Mobile Which mobile vehicle model here performs the best?

[The DB]

Is the ground plane effect being compromised because the antenna is not in the center of the roof, or is the bed of the truck providing a ground plane surface?

A lot of (if not most) people assume the antenna works with both the bed and cab of a pick up truck. However, when I model a pick up with separate bed and cab (connected by a frame below both) the model seems to treat the bed and cab as two separate units. I'm not saying their isn't any interaction between the two, but the modeling shows any interaction is minor at best. The bed and cab have very little influence on an antenna connected to the other, even if it is right at the back of the cab, or a front corner of the bed where the antenna is right next to the cab.

I don't know of any experiment on an actual pick up truck that confirms/deny's this, so take it as you will.


The DB

 

[Recon]

A lot of (if not most) people assume the antenna works with both the bed and cab of a pick up truck. However, when I model a pick up with separate bed and cab (connected by a frame below both) the model seems to treat the bed and cab as two separate units. I'm not saying their isn't any interaction between the two, but the modeling shows any interaction is minor at best. The bed and cab have very little influence on an antenna connected to the other, even if it is right at the back of the cab, or a front corner of the bed where the antenna is right next to the cab.

I don't know of any experiment on an actual pick up truck that confirms/deny's this, so take it as you will.


The DB

Thank you for taking time to reply and explain. I had a gut-feeling that the bed and cab do not pair-up to make a good ground plane platform. As it is now where the antenna is mounted on my truck, there is no ground plane platform or do I have one-half of a ground plane platform? If the radio can transmit and receive within a three to five mile distance, I'll accept it. Thanks again!

 

[Highway Man]

My upcoming (trial and error) experiment for my 2019 F-350 Crew Cab with a 6'-6" box will be as follows.
I found a new 4' Top-loaded Fiberglass Firestick antenna which has been stored for about five years and I'm waiting for the Breedlove Stake Pocket Mount and the coax connector (P/N 205) to arrive. The plan is to install / mount the antenna on the front passenger side stake pocket. I am estimating that only about 29" of the 48" antenna will be above the roof which is probably not a good idea, but I'll see what happens. I have a rubber bed mat in the bed of the truck and I'm wondering if that will affect the SWR, receive and transmit.

passenger side rear corner of truck bed works fine. "semi" directional to front left.
I've had better results there than directly behind cab. Second best only to top dead center on roof.. IMO

 

[W4KVW]

I did not want to start a new thread with this question. There are numerous conversations and comments relating to mobile CB antennas, but how about the length of coax for base or mobile? If my (real old) memory is intact, I remember something about the recommended / ideal coax length should be in 9' increments. We use to buy mag-mount and/or gutter-clip antennas and I think a 18' coax was attached. Lately, I've noticed a few antenna manufacturers are stating / recommending to use either less than 12' or less than 15' of coax for a mobile installation. What's up with that?

Coax length is a MYTH.I use many different lengths of coax for antennas & jumpers & no matter what length I use the SWR does NOT change either direction.There are lots of information on the web about it & I have not seen any proof that it matters & since 1965 I have not had an issue.That includes Amateur bands from 160 meters to 440 mhz & everything in between.

SIX-SHOOTER

 

[Highway Man]

Coax length is a MYTH.I use many different lengths of coax for antennas & jumpers & no matter what length I use the SWR does NOT change either direction.There are lots of information on the web about it & I have not seen any proof that it matters & since 1965 I have not had an issue.That includes Amateur bands from 160 meters to 440 mhz & everything in between.

SIX-SHOOTER

you should let the FTCB guy know this because his O Silly Scope makes funny shapes if its not finely tuned to the exact millimeter.
I'm not questioning you just just saying. I don't know so it will cost me extra

 

[BammBamm]

Mine was my 2017 Ram king cab. Had a triple mag mount with a Tram tbc9 antenna on the roof...it hit EVERYTHING but it performed well with a 980ssb and a kl203p. RIP Ram as I totaled it and now drive a 2019 Mitsubishi Outlander sport.