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Re: [TenTec] OT: Openwire/Window Line and Bad Wx

To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] OT: Openwire/Window Line and Bad Wx
From: "Bob McGraw - K4TAX" <RMcGraw@Blomand.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sat, 3 Aug 2013 20:50:25 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
TX power is easy to generate, RX power isn't. RX is always limited by local and atmospheric noise so a dB here and a dB there doesn't make any difference a it attenuates noise and signal equally. It only affects the NF of the receiver which is typically no issue on HF. Just as you said, a bit more RF makes for a winner and you didn't change your feed line loss or antenna radiation efficiency. That says your receiver is better than your transmitter. Thus you should be running more power to match your receiver capability.
73
Bob, K4TAX




----- Original Message ----- From: "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Saturday, August 03, 2013 4:01 PM
Subject: Re: [TenTec] OT: Openwire/Window Line and Bad Wx


Sri Bob, I disagree with you.
It all depends on how you operate.

If you hang out on the low bands and have local skeds, then you are right.
But if your operations, like mine, are mostly within big contests, it makes
a huge difference.

If I run a contest with 100w from this crappy QTH, I struggle to get through
any kind of pileup.
Most of the time if I hear someone else calling at the same time as I call,
the other guy makes the QSO first.
So I wait patiently and call again.

Different story when I turn on my amp.
I run 600w.  That is perhaps 7 dB or so increase.
In this case I have about a 50% hit rate.
I see a huge difference in 6dB in the kind of operations I do.

However sometimes I just get on the bands and chat with friends. If I turn
my amp on or off, it doesn't make much difference.  They hear me Q5 both
ways.  It's just a little louder with the amp.

I can show you about 20 years worth of contest results and you can easily
spot the contests in which I was running an amp.
If my score was about 400k or 500k points, I was barefoot.
If I was running my amp with just 7dB more, it was around 1Million points.
I call that a difference; a BIG difference!

73
Rick, DJ0IP

-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Bob McGraw
- K4TAX
Sent: Saturday, August 03, 2013 1:42 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] OT: Openwire/Window Line and Bad Wx

As I said in my closing remark in an earlier post:

"I realize that we'd like to eak out every dB we can, but in the end, it
makes little to no difference on HF."

If one can match the load, using what ever means and equipment, then energy
will be transferred.  On receiving, atomospheric and man made noise will
overtake any losses in the antenna system and will over ride most all
receiver noise.

73
Bob, K4TAX




----- Original Message ----- From: "Stuart Rohre" <rohre@arlut.utexas.edu>
To: <tentec@contesting.com>
Sent: Friday, August 02, 2013 2:56 PM
Subject: Re: [TenTec] OT: Openwire/Window Line and Bad Wx


Actual parallel line experience:  One Field Day we arrived at our usual
site to put up a 300 foot around horizontal loop.  We usually corner fed
the Delta shaped loop at a corner with 450 ohm line we keep in Field Day
stocks. About 50 feet at most was our usual feed, but we had a big wooden
spool of various parallel ladder line lengths 450 and 300 ohms.

There had been and continued to be off and on, huge rains.  We could not
set up the tent on the ground that was flooded.  The closest paved area
was over 200 feet away. We tied off ladder line to trees and spliced more
in with wire nuts, and even added in a stock of 300 ohm ladder line, until
we reached the new location of the tent.  The Dentron Super Tuner as
always with that loop; was hooked up with a 4:1 balun external to the
Tuner. Static discharge resistors of 150 k ohms went to a ground rod from
each conductor right at the balun balanced side.

We found that the Tuner had no trouble matching the mixed up combination
of differing impedance ladder lines, nor did we detect any signal losses
compared to the usual shorter ladder line feed.

-Stuart
K5KVH
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