A V.H.F. Lazy-H Antenna
1966 QST Article
with most hobby and how-to magazines, QST has had a long-running monthly
column featuring handy tips from readers and sometimes from the column
editor's (currently Steve Sant Andrea) own experiences. It has taken
various names over the years such as "Gimmicks and Gadgets" and now
"Hints & Kinks." This installment from the December 1966 QST presents
a short introduction to a VHF 'Lazy-H' antenna for mounting in the attic
(outdoor restrictions were common even half a century ago). It is of
simple construction using lamp cord in the configuration and element
lengths given - still useful in 2013.
December 1966 QST
of Contents]These articles are scanned and OCRed from old editions of the
ARRL's QST magazine. Here is a list of the
QST articles I have already posted. All copyrights are hereby acknowledged.
See all available
vintage QST articles.
V.H.F. Lazy-H Antenna
Gimmicks and Gadgets
An Attic Array for Cliff Dwellers
Getting an indoor antenna to perform satisfactorily is not always
easy. Certain sacrifices will result from any attempt to install an
indoor antenna. Yet, by taking advantage of broadband antennas and effecting
the best possible impedance match to them, worthwhile results can be
secured from an "attic special."
The 2-meter Lazy H described
in this article is an old standby which should bring back a few nostalgic
memories to 10- and 20-meter operators who have dabbled with combinations
such as this. The entire system, including 40 feet of 300-ohm ribbon
line, cost the author less than two dollars. It took about 45 minutes
to cut the wire to length, tack the system to the attic wall, and adjust
the matching transformer for an s.w.r. of 1:1. At optimum efficiency
this antenna theoretically should be capable of a maximum gain (bidirectional)
of about 5.9 decibels. The overall efficiency will be governed by the
placement of the array with respect to house wiring, water pipes, gutters
and downspouts. The antenna should be kept as far away from such things
as possible, to lessen the chance of pattern distortion, detuning effects,
and absorption of the signal.
Of any number of simple indoor
antennas tried for operation on 6 and 2 meters, the Lazy-H has been
superior to all others used.
Making The Antenna
A 10-foot length of a.c. zip cord was used for the W1CER Lazy-H.
The cord was split at one end and the two conductors were pulled apart,
making two 10-foot lengths of insulated wire. Each wire was pruned to
a length of 115.5 inches and pinned to the attic wall in the configuration
shown in Fig. 1, so that their center sections B-B, crossed. A piece
of cardboard, 3 1/2 inches square, was used as a spacer at the point
where the two are transposed, permitting uniform spacing to be maintained
between the phasing line. The insulation was stripped from the wires
at the points marked X, permitting the matching transformer to be soldered
into place. The matching transformer was fashioned from a 20-inch length
of 450-ohm open-wire line.
is used at the author's station for coupling the v.h.f. equipment to
the 300-ohm transmission lines which feed the antennas. Initial tests
were made by terminating the transmission line with a 300-ohm noninductive
resistor and applying a few watts of transmitter output power to the
line through an s.w.r. bridge. The Transmatch was adjusted for a 1:1
s.w.r. reading and the dial settings were noted on paper. Next, the
terminating resistor was removed and that end of the feed line was tapped
along T1, experimentally, until a 1:1 match was obtained
at the same setting of the Transmatch controls that gave a 1:1 match
with the 300-ohm termination. The dimensions given in Fig. 1 should
be well within the "ball park" and should provide a close match at 145
Mc. The matching transformer should be adjusted for your favorite portion
of the band. Frequency excursions to other parts of the band will be
possible, but the s.w.r. will rise somewhat as you depart from the part
of the band to which T1 has been tuned. The Transmatch will
permit matching the transmitter to the line and will disguise the slight
mismatch at "off" frequencies, enabling the transmitter to load up normally.
If coax line is preferred, a balun transformer1 can be attached
to T1 in place of the 300-ohm transmission line after the
system has been tuned as just described. This will permit the use of
75-ohm coaxial line, if desired.
Since the Lazy-H is a bidirectional array, it should be oriented
for maximum radiation in your favorite direction. In the author's case,
north-south directivity was desired so the array was tacked to the south
wall of the attic. Although maximum radiation is at right angles to
the plane of the antenna, some side response exists, making it possible
to work in all directions but with reduced efficiency off the ends of
Fig. 1 -
Dimensions for the 2-meter Lazy-H antenna. Make certain that the
center sections, B, are transposed as shown.
During an hour of casual listening with an SR-42 transceiver,
several W2 stations in New York and New Jersey were copied Q5 while
using the Lazy-H. Stations as far north as Massachusetts were also received
well above the noise level of the receiver. Many of the stations heard
were more than 100 miles away, offering proof that the antenna was performing
An antenna of this type should deliver comparable
performance on 6 meters, provided careful attention is given to the
dimensions and to the matching. Complete data covering antennas of this
variety is given in the ARRL Antenna Book, Chapter 4. An outdoor
version of the Lazy-H could be fashioned by mounting the elements on
1 X 1-inch lumber support arms. It would then be possible to rotate
the array, and greater efficiency should be possible since the antenna
would then be out in the clear. - W1CER
1 The Radio Amateur's V.H.F. Manual, pp. 188-189.
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