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Don Forsling April 10th 05 05:03 PM

Antenna Length Formula
 
Folks, I'm old, I'm tired, and I'm lazy. I'm also forgetful.

Would someone kindly provide the formula for deterring the length of a
full-wave antenna for a given frequency ( a full-wave whip comes to mind)?
Then, I can do the math. Better yet, I'll give you the frequency and _you_
can do the math. It's 160.890 mHz.

I will never ask this question again. Sorry. Thanks, etc.

Best,
--

------------------------------------------------------------------------------
Don Forsling

"Iowa--Gateway to Those Big Rectangular States"



Ron April 10th 05 05:43 PM

Try this.

http://www.crompton.com/wa3dsp/hamradio/antcalc.html


"Don Forsling" wrote in message
...
Folks, I'm old, I'm tired, and I'm lazy. I'm also forgetful.

Would someone kindly provide the formula for deterring the length of a
full-wave antenna for a given frequency ( a full-wave whip comes to mind)?
Then, I can do the math. Better yet, I'll give you the frequency and
_you_ can do the math. It's 160.890 mHz.

I will never ask this question again. Sorry. Thanks, etc.

Best,
--

------------------------------------------------------------------------------
Don Forsling

"Iowa--Gateway to Those Big Rectangular States"




sean April 11th 05 01:46 AM

234 / frequency in MHz

234/ 160.890 = 1.45 Ft


"Don Forsling" wrote in message
...
Folks, I'm old, I'm tired, and I'm lazy. I'm also forgetful.

Would someone kindly provide the formula for deterring the length of a
full-wave antenna for a given frequency ( a full-wave whip comes to mind)?
Then, I can do the math. Better yet, I'll give you the frequency and

_you_
can do the math. It's 160.890 mHz.

I will never ask this question again. Sorry. Thanks, etc.

Best,
--

--------------------------------------------------------------------------

----
Don Forsling

"Iowa--Gateway to Those Big Rectangular States"





Dale Parfitt April 11th 05 02:06 PM


"sean" wrote in message
...
234 / frequency in MHz

234/ 160.890 = 1.45 Ft

He is asking for the length of a full wave whip- so multiply the above X4.
However, bear in mind that full wave whip will:
1. Be more difficult to feed as its end Z is around 1K Ohm or higher.
2. Have less gain than a 1/4 wave antenna at useful elevation angles.

Dale W4OP



jamoran April 30th 05 03:02 AM

physsics to the rescue
300/frequency in mhz gives length in meters

the 300 comes form the lv=c calculation

using above a 900mhz frequench has wavelength of .3 meters

I prefer to work in metric because everything is base 10 as in 100
centimeters in a meter but there are not 10 inches in a foot and not
1000 inches in a mile......math is easier in metric

Don Forsling wrote:

Folks, I'm old, I'm tired, and I'm lazy. I'm also forgetful.

Would someone kindly provide the formula for deterring the length of a
full-wave antenna for a given frequency ( a full-wave whip comes to mind)?
Then, I can do the math. Better yet, I'll give you the frequency and _you_
can do the math. It's 160.890 mHz.

I will never ask this question again. Sorry. Thanks, etc.

Best,


Al October 5th 05 08:09 PM

Antenna Length Formula
 
(Don Forsling) wrote in
:

Folks, I'm old, I'm tired, and I'm lazy. I'm also forgetful.

Would someone kindly provide the formula for deterring the length of a
full-wave antenna for a given frequency ( a full-wave whip comes to
mind)? Then, I can do the math. Better yet, I'll give you the frequency
and _you_ can do the math. It's 160.890 mHz.

I will never ask this question again. Sorry. Thanks, etc.

Best,


Once upon a time when I was taught physics, I was told that full wave lenght should be
calculated by dividing the speed of a light (299820km/s) with the frequency(in MHz)/1000,
so for full wave dipole it should be 299820*160.89/1000=1.864m, for half-wave dipole
divide the result by two.

Albert

[email protected] October 6th 05 05:27 PM

Antenna Length Formula
 
2808 divided by the frequency in MHz will give
the length in inches for a 1/4 whip. Roughly
17.5 inches. Times 4 will give you a full wave.

Can't understand why you would want a full wave
whip. The impedence would be very high and
would not match a scanner or two way radio. 1/4,
5/8, or 3/4 in much easier to match.

Jim, K5DIE/9


Al wrote:
(Don Forsling) wrote in
:

Folks, I'm old, I'm tired, and I'm lazy. I'm also forgetful.

Would someone kindly provide the formula for deterring the length of a
full-wave antenna for a given frequency ( a full-wave whip comes to
mind)? Then, I can do the math. Better yet, I'll give you the frequency
and _you_ can do the math. It's 160.890 mHz.

I will never ask this question again. Sorry. Thanks, etc.

Best,


Once upon a time when I was taught physics, I was told that full wave lenght should be
calculated by dividing the speed of a light (299820km/s) with the frequency(in MHz)/1000,
so for full wave dipole it should be 299820*160.89/1000=1.864m, for half-wave dipole
divide the result by two.

Albert



James Robinson October 6th 05 06:26 PM

Antenna Length Formula
 
(Al) wrote:

Once upon a time when I was taught physics, I was told that full wave
lenght should be calculated by dividing the speed of a light
(299820km/s) with the frequency(in MHz)/1000, so for full wave dipole
it should be 299820*160.89/1000=1.864m, for half-wave dipole divide
the result by two.


You need to reduce that number by 5% for typical vertical whip antenna
calculations.

mikeFNB October 6th 05 06:34 PM

Antenna Length Formula
 
if it's for RX the imp matters not

mike

wrote in message
ups.com...
2808 divided by the frequency in MHz will give
the length in inches for a 1/4 whip. Roughly
17.5 inches. Times 4 will give you a full wave.

Can't understand why you would want a full wave
whip. The impedence would be very high and
would not match a scanner or two way radio. 1/4,
5/8, or 3/4 in much easier to match.

Jim, K5DIE/9


Al wrote:
(Don Forsling) wrote in
:

Folks, I'm old, I'm tired, and I'm lazy. I'm also forgetful.

Would someone kindly provide the formula for deterring the length of a
full-wave antenna for a given frequency ( a full-wave whip comes to
mind)? Then, I can do the math. Better yet, I'll give you the frequency
and _you_ can do the math. It's 160.890 mHz.

I will never ask this question again. Sorry. Thanks, etc.

Best,


Once upon a time when I was taught physics, I was told that full wave
lenght should be
calculated by dividing the speed of a light (299820km/s) with the
frequency(in MHz)/1000,
so for full wave dipole it should be 299820*160.89/1000=1.864m, for
half-wave dipole
divide the result by two.

Albert





Al Klein October 7th 05 07:33 AM

Antenna Length Formula
 
On Thu, 06 Oct 2005 17:34:46 GMT, "mikeFNB"
said in rec.radio.scanner:

if it's for RX the imp matters not


That old nonsense again?

SWR isn't directional. Of course impendence matters, unless you don't
care how much signal you lose between the source and load.


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