Butternut® HF9V
80/40/30/20/15/17/12/10/6 Meters
Nine-Band
Vertical Antenna
BUT-HF9V
BUT-HF9V-INS-Revision 4a
© Butternut 2019 Artists rendition
1200 Southeast Ave. - Tallmadge, OH 44278 USA of an installation
Phone: (800) 777-0703 ∙ Fax: (330) 572-3279
Tech Support and International: (330) 572-3200
Introduction
The classic Butternut® HF9V Nine-band vertical antenna operates on 75/80, 40, 30, 20, 17, 12, 15,
10 and 6 meters. Designed with corrosion-resistant aluminum tubing, 26 feet tall and only a 2.2 ft2
wind load, this antenna is very durable and attractive.
Features
Band coverage for 80, 40, 30, 20, 17, 15, 12, 10 and 6 meters
Height is 26 feet
Weight is only 14 pounds
Feedpoint Impedance is a nominal 50 ohms through the included 75 ohm matching line
Power handling: 1,500 W full legal limit on 80/40/20/15/10M
800 W PEP on 17 and 12M
500 W PEP on 30 and 6M
Wind load 2.2 ft2 (80 mph survivability - no ice)
VSWR at resonance: 1.5:1 to 2.5:1 or less on all bands
Bandwidth for VSWR 2:1 or less: 30/20/17/15/12/10M - entire band.
Bandwidth for VSWR 2:1 or less: 140-150 kHz on 40M, 25-30 kHz on 75/80M
Active Element Lengths: 1/4-wavelength on 80, 40, 30 and 15M
3/8-wavelength on 20M
1/2-wavelength on 17M
5/8-wavelength on 12M
3/4-wavelength on 10, 6M
Requires radial system
WARNING!
INSTALLATION OF ANY ANTENNA NEAR POWER LINES IS DANGEROUS
Warning: Do not locate the antenna near overhead power lines or other electric light or power
circuits, or where it can come into contact with such circuits. When installing the antenna, take
extreme care not to come into contact with such circuits, because they may cause serious injury or
death.
Overhead Power Line Safety
Before you begin working, check carefully for overhead power lines in the area you will be
working. Don't assume that wires are telephone or cable lines; check with your electric utility for
advice. Although overhead power lines may appear to be insulated, often these coverings are
intended only to protect metal wires from weather conditions and may not protect you from electric
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shock. Keep your distance! As a suggestion, remember the 10-foot rule; when carrying and using
ladders and other long tools, keep them at least 10 feet away from all overhead lines - including any
lines from the power pole to your home.
Theory of Operation
The first L/C circuit generates enough reactance to bring the whole HF9V to resonance on 80
meters allowing it to act as an electrical 1/4-wavelength radiator. It also generates enough
capacitive reactance to produce another discrete resonance at about 11 MHz.
The second, 40 meter L/C circuit generates enough reactance to resonate the whole HF9V allowing
it to act as a 1/4-wavelength radiator. In order to minimize conductor and I²R losses on 80 and 40
meters where the antenna is physically shorter than a 1/4-wavelength and thus operates with lower
values of radiation resistance, large-diameter self-supporting inductors and low-loss ceramic
capacitors are employed. Where the height of the HF9V is slightly greater than a 1/4-wavelength
on 30 meters, an L/C series tuned circuit taps onto the 40 meter coil for the extra inductance to pull
the earlier 11 MHz secondary resonance down to 10 MHz.
At the same time, a portion of the 40 meter coil is shorted out which allows the circuit to resonate
on 30 meters The addition of this circuit also produces additional resonances at 14 MHz and 28
MHz.
On 20 meters the entire radiator operates as a 3/8-wavelength vertical with much higher radiation
resistance and VSWR bandwidth than conventional or trapped antennas having a physical height of
1/4-wavelength or less. Because the 20 meter radiation resistance will be several times greater than
that of conventional vertical antennas, an electrical 1/4-wavelength section of 75 ohm coax is used
as a geometric mean transformer to match the approximate 100 ohms of feedpoint impedance on
that band to a 50 ohm main transmission line of any convenient length.
The HF9V operates as a slightly extended 1/4-wavelength radiator on 15 meters, a 1/4-wavelength
stub decoupler providing practically lossless isolation of the upper half of the antenna on that band.
On 10 meters the HF9V becomes a 3/4-wavelength radiator with considerably greater radiation
resistance and efficiency than 1/4-wavelength trapped types.
On 17 and 12 meters the coils act as packets of reactance which allow the entire radiator to operate
as a 1/2-wavelength or 5/8-wavelength vertical. Capacitance for these circuits comes from what
exists between the windings, the radiator and the capacitance hat.
On 6 meters the vertical wire, together with the adjacent section of antenna, form a short-circuited
1/4-wavelength transmission line which cancels current flow. At the lower, open end of the 1/4wavelength section a very high impedance is created the effectively divorces the upper part of the
antenna leaving the lower section to radiate as a 3/4-wavelength vertical.
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Tools Required
Straight Slot Screwdriver
Phillips Head Screwdriver
1/4” Nut Driver or socket set
11/32” Nut Driver or socket set
3/8” Nut Driver or socket set
Tape measure
Pencil
NOTE: Please read all instructions thoroughly before proceeding to the assembly.
There are parts made from fiberglass in this kit. Take normal precautions when handling any
fiberglass material. There may be fiberglass dust, slivers or particles present when the fiberglass
parts were manufactured. The use of typical fiberglass handling safety gear (gloves, dust mask, eye
shield, clothing, etc.) when handling and working with fiberglass is recommended. Use a damp rag
to wipe the parts. Do not use compressed air to clean fiberglass parts. Measures can be taken to
reduce exposure after a person has come in contact with fiberglass. Eyes should be flushed with
water and any area of exposed skin should be washed with soap and warm water to remove fibers.
Clothing worn while working with fiberglass should be removed and washed separately from other
clothing. The washing machine should be rinsed thoroughly after the exposed clothing has been
washed. Check with your local or state safety and/or environmental agencies for more detailed
precautions.
Additional Material Needed But Not Supplied
Jet-Lube™ SS-30 Aniti-Oxidant Corrosion Inhibiting Lubricant
Ground Rod installed near base of the antenna.
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Additional Material Needed But Not Supplied
JTL-12555 Jet Lube SS-30 Aniti-Oxidant Corrosion Inhibiting Lubricant
Suggested Parts Not Included
ERO-611360 Ground Rod installed near base of the antenna
DXE-RADW-32RT or 65RT Radial Wires
DXE-RADP-3P Radial Plate
Guying Kit for Vertical Antennas - Some vertical antenna manufacturers indicate their antennas
do not need guying. During times of high winds or ice loading, some of these vertical antennas may
sustain damage or fail altogether. With the small amount of effort needed to install a four point
guying system, the risk hardly seems worth taking. A four-point guying scheme provides the best
mechanical advantage to reduce wind stress, regardless of direction. Information on guying the
Butternut® HF9V is included in this manual. Information on guying the Butternut® HF9V can be
found in the section “Guying the HF9V Antenna”.
BUT-GRK Ground Radial Kit for ground mounting - 80 through 6 meter operation
BUT-RMK-II Roof Mounting Kit for roof mounting - 80 through 6 meter operation
Site Selection
Ideally, select a mounting location clear from power lines, structures and other antennas by a
minimum of 45 feet. Consider overhead power lines, utility cables and wires.
The vertical should be mounted away from local noise sources or other metallic objects which can
re-radiate noise and affect the tuning, radiation pattern and SWR.
Determine the direction you want the antenna to tilt down and make sure there is adequate clearance
(at least 45 feet). There should also be a clear diameter of 70 to 130 feet from the antenna for the
guying and radial systems that will extend away from the antenna.
As with all Amateur Radio antennas there maybe compromises and the ideal site may not be
available.
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Mounting Tube (A) Installation
When the bottom tube with insulator (A) is ground mounted, it should be protected against
corrosion if placed in concrete, damp acidic or alkaline soil. Asphalt roofing compound,
polyurethane varnish or other sealant that protects against moisture may be used. Concrete may be
used in areas of high winds for greater strength, in which case the post may be twisted slightly
during setting for easy removal later. Ensure it is not mounted at an angle. You want the antenna to
be vertical when fully installed. To help maintain the antenna base, place a larger diameter metal
tube, such as the BUT-MPS Mounting Post Sleeve in the ground, then you can slip tube w/insulator
(A) in and it will be protected from direct contact with the concrete.
Tube with insulator (A) must be installed in a hole approximately 21” deep so
that the upper end of the fiberglass insulator is approximately 7” above ground
level. Pack earth tightly around tube w/insulator (A) so that it remains vertical.
When installed, you want the top of tube A at 2-3” or less above ground level
to keep the feedpoint below 5” above ground level.
NOTE: HAMMERING TUBE W/INSULATOR (A) INTO THE EARTH
MAY CAUSE THE INSULATOR TO SPLINTER. If the post must be hammered into the earth,
protect the end of the insulator with a block of wood
NOTE: DO NOT USE U-BOLTS TO ATTACH TUBE W/INSULATOR (A) TO A MAST,
TOWER ETC. WITHOUT ADDED PROTECTION. U-BOLTS WILL EVENTUALLY CUT
INTO THE TUBING AND WEAKEN THE INSTALLATION. If U-bolts are used, place a larger
diameter metal tube, such as the BUT-MPS Mounting Post Sleeve over tube w/insulator (A).
Similar precautions should be observed when using TV style towers with locking bolts.
The BUT-RMK-II Roof Mounting Kit includes the BUT-MPS as well as the BUT-STR-II Stub
Tuned Radial Kit.
Radial System
The use of a radial system is a key requirement for any high performance quarter wave vertical
antenna system. With any vertical antenna system, the radials are the second half of the
antenna. The radials contribute to the radiation efficiency of the entire vertical antenna
system.
The exact number of radials required for low SWR and reasonably efficient operation will depend
in large measure on local earth conductivity, and this may vary considerably from one place to the
next and from one frequency band to the next, especially if your radials are not long enough. For
most installations the soil conditions will be poor to very poor when it comes to conductivity.
The best procedure is to assume that most earth is a poor conductor over the HF range and that
some radial wires will be needed. Radials may be placed on the surface of the earth or buried
slightly below the surface to get them out of the way, and their length is largely a matter of
convenience. In general, a large number of short radials are preferable to a small number of longer
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radials for a given amount of wire, especially if fewer than a dozen radials are to be used. Unlike
resonant radials that must be cut to the proper lengths for use with elevated verticals, ground-level
radials need not to be cut to any particular length; their sole purpose is to provide less lossy return
paths for currents flowing along the earth than the earth itself can provide. And, since "return"
currents will be flowing back to the antenna from all points of the compass, the radial wires should
be spaced uniformly over 360 degrees, although physical circumstances will often make this "ideal"
distribution impossible. For a discussion of ground system for elevated verticals, see the section
entitled "Above Ground Installations" following Checkout and Adjustment instructions.
At a minimum, 20 radials, each 32 feet long, may be used with this antenna. Using 32 radials at 65
feet long are preferred and highly recommended for the best performance on 80 meters with this
antenna. The extra radials help overcome unknown poor-soil conditions, improve bandwidth, and
ensure the best performance efficiency possible from the Butternut® HF9V antenna. Radial Wire, a
14 gauge stranded copper with black relaxed PVC insulation wire is suggested for the best results
for ease of installation and being able to withstand foot traffic over the radial wires without
breaking smaller gage wires.
The wire radials should placed as symmetrically as possible
straight from the feedpoint around the vertical antenna and spaced
evenly, regardless of how many radials are used. Do not cross or
bunch any radial wires as this nullifies their effectiveness. If you
have limited space, put in as many straight radials as you can. The
radials must be connected to the shield of your feedline. A
Stainless Steel Radial Plate is the ideal optional item which
provides an excellent system for attaching radial wires to your
vertical antenna system.
Radial wires can be laid on the roots of the grass or on bare ground
using Radial Wire Anchor Pins to hold them down. Using enough
staples will ensure the wires will not be snagged by mowers, people, or animals. Depending on
where you live and the type of grass you have, grass will quickly overgrow the radials and it will be
virtually impossible to see them. An article describing this process is available at:
https://www.dxengineering.com/techarticles/verticalantennainfo/how-to-put-amateur-radio-radialwires-down-without-digging. Radials can also be buried just under the surface (approximately 1” -
anything deeper and you will start losing effectiveness) by using a power edger to make a slit in the
soil.
NOTE: The function of a ground rod is to place the antenna at dc ground potential. It cannot take
the place of an effective RF ground system, such as a number of radial wires, regardless of its depth
in the earth. It does, however, serve as a convenient tie-point for such radials, as does the bolt
through mounting post w/insulator (A) to which radials can be connected by means of the remaining
#8 hardware.
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The Optional Butternut Radial Plate
Caution
Aluminum tubing edges can be very sharp.
Take precautions to ensure you do not get accidentally cut.
A Stainless Steel Radial Plate is an ideal option for the radial system that is needed for the
Butternut® HF9V vertical antenna. The radial plate can be set on the ground. When the antenna is
installed, run a short piece of copper strap from the radial plate to the lower connection of coil Q
mounted on tube (A) of the HF9V or mounted on the antenna base if the optional BUT-MPS
Mounting Post Sleeve is used. In either case, a ground wire attachment from the lower tube (A) to
the Radial Plate should be made to ensure a good RF connection. This is the same stainless steel
Radial Plate that is used on all Butternut vertical antennas and has proven itself to be an
enhancement that really works well for vertical antenna systems.
Optional Radial Plate shown installed.
Note: The DXE-RADP-3 has a mounting area for a dual SO-239. This is NOT used for the
Butternut HF Verticals because of the matching 20 meter 75 ohm coax cable that is used. Leave the
mounting hole blank.
Aluminum Tubing Information
When assembling any telescoping aluminum tubing sections you should take the following steps:
1. Make sure the edges are smooth and not sharp. Deburring may be necessary, since burrs and
shavings can occur on seams as well as edges. All surfaces need to be completely smooth to
allow easy assembly of tubing sections.
The raised particles and shavings that appear when the aluminum tubing is machined are
referred to as burrs, and the process by which they are removed is known as deburring.
Butternut aluminum tubing is machine cut on both ends.
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2. Clean the inside of the aluminum tubing to clear out any dirt or foreign material that would
Note: For reference, a completed HF9V Antenna is shown at the end of this manual
following the detailed parts list.
Note: Jet-Lube™ SS-30 Anti-Oxidant should be used between all antenna element sections.
Jet-Lube™ SS-30 is an electrical joint compound to affect a substantial electrical
connection between metal parts such as telescoping aluminum tubing or other antenna
pieces. It ensures high conductivity at all voltage levels by displacing moisture and
preventing corrosion or oxidation.
Jet-Lube™ SS-30 should also be used on all coil clamps, element clamps, bolts and
stainless steel threaded hardware to provide good electrical contact, prevent galling,
allow easier disassembly and to ensure proper tightening.
cause the aluminum tubing sections to bind during assembly. Do not use any type of oil or
general lubricant between the aluminum tubing sections. Oils or general lubricants can cause
poor electrical connections for radio frequencies.
3. Clean the outside of the aluminum tubing to clear any dirt or foreign material that would cause
the clamps to malfunction during assembly.
4. The use of Jet-Lube™ SS-30 Pure Copper Anti-Seize is highly recommended. Jet-Lube™ SS30 is an electrical joint compound which effects a substantial electrical connection between
metal parts such as telescoping aluminum tubing or other antenna pieces. Using Jet-Lube™ SS30 assures high conductivity at all voltage levels by displacing moisture and preventing
corrosion or oxidation.
5. When assembling the aluminum tubing sections, ensure the area is clear of grass, dirt or other
foreign material that could cause problems during assembly of the closely fitted telescoping
sections.
Assembly
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1. Check to be sure that no parts are missing (see assembled antenna pictorial page)
2. If the antenna is to be installed at ground level, install mounting tube (A) in a hole
approximately 21 inches deep so the upper end of the fiber rod insulator (feedpoint connection)
is approximately 3 inches or less above ground level. Ensure it is not mounted at an angle.
You want the antenna to be vertical when fully installed.
Pack earth tightly around mounting tube (A) so that it will remain vertical. Concrete may be
used in areas of high wind for greater rigidity, in which case the mounting tube should be
rotated while the concrete is setting so that it may be easily removed later. If the antenna is to be
mounted in concrete or in damp, acidic or alkaline soil, the
mounting tube should be given a protective coating of asphalt
roofing compound, polyurethane varnish, or another suitable
covering to protect the metal against corrosion. You may also
want to use the optional BUT-MPS Mounting Post Sleeve which
fits over tube (A) to help protect it from contamination.
NOTE: DO NOT HAMMER THE MOUNTING POST INTO THE GROUND AS THIS
CAN SPLINTER THE FIBER ROD INSULATOR AND COMPLICATE
INSTALLATION.
Note: Step 3 starts the antenna assembly minus Tube A (with insulator). The antenna assembly
will be mated to tube (A) when ready to be installed for final assembly steps. In all subsequent
steps, assembly should be done indoors or in an area where dropped hardware may easily be
recovered.
3. Locate Tube (B) and (B1). Slide the insulator on tube (B1) into the top of tube section (B) and
secure with a #8 x 1-1/2" bolt, #8 lock washer and #8 hex nut. On tube B1, the hole that is
drilled 5/8” from the end goes toward the top of the antenna.
Tube (B) 1-1/8” x 48” long Tube (B1) 1-1/8” x 12” with insulator
NOTE: Tube (B) has the mounting hole located 1/4" from the end.
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