Freq Wavelength Question.
 

Hi all,

I've been away from ham radio for quite some time, and I am looking to
get my ht up and running. I want to make a J-pole.

Although I have found some plans to do so, I was looking more for the
science behind it.

I see that the stub is 1/4 wave and the other side is 1/2 or 3/4.

I forget the formula to find the wavelength. Was it the freq divided
by 468 or 234?


any help would be great.

kb2tfa

Freq Wavelength Question.
 

See BuxCom at URL:
http://www.commparts.com/antutorial.htm#2mjpole

Also URL:
http://www.cmara.org/N1WAS1.htm


wrote in message
oups.com...
Hi all,

I've been away from ham radio for quite some time, and I am looking to
get my ht up and running. I want to make a J-pole.

Although I have found some plans to do so, I was looking more for the
science behind it.

I see that the stub is 1/4 wave and the other side is 1/2 or 3/4.

I forget the formula to find the wavelength. Was it the freq divided
by 468 or 234?


any help would be great.

kb2tfa

Freq Wavelength Question.
 

wrote in message
oups.com...
Hi all,

I've been away from ham radio for quite some time, and I am looking to
get my ht up and running. I want to make a J-pole.

Although I have found some plans to do so, I was looking more for the
science behind it.

I see that the stub is 1/4 wave and the other side is 1/2 or 3/4.

I forget the formula to find the wavelength. Was it the freq divided
by 468 or 234?


any help would be great.

kb2tfa

Try looking in wikipedia for Wavelength.

Freq Wavelength Question.
 

wrote:
I forget the formula to find the wavelength. Was it the freq divided
by 468 or 234?

Wavelength is 984 divided by the frequency. 468/f is the
length of a 1/2WL dipole and 234/f is the length of a
1/4WL monopole both taking end effects into account.
--
73, Cecil http://www.w5dxp.com

Freq Wavelength Question.
 

"fergus" wrote in message
...
On Sat, 17 Feb 2007 20:25:07 GMT, Cecil Moore
wrote:

wrote:
I forget the formula to find the wavelength. Was it the freq divided
by 468 or 234?

Wavelength is 984 divided by the frequency. 468/f is the
length of a 1/2WL dipole and 234/f is the length of a
1/4WL monopole both taking end effects into account.

I thought wavelength was speed of light divided by frequency. ie. 3 x
10^8/freq. Or is the 984 in non SI units?


--

Fergus

no..in US they have strange formulas involving feets and inches... (sigh)
nothing to do with established SI

cheers,

Freq Wavelength Question.
 

On 17 Feb, 12:49, "christine" wrote:
"fergus" wrote in message

...





On Sat, 17 Feb 2007 20:25:07 GMT, Cecil Moore
wrote:

wrote:
I forget the formula to find the wavelength. Was it the freq divided
by 468 or 234?

Wavelength is 984 divided by the frequency. 468/f is the
length of a 1/2WL dipole and 234/f is the length of a
1/4WL monopole both taking end effects into account.

I thought wavelength was speed of light divided by frequency. ie. 3 x
10^8/freq. Or is the 984 in non SI units?

--

Fergus

no..in US they have strange formulas involving feets and inches... (sigh)
nothing to do with established SI

cheers,- Hide quoted text -

- Show quoted text -

Christine,
when I was young I went to the tool room in East London and asked
for 1 inch round by 6 foot and I was admonished up and down dale for
using the measurement inches. I went back to my lathe and worked it
out all again.
At the tool room I asked for 25mm by 2 metres length of steel only to
find out it only came in six foot lengths! Go to the top of the hill
in Greenwich park at the old observatory and on the wall you will see
examples of lengths from the old days so it was you that started this
mess.
By the way we don't have dual carrageways over here either and we
drive on the other side of the road. I understand Sweden has changed
over now, cars changed over on Sunday and trucks changed over the
following day. That week end is still known as black Sunday I
understand.
Art
on the other side of the pond

Freq Wavelength Question.
 

On Sat, 17 Feb 2007 22:49:46 +0200, "christine"
wrote:

no..in US they have strange formulas involving feets and inches... (sigh)
nothing to do with established SI

We also inherited the speed of light as 1.8x10^14 Furlongs per
Fortnight.

73's
Richard Clark, KB7QHC

Freq Wavelength Question.
 

On Sat, 17 Feb 2007 13:27:19 -0800, Richard Clark
wrote:

1.8x10^14 Furlongs
actually
1.8x10^12 Furlongs per fortnight

73's
Richard Clark, KB7QHC

Freq Wavelength Question.
 

fergus wrote:
I thought wavelength was speed of light divided by frequency. ie. 3 x
10^8/freq. Or is the 984 in non SI units?

It's actually 983.572 and it's in English units
based on the "standard" length of the foot of
one of the British kings.
--
73, Cecil http://www.w5dxp.com

Freq Wavelength Question.
 

christine wrote:
no..in US they have strange formulas involving feets and inches...

Strange? - It's the *English* system that we
adopted from our Mother Country.
--
73, Cecil http://www.w5dxp.com

Freq Wavelength Question.
 

art wrote:
when I was young I went to the tool room in East London and asked
for 1 inch round by 6 foot and I was admonished up and down dale for
using the measurement inches.

Did you remind them that the inch was based on
the length of a thumb joint of an *ENGLISH* King?
--
73, Cecil http://www.w5dxp.com

Freq Wavelength Question.
 

So what does this translate to , in Fathoms per
milleniam ? (something akin to exponetional light
years??) :)

Richard Clark wrote:
On Sat, 17 Feb 2007 13:27:19 -0800, Richard Clark
wrote:

1.8x10^14 Furlongs
actually
1.8x10^12 Furlongs per fortnight

73's
Richard Clark, KB7QHC

Freq Wavelength Question.
 

On 17 Feb, 14:58, Cecil Moore wrote:
art wrote:
when I was young I went to the tool room in East London and asked
for 1 inch round by 6 foot and I was admonished up and down dale for
using the measurement inches.

Did you remind them that the inch was based on
the length of a thumb joint of an *ENGLISH* King?
--
73, Cecil http://www.w5dxp.com

Yup, that is what is on the wall i.e. a foot, a yard e.t.c so that
when there is a dispute in commerce one then goes to the wall and
compare to the standard. As for the King it may have been Henry the
Eight since he liked to hunt on the north (other )side of the river
which was called The Isle Of Dogs but now it is probably named Canary
wharf or something like that.Anne Boleyn lived a couple of miles away
so maybe that is how she met the King. The observatory which is along
side the meridian line at Greenwich was abandoned when London was
electrified which thus disturbed the heavens.
It was also at the northside of the river of this point that most of
the prisoners/convicts left for America to serve their sentences .
After the revolution the prisoners/convicts had to go to Australia to
serve their sentences. After a few years they had to scour the prisons
for women to send to Australia so the men became settlers.So Cecil you
could easily be an Aussie if your ancesters timed things right or you
may not be even around if you were related to Cardinal Moore but don't
lose your head over it like he did.
Art