[TowerTalk] Antennas 101

[Bill via TowerTalk]

Not always true Charley.  Those are not ALWAYS "good  heights".   You 
forgot one important thing for grade  one....HFTA.  Without HFTA  those heights 
are just guesses.  Most  hams' stations are not on a flat plane and those 
numbers can be very far from a  "good height".
 
How do I know this?  When I lived in KH6 I modeled my QTH  and found that 
anything than 90 feet for 20, 15 and 10 would suck.  In fact  anything higher 
than 50 feet or so would be lousy on 10.  Now mine was a  pretty extreme 
case with a ton of rolling hills and mountains, but I've modeled  dozens of 
QTHs all over including FL and have found that even relatively  flat locations 
can affect optimal antenna height.
 
HFTA, HFTA, HFTA!
 
One other thing, rather than getting a long boomed monster it is  better to 
have two small 3 element antennas stacked...better performance, which  
includes the ability to BIP/BOP/TOP/BOT.  I wouldn't trade my two little  A-3WS 
on 12/17 stacked for a 6 el at the height of the top one.  Not only  that, 
the small antennas are easier to install and maintain than a 6 el  monster.
 
K4XS
 
 
 
 
In a message dated 4/16/2015 11:34:16 A.M. Coordinated Universal Tim,  
k4vud at hotmail.com writes:

1.   Put lots of aluminum and wire in the air.   The more elements on  your 
yagi and the wider spacing the better.  The good heights are 70,  120, or 
140 feet.  Running an IC-718 into six elements is way better than  a IC-7851 
into a C-3 or a 5BTV.  Double your budget for the  rotor.