[Antennas] Vertical

[Charles Greene]

Hi,

I made up a 20 meter vertical for portable use and installed it on my sea 
wall for test.  It is full size, and I used some junk 1" Alunimum tubing I 
had in my attic.  It has two radials elevated 1' above the ground.  I made 
the radiator slightly short and the radials about 2' long to bring up the 
feed impedance to 50 ohms and also the impedance of the radials so one of 
them does not hog the current which it is inclined to do if all radials are 
at zero ohms.  The first contact I made was day before yesterday, and I got 
a S9+20 report from the Fiji islands, running 30 watts on PSK31.  Then I 
ran some tests on it. It is loacted about 50' farther away from the house 
than my 6BTV and G5RV.  Using Spectrogram, I determined the noise ground 
floor was 10 db (voltage) lower than the 6BTV and 16 DB lower than the 
G5RV.  The received signals were about the same as the other two, with a 
slight edge, 1 to 2 Db stronger.  On comparitive reports I have received on 
transmit, it is running "slightly" to 1 S unit more than the other two.  On 
DX, it is at the edge and 8' above sea level at high tide of Narragansett 
Bay, 4 miles wide at this point.  On the other two antenna, my 6BTV has 22 
radials of 480' of wire, and the G5RV is 30 ft high.  Both seem to work 
well.  I knew the G5 was noiser than the 6BTV, but that usually does not 
come into play unless the signals are so weak they are in the noise level.

I really can't explain why the vertical is so low noise (my house isn't 
that noisy), and I would have guessed it would have performed a little less 
well than the fixed antenna with a fair number of radials.  I can 
understand why it is better on the long haul stuff, as it has nothing 
between it and the frezonal zone a mile of two away.  I would appreciate 
any comments.

73, Chas, W1CG
K2 #462