New truck cb/antenna issues,why?

How long is the riser?

 

Ridgeline, I see where you got some of the info about the question of what a vehicle represents: a ground plane, a counterpoise, etc. The info came from the famous kObg site that Craig-sez cited in Post #1.

Here are a couple of quotes from that site:

..."A vehicle is not a ground plane, but rather acts like a capacitor between the antenna and the surface under the vehicle which acts as the ground plane...

"...There are a few pundits who are under the misguided belief, that running a braided bonding strap along the frame of a body-on-frame vehicle, bonded every few inches, will drastically improve the less than perfect ground plane a vehicle represents. It won't!...."

The two pertinent and inconsistent phrases from the quotes:

"A vehicle is not a ground plane"

"ground plane a vehicle represents"

No wonder the nomenclature confusion. Even the experts struggle with it. Now I don't feel so bad.

 

I use alan’s site as a central reference source so you guys can read details.

 

Maybe ditch the riser and start over?
I think you might be chasing rabbits trying to improve your antenna system. My philosophy, as far as this, if it's decent to good leave it alone. Your never going to get it perfect due to the known issues regarding mobile installations. It's your time to spend regarding your quest, but much like trying to make a co-phase system work, is the "juice worth the squeeze"?
Carry on Craig and I hope you get where you want to be!

JD

 

Is the 10" riser a functional part of its RF electrical length? If not, perhaps the 102" stinger is a bit short for a true quarter-wave? The antenna analyzer should indicate the situation.

 

@craig_sez just a random thought...........Maybe you have TOO Many ground straps?
I watched a couple of your Youtube vids and it looked like your antenna was in pretty good shape.
When I was running a mail inserting machine years ago, a Pitney Bowes mechanic always stressed, when someone would look to adjust something to make it run better.......If it ain't broke, don't fix it!

JD

 

Quote: "...I clipped it at the very end where threaded piece is attached to the whip..Whip is at full extention and its better on 40 than 1 by a good bit...."


It's my understanding that the RF electrical effect starts at where the antenna's conductive wire is connected to the stinger, and the electrical effect extends to the tip of the antenna, all of which determines its electrical length in regards to resonance and, less precisely, its SWR.

The reason I asked the questions is that any object serving as the point that the antenna stinger is screwed onto and isolated from, which could be a riser pipe, is not included in this electrical length.

One way to interpret your quote above is that the 102" stinger is screwed onto an insulated 10" riser pipe, and that the wire begins at that threaded junction point. If this is the case, then the antenna is electrically at 102", which is shy of a quarter-wave and thus would be better suited for channel 40 than channel 1 because it's too short and should be lengthened by about six inches or so.

But, I probably have misinterpreted the situation and, if so, apologies in advance