High swr

kor b is right,i've always used coax for my grounds..:smt017..thats old school way

 

My 04 379 has factory grounding for the mirror brackets, to the chassis. When I checked mine it has no resistence from bracket to frame. I would imagine yours would be the same. I did have high swr issues when I installed my new stryker. I ended up having to run a new coax and I put a k40 with it instead of my usual 4ft fiberglass. The k40 still required a lot of trimming to get my swr down.

 

Learn how too tune your antenna system... Here is a link to a world of info including how to tune your system.... http://www.firestik.com/Tech_Docs.htm
In short if channel 40 is higher than channel 1 then your antenna is too long, If you have an adjustable antenna shorten it, if it's not then trim about 1/8 to 1/4 inch at a time to get the SWR on channel 40 down. once you get it close to channel 1's reading then check channel 20... Read up on tuning the system before you go cutting any thing off.

http://www.firestik.com/Tech_Docs.htm

 

You've just experienced (and thoughtfully reported for our other users here) how physical length can affect an antenna's bandwidth. The shorter your antenna is (at resonance -- a/k/a correctly tuned) the narrower will be your "VSWR bandwidth". Like, f'r instance, that at ch 29 you've got 1.3:1, but as far away as you can get at each end of the 40 CB channels, the SWR is measurably higher.

The way to reduce the "ideal" CB antenna length of ~108 inches is by converting some of the physical length into a loading coil. That coil "loads" the transmitter by substituting some inductive reactance (it's what coils in series typically do) to the relatively short straight whip. Not so surprisingly, the antenna's performance will be worse than a longer antenna because the only part of the antenna that radiates is....wait for it..... the straight whip. Without the coil, that short whip would have such teensy "radiation resistance" -- think of it as a two-stroke motorcycle running with no muffler or exhaust pipe. So even though that CB puts out 4 watts (wink, wink), the only part of the antenna that's spewing it out onto the "airwaves" is that whip. And the more coil there is, the closer you have to stay to the resonant frequency of the entire antenna. The coil works somewhat like a resistor and really doesn't radiate.

So even though your Li'l Wil can be tuned to some point in the 11 Meter band, it may not cover all of the band. You kinda lucked out; you likely have more of a metallic counterpoise (like a rooftop) than someone who sticks one onto a ladder rack of a post that doesn't have as much horizontal metal at the level of the feedpoint (or really close, like in a magmount). BTW, that's why ladder racks often don't work as well as a mounting point as a hole through the roof just 5 inches lower than the rack.

And keep in mind that the more of the antenna that is simulated by coil value, the closer it becomes to being a dummy load. Put a dummy load on the antenna end of the coax and check the VWSR, and it'll be under 1.1:1 on any frequency for which the dummy load is designed. Won't talk across the median, but by golly, the VWSR will be darn near perfect

73

 

Well stated handlebar.....thanks!

 

Aww, gawrsh........y'all are gonna make me blush And thanks for the vote of confidence


As it was way late when I posted, please replace my fingergraphical errors of "VWSR" with "VSWR". Or just "SWR" as it's usually referred to.

But I digress. I do that a lot; I'm old. But I digress.....

73