Antenna Length Fomula-Wanted
 

DF,

Wondering when you were going to say something!!!

Burr
I am a member of your group

BURR,
=2E
" I'm old, tired, lazy and forgetful. " - Arn't We All !
[ Or, At Least Hope To Be Some Day . . . ]
=2E
Yes as always - I am shamelessly promoting (whor*** for)
the Shortwave Listener (SWL) Antenna eGroup on YAHOO !
http://groups.yahoo.com/group/=ADShortwave-SWL-Antenna/
=2E
be the best that your can be - enjoy a full life ~ RHF
=2E . . . .

On Sun, 10 Apr 2005 15:45:35 -0400, dxAce
wrote:



-=jd=- wrote:

On Sun 10 Apr 2005 01:58:30p, dxAce wrote in
message :



David wrote:

On Sun, 10 Apr 2005 13:04:13 -0400, dxAce
wrote:



Brian Hill wrote:

"dxAce" wrote in message
...


Brian Hill wrote:

"Don Forsling" wrote in message
...
Yes, I'm iold, tired, lazy and forgetful. That said, can
someone
remind
me
of the formula for calculating the length of a full-wave
antenna wire
if
the
frequency is known (think whip and a frequency of 160.890
mhz).

Your ant would be 2.9088196904717508856983031885139. So about 2
15/16 or
so
inches. I wouldn't recamend a dipole config. LOL!!!

Are you sure about that length? A dipole at 144 MHz is much, much
larger
than
that, so something at 160 MHz or so isn't going to be that much
smaller.

dxAce
Michigan
USA



I don't know what the logistics of VHF and above would be but the
math says it's so. I'll have to refer to my ARRL handbook. I'm a HF
guy and the math works for that spectrum.

A half wavelength dipole for 160.890 MHz would be be right about 3.06
feet long.

This is found by dividing 492 by the frequency in MHz.

dxAce
Michigan
USA


Meters times megaHertz equals 300.

300 what?

dxAce
Michigan
USA



I think he mis-typed and meant to say, "3 Meters times 100 megaHertz equals
300 meterHertz."

I have no idea what he was trying to say!

dxAce
Michigan
USA

Man, y'all are ****in' dense. Would you believe Arnie Coro?

''...for example, let's say you want to pick up Radio Havana Cuba's
ever popular 9820 kiloHertz frequency... First let's calculate 9820
kiloHertz 's wavelength... easy too... Wavelength in meters, equals
the constant 300, divided by the frequency in megaHerz... which is 300
divided by 9.820, and that equals... let's see 30.54 meters
wavelength...''

Brian Hill wrote:
"dxAce" wrote in message
...


Brian Hill wrote:


"Don Forsling" wrote in message
...

Yes, I'm iold, tired, lazy and forgetful. That said, can someone

remind

me

of the formula for calculating the length of a full-wave antenna wire

if

the

frequency is known (think whip and a frequency of 160.890 mhz).

Your ant would be 2.9088196904717508856983031885139. So about 2 15/16 or

so

inches. I wouldn't recamend a dipole config. LOL!!!

Are you sure about that length? A dipole at 144 MHz is much, much larger

than

that, so something at 160 MHz or so isn't going to be that much smaller.

dxAce
Michigan
USA




I don't know what the logistics of VHF and above would be but the math says
it's so. I'll have to refer to my ARRL handbook. I'm a HF guy and the math
works for that spectrum.

B.H.


At 160 MHz the halfwave length would be 2.9 feet.

David - " Would you believe Arnie Coro ? "

He's right for a half wave. The guy asked for a full wave though. Just
double it.

"dxAce" wrote in message
...


Brian Hill wrote:

"Don Forsling" wrote in message
...
Yes, I'm iold, tired, lazy and forgetful. That said, can someone
remind
me
of the formula for calculating the length of a full-wave antenna wire
if
the
frequency is known (think whip and a frequency of 160.890 mhz).

Your ant would be 2.9088196904717508856983031885139. So about 2 15/16 or
so
inches. I wouldn't recamend a dipole config. LOL!!!

Are you sure about that length? A dipole at 144 MHz is much, much larger
than
that, so something at 160 MHz or so isn't going to be that much smaller.

dxAce
Michigan
USA

Use 492 if you want theoretically correct length. 468 takes into account end
effects, ect.

"Brian Hill" wrote in message
...

"dxAce" wrote in message
...


Brian Hill wrote:

"dxAce" wrote in message
...


Brian Hill wrote:

"Don Forsling" wrote in message
...
Yes, I'm iold, tired, lazy and forgetful. That said, can
someone
remind
me
of the formula for calculating the length of a full-wave antenna
wire
if
the
frequency is known (think whip and a frequency of 160.890 mhz).

Your ant would be 2.9088196904717508856983031885139. So about 2
15/16 or
so
inches. I wouldn't recamend a dipole config. LOL!!!

Are you sure about that length? A dipole at 144 MHz is much, much
larger
than
that, so something at 160 MHz or so isn't going to be that much
smaller.

dxAce
Michigan
USA



I don't know what the logistics of VHF and above would be but the math
says
it's so. I'll have to refer to my ARRL handbook. I'm a HF guy and the
math
works for that spectrum.

A half wavelength dipole for 160.890 MHz would be be right about 3.06
feet
long.

This is found by dividing 492 by the frequency in MHz.

dxAce
Michigan
USA



Maybe some other math comes into play above a cirtain freq? Your right
because I've owned several ants I have bought for the higher freqs that
are
bigger. 468 is the number you use for figuring SW ants though. I do know
that for sure.

B.H

A meter is a little over three feet.I didn't have to look it up either,I
have always known that.Hey,a few years ago when that married Irish woman
and her hubby were visiting Disneyworld in Florida,I sent them some
gifts to the hotel in Orlando.(Safari Hotel) A couple of the gifts I
sent via UPS was a little bag of Martha White cornmeal and a Southern
Recipe cookbook.I told her on the phone when she gets back home in
Bognor Regis (England) to make some cornbread.After they got back home,I
got an email from her because she didn't have any kitchen measuring
spoons and measuring cups that have the measurments in American
measures.She once got in a spoon fight (almost) with a woman who works
at the cafeteria at the Sainsbury food store over there.The woman
accused her of putting some spoons in the wrong spoon container
thingy.One time she got in a heated arguement with a sales clerk at the
Boots department store over there about some high priced frog (french)
lipstick that she had bought at the Boots department store in Bognor
Regis.She already had used up about half of the lipstick and the
lipstick had broken off in the bottom of the lipstick tube.She went home
and fired off a snail mail letter to the mananger of Boots and she wound
up getting a big apology and some free lipstick too.
cuhulin

468/Freq in Mhz.

Don Forsling wrote:
Yes, I'm iold, tired, lazy and forgetful. That said, can someone remind me
of the formula for calculating the length of a full-wave antenna wire if the
frequency is known (think whip and a frequency of 160.890 mhz).

Sorry to ask about such simple stuff, but your help will be appreciated.'

Thanks,

Don

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

"Iowa--Gateway to Those Big Rectangular States"

On Mon, 11 Apr 2005 04:44:02 -0400, dxAce
wrote:

''...for example, let's say you want to pick up Radio Havana Cuba's
ever popular 9820 kiloHertz frequency... First let's calculate 9820
kiloHertz 's wavelength... easy too... Wavelength in meters, equals
the constant 300, divided by the frequency in megaHerz... which is 300
divided by 9.820, and that equals... let's see 30.54 meters
wavelength...''

So... what did that have to do with your original statement?

dxAce
Michigan
USA

''Meters times MegaHertz equals 300''.

"David" wrote in message
...
On Mon, 11 Apr 2005 04:44:02 -0400, dxAce
wrote:

''...for example, let's say you want to pick up Radio Havana Cuba's
ever popular 9820 kiloHertz frequency... First let's calculate 9820
kiloHertz 's wavelength... easy too... Wavelength in meters, equals
the constant 300, divided by the frequency in megaHerz... which is 300
divided by 9.820, and that equals... let's see 30.54 meters
wavelength...''

So... what did that have to do with your original statement?

dxAce
Michigan
USA

''Meters times MegaHertz equals 300''.



Hello Mr. Meterhertz. How are you today?

B.H.

Yeeeeee Hawwwww!,,,, one little simple question the guy asked and so
many different answers.I replaced a couple of eaves boards on my house
not long ago.Now,if a board is too long,I know what to do with it,but if
that damn board is too short,that is a problem.Say there,Cousin
Anders,don't forget to tell them pretty wimmins over there in Danske
that old Hansom Larry (that's me,y'all wimmins) loves them.
cuhulin

David wrote:

On Mon, 11 Apr 2005 04:44:02 -0400, dxAce
wrote:

''...for example, let's say you want to pick up Radio Havana Cuba's
ever popular 9820 kiloHertz frequency... First let's calculate 9820
kiloHertz 's wavelength... easy too... Wavelength in meters, equals
the constant 300, divided by the frequency in megaHerz... which is 300
divided by 9.820, and that equals... let's see 30.54 meters
wavelength...''

So... what did that have to do with your original statement?

dxAce
Michigan
USA

''Meters times MegaHertz equals 300''.

So if I take 10 meters, multiply it times 10 MHz. and I'll get 300?

You'd better check that obscure math.

dxAce
Michigan
USA

Anders Henriksen wrote:

wavelength [m] = 285/f[MHz] = wavelength = 285/160.89 = 1,771 m

A dipole should normally be half of this lenght: 1,771/2 = 0,886 m, that
would be 2.91 feet. Each leg of the dipole should be 44.3 cm or 1.45 feet.

I am not sure I remember the factor between metres and feet correctly,
but the picture should be clear to all.


HA HA! Didn't take me long to show off my 'tardism... "," should be
replaced by "."

Regards,
Anders Henriksen
oz7ahr, Denmark

RHF wrote:

DF,
.
And the 'original' Question Is (Was) :
" formula for calculating the length of a full-wave antenna wire "
.
"How Do I" ? Calculate the Length of Wire I need to build a Wire
Antenna ?
http://groups.yahoo.com/group/Shortw...a/message/2884
.
This webpage does a very good job of providing an answer.
- - - How Do I Find the WaveLength of a Frequency ? - - -
.
GoTo= http://www.radiomods.co.nz/radiomath.html
.
IN THEORY - The Numbers Are :
Meters = 300 Divided by Frequency in MHz
Feet = 984 Divided by Frequency in MHz
Inches = 11,811 Divided by Frequency in MHz.


Not "In theory" but in free space.


IN PRACTICE - {The-Real-World} - The Numbers Are :
Meters = 285 Divided by Frequency in MHz
Feet = 936 Divided by Frequency in MHz
Inches = 11,235 Divided by Frequency in MHz.


This is caused by the propagation delay in the conductor the antenna
is made of. In other words, the wire is measurably slower that free
space. This is speced as the "Propagation Delay" and is stated as a
percentage. Look at the data on Coaxial cable for examples.


Other Questions - Asked-and-Answered :
* How do I find the frequency of a wave length ?
* How do I Calculate the Length of Wire I need to build a Wire
Antenna. ?
[ You must use the following Math to Correctly Cut an Antenna. ]
- One {Full} Wave Length (WL)
- Three-Quarter Wave Length (3/4 WL)
- Five-Eighths Wave Length (5/8 WL)
- One-Half Wave Length (1/2 WL)
- One-Quarter Wave Length (1/4 WL)
- One-Eighth Wave Length (1/8 WL)
.
FULL WAVE LENGTH WIRE (WL) ANTENNA
IN FEET = 936 DIVIDED BY FREQUENCY
.
Plus the Age Old - How Do I Convert :
* Meters-to-Feet ?
* Feet-to-Meters ?
.
.
iane ~ RHF


--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

David wrote:

On Mon, 11 Apr 2005 12:19:14 -0400, dxAce
wrote:



David wrote:

On Mon, 11 Apr 2005 04:44:02 -0400, dxAce
wrote:

''...for example, let's say you want to pick up Radio Havana Cuba's
ever popular 9820 kiloHertz frequency... First let's calculate 9820
kiloHertz 's wavelength... easy too... Wavelength in meters, equals
the constant 300, divided by the frequency in megaHerz... which is 300
divided by 9.820, and that equals... let's see 30.54 meters
wavelength...''

So... what did that have to do with your original statement?

dxAce
Michigan
USA

''Meters times MegaHertz equals 300''.

So if I take 10 meters, multiply it times 10 MHz. and I'll get 300?

You'd better check that obscure math.

dxAce
Michigan
USA

If you know the frequency in megaHertz, divide it into 300 to get the
wavelength in meters.
Jesus ****!! This is goddam kid's stuff from the '50s.

Sure thing 'tard boy... but ''Meters times MegaHertz equals 300''... NOT!

You just keep trying, and please... take your meds!

dxAce
Michigan
USA

Brian Hill wrote:

"David" wrote in message

Jesus ****!! This is goddam kid's stuff from the '50s.


Now that was a terrible thing to say Mr.Meterhertz. I don't think
Stanford.edu would like that kind of talk.

Stanford? Well hell, that sure explains a lot... no wonder he's a scared little
girl.

dxAce
Michigan
USA

So if I take 10 meters, multiply it times 10 MHz. and I'll get 300?

No, but the 10-Meter band is not 10 MHz, either.

Nawww,Cmd Buzz Corey,,, I do things the right way.Measure twice (but in
my case,I measure a bunch of times and even then,once in a great while,I
mess up :{) and cut once.I am not perfect,but almost so.
cuhulin

The Stanford Standard School for Girls.They wouldn't let me "in" All
kidding aside though,I think Standford is a good College.
cuhulin

David wrote:

On Mon, 11 Apr 2005 17:09:32 GMT, "Michael A. Terrell"
wrote:

RHF wrote:

DF,
.
And the 'original' Question Is (Was) :
" formula for calculating the length of a full-wave antenna wire "
.
"How Do I" ? Calculate the Length of Wire I need to build a Wire
Antenna ?
http://groups.yahoo.com/group/Shortw...a/message/2884
.
This webpage does a very good job of providing an answer.
- - - How Do I Find the WaveLength of a Frequency ? - - -
.
GoTo= http://www.radiomods.co.nz/radiomath.html
.
IN THEORY - The Numbers Are :
Meters = 300 Divided by Frequency in MHz
Feet = 984 Divided by Frequency in MHz
Inches = 11,811 Divided by Frequency in MHz.


Not "In theory" but in free space.


IN PRACTICE - {The-Real-World} - The Numbers Are :
Meters = 285 Divided by Frequency in MHz
Feet = 936 Divided by Frequency in MHz
Inches = 11,235 Divided by Frequency in MHz.


This is caused by the propagation delay in the conductor the antenna
is made of. In other words, the wire is measurably slower that free
space. This is speced as the "Propagation Delay" and is stated as a
percentage. Look at the data on Coaxial cable for examples.


Other Questions - Asked-and-Answered :
* How do I find the frequency of a wave length ?
* How do I Calculate the Length of Wire I need to build a Wire
Antenna. ?
[ You must use the following Math to Correctly Cut an Antenna. ]
- One {Full} Wave Length (WL)
- Three-Quarter Wave Length (3/4 WL)
- Five-Eighths Wave Length (5/8 WL)
- One-Half Wave Length (1/2 WL)
- One-Quarter Wave Length (1/4 WL)
- One-Eighth Wave Length (1/8 WL)
.
FULL WAVE LENGTH WIRE (WL) ANTENNA
IN FEET = 936 DIVIDED BY FREQUENCY
.
Plus the Age Old - How Do I Convert :
* Meters-to-Feet ?
* Feet-to-Meters ?
.
.
iane ~ RHF
The wave doesn't travel as fast in a solid conductor and the voltage
reverses sooner (i.e. closer to where it started.)


That's another way to describe propagation delay.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

"dxAce" wrote in message
...


Brian Hill wrote:

"David" wrote in message

Jesus ****!! This is goddam kid's stuff from the '50s.


Now that was a terrible thing to say Mr.Meterhertz. I don't think
Stanford.edu would like that kind of talk.

Stanford? Well hell, that sure explains a lot... no wonder he's a scared
little
girl.

dxAce
Michigan
USA



Yep it sure does. He was planted here by the radical leftist elites.

B.H.

Brian Running wrote:

So if I take 10 meters, multiply it times 10 MHz. and I'll get 300?

No, but the 10-Meter band is not 10 MHz, either.

Of course not...

dxAce
Michigan
USA

wrote in message
...
Yeeeeee Hawwwww!,,,, one little simple question the guy asked and so
many different answers.I replaced a couple of eaves boards on my house
not long ago.Now,if a board is too long,I know what to do with it,but if
that damn board is too short,that is a problem.

You need a board stretcher. On the rare occasions that we need one at work,
we send a laborer or a truck driver to either a dedicated rental company or
a lumber yard. (Some of them also rent out tools.) You should try that
option the next time you need one. I recommend the DeWalt brand, myself.

Amazingly, no one has expressed what units these constants 300 and 984, etc.
represent or the fundamental formula:

wavelength = velocity of propagation/frequency
= velocity (units of length per second)/frequency (cycles
per second or Hertz)
= length per cycle
If the velocity is expressed in meters per second, the wavelength is
expressed in meters, if feet per second then in feet.

In free space, velocity of propagation of radio waves is 300 million metres
per second or 984 million feet per second. When divided by frequency in
millions of cycles per second (MegaHertz), we get the length of one cycle or
wavelength in meters or feet, respectively.

In air, the velocity slows down slightly so a wavelength is slightly
shorter. The coefficient of velocity (or velocity factor) expresses the
fraction the speed is relative to that in free space. In air, it is 99.7%.
In denser media, it is slowed more.

Typically, we don't consider velocity of propagation as the reason for the
approx 95% factor for antenna calculations below 30 MHz but as a convenient
way of accommodating the real-world effects of conductor diameter and
capacitance at the ends on the resonant frequency. It is a rule-of-thumb
factor as a starting point for trimming an antenna for resonance at a
certain frequency - not critical for receiving.

Relative velocity of propagation is important in transmission lines, when
used to set the relative phase at each element of an array of driven antenna
elements, and can be as low as 66% that of free space in coaxial cables
using polyethylene insulation between the inner conductor and the shield.

Thus, at 10 MHz, a wavelength is:
- 30 metres, in free space
- 29.91 metres, in air
- ~ 28.5 metres for a 'full wavelength' resonant antenna (varies with end
effects and conductor diameter)
- 19.79 metres in Belden 8241 (RG-59) coaxial cable.

Regards,

Tom
..
"Michael A. Terrell" wrote in message
...
David wrote:

On Mon, 11 Apr 2005 17:09:32 GMT, "Michael A. Terrell"
wrote:

RHF wrote:

DF,
.
And the 'original' Question Is (Was) :
" formula for calculating the length of a full-wave antenna wire "
.
"How Do I" ? Calculate the Length of Wire I need to build a Wire
Antenna ?
http://groups.yahoo.com/group/Shortw...a/message/2884
.
This webpage does a very good job of providing an answer.
- - - How Do I Find the WaveLength of a Frequency ? - - -
.
GoTo= http://www.radiomods.co.nz/radiomath.html
.
IN THEORY - The Numbers Are :
Meters = 300 Divided by Frequency in MHz
Feet = 984 Divided by Frequency in MHz
Inches = 11,811 Divided by Frequency in MHz.


Not "In theory" but in free space.


IN PRACTICE - {The-Real-World} - The Numbers Are :
Meters = 285 Divided by Frequency in MHz
Feet = 936 Divided by Frequency in MHz
Inches = 11,235 Divided by Frequency in MHz.


This is caused by the propagation delay in the conductor the antenna
is made of. In other words, the wire is measurably slower that free
space. This is speced as the "Propagation Delay" and is stated as a
percentage. Look at the data on Coaxial cable for examples.


Other Questions - Asked-and-Answered :
* How do I find the frequency of a wave length ?
* How do I Calculate the Length of Wire I need to build a Wire
Antenna. ?
[ You must use the following Math to Correctly Cut an Antenna. ]
- One {Full} Wave Length (WL)
- Three-Quarter Wave Length (3/4 WL)
- Five-Eighths Wave Length (5/8 WL)
- One-Half Wave Length (1/2 WL)
- One-Quarter Wave Length (1/4 WL)
- One-Eighth Wave Length (1/8 WL)
.
FULL WAVE LENGTH WIRE (WL) ANTENNA
IN FEET = 936 DIVIDED BY FREQUENCY
.
Plus the Age Old - How Do I Convert :
* Meters-to-Feet ?
* Feet-to-Meters ?
.
.
iane ~ RHF
The wave doesn't travel as fast in a solid conductor and the voltage
reverses sooner (i.e. closer to where it started.)


That's another way to describe propagation delay.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida

Didn't read the "inches". Should have been feet. Right numbers, wrong unit.

"CW" wrote in message
...
He's right for a half wave. The guy asked for a full wave though. Just
double it.

"dxAce" wrote in message
...


Brian Hill wrote:

"Don Forsling" wrote in message
...
Yes, I'm iold, tired, lazy and forgetful. That said, can someone
remind
me
of the formula for calculating the length of a full-wave antenna
wire
if
the
frequency is known (think whip and a frequency of 160.890 mhz).

Your ant would be 2.9088196904717508856983031885139. So about 2 15/16
or
so
inches. I wouldn't recamend a dipole config. LOL!!!

Are you sure about that length? A dipole at 144 MHz is much, much larger
than
that, so something at 160 MHz or so isn't going to be that much smaller.

dxAce
Michigan
USA