want to do it myself

Again you guys are thinking too much into this, this is CB mobile and not microwaves where it is critical to take in account these things.

Where does the radio see 20 ohms?

On the feedline?

Seriously?

 

I've never seen one in a CB shop or truckstop, although they're probably available somewhere else.

 

Since the feedpoint impedance only occurs every 180 degrees in the cable, it drastically changes between those two points with a quarter-wave impedance transformer occuring at the halfway point, and depending where you cut the cable you can easily see 20 ohms or 75 depending on the feedpoint impedance. The odds for a random length cable presenting 50 ohms to the transmitter are fairly astronomical.

 

Look Rabbi, you are making this into a BIG issue when it isn't.

Why?

Because the frequency dictates the tolerances of the system that is being used to communicate. As you may not seem to get, we are not talking about super high performance equipment, but rather mass produced copy cats of the same circuits with small deviations. AND at the 11 meters, the need for tight tolerances are not required for communications.

For the AVERAGE user, it does not matter, no one will notice the difference between 11 or 13 or 18 feet in a mobile application unless other variables are corrected for maximum efficiency at that given band.

As I said, phasing comes into play more at higher frequencies than it does in the HF region.

 

This has nothing to do with phasing multiple antennas but it has everything to do with keeping your mosfets from self-destructing.

 

Every thread it always ends up with words my little brain don't comprehend well. I wish someone would be very generous and explain how to get the best setup you can in really over simplified jargon and what needs to be done to fix abc so your results are good.

 

The simplest thing to do is follow the hams advice and use any length of cable you choose and purchase an antenna tuner and velcro it to your dashboard and life will be simple and wonderful.

 

Follow the advice given by Ridgeline he generally keeps things simple realizing that the mojority of us are not Hams and are just trying to setup an efficient mobile cb/ antenna combo that will work good.

 

You may also want to associate with a reputable cb shop/ tech and allow them to guide you in your installments efforts, in most cases they are competent in what they do, not all of them are hacks, and if you research previous threads on this forum and others you will find some valuable information.

 

Reputable is a relative term.
Reputable among the 2-mile crowd? Reputable among the Ten Mile crowd? Reputable among the 30-mile crowd?
Reputable among the Channel 28 crowd? Reputable among the Channel 6 crowd?
A technician is judged based on the performance of his customers radios.
Mike has a reputation for being one of the best technicians in the country,
but his tune isn't exactly known for being idiot-proof as shown in this video.