Topband: Need assistance with 160m Marconi

Craig D. Smith craig at powersmith.net
Sat Sep 19 08:55:18 PDT 2009


Hi Paul ...

Is the 0 + j122 a typo?  The j122 is quite plausible, but not the 0.  I
would expect the real part to be somewhere between 10 and 40 ohms, depending
upon your ground condition and radial system.  I'm not at all familiar with
the Palstar analyzer, but 0 isn't an acceptable result.  Your first priority
should be to understand/correct this reading.  You might try some low value
resistors and see what you measure, or look for some type of misconnection
in your setup.

The +j122 simply means that your antenna (top wires) are somewhat too long.
Not unusual with the first cut at a new antenna.  You would correct this by
shortening the ends of the top wires by an equal amount until you get
resonance at the desired frequency.  This is priority #2.

Priority #3 would be to build a UNUN to optimize the match at the base.  But
you will need to do #1 and #2 first.

       73   Craig   AC0DS





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