic box, paid good money for the power block too!

I wonder if i could use these along with MOVs to protect the low side from surges
 

debe

Oct 15, 2011
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Here they are on a circuit diagram. Display unit Koden radar. Have long thrown out all the TV circuits that I had as they are not worth repairing here.SPARK GAPS.jpg
 

debe

Oct 15, 2011
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I did actualy find a manual for a mid 70s TV that used that type of spark gap, Toshiba C-410 colour TV.SPARK GAP.2.jpg SPARK GAP.3.jpg
 
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