[TowerTalk] quads

[thompson@mindspring.com]

The discussion seems to have gotten around to quads and it seems they take a
bad rap every time.

My first quad was the awful Skylane 3 element tri-band quad.  The boom was
ribbed aluminum and if you stood on it
flattened out (like the old Gotham beam series).  As awful as it was it
worked fair on 10 and 20 but was a real killer
on 15.  I could work JA's from Eastern W5 even over such contest stations as
W6RW and W6HJT (later K6PU).  Boom length was 16 feet.  My only comparison
was the old Gonset Tri-bander modified to W1PDF and W1ONK specs.   Boom
length was 18 feet.  This antenna was a killer on 20 during the ARRL SS but
was only fair for DXing.    The Skylane was about the same on 20 and 10, but
was far superior on 15.  The rub was the beam stayed up and the quad blew
off in a spring storm.

My next quad was the W5HVV/7 version in QST in 1966.   This was a 3 el on 20
and 4 el on 15 and 10 on a 20 foot boom.    This was an improvement on 20
and 10 over either of the previous antennas.   On 15 the W5HVV was the equal
of the Skylane.   Even though this antenna was heavy, well built, and I had
the assistance of a mechanical engineer the W5HVV disappeared in another
spring storm into the Bayou behind the house.  The mast snapped off just
above the rotor so any antenna would have probably gone into the wind.
I had a Mosley TA-36 and for two years I used this with a 40 meter
extension.   The Mosley did not even measure up to the Gonset beam except on
10 where it worked very well.    All the above antennas were at 49.5 feet on
a telephone pole.

I moved to another nearby city and got both a 71' crank up (still use) and a
4 el GEM Quad.    I was disappointed in the GEM Quad as being mounted on a
metal tower detuned the antenna on each band.   The Dx gang in the city told
me the only partial remedy was to
get the quad above the metal tower.    W5AO (EX W5CKY) got me a 15 foot
piece of aluminum thick wall mast and putting the antenna 10 feet above the
top of the tower did improve front to back but not performance.   With
W5AO's help we measured front to back as minus on 20 and 15 and 5 Dbd on 10.
Raising the quad improved this to 6 dbd on 20 and 15 and to 11 dbd on 15.
This was measured at 250 feet with a commercial field strength meter with a
Db meter (Motorola).   I watched the quad through Hurricane Camille and
became so worried that back up went the TA-36 and 40 meter extension.

During this same time frame Dunc Carter W5IOU was building his big quads at
his station and W5WMU.   Dunc swore by big quads
(multi element on Rohn 25 booms).  Dunc even helped K3MBF design his 2 el 75
quad that was featured in QST mounted as part of his Telrex christmas tree
array on a Big Bertha rotating tower.   Funny, W5WMU really liked the quads
but living in South Louisiana took its toll and he switched to long boom
yagis.

Recently W8JI pointed out that the quad does not exist in commercial and
military applications (99% yagi).   The only place I saw quads was at Mitre
Labs near Boston.   They are non-existent in military installations which do
often have curtain arrays or Yagis.

The first real bashing of the quads was done by N6NB (Ex K6YNB) in the early
80's.   Others like K4JC could not tell ant difference between a 5 el mono
bander and a 4 el quad on 80 foot telephone poles.   So I guess the bottom
line is Quads and Yagis are both high performance endfire antennas.   The
place where the quad (loop) shines in that it is better than a yagi dipole
(single element).  W7RM uses his 160 loop on all the bands and it works very
well.   The construction required for a quad or delta loop is more rigorous
than for a yagi and both work very well when tuned and matched.

Dave K4JRB



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