Kg3v Ham Radio Blog

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Tornado Near-miss on 8-4-2020

Posted: 19 Aug 2020 05:47 AM PDT
https://kg3v.com/2020/08/19/tornado-...s-on-8-4-2020/


With the recent Tropical Storm passing through the Northern Neck area on
August 4th, we had an unwelcome visitor. The storm threw a tornado in our
direction. It missed our house by about 1000 feet, but put two trees on our
house. We were relatively lucky, as it only damaged our screened-porch.
Some others in the White Stone area were not so lucky.
Wire Antennas Down

All of my wire antennas were destroyed and have to be replaced. This is the
one time I am glad I do not have any valuable metal antennas or supporting
structures. Wire is cheap. My total antenna loss is probably about $ 150.
Of course, it will take me weeks to get them reinstalled. I did manage to
get my 80 meter Broad-band Dipole installed last week, just in time for the
NAQP SSB Contest.
6BTV Vertical Antenna Survives

I have a Vertical mounted on my pier, over the Chesapeake Bay. There is
only one set of guys, using parachute cord. It survived with no signs of
damage. Crazy how a storm can snap a 36 diameter pine tree in half, 50 feet
away from this vertical, which did not even notice the winds.
Balun Damaged Internally

I had a 1:1 Balun on my 80 meter Dipole that ended up on the ground after
the Storm. I took the cover off, just to see that it was not full of water,
bugs, or other surprises. Looked OK, so I put the antenna together with new
wire. I hoisted it to about 20 feet and did a quick scan with my Rig Expert
antenna analyzer. DEAD! The SWR was insanely high across the 80 meter Band,
and most other low HF Frequencies. I brought it down and removed the balun.
It had an OPEN on the Ground/Negative labeled side.

Guess I should have looked more closely at this Balun, when I had removed
the cover for inspection. On the balanced-side shield-terminal the ground
shield had only been tacked to the lug with solder. The shield had
separated from the lug, and there was no sign of any solder ever being on
that lug. Guess it was a cold joint all along. I wrapped some wire around
the coax shield and through the lug, and made a strong solder joint. I then
scanned again, and the shield side was STILL OPEN!

Looking at the shield connection to the coax connector on the Unbalanced
side, the shield was loose inside the lug that had been soldered onto the
shield. I could move it freely, and could have pulled it right out of the
solder lug. Another Cold solder joint. I resoldered that, closed it up, and
reinstalled the antenna. Now it again looks like a Broadband 80 meter
Dipole. It played perfectly in the NAQP Contest.
Lesson Learned

The forces from falling 35 feet are strong, and can do internal damage to
antenna components. I now see that you can get a factory-made balun (or
anything else, I guess) with poorly soldered connections. The approach used
to build this balun would not have passed a vibration test, but I am sure
the design was never subjected to such a test. In the future, any antenna
components I buy, will be examined internally, for poor assembly and
strengthened if required, before they go into the air.