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[TowerTalk] TH11 and Shorty 40, Revisited

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Subject: [TowerTalk] TH11 and Shorty 40, Revisited
From: k3gt@pgh.net (Bob Thacker)
Date: Tue, 3 Aug 1999 00:19:02 -0400
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Just got the TH11 up and find out that the VSWR on 17 meters is =
relatively high, about 1.9.  BTW, rechecked all measurement 4 times =
while on the ground, so there is no chance for a wrong element length. =
All traps where disassembled and checked for integrity. The Autek =
analyzer calculates a 1.0 VSWR at 17.760 Mhz though. Approximately 10 =
feet above the TH11 is an old Hy-Gain 402BA which is as high as the mast =
will allow. The TT archives say that acceptable spacing is anywhere from =
8 to 14 feet. IMHO, I think the trouble is the 40 interaction causing =
the VSWR to rise.=20

Any thoughts and possible cures, short of a new mast?

73,
Bob, K3GT

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<DIV><FONT color=3D#000000 size=3D2>Just got the TH11 up and find out =
that the VSWR=20
on 17 meters is relatively high, about 1.9.&nbsp; BTW, rechecked all =
measurement=20
4 times while on the ground, so there is no chance for a wrong element =
length.=20
All traps where disassembled and checked for integrity. The Autek =
analyzer=20
calculates a 1.0 VSWR at 17.760 Mhz though. Approximately 10 feet above =
the TH11=20
is an old Hy-Gain 402BA which is as high as the mast will allow. The TT =
archives=20
say that acceptable spacing is anywhere from 8 to 14 feet. IMHO, I think =
the=20
trouble is the 40 interaction causing the VSWR to rise. </FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT color=3D#000000 size=3D2>Any thoughts and possible cures, =
short of a new=20
mast?</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT color=3D#000000 size=3D2>73,</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>Bob, K3GT</FONT></DIV></BODY></HTML>

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