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Jerry October 8th 05 02:46 AM

Antenna Length Formula
 
On Fri, 07 Oct 2005 02:33:10 -0400, Al Klein
wrote:

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.


Ah yes, that old nonsense again,

Yes, it is true that you will not damage a receiver with impedance
mismatch, but you will have less signal. Signal budget, system budget,
call it what you may.

And the beat goes on . . . . .

Jerry
ARINC LAXMM


kla1899 October 12th 05 07:25 PM

Antenna Length Formula
 
(Al) wrote in
:

(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


To easy Al click the link

http://mysite.verizon.net/moment_1/s...alculation.htm


--
kla1899



kla1899 October 15th 05 02:53 PM

Antenna Length Formula
 
wrote in
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




Due it's to simple, click the link:

http://mysite.verizon.net/moment_1/s...alculation.htm

put in your frequ hit Calculate "DUNE"

--
kla1899



Brian Aase October 17th 05 02:38 AM

Antenna Length Formula
 
Does this (or should it?) include any correction for propagation
factor?
---
On Sat, 15 Oct 2005 13:53:29 GMT, kla1899 wrote:

wrote in
oups.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.

cut

Due it's to simple, click the link:

http://mysite.verizon.net/moment_1/s...alculation.htm

put in your frequ hit Calculate "DUNE"



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Al Klein October 17th 05 02:51 AM

Antenna Length Formula
 
On 17 Oct 2005 01:38:34 GMT, Brian Aase said in
rec.radio.scanner:

Does this (or should it?) include any correction for propagation
factor?


For a whip? Not unless you're running a ground wire alongside it. Did
you mean correction for end effect? (The prop factor is affected
mainly by the capacitance between conductors along their length.)


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