On Tue, 08 Nov 2005 12:03:11 -0500, Amos Keag
wrote:

Cecil Moore wrote:

Reg Edwards wrote:

Thank heavens, on the Internet, the English and American lanuages are
drawing closely together. But I am still inclined to draw a
distinction beween Americans and USA citizens. They are different!


And Texans are even more so.

SNIPPED: That great ICON of America, John Wayne of Blessed Memory,
asserted that the residents of Texas were TEXICANS! [Not Americans and
NOT citizens of USA]. How does this impact citizenship??

I believe Texas also used to be its own independent country, the
Republic of Texas. Sam Houston was president. We were called Texians.
(And John Wayne was not a Texian, Texican, Texan or any other
deriviative.)

Bob
k5qwg



Cecil, you opened a bag of Texas Nightcrawlers [Bass bait worms] with
your Texas comment. :-)

AK

Ours is the only state whose
flag is allowed to be flown at an equal height with the
US flag. (Some places around here fly the Texas flag an
inch or so higher than that damned Yankee flag. :-) Texas
was the only state having the legal right to seceed from
the USA during the Civil War. The last battle of the Civil
war was fought near Brownsville, TX and the South won.

Reg, I saw a program on "The Discovery Channel:
Ice Age Columbus: Who Were the First Americans?" It
said, based on the latest arrowhead and tool archaeological
evidence, that America was discovered by sea-going ice-age
Europeans 17,000 years before Columbus made his voyage. It
was asserted that some Native Americans still carry the
genetic markers donated by those early Europeans.

I choose a ladderline length to always feed the antenna at a current node.

"Owen Duffy" wrote in message
...
On Mon, 7 Nov 2005 22:21:35 -0500, "Fred W4JLE"
wrote:

How many hams find a feedline length of 100 Meters acceptable? Lets look
at
a more realistic length of 100 feet and the loss is less than 2 dB at 30
Mhz. The loss is much less on the lower bands. With all due respect, your
example sucks!

BTW, I make your example 2.7dB, not less than 2dB. (Perhaps you labour
under the misaprehension that loss per unit length is a constant in
this situation).

Fred, what you have highlighted is the unstated assumption of some
limit on length. You know enough to choose a length so that the ROT is
true, but does a learner soaking this up know as much?

Owen
--

Amos Keag wrote:
SNIPPED: That great ICON of America, John Wayne of Blessed Memory,
asserted that the residents of Texas were TEXICANS! [Not Americans and
NOT citizens of USA]. How does this impact citizenship??

Some Texans never wanted to join the United States and it
was a close vote back when Texas was an independent country.
Sam Houston was probably the deciding factor. If Texas had
not joined the US, we probably would still have plenty of $60
a gallon oil. (Inside intel as opposed to Intel Inside(R)):
I once worked for Schlumberger and Texas is definitely NOT
out of oil, i.e. Lots of oil is being held in reserve in
cases of arrested development as it is in Florida,
California, and Alaska.)
--
73, Cecil http://www.qsl.net/w5dxp

Fred W4JLE wrote:
I choose a ladderline length to always feed the antenna at a current node.

And because a current node is guaranteed to occur at least
every 1/2WL, an HF feedline need never be longer than 164
feet, Owen's 100 meter feedline notwithstanding. :-)
--
73, Cecil http://www.qsl.net/w5dxp

On Tue, 08 Nov 2005 15:33:01 GMT, Cecil Moore wrote:

Owen Duffy wrote:

Cecil Moore wrote:
If 100m (325 feet) of ladder-line results in 6dB loss, then a more
realistic 75 feet of ladder-line will result in about 1.4 dB of loss.

Close, I make it 2.2dB.

What matched line loss are you using? The wireman says that line
has about 0.2 dB of matched line loss per 100 ft at 30 MHz. According
to the chart in my ARRL Antenna Book, an SWR of 25:1 at the load
would cause about 1.5 dB loss in 75 feet.

I am using Wes's characterisation of Wireman 551. Dan's TLDETAILS prog
or my online calculator ( http://www.vk1od.net/tl/tllce.php ) both use
(slightly different) models derived from Wes's published measurements.

I don't have the ARRL Antenna Book with me at the moment, but I
suspect it is not based on the same Matched Line Loss model, and does
not estimate loss from the actual reflection coefficients but from an
"average SWR" model which gives an averaged loss per unit length that
doesn't take account of the fact that loss is usually highest in the
region of current maxima.

My calculator produces a figure of 2.2 dB for your example. I haven't
rechecked Dan's this morning, but it is close.

Grab Dan's calculator or mine and try it out. Dan's is really neat and
a stand-alone Windows app, my online calc has less graphics, doesn't
display (or even calculate SWR), knows about more transmission lines,
and only needs a browser to access it. I use them both.

In my 100m of W551 with a 16+j0 load at 30MHz, the loss in one metre
of line nearest the load is over 4%, the good news is that since 75%
of the transmitter power is already lost, the weighted effect of that
4.3% is nearer 1% of tx output.


... waiting for me to forget to cross an 'i' or dot a 't'.

Of course I don't, otherwise I would have mentioned ...!

Did you miss the humor?

Must have.

73
Owen
--

Owen Duffy wrote:
In my 100m of W551 with a 16+j0 load at 30MHz, the loss in one metre
of line nearest the load is over 4%, the good news is that since 75%
of the transmitter power is already lost, the weighted effect of that
4.3% is nearer 1% of tx output.

What the heck is one "metre"? Netscape says that is misspelled and
probably should be corrected to "metro". Why aren't you guys on
the English system?

If the loss in each meter is 4%, wouldn't the loss in 100 meters
be 400%? What am I missing?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:

SNIPPED


I once worked for Schlumberger and Texas is definitely NOT
out of oil, i.e. Lots of oil is being held in reserve in
cases of arrested development as it is in Florida,
California, and Alaska.)

Some day the Near East will figure out that USA long term policy is to
devoid the Near East of oil. After that, the USA reserves in California,
Oklahoma, Florida, and Alaska [Wildlife Refuge] will put the USA in a
dominant and controlling position in the world economic situation.

"Use Everyone's, Save Ours!!"

AK

Cecil Moore wrote:

Owen Duffy wrote:

In my 100m of W551 with a 16+j0 load at 30MHz, the loss in one metre
of line nearest the load is over 4%, the good news is that since 75%
of the transmitter power is already lost, the weighted effect of that
4.3% is nearer 1% of tx output.


What the heck is one "metre"? Netscape says that is misspelled and
probably should be corrected to "metro". Why aren't you guys on
the English system?

If the loss in each meter is 4%, wouldn't the loss in 100 meters
be 400%? What am I missing?

C'mon Cecil, you know it's an exponential decay.

I just started reading this thread. Is the loss in a 'per meter' or 'per
wavelength'? In the olden days, we quoted loss as Nepers per
wavelength. When did it change to 'percent per meter'?

AK

Amos Keag wrote:

Cecil Moore wrote:
If the loss in each meter is 4%, wouldn't the loss in 100 meters
be 400%? What am I missing?

C'mon Cecil, you know it's an exponential decay.

The maximum HF current point could exist in the first foot of
feedline at the source. Why would the HF losses in the transmission
line at the load ever be greater than at that maximum HF current point?
--
73, Cecil http://www.qsl.net/w5dxp

At the same time velocity factors were converted to furlongs per
fortnight... :)

"Amos Keag" wrote in message
. ..
I just started reading this thread. Is the loss in a 'per meter' or 'per
wavelength'? In the olden days, we quoted loss as Nepers per
wavelength. When did it change to 'percent per meter'?

AK