Alpha Delta Switch Arc-Plugs

Gas Discharge Tubes

I recently bought a couple of Alpha Delta coaxial switches, and noticed they come with a built-in surge arrester which can be replaced after a surge. They call them “Arc-Plugs”. These are on sale at DX Engineering for $9.99 each. I thought that was a little steep.

When the switches arrived, I took at look to verify what these were, looking for part numbers, etc, and discovered they are actually Littelfuse CG21000 gas discharge tube surge arresters. These are a common component often use in telecommunications and other surge-prone areas of electronics.

These can be found online at Mouser or Digikey for around $2.99. All you would need to do would be to order the leaded variant, snip off the leads with a pair of cutters, and you’re good to go. After all, that’s what it looks like Alpha Delta are doing too.

I don’t know about you, but I like cheaper.

If you would like to know more about how these surge arresters work, check out this detailed PDF from Bourns:

Thanks to N5UWY for setting me off on this curiosity!

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AD5GG works in the real world as an RF design engineer. Occasionally, he posts articles on this very site. Sometimes they're even worth reading. Please feel free to comment on posts using the comment system at the end of each post.

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5 years ago

I’ve used A-D TransiTraps as long as I’ve had antennas outdoors. What I’m more interested in is how you would ever know that these are “bad” or “used up”. Do they fail-safe? If they do, would my antennas be, essentially, grounded?

4 months ago

Well this is great and truly a savings, however your link takes you to the Gas tube WITHOUT LEADS, you need to order that gastube with leads so the CG21000L “L” is important else you will spend more money ordering twice when you could have ordered from Gigaparts and saved the hassle. Just be aware this is a money saver if you order 4 $3 ea plus $8 shipping you will have 4 spares for the price of 3 from Gigaparts. AD5GG thank but no thanks for making me spend twice as much then I needed to do to your incorrect link

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