Bonding Vehicle

[Nick23]

Would it do any good to bond your vehicle if you have a mag mount antenna?

 

[M0GVZ]

Would it do any good to bond your vehicle if you have a mag mount antenna?

Absolutely. What makes a good path for DC doesn't necessarily work for RF.

A good indication to see if your bonding is working is to use an antenna analyser. Note the frequency where X=0 and start bonding. Start with the horizontal surfaces - the hood and trunk or pickup bed - then re-check. You should notice that the frequency where X=0 has dropped. Using a lip mount I saw a drop of 300kHz by the time I'd finished.

Flattened RG213 braid makes for a good strap. Wire isn't suitable as it has a very small surface area and as RF flows over the surface of a conductor and not through it, we want as much as possible.

Bonding of the exhaust and engine to the main body helps reduce electrical interference.

A bit of light reading:

http://www.k0bg.com/bonding.html

And an example of one side of my hatchback to main body bond..

 

[Nick23]

Yes that website is great for explaining stuff like this. I plan on doing a hard mount as soon as I get my new vehicle. Untill then I have to make due with a mag mount. Trying the make the mag mount as effective and efficient as I can.

Thanks for the reply,
Nick

 

[Lil'Yeshua]

Grounding the radio case to ground helps. My 959's case ground isn't the same as it's (-) ground wire. Doing that stopped my K40 magmount antenna I had at the time from having a floating ground.

 

[M0GVZ]

Bad advice because all you do is create ground loops.

 

[Lil'Yeshua]

Then that's K40's bad advice then. I got the advice from them. It solved my constantly changing swr reading.
Let me say again,my Galaxy DX-959's ground wire is at a different potential than my 959's case. They might have had something to do with it but K40 told me that I had a floating ground and that grounding the radio's case to let's say,the same ground point as my 959's ground wire,which I did,fixed it.

 

[M0GVZ]

It didn't fix it, it masked the problem. My bet is a broken braid connection inside the magmount.

 

[Nick23]

I have an SUV. Not counting the electrical exhaust grounding. What should I ground? One strap or two on the hood. Anything else?

 

[Cozy]

Like M0GVZ said... read all about it here: Bonding

 

[Nick23]

As I said I have been on that website. I got a lot of good info there. I had a more specific question though. Should I use one or two ground straps on the hood? Should I then connect the strap from the hood to the fender to the frame? This is not on the website.

 

[Lil'Yeshua]

Bonding
http://www.eham.net/articles/25453

The EHam article says to use two bonding straps,one at each hinge location.

 

[Nick23]

Thanks Yeshua. I have never been on that site.

 

[psycho]

I have an SUV. Not counting the electrical exhaust grounding. What should I ground? One strap or two on the hood. Anything else?

Since RF travels only on the surface of grounding straps, use only 1" wide straps or bigger. Also make sure the straps are 12" long or shorter.

 

[Nick23]

Where do you guys buy yours. Saw some on Ham Radio Outlet for 25$ good price or have you guys found cheaper?

 

[Captain Kilowatt]

I use short pieces of old RG8 coax braid. Really wide strap is not really necessary unless you are running lots of power. It's all about the RF currents that each piece needs to carry. If in doubt use two pieces. Anywhere there is a hinge like doors,hood, and trunk should have a strap bridging the hinge.Exhaust should also be bonded in at least two places.