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WARNING !!! i was thinking............

B

BOOTY MONSTER

Guest
let me warn you up front......ive had too much spare time today and ive ben thinking . :twisted:

a 102 inch (9 foot) antenna is a 1/4 wave antenna on a mobile . soooo.a 204 inch (18ft) is 1/2 wave and 408 inch (36ft) is full wave . is that correct?

if so.....(if im wrong read no further as it dosnt matter ...lol)

most mobile antennas have coils to reduce the physical length of them . now........if you took the basic design of the open air coil antenna (10-k,mm,coily but mostly 10-k because of reduced wind load and weight)and made it one big series of coils from top to bottom couldnt you make a full wave antenna for mobile use that isnt too tall for most vehicles ? isnt 1/2 better than 1/4 ?5/8 better than 1/2 ? and full wave better than 5/8 ? the bigger the antenna the stronger the signal ?(assuming its tuned to the correct band)

im sure theres got to be something wrong with doing it or somebody would be making them . :shock: :shock:
 

if it was that easy, then there would already be full wave mobile antennas out there that was feasible to have on the mobile. the antenna gods will come in and speak there minds here shortly.

Dont worry, I have pondered on the same thing!!
 
Don't them 4 foot firesticks supposedly be 5/8 wave Ann Tina's?

end fed full wave antennas have a serious matching problem to your 50 ohm coax and radio, and are not better. Only if it was a full wave loop antenna, but you would still have to match it and it would not work well all coiled up.

Think of it like a sail on a sail boat, with the sail all folded up.
 
the reason you dont see it as there is hardly any gain after 5/8 wave. material\ packaging\ weight outweight the small gains. 5/8 usually is usally the best compromse for angle of takeoff as well.
 
BOOTY MONSTER said:
....if you took the basic design of the open air coil antenna (10-k,mm,coily but mostly 10-k because of reduced wind load and weight)and made it one big series of coils from top to bottom couldnt you make a full wave antenna for mobile use that isnt too tall for most vehicles ? isnt 1/2 better than 1/4 ?5/8 better than 1/2 ? and full wave better than 5/8 ? the bigger the antenna the stronger the signal ?(assuming its tuned to the correct band)...
Click to expand...

Well, there is no real advantage to a full-wave antenna. In fact, you will notice that there are no full-wave antenna designs around.

Without getting into a lot of math, full-wave antennas don't work well.

In theory "quarter-wave" antennas actually act like a half-wave. A half wave works pretty well, and a 5/8-wave is generally accepted as the highest gain single element antenna.

With any of these, if you use loading coils to physically shorten the antenna you lose performance. The shorter you make it, the less signal--both receive and transmit.

If you "stack" elements into an array you can increase performance. But if you shorten the array element with loading coils you lose performance.

So, having made a short story long--A. Full-Wave antennas are not a good idea, and B. physically shortening an antenna with loading coils is a compromise where we trade performance for convenience (like not scraping it off the vehicle in drive-throughs).

Now for a base station there are several antenna array designs that can punch up your signal and still maintain a good omni pattern. Of course, for 11 meters they are not going to be small. For any band they are also more complicated to build and tune.

Dave_W6DPS
 
The higher wavelength antenna's are only better performers if they are PHYSICALLY 1/2, 3/4 wavelengths long etc. If you took a full wavelength of stainless rod and wound it into a coil to shorten it you have increased the losses.The antenna becomes shorter (why not use a shorter one to begin with) and you now have coil losses that you did not have before with a regular 1/4 wave antenna.The only full wavelength antennas that are common and work well are full wave loops but they are kind of hard to run mobile with. ;)
 
BOOTY MONSTER said:
let me warn you up front......ive had too much spare time today and ive ben thinking . :twisted:

a 102 inch (9 foot) antenna is a 1/4 wave antenna on a mobile . soooo.a 204 inch (18ft) is 1/2 wave and 408 inch (36ft) is full wave . is that correct?

if so.....(if im wrong read no further as it dosnt matter ...lol
_____________________________________________________

Have you given any thought to a quad :roll:

Mike, aka. Hook and myself and another guy believed he used
the handle Mag Mount all ran Imax 2000s on our trucks.

Was kind of a different experiment :shock:

Speaking for myself I received some interesting looks, also
a nice warning from the TDPS... aka.Highway Patrol 8)

Regards,
John
Click to expand...
 
my caculator is fine....
i just didnt use it..i relied on my brain and it lied to me

or maybe it was the 3 whisky sours ????
 

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