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[TowerTalk] Noise problems on 80 and 160

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Subject: [TowerTalk] Noise problems on 80 and 160
From: (David L. Thompson)
Date: Mon, 27 Apr 1998 13:23:50 -0400 (EDT)
I need some troubleshooting assistance with problems that have just come up
on the low bands.

I have one tower (Tristao nee US Tower) 71' crank up.  I have a 2 el 12
meter X beam at 71', a KT34XA at 77', a 2 el Cushcraft 40 at 88', and a 2
meter AEA Isopole 2 meter at the top.  The tower is guyed and then pinned so
there is no extra weight on the pully wires.  I have an 80 meter half loop
and a MULTEE 160 with 6 elevated radials made from short wires loaded with
Spi-Ro coils.  I have a Uni-Hat 160/80 short vert but it is down for more
repairs from a windstorm 5 months ago.  I use a 300 foot receiving loop made
from coax as a shielded loop (AB0Z article Aug 1989 CQ).

Three things happened during our near miss with the tornadoes 2 weeks of the 12 meter X beam wire backs is hanging down loose; one side
of the half loop (not the side fed) broke off (fixed), and the shielded loop
has a break in the shield that I have not yet found.  It lays on my roof and
then across trees in the back yard at 15 to 20' height.
Porblem may be at the feed point on the roof.

Before the storm I had a few problems but none like now.  I am 1/4 mile from
a high voltage cross country line.  S4 to 5 line noise on TX antennas and S4
on any RX antenna I try.  Sometime I have problems on 75/80 with S4
noise, too.  On the RX loop I did get a few intermod sigs (you know the kind
that have that raw sound as you tune them in.)  1841 and 1823 were the bad
spots. S7 during the day.

Now I get the intermod noises all over 160 and 80.  S9 for example on 1825
and 3793.  S8 on 3799 as it covered up VK3DZM (heard 100% on my 40 meter
beam tho)at 1100Z today.  The 1825 noise wipes out FO0FR.  So far only
VP8/G4VFU, EA3JE, and CE8ABF get above the noise on 160.  The noises are
about every 3 khz with peaks to S9 every so often.

I am on 1/2 acre with lots of wire et al, but what would cause this to
happen????  I am about 1/2 mile from the nearest area of storm damage altho
they have re-wired a good number of telephone, power, and TV cable lines
near me.  I am 5 miles from WCNN (omni daytime, beam SW night..away from me)
and 12 miles to WSB (omni clear channel).  I don't see any extra pick up on
BC intermod...these are all unmodulated except for the raw buzz.

They are almost like touch on lights except they are fixed and don't roam.

Thanks in advance for any ideas!

73, Dave K4JRB 

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