| Author |
Message |
    
Kattracker
| | Posted on Thursday, September 04, 2003 - 10:02 pm: | 
|
I am considering adding bonding straps to my hood, doors, and also the frame to improve my antenna ground.
Since my antenna is direct mounted to the pickup truck roof, I thought improving the grounds, especially at hinged points (doors and hood) might be a benefit. Kind of enlarge the ground plane, so to speak.
Yes, I am aware the frame especially should already be well grounded, and the doors and hood too, but when vehicles get old (1991) the connections are not as good as they used to be.
For example, I have taken cabs and beds off frame rails and the rust and scale between the mounting points where really bad. Imagine what kind of resistance that could make.
As far as the doors,...when GM used nylon bushings on the hinges I bet the doors could benefit from improved grounding.
I recall years ago when I was a mechanic, I worked on some of the city, county and state police cars. They had bonding straps everywhere. They even had them on the exaust system.
Has any body reading this ever tried improving your grounds? If so did you notice any improvement?
Kattracker |
Bullet
| | Posted on Thursday, September 04, 2003 - 10:36 pm: |
|
kattracker,
yea ive done alittle grounding from my bed to the frame and to the cab and frame.
but i didnt really see a differance, just wanted to be sure it was grounded well whitch i assume it was since i seen no change.
i didnt fool with the doors.
and what the heck it surly couldnt hurt rite! |
Bigbob
| | Posted on Thursday, September 04, 2003 - 11:27 pm: |
|
YES,just a simple connection of one piece of mini-8 braid between the box and cab reduced swr .3,rf travels on the surface of conductors not through so bonding the hood and box will improve radiation patterns and remove stray capacitance and may lower swr slightly and/or shift it across the band,bonding the frame helps in decreasing or eliminating rf traveling back down the outside of coax braid creating all sorts of weird symptoms,my truck has heavy galvanize so I've yet to experience rust and scale,but by all means do it and just 2 coax braids per panel should be all you need,oh and use stainless fasteners and seal them with rtv. |
RCI 2990
| | Posted on Friday, September 05, 2003 - 1:32 am: |
|
I grounded the you-know-what out of my 1994 pontiac sunbird and i grounded the doors (all since it is a 4 door sedan) trunk lid, hood, alt and seats all to the frame and so far its made a little difference.. But my RCI 2970 still has that annoying whine in the RX end so i think its either the alt. or the fuel pump......... |
Pig040
| | Posted on Friday, September 05, 2003 - 10:34 am: |
|
I had that electric fuel pump whine, I was using a trunk mount, took it to the roof, and got one of those interference reducers, and it went away. The ranger seemed to be most affected by it, I tried other radios in the same car, and the interference was not as pronounced. |
de
| | Posted on Friday, September 05, 2003 - 7:59 pm: |
|
SINCE YOU ARE GROUNDING>>>>>>
Dont forget to ground the exhaust pipe to the chassis. These theings are held in place only by clamps and very frequently there is dirt and all kinds of crud between the exhaust pipe AND the chassis. |
Stepchild
| | Posted on Monday, September 08, 2003 - 2:44 pm: |
|
I have a 2000 Chevy Silverado.I mounted a 4' wilson fiberglass on the front bed rail next to the cab,not only did I not get out very well swr's were about a 3:1.I went thru about 5 or 6 differant antenna's and finally checked the ground and....There's not one,at all,none!The whole bed is isolated from the rest of the truck.Maybe it was a screw-up from the factory,but I could take the volt meter and couldn't find a grounding point no were.So I took about 3' of 12ga stranded copper and went from the ant, mount to the frame.Fixed.As for the rest location,same spot,antenna,102 SS whip/w spring,SWR's,1.1:1 26-28,fuel pump whine cut in half. |
Kattracker
| | Posted on Monday, September 08, 2003 - 7:20 pm: |
|
Stepchild,
A bit of advice. When you mount a antenna as you did, you need a taller antenna. You should have a minimum of 2/3rds of the height above the cab. You are radiating into the metal cab.
Believe me, I had the same setup as you. I e-mailed Firestik and they said my set-up would work okay as long as I used a long enough antenna
To be long enough for the 2/3rd theory, that took a 6 foot antenna.
Glad to hear you still got the swr down, but install a 6 footer on there and there will be a big performance difference.
Kattracker |
|
