Welder's Magnetic Ground

[W8LV]

Came across an "interesting" little item...it's called a Welder's Magnetic Ground. Here's a picture of one: http://www.northerntool.com/shop/tools/product_200381761_200381761 It's actually for arc welding. It is merely a magnet with a "contact point". You stick it on anything a magnet will stick to, and run that to the wire on your welder ground wire. But if you have anything iron or steel that's big and no way to connect an antenna to it...who knows? You might be able to load it up with a tuner via this contraption as an access point, or use it for a receive only antenna for your portable receiver....

Has anybody tried this?

[NA4IT]

Well, "might" is the key word here. I have seen one of those in use as a welding ground. And, they hugely problematic. If you ever watch someone strike an arc using one of those, there is a huge burst of sparks from beneath it. What does that mean? Well, it means the electrical connection is very "capacitive" and the arc shows it is burning through oils, dirt, what ever to make a contact. And, in some instances, you see this almost at every arc. So, unless the metal you plan to use as an antenna has a very clean spot, and the magnet contact is very clean, and very firmly attached, it will probably act like an antenna with a broken coax.

Most welders have words they say about magnetic contacts, and since I don't use them, I won't repeat them here...  

[MDNITERDER]

 It is a large spring loaded contact, If you think about it in this way your NMO mount antennas use this same idea, Just a lot smaller, Also remember welders are using 30 to 300+ amps at around 28 volts or more.

[N5XTR]

As a long time welder, these magnet ground clamps are convenient but cause problems.  They are fine when welding clean steel but not so good on painted, coated and rusted surfaces.  So if you use for RF purposes, just use a wire brush to clean the mating surface and keep the contact point of the clamp clean.