----- Forwarded Message -----
From: HAROLD SMITH JR <w0ri...@sbcglobal.net>
To: "thoy...@verizon.net" <thoyer1@v
Sent: Saturday, October 29, 2016 10:25 PM
Subject: Fw: Topband: Battle Creek Special - 160 Resonance
Hello Tom, You might want to contact George W8UVZ or George K8GG about your
problems. The frequency of the lowest VSWR is most of the time NOT the resonate
frequency.
The resonate frequency can be measured by disconnecting the feed-line and
replace with a few turn link at the feed point and check with a good Grid-Dip
meter. Then adjust the antenna to the frequency that you want and the check the
VSWR. Then match the antenna to the feed-line.
--
From: thoyer <thoy...@verizon.net>
To: topband@contesting.com
Sent: Saturday, October 29, 2016 5:16 PM
Subject: Topband: Battle Creek Special - 160 Resonance
I built this antenna several years ago. I never really had a good resonance
on 160 though. Best I could do was 3.5:1 or so. I used the xcvr ant tuner to
match it without issue.
Since it had been up for many years I brought it down a couple weeks back
for maintenance. I reworked the traps and adjusted the length of the first
section to give me a better match in the CW portion of 40m.
The reworked traps dip at approx 7.12mhz for the 40m trap and 3.5mhz for the
80m trap.
Put the antenna back up today and have a nice match in the CW portion of 40,
but the 80m resonance has shifted down to around 3.3mhz and I see no
resonance on 160m.
Some numbers from the MFJ analyzer:
40m 7.05mhz 44, 10 and 1.2 VSWR
80m 3.51mhz 91, 136 and 5.8 VSWR
160m 1.81mhz 18, 37 and 4.1 VSWR
I have about 40 radials varying in length from 50 to 60 feet depending on
the yard.
The 80m loading wire is approx 15' long
The 160m "L" is approx 72 feet long
The overall height of the antenna is 50ft.
Any suggestions for how to obtain a better resonance on 160?
Tom
W3TA
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