Controlling Static in mobile installations

[loosecannon]

Howdy all,

the capacity hat thread took a short side track for a minute to discuss controlling static in a mobile setup, and i thought that deserved its due as a discussion topic, as i believe that greater than 50% of CB installations are mobile installations, and that a large number of those mobiles drive within the city limits quite often.



here is the article by K0BG that i will be referencing:
Controlling Static

in this article, he suggests three ways to reduce the static in the receive.
i will be trying these techniques one at a time (may take some time) and will post the results here.

first is to add a corona ball on to the top of the antenna that is of sufficient size to adequately serve its purpose.

any input on this as too how big it should be, how well it might work, and where to get one is appreciated.


second is DC grounding the vertical radiator to the vehicle body through a coil.
this coil would present great resistance to the 27mhz RF signal but would provide for a static discharge to the body of the vehicle.

any input on how effective this might be, and the exact dimensions of the required coil (or the math to figure it out) would be great.


the third one is to mount a short length of aircraft cable to the vehicle's frame near the rear, so that the free end drags on the pavement below the vehicle.
the individual wires that make up the strands that make up the cable are splayed out at the free end.

any input on how effective this might be is appreciated.

thanks to any and all that wish to lend their expertise to this thread.
i will be trying these things, but we all know how subjective a test like this could be. thats where sound RF theory would help.
LC

 

[Moleculo]

I have had successful results by using using a decent sized corona ball in my mobile. I order the Hustler replacement whips and cut the whip off and just use the corona ball. The Hustler whips are too thin and brittle and break after getting whacked a few times. Instead, I cut the whip right at the ball with a dremel tool, measure the diameter of a higher quality whip (usually a shortened 102" whip), drill a new hole in the corona ball, and then use JB Weld to hold it together.

For me, this has proven to help cut down on annoying static pops, especially on the lower bands while driving.

 

[loosecannon]

thank you so much for the suggestion moleculo, i will look into that.

one question though, not knowing how conductive JB weld is; are you concerned about the connection from the whip to the ball?
LC

 

[Bigmic919]

Have you guys thought of Gunnypucks.com he has a nice lookin corona ball.

 

[Moleculo]

one question though, not knowing how conductive JB weld is; are you concerned about the connection from the whip to the ball?
LC

It's not conductive, which is why I carefully measure the whip diameter and choose the same size drill bit. The ball is then tapped into place.

Have you guys thought of Gunnypucks.com he has a nice lookin corona ball.

Didn't know about it, but I found the site here: Page Title. If I had known, I would have just ordered that.

 

[loosecannon]

gotcha mol'.

thanks for the link bigmic! i wish more of the CB machinists would make these things.

this is what i will be buying within a week or so.
LC

 

[Bigmic919]

Not a problem. Gunny is A number one to deal with too. He will do ya right. I gotta order me one of them coronas as well.

 

[mackmobile43]

Howdy all,

the capacity hat thread took a short side track for a minute to discuss controlling static in a mobile setup, and i thought that deserved its due as a discussion topic, as i believe that greater than 50% of CB installations are mobile installations, and that a large number of those mobiles drive within the city limits quite often.



here is the article by K0BG that i will be referencing:
Controlling Static

in this article, he suggests three ways to reduce the static in the receive.
i will be trying these techniques one at a time (may take some time) and will post the results here.

first is to add a corona ball on to the top of the antenna that is of sufficient size to adequately serve its purpose.

any input on this as too how big it should be, how well it might work, and where to get one is appreciated.


second is DC grounding the vertical radiator to the vehicle body through a coil.
this coil would present great resistance to the 27mhz RF signal but would provide for a static discharge to the body of the vehicle.

any input on how effective this might be, and the exact dimensions of the required coil (or the math to figure it out) would be great.


the third one is to mount a short length of aircraft cable to the vehicle's frame near the rear, so that the free end drags on the pavement below the vehicle.
the individual wires that make up the strands that make up the cable are splayed out at the free end.

any input on how effective this might be is appreciated.

thanks to any and all that wish to lend their expertise to this thread.
i will be trying these things, but we all know how subjective a test like this could be. thats where sound RF theory would help.
LC

I have tried this only with a piece of log chain on a combine while harvesting to relieve the static building up on the machine due to all the moving metal parts against the grain and it's associated plant debris with little or no effect and that's touching old mother earth and as far as dragging it on asphalt I would not expect it to help or maybe create more static build up not to mention the possible sparks created

I think a person would benefit more from bonding all body parts to each other and then to the chassis.

 

[loosecannon]

thanks for the input mack.

nice to know someone has tried this before.

i agree that bonding all the metal together with the frame is the first step.

i do wonder about the ability of the chain itself to dissipate the static.
in K0BG's article he mentions the importance of splaying out the ends of the cable in the same way they do on airplanes.
if galvanized aircraft cable is used, there should not be any sparks.

this will be an easy one to try for me, as i work with this cable all day every day, and i can mount it under the truck and do simple with/without tests while driving to work.

this will probably be one of the first things i try.
i picked a stupid time to do this, as im really busy, but oh well, i got excited and we'll just go with it.
LC

 

[HomerBB]

If you take note of the way it is done with airplanes you begin to wonder how long the cable must be to touch the road when the airplane is traveling 150 MPH at 18,000'.

I tend to see that it isn't about touching the ground at speed, but simply something of the right properties being dragged through the air dissipating the static buildup instead of the antenna itself. Perhaps the electrical static follows the path of least resistance. Or maybe the increased speed of the air under the vehicle due to the the air being forced into the smaller space has something to do with the static more readily bleeding off the cable beneath the car . . .
Whatever it is, I'm fairly confident it hasn't anything to do with it dragging on the road.

 

[W5LZ]

HomerBB is right, that 'static strap' doesn't touch the ground at all. It's just like the ones on the trailing edge of larger aircraft, a conductive metal section of cable/braid/whatever that the end is 'fuzzed' out on. The 'ends' of each strand provide a 'sharp' point that will discharge static electricity. If that strap did drag on the ground/road it would cause more static than it would ever dissipate. Ask the DOT about static straps!
- 'Doc

 

[loosecannon]

thank you homer and doc.

makes sense to me!

this makes it even easier.

cant wait to try this one.

the next few days will be all about noting the locations on my drive home that cause me the most interference, so that i will hopefully be able to tell if the static bleeder is helping or not.
LC

 

[BDOG-T7]

A Few Pictures of Gunny's Corona Balls!

I bought a few of Gunny's Corona Balls. Here are a few pictures of mine.

 

[Bigmic919]

Had a feeling you would chime in Bdog. I am going over to his site to order one now.

 

[mackmobile43]

HomerBB is right, that 'static strap' doesn't touch the ground at all. It's just like the ones on the trailing edge of larger aircraft, a conductive metal section of cable/braid/whatever that the end is 'fuzzed' out on. The 'ends' of each strand provide a 'sharp' point that will discharge static electricity. If that strap did drag on the ground/road it would cause more static than it would ever dissipate. Ask the DOT about static straps!
- 'Doc

makes sense, I'll give that a try