This is an interim report on the MSWE antennas.
I installed the TH-3 antenna contributed by Eddie of River Oaks Stereo on a 15
foot pole on my well house. The antenna went together very fast with the help
of the color coding by Michael Monsour and his helpers who disassembled and
picked up the antenna. The only problem that I found were that a couple of the
hose clamps were on the wrong piece of aluminum and the two bolts that hold the
clamp to the mast were 2" bolts that should have been 2-3/4" to allow for a
mast in the clamp. I will get a couple more stainless 5/16 bolts and put the
clamps on the right piece of aluminum when I disassemble the antenna. The
antenna was assembled using the weather marks on the aluminum and the SWR on
the assembly has good SWR on 20, 15 and 10 in the phone band. It is about 2.5
at the bottom of the CW band on 20 and 15 which is not surprising because the
TH-3 is a bit narrow banded for both modes. The triplexer and band filter add
very little to the SWR
when installed. The 10 meter SWR drops to 1.75 at 28.000 and 1.25 at 28.4 and
does not cross 2.0 until 29.200. With the triplexer and filter the SWR is 1.5
at 28.0 and drops to 1.25 at 28.150 then rises to 2.0 at 28.380 and continues
to rise to a peak of 3.0 at 28.690 then drops to 2.0 at 29.000 and 1.5 at 29.3
and back up to 2.0 at 29.5. It appears that this Filter is optimized for PSK
and FM. Tests were made with TS-480, AIM-4170C. Results generally confirmed
by TS-480 SWR meter and Daiwa CN-101. The TS-480SAT auto tuner will resolve
all high SWRS to give full output from the TS-480 and better than 80%
efficiency. No attempt to resolve tuning was made as there are no external
controls provided. No attempt to tell whether the triplexer of filter is
causing the curve and no trials were made with the items separated.
A 40 foot pole was constructed with the bottom 18 feet being a steel push pole
(bottom two sections of a 44 ft pole) and 22 feet of fiberglass surplus mast.
This will be available with halyards to hoist one or two wire antennas. An
Alpha-Delta 80/40 meter antenna is available, but has not been installed and
tested. The pole has been raised by a single person, but will be easier and
quicker to raise with multiple persons.
Willis 'Cookie' Cooke, BVARC MSWE Chairman, TDXS DX Chairman
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart
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