Coax grounding 101

Status
Not open for further replies.

daveleonard

Member
Joined
Feb 25, 2014
Messages
40
Location
Washington DC
I made a common plate on which I will ground all of my equipment but how do I join my coax cable to that common plate? Do I peel back a portion of the outer skin of the coax, exposing the braid, then connect copper braid or a very large gauge copper wire to it by solder and then connect that wire to the common?
 

popnokick

Member
Premium Subscriber
Joined
Mar 21, 2004
Messages
1,919
Location
Northeast PA
Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 7_0_6 like Mac OS X) AppleWebKit/537.51.1 (KHTML, like Gecko) Version/7.0 Mobile/11B651 Safari/9537.53)

If you're using coax connectors usually you get the chassis / panel mount jacks, mount them as pass-thru connectors, and use copper braid to bond to the common ground. You can put braid right under the panel jack as you mount it. There are also large spade and ring lugs made to handle copper braid or large copper wire gauges. Go to the electrical section of your home hardware store.
 

daveleonard

Member
Joined
Feb 25, 2014
Messages
40
Location
Washington DC
Reply

Thanks for the info and no doubt that what your said is the professional way to do the ground. The problem is I live a "third world" country at the moment and I must make do with what I can do. Hardware stores here on this tiny island have just the bare electrical essentials, nuts and bolts to work with. Will what I proposed to do work or is there a problem with the way I need to do it? I know it won't be the best way to do it but will it get the job done? Thanks.
 

WA0CBW

Member
Joined
Dec 8, 2011
Messages
1,273
Location
Shawnee Kansas (Kansas City)
You can also use a standard "feed-thru". Drill a hole in the panel and fasten the feed-thru with a nut on each side of the panel. Cut the cable and put a connector on each end. Screw the connectors one on each end of the feed-thru.
BB
 

mmckenna

I ♥ Ø
Joined
Jul 27, 2005
Messages
11,036
Location
SNCZCA01DS0
Easy way to do this that shouldn't require much hardware is to strip an inch or two of the coaxial cable jacket off near the grounding plate. Use a piece of scrap wire or some left over outer braid and wrap it around it tightly. Wrap the whole thing in a layer or two of tape to seal it.
Connect the other end of the wire to your ground plate. Use a crimp lug, or make a loop and bolt it to the plate.

This is a very rudimentary way of grounding the outer shield, and very similar to how we do it on commercial systems. The type we use to ground the cable at the top and base of the tower is similar to this: https://www.tessco.com/products/displayProductInfo.do?sku=320885&eventGroup=4&eventPage=1

Here is a picture of some installed at the entrance to a hut:
http://www.engineeringradio.us/blog/wp-content/uploads/2012/03/3-inch-coax-grounding-kit.jpg
 

daveleonard

Member
Joined
Feb 25, 2014
Messages
40
Location
Washington DC
Thanks

Thank you, that is exactly what I planed to do, I just need some confirmation so I didn't mess anything up. Have a great day. Dave.
 

mmckenna

I ♥ Ø
Joined
Jul 27, 2005
Messages
11,036
Location
SNCZCA01DS0
I wouldn't recommend soldering directly to the outer braid of the coax as the risk of melting the inner dielectric could result in issues. Wrapping it tightly around and taping it would be sufficient. You just want to keep moisture out of there.

Salvaging the outer braid from old coaxial cable makes for great ground braid. You can work a hole in the braid and then solder it to make a nice lug.
 

prcguy

Member
Joined
Jun 30, 2006
Messages
8,242
Location
So Cal - Richardson, TX - Tewksbury, MA
What's the purpose for the grounding, lightning protection or safety? If you have no central ground connection where power enters the building then you could be creating a hazard with improper power grounding. Sounds like you don't have any specific electrical code to work towards.

If you live in an area with little or no history of lightning strikes then why bother? Its beyond the scope of casual hobby folks to adequately ground an antenna/radio system to protect it from a lightning strike. If your antenna is the high spot on the property its usually better to disconnect it a move the coax away from everything when not in use or when lightning is possible. Just my 2c.
prcguy
 

daveleonard

Member
Joined
Feb 25, 2014
Messages
40
Location
Washington DC
Newbie

I am just starting out so I don't claim to know much so I try to follow what I pick up in my studies and from other hams. Station grounding I suppose is to drain static electricity from the equipment and they perform better being grounded. The antenna coax grounding might not be that important especially since I am planning to use a vertical Cushcraft if I can find one. It may not even need grounding. But just in case static electricity could build up on the coax line, I figured why not ground it and be safe. But you are dead on about the house grounding. I don't know what affect all my station, coax, mast and antenna grounding will have in the total scheme of things if the house isn't even grounded. Like I said no house here in the barangay has safety grounding. I will also use a coax switch so I can go to neutral and disconnect when not in use. But I don't think anything I can do would protect against a direct lightening strike. My grounding is my attempt to meet standard amateur practice as I learn it but its mainly for static electricity build up and good operation.
I do plan to unplug my equipment when not in use and also the antenna but I have no illusion that what I am doing will protect me from a lightening strike. It won't!
 
Status
Not open for further replies.
Top