Let's talk Antennas!
Inverted Ls and Vs - Antennas to Connect you to the Ether
(And Have a Beverage While You're At It!)
There are SO many types of antennas to choose from. I knew the standard dipole and inverted V antennas would work based on my 50 years experience, so I focused on them. The ARRL "Antenna
Handbook", and ON4UN's "Low-Band DXing " are excellent sources of information on building antennas.
The Inverted L
My 160 meter antenna is an Inverted L. The length of wire required at 1.835 MHz is approximately 127 feet. I used one of the pulleys on my tower to raise the vertical section to the top of
the tower, then ran the rest of the wire horizontally to the top of a tree.
Using a slingshot, I launched a heavyweight UV resistant 1/4 inch dacron rope over the top of the tree, then hoisted the wire, connected to the rope
with an insulator. It worked just fine. An antenna tuner must be used with the Inverted L to assure a proper match when operating away from the resonant
frequency due to the narrow bandwidth. Since my concentration was to be CW, I didn't need the tuner as long as the antenna was resonant at the low end of the band. The Palstar ZM-30 Antenna
Analyzer made short work of that job.
A good radial system is also required for increased efficiency in operating. I have 80 #14 insulated copper wires, each 120 feet long running out in an array under the tower to provide a good
RF ground system.
The Inverted V - Multiband Antenna
for for 80, 40, and 30 Meters
The inverted V antenna is essentially a dipole antenna that is about 5 percent shorter than a standard dipole, and slopes toward the ground, rather than
being parallel to it. I decided to use a multi-band approach so the antenna would work on 80, 40 and 30 meters. I made three dipole antennas cut to the
appropriate length for resonance in the band segment I wanted to operate (CW).
I connected the wires to a balun (there are three wires connected to each side of the balun) and ran a coaxial cable down to the antenna relay in the
junction box. A rope attached to the balun allows me to raise and lower it with a pulley at the top of the tower.
I attached a rope to the longest wire (80 meter dipole), and again used plastic soda straws and string to tie the
remaining wires to the longest wire so they are supported at a fixed distance away from the 80 meter dipole.
The ropes are tied to trees so that the angle of the wires to the ground is approximately 45 degrees. Although a compromise, this antenna works very
well on all bands. Using my antenna tuner, I can operate operate in the SSB portions of the band on 80 and 40 meters (30 meters is CW/digital only, and
the antenna is wide-banded enough not to need a tuner).
Grab yourself a "beverage"
and build a "Beverage"!
- a RECEIVE ONLY Antenna
The Beverage antenna is an "ancient" antenna, named after the gentleman who discovered it. Essentially, it is a VERY LONG antenna, typically placed at a
level of 10 feet or less above ground. The Beverage antenna is referred to as a "wave" antenna, and is directional, if terminated with a resistor, in the
direction it is aimed.
Since I have lots of deer and elk wandering through my property, placing it at a height where the critters could end up wearing it wouldn't improve their
demeanor, nor reception on the low bands. I discovered that when placed ON THE GROUND, it is known as a "snake" antenna. And that is what I did.
That flies in the face of most antenna concepts, where higher is better. But I'll be darned if it doesn't WORK!
The benefit of this antenna is that it eliminates or reduces the static and leaves only the signals you're trying to hear , providing a better signal to noise
ratio. I use it on 160 - 80 meters exclusively as a receiving antenna. It also improves 40 meter reception, but nearly as dramatically.
The diagram (right) demonstrates the general layout of a low band Beverage antenna system that may be switched for improved reception in two directions.
If you terminate the wire at the end, it will be directional, favoring the signals coming to you from the direction it is pointed.
If you do NOT terminate the antenna, then reception will be from both directions for that particular Beverage wire. Having two Beverage antennas,
selectable with a relay, lets you choose the direction you want to listen to.
There are very few "tricks" to putting this antenna together. At the far end (one of mine is aimed toward Europe) of a 275 foot long #14 wire, solder a
470 ohm, 1/2 watt non-inductive (not wire wrapped) resistor to the end of the wire, and then connect it to a good ground system.
An antenna analyzer will let you determine the appropriate terminating resistance (470 ohms is a good start), as well as the exact number of turns of wire
on the toroid to provide a 1:1 SWR.
Construct a simple matching transformer consisting of a number 43 or 77 toroid and 12 turns of wire wrapped around it. Leave a tap (bare wire) after the
third turn to provide a ground connection for both sides of the transformer. The earth serves as the common "return" for the ground side of the antenna.
The transformer matches the 470 ohm impedance of the Beverage antenna to your 50 ohm receiver.
At the receiving end, I attached the ground wire from the toroid to the single point ground rod for my station. After I found out how well the Beverage
works to reduce static (QRN), I put in a second Beverage aimed toward the northwest and use a small relay to switch between them. The second Beverage
isn't terminated, and I can hear stations to the northwest, as well as stations in Central and South America FAR better than I had imagined with any of the
other 160 and 80 meter antennas I'm using.
Final thoughts: This is a RECEIVE ONLY antenna. Don't be too concerned about obtaining a perfect 1:1 SWR - even with a 2:1 or higher SWR, you'll
notice very little difference in the received signal strength. I encourage to give it a try and not be too conerned about theory - practical results are what
Since 160 meters is primarily open during the winter, I leave the antennas on the ground until spring arrives - pick them up - and put
them back in the fall. Since the "snake" antenna isn't mounted on supports, it's easily moved as well, to give you coverage toward different parts of the
world. Give it a try - and have fun!