BUILD THIS MULTIBAND FAN
FOR ALL BAND HF ANTENNA
Here is a fairly simple and easy to build multi band
horizontal fan type dipole that can be constructed for all band
operation from 160 meters up thru 6 meters or even higher.
drawing above, it is shown for just four bands, 80 thru 10. One
separate dipole for each band needed. However you can build it to
suit your own preferences by using the standard formula for a
468/freq mhz = total length for each band. Use the
formula for your desired center frequency.
Each dipole length above in RED
is in feet
and tenths of a foot for the center of the General portion of each
band and is derived from the above
formula and should be cut longer for swr trimming. USE #12 TO #14 GAUGE COPPERWELD WIRE
IF POSSIBLE or use what you have on hand. The top most dipole must
support the entire weight of the antenna.
Start with your lowest
(in frequency) band of operation as the main (top) support for the
entire setup. Cut it per the formula but add a couple of feet on
each end for tuning. Try to use a wire size that will support the
This is the main support for all the other
dipoles and must carry their weight.
Cut a dipole for each band
of operation. (SEE EDITORS NOTE AT BOTTOM OF
Cut each full length in
half....example: for the 10 meter length from the formula you get
16.1 feet for the total length. Cut it in half at about 8
feet per side. Make sure you cut each length about a foot or more
longer for swr trimming and attaching to center and end
If you are building the four band dipole above, you
should have 8 lengths of wire scattered all over your work
It is assumed that you have your end support
poles, trees, center and end insulators, pulleys all ready to go
before you start working on the actual
important part of this design is the installation of the pulleys (in
yellow on drawing) on each end attached to each side
They are added to this design due to the swr trimming
process and make it very easy to pull the entire antenna up and down
while making the swr adjustments. Mount a suitable size pulley
on each end attached to your pole, trees, etc for the diameter of
cord or rope used to support the system.
Start your antenna
trimming with the top dipole.... attach your coax to the center
insulator leaving several inches of the center conductor and shield
exposed. Each half of each dipole will be connected to the coax
center pigtail and the shield separately. In other words, connect
one side of the dipole to the center conductor and the other side to
Attach the other end of each half of the longest wire
to the support cord and run thru the pulley on each end and pull the
dipole up into the air between the end supports. Check swr.
as needed with low power for lowest swr possible, lower with
pulleys, attach the next highest band dipole electrically to the
same point as the first dipole, raise it to operating height, check
swr, lower for trimming, up and down, up and down.........due the
same for all other dipoles for each higher band of
When you are finished with the highest band of
operation, pull the entire system up with the pulleys and tie of at
the bottom securely.
Make certain that the coax center conductor
is attached to one half of each dipole and the shield to the other
half. All dipole ends at center insulator are connected
This may not be very clear to the new antenna builder
so please see the drawing below for the center insulator
The white areas in the
center support drawing above are mechanical supports, clamps, wire
ties or whatever your genius can come up with to support the main
(top wire) and the weight of the coax.
Remember, all the weight of this antenna system is
supported by the top wire.
The connections should be soldered and
all should be sealed including coax end from water, ice, snow
Use a 1:1 balun like the "Ugly Balun" project close to the
center before coax goes to your
performance get it as high as possible and remember that since this
is a dipole arrangement, it will be somewhat bi-directional towards
and away from you as viewed in the drawing. (BROADSIDE)
Remember that all elements will interact with each
other in the tuning process and the final setup must be
secured so the angle or distance between each dipole does not change
when blowing in the wind, etc.
The angle or distance between each
dipole is not critical but the final spacing must be
It will take lots of work (trial and error) in
getting each dipole to the lowest SWR. Just keep TRYING.
should also be noted that the antenna can be used in an inverted v
fashion but remember the spacing should be secure in the final
operating position. Tune it as in all the above instructions. You
may use a tuner with this antenna un-trimmed to save a lot of
multiband fan dipole can be very difficult to tune for lowest swr in
some installations. There are many variables that will make tuning
difficult. Height above ground, sometimes the angle of each dipole
relative to the other dipoles, surroundings , etc. If you can get
the swr to around 2 to 1 or lower for each band....don't worry too
much about it.
You might also consider using a good antenna tuner
if you are having major tuning problems. A 2:1 SWR can be handled by
might also consider removing HF combinations such as 40/15 meters
and 80/30 meters.
For these cases, cut the element for the lower
frequency and let it serve double duty at the
odd harmonic. In other words, cut the 40 meter element and let
it serve also as the 15 meter element which eliminates the 15 meter
Make sure that the distance between all dipole elements
does not change when tuning.
They must be in a fixed position
always with some sort of spacer. In theory, we could fashion a
four-wire antenna for the 80, 40, 30, 20, 15 and 10-meter bands.
In practice, it may be difficult to obtain a good match on
Since the resonant length of a given element in the
presence of the others is not the same as a dipole by itself, tuning
can be a tedious and difficult procedure. Adjust elements for
resonance in order from lowest frequency to the highest such as in
an 80 40 20 10 combo.....start with 80 first.....then go to next
higher frequency dipole.
Always cut each dipole a lot longer than
required for each band to make tuning easier.
Trim as needed for
your operating frequency.
All of these bandwidth, adjustment and
matching problems are easily solved with an antenna tuner at the
transmitter, feeding the antenna through 100 feet or less of RG-8