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On 30 Jul 2007 18:50:13 GMT, Ed
wrote:

I think I need to just haul my Wattmeter up to the feedpoint and
measure the loss for myself!

Hi Ed,

That won't fully demonstrate the magnitude of the problem either. The
Wattmeter will only be calibrated into a matched load and if you
provide the matched load, then you won't suffer the Mismatch Loss
(where the drama of this soap opera resides).

You will then be back into a technical discussion complete with loss
multipliers or transmission line mechanics that will act as a narcotic
to your audience. If you supply the mismatch then you are going to
have to juggle the forward and reverse powers (and explain why forward
isn't as high coming out as it is going in the line).

The result is the appearance of a game of three card Monte .

You may as well treat them like full-fledged technicians and lay out
the entire problem from the beginning with a technical solution at the
end.

73's
Richard Clark, KB7QHC

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I think Richard is unnecessarily complicating the matter. Assuming you
have a directional wattmeter, you determine the power at the line input
by subtracting the "reverse power" from the "forward power" at that
point. The power at the line output is determined the same way. 10 times
the logarithm of the ratio of the input power to output power is the
line loss in dB.

Use or even knowledge of mismatch loss isn't necessary. In fact,
attempting to apply it to the problem at hand will very likely lead to
incorrect conclusions.

Roy Lewallen, W7EL

Richard Clark wrote:
On 30 Jul 2007 18:50:13 GMT, Ed
wrote:

I think I need to just haul my Wattmeter up to the feedpoint and
measure the loss for myself!

Hi Ed,

That won't fully demonstrate the magnitude of the problem either. The
Wattmeter will only be calibrated into a matched load and if you
provide the matched load, then you won't suffer the Mismatch Loss
(where the drama of this soap opera resides).

You will then be back into a technical discussion complete with loss
multipliers or transmission line mechanics that will act as a narcotic
to your audience. If you supply the mismatch then you are going to
have to juggle the forward and reverse powers (and explain why forward
isn't as high coming out as it is going in the line).

The result is the appearance of a game of three card Monte .

You may as well treat them like full-fledged technicians and lay out
the entire problem from the beginning with a technical solution at the
end.

73's
Richard Clark, KB7QHC

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On Mon, 30 Jul 2007 18:51:07 -0700, Roy Lewallen
wrote:

Use or even knowledge of mismatch loss isn't necessary. In fact,
attempting to apply it to the problem at hand will very likely lead to
incorrect conclusions.

Hi Roy,

Well, I suppose offering a palliative often suits both sides of the
podium.

73's
Richard Clark, KB7QHC

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Owen Duffy wrote:

BTW, someone suggested a vertical. Vertical's have very low gain at high
angles, so relatively unsuited to NVIS.

Owen

This would explain why the vertical would work into GA,Fl, VA, from NC
but not into a station in SC less than 100 miles away.


Jimmie

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JIMMIE wrote:
Owen Duffy wrote:
BTW, someone suggested a vertical. Vertical's have very low gain at high
angles, so relatively unsuited to NVIS.

Owen

This would explain why the vertical would work into GA,Fl, VA, from NC
but not into a station in SC less than 100 miles away.

On what band? That would be pretty normal on 20 meters.

- 73 de Mike KB3EIA -

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"Michael Coslo" wrote in message
...
JIMMIE wrote:
Owen Duffy wrote:
BTW, someone suggested a vertical. Vertical's have very low gain at high
angles, so relatively unsuited to NVIS.

Owen

This would explain why the vertical would work into GA,Fl, VA, from NC
but not into a station in SC less than 100 miles away.

On what band? That would be pretty normal on 20 meters.

- 73 de Mike KB3EIA -

Sorry its been years since its been in use. I was on a gov shortwave freq
and I dont remember. Normally we answered a net that was being controlled
from Atlanta. I had always assumed we couldnt here the station in SC because
of its antenna orientation but after I had a chance to visit the station I
realized there pattern should have been pretty much omni=directional.

Jimmie