Modifying a Buddistick Pro for HOA
Bob Nolte KD7YOX
July 1, 2025
Background
I work exclusively with FT8 and thus am tuning to specific frequencies. The antennas
are sitting on the ground and therefore do not come under the perview of the
association’s CC&Rs. They are not visible from the street and the whips are difficult to
notice. They could be moved indoors in just a few minutes. I have made no attempt to
conceal their presence.
I first used tape measures for radials because my groundskeepers kept bumping into
the thin radial wires. I have since realized that they make antenna tuning much easier.
Support for the short masts is by using 1.5” PVC pipe with a patio umbrella base
underneath. The bases are filled with water and weigh 40 pounds. 50mph winds are
not uncommon here and they have no tendency to tip over. You can find more
information on my website at KD7YOX.COM. Only the 40 meter antenna requires a
loading coil which comes with the Buddistick Pro. Both the 20m and 40m antennas
have 1 Buddistick extension arm underneath the whip which adds some length and
assists in final tuning. The whip antennas on all 3 are Chameleon SS17 and are just
under 17 feet when fully extended. I would strongly urge you to purchase a Buddistick
Pro to get started.
Tuning
First, get yourself a RigExpert antenna analyzer. I have the AA-35 Zoom and it is one
of my most valued ham tools. When you’re tuning, you’re going to need it or
something similar. Your goal should be to get the antenna tuned so precisely that the
tuner on your radio has very little to do. It will also help you ensure that the return loss
at your radio is acceptable.
The process for tuning the antenna(s) is basically the same. Most of what I’ve seen on
the net focuses on tuning with the radial. I start by setting the length of the radial to
the calculated length and then proceeding to tune the coil and whip. This is
because the radial is half of the dipole and the coil/whip make up the other half. You
can find the element length at Dipole Antenna Calculator. Once this is done, you’re
ready to tackle the other half with the coil and whip.
A few words about the coil.
A loading coil in an antenna makes the antenna electrically longer. The price that you
pay for this is that it becomes a High-Q antenna, and the usable bandwidth will be
much narrower. This is necessary on 40m because I don’t believe anyone makes a 33
foot long whip. More about this when we tune the 40m antenna. If you are tuning 20m
down to 10m, you don’t need a coil if you use the longer Chameleon SS17 whip
instead.
40 Meters
You can use the 9’ whip that comes with the Buddistick Pro, or replace it with the SS17
which I prefer because the antenna is taller and you are only using half of the coil,
which helps to mitigate the Q effect. If you decide to use the supplied antenna, just
follow the book and it should work. Now you’re going to need the antenna analyzer.
The remainder of these instructions will only deal with the SS17 whip.
The first thing that you should do is make certain that the VersaHub is attached to a
solid mast, as the tripod legs will not hold up the SS17 and it will fall over.
Next, we will tune the coil with the SS17 antenna attached at full length above the coil
and just 1 extension arm beneath the coil. We only need one arm because it gives us
just enough length and gets the coil up above the screw that attaches the radial to the
VesaHub.
Now comes the fun part. Attach your RigExpert to the VersaHub. Now place the coil
tap on 18, which is where I set mine. The Buddistick book says 39 because its whip is
shorter. Set the RigExpert to 07.074 ± 3000 and take a SWR scan. Look at the graph.
The minimum dip should be either right or left of the target of 07.074. Here is an
example. Don’t get tempted to adjust the radial yet.
It’s 6534khz and we want it to be
7074khz. We want to raise it by
500+khz.
To do that, we Retract the antenna,
which will Raise it. Likewise, if the dip
is to the right of the target, we need
to Lengthen the antenna to move it
Lower. Retract to raise, Lengthen to
lower is the rule. As you get closer,
you can move the ± to 500 or so.
If the dip is to the right and the
antenna is already at full length. We
can’t lengthen it, so we need to
adjust the coil by moving the tap
down one turn with the antenna at full
length. We need to get the Min to the
left so that we can adjust it upward
by retracting the antenna.
This is why we didn’t want to fuss
with the radial. It would just add a
third variable. When we finally get
there, we can tweak the radial by an
inch or so if necessary.
20 Meters
Follow the same process as for 40 meters. Just omit the coil and set the radial to the
proper length. Adjust with the antenna length.
10-17 Meters
Just screw the antenna into the VersaHub. Omit the extension arm. Set the radial to
the proper length and adjust with the antenna.
If you get stuck, I’d be pleased if you’d give me a call at (520)391-0143 and we can
talk about the problem.
One final bonus. Try using AI on your ham radio problems with chatGPT.com. It is
conversational with your ability to ask follow-up questions and get answers. Much
better than googling. I asked GPT to evaluate my antenna setup. Here is the report.
