Swr problem

What kind of truck? And are you an O/O or a company driver?

 

Something is not right with that antenna setup.. Moving should not affect the swr like that. My thought is the wind is somehow ungrounding the antenna.. Are all the moveable parts of the antenna tight?

 

Clarification please...

Were you rolling down the road at highways speeds when you got the SWR reading of "2"?

If so...thats normal (depending on antenna type, mounting location, and whats near it...such as stacks)

 

Ground the antenna...but don't run a single length of wire down to the chassis...it should be done in sections.

For example....from the antenna mount to the top of the door hinge (for the "piano hinge" type)...then another section of wire from the bottom of the door hinge down to the chassis.

Folks on here have argued with me over the necessity of the "sections"...and my answer to that is...I've hooked up a lot of radios ranging in power from 5 to 500 watts (the more power, the more finicky the system will be) and I've never had antenna ground issues when doing it in sections...but I have had problems with a single length of wire (erratic SWR)

Put simply...if the ground wire is too long...it starts thinking it is an antenna.

 

You are right on the sections......(there is a technical explanation for it that I will leave to those more qualified) Finding the braided ground strap, which is the best to use, is the hardest part.

 

If the ground runs are short enough then you can actually use regular 10 gugage wire. I have done this for short runs of a couple inches with no ill effects.