Antenna Coil Question

Coils help make the antenna the proper wave length while allowing a shorter overall height.

 

That is correct.

 

And plus, when you surround the coil with a see-through plastic casing and fill it with some "cooling" liquid, then tell a driver it will allow them to talk to drivers on other planets, the driver will believe it... and will pay three times the money.

 

You are right on target. The ONLY thing multiple coils do is----sell antennas to gullible drivers who think that "BOY! THAT THING LOOKS MEAN AND GETS OUT TO THE MOON!"

YOU know your stuff! Can't fool you! Loading coils do one MAIN function: shorten the antenna so you can get under stuff. They DO NOT make the antenna "get out" better. IN fact, they cause R E S I S T A N C E in the system that can be used by the builder in several ways:

1. Make it look BIG AND BAD as it would "get out better"! NOT!

2. Increase the broad-band capability (in some cases) so it appears that
it "gits out better AND covers more of those coveted 'extra channels'"
(The trade-off is lower performance that the builder hopes you won't
notice because the thing just seems to do so well! Placebo effect.

3. Sell antennas to unsuspecting drivers.

4. The most obvious one: shorten the antenna (MAIN function).

And stay away from "ground planes"---those little doo-hickeys with the short "rubbery" thingies sticking out under the coil. They do ABSOLUTELY NOTHING FOR YOUR SIGNAL!! Their REAL name is "capacity hat" and it does NOTHING! ZIP! NADA! They are a RIP OFF!
Stick one on under your coil antenna and watch your SWR go sky high! The technician will then "tune" your "swr'ssssssssssssssssss" by shortening your whip and tell you how great you will do. BULL! A "ground plane" Is part of GROUND!!!! That little thing-a-mabob he put on your antenna and charged you $$ for is PART of the 'HOT" or RADIATING part of the antenna!!!! It has NOTHING to DO with "ground" IT will do
NOTHING for your signal! Except remove $$$ from YOUR pocket and put it into YOURS!!! KER-CHING!!!!!!!!

Gadfly

 

Electrical wave length verse physical.

468 divided by the freq in mhz. make for a 1/2 wave dipole in free space.

ie: For channel 19 = 27.185 mhz the length of a half wave dipole antenna would be 17.2 feet.
For mobile vertical antenna we use 1/4 wave length, thus we divide 17.2 by 2 and the antenna would be 8.6 feet tall. The coil allows us to physically shorten the antenna. If you were to take the coil apart and stretch the wire out the length would be aprox 8.6 foot (Minus the whip)

Sorry for the technical overload.

Short answer.....coil shortens the antenna

Brent