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Message |
    
Skifly
New member
Username: Skifly
Post Number: 5
Registered: 10-2004
| | Posted on Saturday, November 06, 2004 - 7:57 pm: | 
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Hi,
Anyone have experience with this kind of truck? I got a Magnum S3 and at the same time I changed trucks, My last truck a KW cab over With 13' 6" enclosed Carhaul trailer, good numbers.
This truck a Freightliner cab over same trailer configuration
The KW had mounts on the side of the cab rails the Freightliner factory mirror mounts.
I cant get below 1.6:1 on Freightliner on CH 20,
RF limited says get below 1.5:1.(4'Firesticks RG 59A/U cophased cable)
BUT when moving down the road it gets better,
I ground strapped the mounts to the cab from mount to door to hinge to cab and has a good ground to frame.
The truck has a aluminum cab but a large fiberglass air dam.
Any info would be apreciated
Thanks
Mark |
Crafter
Senior Member
Username: Crafter
Post Number: 1031
Registered: 12-2002
| | Posted on Saturday, November 06, 2004 - 10:50 pm: |
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Thats always been a problem with the cabs, is grounding but sounds like ur on the right track. |
The ELCO guy (Unregistered Guest)
Unregistered guest
| | Posted on Sunday, November 07, 2004 - 8:43 am: |
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OK try this....
There may be several problems. Your antenna clamp may be clamped onto a 'Painted' surface and not making a good bare metal to bare metal contact.
OR, the mount attaching your mirror to the truck may NOT be metal to metal but rather painted surface to painted surface.
OR your cab and chassis may NOT be a complete ground unit for RF.
Solutions:
Or should I say possible solutions.
Suggestion 1, mark where you will bolt the antenna bracket on the mirror bracket. Get some sand paper and with care sandpaper off all the paint on the mirror bracket so that the bracket will mount bare metal to bare metal within the area covered by the bracket.
Suggestion 2, check the mirror bracket to see if the bracket to see if the bracket is a bare metal to bare metal contact. IF not mark out and do as you did in suggestion 1 above for the mirror bracket so that you will have a bare metal to bare metal to bare metal on the antenna bracket on at least ONE of the mounting points.
Suggestion 3, get a Volt Ohm Meter and set it to read resistance. Use the antenna clamp as the ground for the meter and touch the door, the cab, the chassis and other metal parts of the truck with the positive red probe. IF the meter does NOT SHOW very low reisitance (needle barely moves you know that those metal parts are NOT gouunded very well. Get some coax shielding and jumper all the non grounded parts to each other AND TO the chassis (discretely of course). This will make the entire truck body and cab one complete electrical unit.
IF you have a fiberglass cab you will probably have to discretely run a counterpoise to act as an artificial ground. A counterpoise is a length of wire that is a quarter wave length long that acts as an electrical ground. Give it a try just hanging there. If it works then just discretely run it into the fiberglass cab. Recheck after final install.
OR if you have one of those big steel load stops, or whatever it is called, that stops a load from sliding into the cab becomming your second seat then you might try mounting the antenna on top of this part of the truck. If I remember this safety device is welded to the chassis.
Best of luck
That ol Elco guy.. |
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