Unified Microsystems BevFlex-4X User manual

BevFlex-4X Low Noise Receiving Antenna
Installation Manual
Rev 2.23 November 2019
Unified Microsystems
PO Box 133
Slinger, WI 53086
https://www.unifiedmicro.com/bevflex4x.html
BevFlex-4X System Description and Performance Guidelines
The Unified Microsystems BevFlex-4X is an upgraded version of the BevPro-1 and BevFlex-4 Beverage antenna systems
now in use worldwide for weak signal, low noise reception. This product retains ALL of the features of the original
BevPro/BevFlex series while adding the flexibility to accommodate a total of five different antenna systems where the
installation of a classic, above ground, Beverage is impractical due to space constraints. A key feature of the BevFlex-4X
system is the ability to install ANY of these four antennas using the SAME components included with the BevFlex-4X kit.
Descriptions for each antenna configuration follow.

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Figure-1 Components in BevFlex-4X Kit
Included Items in BevFlex-4X Kit
QTY
Description
2
Antenna End Terminator Units
1
Antenna Feed Unit
1
BevFlex-4X Switch Unit
1
BevFlex-4X Quick Start Guide
1. Getting Started
The BevFlex-4X is a versatile system that can be used to build five types of low band, low noise, receive only antennas. This
manual has a separate section for each type. You should read the first part, Classic Beverage System, first regardless of

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which antenna type you plan to install. That section covers the basic component operation and installation instructions that
apply to all antenna configurations.
2. Classic Beverage system
The Beverage receiving antenna was invented by Harold H. Beverage in 1921 and is a proven performer for receiving weak
DX signals in the presence of atmospheric and man-made noise. The Beverage antenna is not suitable for transmitting since
its overall relative gain is typically 10dB or more lower than a dipole antenna. You may ask why a receiving antenna with
such low overall gain is useful as a receiving antenna. The answer lies in the fact that the noise levels on the long wave,
medium wave, and lower HF bands are far above the sensitivity of modern receivers. While the overall gain of the Beverage
receiving antenna is much lower than most transmit/receive antennas, the signal to noise ratio of signals received in the
favored direction of the Beverage antenna will be typically significantly higher than on the main, transmit/receive antenna.
The physics behind the antenna design itself are well documented and well understood. You will find many reference articles
on-line that fully describe a wide range of creative implementations of Beverage antenna designs ranging from simple to
complex.
The performance of the BevFlex-4X Beverage antenna system will be as good as or better than conventional Beverage
system installations of the same height and length. The BevFlex-4X design uses RG-6 coaxial cable that is inherently easier
to install and more stable than reversible systems employing “open wire”, “window/ladder line“, or “twisted pair wire”. The
BevFlex-4X provides increased performance and ease of adjustment in real world installations. The basic Beverage
antenna consists of a wire antenna element, a terminating resistance at the far end, and a feed system to bring the signal
back to the receiver. Reversible Beverage systems provide the additional feature of switching the termination and feed ends
of the antenna system to provide bi-directional performance.
The BevFlex-4X uses a common mode, receiving antenna, wire element, consisting of the outer shield of the RG-6 coaxial
cable that extends to each end point of the antenna. The outer shield of the coaxial cable is continuously connected
regardless of where the unique feed system is placed along the entire length of the antenna. The terminating resistances to
correctly match the impedance (Zo) of the antenna at each end point are replaced with precision reflection components to
couple the signals from each end as differential signals inside the coax between the center conductor and shield of the
coaxial cable. The center conductor of the coaxial cable can be separated at any point along the entire antenna element
length where these differential signals from each end are then brought to the receiver location via the feed point coupling unit
to two individual, coaxial feed cables. Regardless of where the feed point is installed along the antenna, the entire length of
the antenna is always utilized. The coaxial cable used as the antenna wire simultaneously operates as a common mode
antenna and as a differential mode transmission line to bring the signal back from the one end of the antenna while also
providing the correct terminating resistance to the other end of the antenna. At the receive location, a switching and
impedance matching system is employed to reflect the correct terminating resistance value back to each end of the antenna
via the inner conductor of the coaxial cable. While all this sounds simple, it has taken years of prototyping and testing by
W8GNM, WC4X, and W9XT with precision test equipment to get the various components designed and developed to the
point where a product can be manufactured in quantity to get predictable results.
The exact performance of any given beverage antenna system is dependent on many variables, such as ground conductivity
and mounting height above ground, but the most common variable under the control of the operator is the overall antenna
length. The following chart in Table-1 can be used as a general guideline to aid in typical installation decisions. The bulk of
field experience with the BevFlex-4X design has been with systems ranging from 270 ft. to 800 ft. in length, but testing with
antennas as short as 150 ft. in length has yielded encouraging results, especially for the 40 meters to 15 meter bands.
Figure-2 shows a typical antenna pattern for a 500 ft. antenna at 4 MHz, and Figure-3 shows a typical antenna pattern for a
500 ft. antenna at 1.9 MHz.
Table-1 BevFlex-4X
Performance Guidelines
Above Ground Beverage

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Antenna
Antenna Length
Overall Performance Vs. Band
Relative Directivity
160m
80m
40m
30m
20m
15m
160m
80m
40m
30m
20m
15m
100 ft.
P
F
G
G
E
E
Nil
P
G
E
E
E
150 ft.
F
F
G
E
E
E
Nil
F
G
E
E
G
250 ft.
G
G
E
E
E
E
F
G
E
E
E
G
350 ft.
E
E
E
E
G
G
G
E
E
E
G
F
450 ft.
E
E
E
E
F
F
G
E
E
E
F
P
550 ft.
E
E
E
E
P
P
E
E
E
E
P
P
750 ft.
E
E
E
G
P
P
E
E
G
G
P
P
950 ft.
E
E
G
G
P
P
E
G
G
P
P
P
E=Excellent, G=Good, F=Fair, P=Poor,
NIL=Insignificant

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Figure-2 Typical Antenna Pattern for a 500 ft. BevFlex-4X Antenna @ 8 ft. above ground (4 MHz)
Figure-3 Typical Antenna Pattern for a 500 ft. BevFlex-4X Antenna @ 8 ft. above ground (1.9 MHz)
The Unified Microsystems BevFlex-4X Beverage antenna kit will enable you to construct a Beverage receiving antenna that
has a uni-directional receiving pattern that can be reversed. In either of its two directional patterns, it is capable of providing
3 dB Beam-width: 59.6°
Front to Back Ratio: 20.6 dB
Elevation Angle 29.0 deg.
Outer Ring -4.4 dB ref.
NEC-4 EZNEC Pro/4
3 dB Beam-width: 86.2°
Front to Back Ratio: 15.0 dB
Elevation Angle 30.0 deg.
Outer Ring -11.3 dB ref.
NEC-4 EZNEC Pro/4

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outstanding results for the reception of weak signals that are otherwise unreadable using your normal transmit antenna. The
key receiving benefit of the BevFlex-4X is not to increase the received signal level, but to improve the received signal to
noise ratio in the favored direction, especially on signals arriving from distant stations at a low elevation angle. All received
signal levels will be lower on the BevFlex-4X than receiving on your transmit antenna, but you will now be able to hear
signals that were buried in the noise on your transmit antenna. “If you can’t hear them, you can’t work them,” even if they
can hear you!
As a reminder, this is a RECEIVE ONLY ANTENNA AND MUST NEVER BE CONNECTED DIRECTLY TO THE OUTPUT OF A
TRANSCEIVER. The application of more than a few milliwatts of power into the system will result in damage, and such damage
is NOT covered by the warranty.
Figure-4 Above Ground Beverage Antenna
Receiver
Control Unit
Coax
RG-6 Coax
RG-6 Coax
Ground Rod Ground Rod
Ham Shack
Terminator Unit Terminator UnitFeed Unit
Ant
Rev
Ant
Fwd
A OUT B OUT
RX
Forward
Reverse
BevFlex-4X Block Diagram - Beverage Configuration
RG-6 feed lines to shack
Any length, do not need
to be the same length
Typical Beverage length: 200 ft to 1000 ft, elevated 7-10'
FWD IN REV IN
Feed unit may be placed at
any point between terminators
REV END
Direction refers to direction
of main receive lobe.
Terminal
1 to GND
FWD END
Terminal
1 to GND
Figure-4 shows the wiring diagram for the entire Beverage antenna system.

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Prior to installation, determine the directions you want the antenna to cover. For example, in the Northeast USA, pointing the
antenna element axis at 45 degrees in the forward direction and 225 degrees in the reverse direction, allows optimum
reception from Europe or the South Pacific areas. The uni-directional receiving pattern of the antenna will typically be about
60 degrees wide at the -3dB response points. Antenna directivity patterns will typically allow reception well off the primary
axis of the antenna, which, unlike a dipole antenna, is off either end of the BevFlex-4X antenna element.
GENERAL INSTALLATION INSTRUCTIONS
In addition to the BevFlex-4X kit, you will need to have the following items as part of your Beverage antenna installation:
RG-6, 75 Ohm, CATV, coaxial cable: Sufficient RG-6 coaxial cable for use as the actual antenna element, plus (2)
separate, feed lines from the feed point anywhere along the antenna element to your receiver location. Any good quality RG-
6 coaxial cable with or without a messenger support wire can be used. (1000 ft. spools of RG-6 cable can be obtained at
local builder’s supply stores or over the Internet.)
Use of 50 ohm coax is not recommended for either the Beverage antenna element or the feed lines back to the shack. The
BevFlex-4x is designed for 75 ohm coax. Using coax with a different impedance will negatively affect the performance.
Ground rods: You will need one 4 ft. copper clad, steel, ground rod (1/2” or ¾” copper water pipe can be used in soft
ground), a wire clamp, and a short piece of #12 or #14 hook up wire for each end of the BevFlex-4X.
Cable supports: You will need insulated support devices to hang the RG-6 coaxial cable from trees or other supports.
Simple plastic cable ties or electric fence wire insulators work well for this application.
Weather proof Coaxial Connectors: You will need at least (8) outdoor type “F” connectors and the proper tools to attach
them to the coaxial cable. Weatherproof, compression type, “F” connectors with “O-ring” seals are recommended.
The application of a small amount of silicon grease to the threads on each of the “F” connectors during assembly is also
recommended to keep the connections weatherproof and free of corrosion. Wrapping the connections with silicone rubber
type fusion tape is recommended for a good weather tight seal that is easily removable for future repairs.
Figure-5 “F” Connector Installation

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BEVERAGE ANTENNA INSTALLATION:
1. Determine the location for your BevFlex-4X antenna and install a 4 ft. ground rod at one end. (Scrap copper water pipe
can also be used in soft ground). Try to locate the BevFlex-4X antenna element as far as possible from your transmitting
antenna and its counterpoise radials. Undesirable coupling between the BevFlex-4X and other antennas can degrade the
directivity and noise performance of the BevFlex-4X. Close coupling of the BevFlex-4X to a transmitting antenna can also
result in damage to the BevFlex-4X components and the receiver. It is recommended that the BevFlex-4X be spaced a
minimum of 50 ft. from a transmitting antenna operating at power levels up to1500 Watts. There is one exception to the
spacing rule. Two BevFlex-4X antennas can be placed perpendicular to each other to provide reception in four different
directions. In this case, the two perpendicular antennas can cross over each other as long as at least 12” of spacing
between the two coaxial antenna elements is maintained. Multiple BevFlex-4X’s can be used as a phased array, but this
application is beyond the scope of these instructions. Using the measurement tool within Google Earth to place the antenna
location and directional heading on your property can be a very helpful planning step.
2. The factory default settings for the internal jumpers in the termination units are for the Beverage/BOG configuration. See
Table-3, Figure-19, and Figure-20 for more information.3. Connect one end of the RG-6 coax cable used as the antenna to
one of the Termination Units in the kit.
4. Connect a short piece of hook up wire (non-critical, #12 or #14 recommended) between the ground rod clamp and terminal
stud # 1 of the end box for the above ground Beverage configuration or to stud #2 for the Beverage On Ground (BOG)
configuration (using the default internal jumper settings). It is recommended that the Termination Unit be located near
ground level and close to the ground rod with the F connector toward the ground.
5. Run the RG-6 coaxial cable between the two end points maintaining relatively constant height above ground and keeping
track of your direction of travel. The RG-6 coaxial cable should be insulated from the supporting trees or other supporting
structures. Several different types of electric fence insulators are readily available for this purpose. A height of 7 to 10 feet
above ground is ideal and keeps the wire high enough to allow mowing under the antenna and to reduce the possibility of
damage from passing people or animals. (antenna heights as low as 18 inches above ground level can be used, but make
the antenna more vulnerable to damage) Variations in the height above ground due to uneven terrain or uneven support
heights will have little effect on the antenna performance.
The RG-6 coaxial cable can follow the general contour of the land if you are going up and down hills and can be supported
by tree limbs with cable ties or tree trunks with “nail on” electric fence insulators. Whichever type of supports you use, allow
the coaxial cable antenna element to slide freely though the supports to allow for expansion and contraction as well as
movement of the supporting trees, etc. The RG-6 coaxial cable comprising the antenna element does not have to go in an
exact straight line on the desired heading. It is OK for the antenna to zig-zag a few feet in either direction as long as the
average heading of the antenna element is maintained. A moderate amount of symmetrical zig-zag of the antenna element
coaxial cable actually introduces some “electrical loading” and reduces the velocity factor of the antenna, making it perform
as if it were physically longer than it actually is. BE SURE TO ALLOW A FEW EXTRA FEET OF RG-6 COAXIAL CABLE
AT THE POINT WHERE YOU INTEND TO FEED THE SIGNALS BACK TO YOUR SHACK. It is necessary to provide
stress reduction loops where the Feed Unit will be connected.
Using RG-6 cable with a messenger wire is suggested for elevated Beverage antennas with widely spaced supports. The
messenger wire provides support for the coaxial cable. Follow these guidelines when using this type of coax.
-The ends must be insulated from ground and metal objects at the ends.
-Connect the ends to the F connector on the Terminator Units. Use a 3/8” ring lug and a 3/8” hex nut over the
threaded portion of the Terminator F connector. Leave enough length to provide a drip loop to prevent water from
entering the Terminator unit. You might want to splice stranded wire to the messenger wire and use that to the
ring lug for flexibility.
-Maintain continuity of the messenger wire at the Feed Unit. If necessary, splice the messenger wires from the two
coaxial antenna sections.
-Waterproof messenger wire connections as you would any other antenna conductor

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6. At the far end of the antenna, install the other Termination Unit from the kit the same way as in instructions #2 and #3
above.
7. The feed point for the BevFlex-4X can be located at any point along the entire length of the coaxial cable antenna element.
If you are feeding it from either end, simply connect the feed box from the kit directly to the end box with a short RG-6 coaxial
jumper or an “F” male to male barrel adapter. Locate the feed point at the position most convenient to your receiver
location. The entire length of the coax run is always used as the antenna regardless of where the Feed Unit is placed.
8. Install two RG-6 coaxial cables from the Feed Unit supplied with the kit to your receiver location. You can use two
independent runs of RG-6 coaxial cable or the “Siamese twin” type dual RG-6 coaxial cable. The length and matching of the
length on these feedlines are not critical. The Feed Unit provides both common mode RF and DC / Ohmic isolation of the
feedlines from the antenna. It is recommended that the shields of the two feedlines be connected to the station ground at the
entrance to the ham shack to provide static discharge and lightning protection. This can be easily accomplished using a
standard CATV, dual, grounding block like the one shown in Figure-6. Winding each coax through separate ferrite toroids will
help reduce any common mode noise picked up by the feed lines.
Figure-6 F Connector Grounding Block
9. NOW IS A GOOD TIME TO INSPECT AND WEATHERPROOF ALL OUTDOOR CONNECTIONS! Silicon rubber type
fusion tape is recommended for a good weather tight seal that is easily removable for future repairs. The application of
silicon grease to the threads on the “F” connectors also helps to keep the connections weatherproof and free of corrosion.
All connections to the outdoor BevFlex-4X Terminator and Feed Units must have drip loops installed, or the wire or RG-6
coax must orient towards the ground. This prevents water from accumulating at the connection point and possibly entering
the enclosures. Figure-7 shows proper wire and coax routing.

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Figure-7 Proper Wire and Cable Routing. Note picture also this shows the wire attachment for loop
configurations. Beverage and BOG configurations would only have the coax and wire to the ground rod on one
of the screw terminals.
10, Connect the two RG-6 coaxial cables to the feed point box, making note of which cables connect to the “A” and “B”
labels on the box. Mark the cable ends on both cables and connect them to the corresponding “Forward” and “Reverse”
labels on the indoor Switch Unit. (Note: these connections are reversed in the EWE and FLAG configurations)
11. Connect a user provided, 50 Ohm coaxial cable (impedance not critical) from the “RX” terminal on the Switch Unit to
the RECEIVE input on your radio. (User provided RCA phono or BNC adapters may be required to mate with the control
unit and the appropriate input on your transceiver)
DO NOT CONNECT THE BevFlex-4X TO ANY TERMINAL CAPABLE OF TRANSMITTING, AS YOU MAY DAMAGE
THE BevFlex-4X ANTENNA COMPONENTS! If your receiver or transceiver does not have a separate “receiver antenna”
input terminal, you will need to provide an external transmit/receive relay that is controlled by the PTT function on your
transceiver such as:
DX Engineering RTR-2 Receive Antenna Interface
MFJ-1707 AUTOMATIC RF SENSE ANTENNA SWITCH
Notes of caution:
As stated at the beginning of this document, the BevFlex-4X is a RECEIVE ONLY antenna system and must be
protected from accidental application of RF power to the Rx output “F” connector or any of the other system RF
connectors. The BevFlex-4X antenna should be located as far as possible from transmitting antennas ( 50 ft
minimum separation from a 1500W transmitting antenna) to provide best receive performance and to protect the
receiver from damage. The BevFlex-4X antenna switching and termination unit has RF limiting diodes to protect
the receiver from nearby transmitted signals up to a fairly high level of 100 mW (0.1 Watt) or +20dBm, but the

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system can still be damaged from close coupling to a transmitting antenna. The limiting diodes begin to operate at
1.1Volts RMS or +12dBm and reach a fully limited output of 3.0Volts peak to peak at +20dBm. If you are close to a
broadcast transmitter that drives the protection diodes into conduction, you may experience intermodulation
distortion to the desired signals you are trying to receive. Try re-orienting the BevFlex-4X to reduce the nearby,
strong, interfering signal, or contact Unified Microsystems Antennas for other suggestions.
The antenna switching and termination unit is also protected against accidental application of RF power from the
transmitter by a small fuse, which can be seen if you open the unit (See Figure-10). Should you accidently blow this
fuse, the unit will be non-operational. If this occurs, you can replace this fuse with an identical 50 ma fuse available
from Unified Microsystems (Bell P/N MRF 50, available from DigiKey and Mouser ) or insert a small jumper wire or 10
ohm resistor across the pads G2.If you bridge the blown fuse with a resistor or jumper, the future protection of the
BevFlex-4X system will be compromised.
The inputs from the antenna feed lines have Ohmic isolation from the feedline to the receiver input. If you have a
reason to provide a DC connection between the feedline shields and the shield of the coaxial cable to the receiver
input, you can make the connection with a jumper wire in the G1 pads inside the Switch Unit. It is recommended
that you leave this jumper out (factory default) because it provides better isolation to your receiver and also reduces
common mode noise that might be picked up on the feed lines from the Feed Unit.
Figure-8 Indoor Antenna Direction Switch Unit Front Panel

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Figure-9 Indoor Antenna Direction Switch Unit Rear Panel
Figure-10 Indoor Antenna Direction Switch Unit Fuse Location
50 ma. Fuse
If your transceiver does not have a separate receive antenna connector, be very careful about using an external
switching arrangement to create a receive antenna function external to the transceiver. Many of these external T/R
relays do not have enough isolation and fast enough switching time to protect the BevFlex-4X. If your transceiver
has an adjustment to delay RF output for a time interval after the PTT keying is activated, this delay should be set to
at least 25 milliseconds to avoid hot RF switching, and possible damage to receiver or the BevFlex-4X receive

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antenna system. It is known that the SPE Expert linear amplifier internal antenna switch will not adequately protect
the BevFlex-4X.
TESTING AND OPERATION
An antenna analyzer can be useful to determine that the antenna is correctly installed and functional. By connecting the
analyzer to the “RX” port on the Switch Unit and sweeping the frequency from 1.8 to 10 MHz, you should see a relatively flat
and non-fluctuating (but not necessarily extremely low) VSWR that is less than approximately 2:1 (referenced to 50 Ohms).
Listening to various signals, you should observe lower atmospheric and man-made noise levels than on your transmit
antenna as well as a significant (sometimes more than 20 dB) front to back ratio when switching directions.
Spend time listening to signals from several directions on different frequency bands and compare the signal to noise ratio to
your other antennas. There are several HF broadcast signals that can be helpful in determining the performance of your
BevFlex-4X receiving antenna system.
For example, in the eastern USA:
Gander and New York aviation weather broadcasts on 3,485kHz and 10,051kHz (USB mode)
CHU Canada time and frequency references on 3,330 kHz and 7,850 kHz
WWV time and frequency reference on 2,500, 5,000, and 10,000kHzThese are all reliable and predictable HF sources that
can aid in understanding the performance of your antenna.
Also, try listening to AM broadcast stations in known directions relative to your BevFlex-4X’s favored directions. Listen to
both daytime ground wave and night time skywave. Note that F/B measurements should be made during daylight hours. At
night, stations off the back end will pop in and out quickly, making accurate F/B measurements difficult.
You will notice that all received signal levels will generally be more than 10dB lower than on your transmit antenna, but the
signal to noise ratio on the BevFlex-4X will typically be much better than on your transmit antenna for signals coming from
the favored direction of the BevFlex-4X antenna. The lower overall received signal strength is not usually a problem since
the sensitivity and excellent noise figure of modern receivers/transceivers are good enough to make up for this difference in
strength. The signal and noise levels on the lower HF bands below 10 MHz are far above the receiver signal to noise
thresholds even when using the BevFlex-4X antenna system.
We hope you will find the BevFlex-4X receiving antenna system a highly useful and satisfying tool for digging signals out of
the noise to hear what you could not hear on your other antennas.

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3. Beverage-On-Ground (“BOG”) or Beverage-In-Sod (“BIS”)
The BOG antenna that is sometimes referred to as a “snake” antenna is nothing more than a BevFlex-4X installed on or just
under the ground surface. While it might seem counterintuitive to have your receive antenna at or slightly (less than 1 inch)
below ground level, it does work and has some interesting feature differences when compared to an above ground Beverage
installation. The BevFlex-4X installed as a BOG retains the same advantages with respect to the use of RG-6 coax for the
antenna element and feed lines as well as the ability to feed it from any point along its length. In addition, since the velocity
factor of the antenna wire at ground level is much lower than a wire above ground, the overall electrical length of the antenna
is nearly twice as long as the physical length of the antenna. This extended electrical length characteristic, along with the
ability to hide the antenna in sod, can put the advantages of this low noise receiving antenna within reach of those with
limited space or HOA restrictions on antennas.
The BOG installation performance will be close to that shown in Table-2 and Figure-11. One major difference, however, will
be that the overall signal level will be lower than a traditional above ground Beverage antenna. While signal levels from a
BOG will normally be sufficient for lower frequencies below 7 MHz, the use of the BevFlex-4X in a BOG configuration above
7 MHz may require the use of a low noise preamplifier at the output of the switch box.
Table-2
BevFlex-4X Performance Guidelines for
Beverage Antenna On Ground (BOG)
Antenna Length
Overall Performance Vs. Band
Relative Directivity
160m
80m
40m
160m
80m
40m
100 ft.
F
G
G
F
F
G
150 ft.
F
G
G
G
G
G
200 ft.
G
E
E
G
E
E
250 ft.
E
E
E
G
E
G
300 ft.
E
E
E
G
E
G
E=Excellent,
G=Good,
F=Fair, P=Poor,
NIL=Insignificant
Operation at 40m and above
may require a pre-amplifier

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Figure-11 Typical Antenna Pattern for a 175 ft. BevFlex-4X Beverage on Ground Antenna
(BOG @ 1.9 MHz)
Figure-12 Beverage-On-Ground Antenna Block Diagram
Receiver
Control Unit
Coax
RG-6 Coax
RG-6 Coax
Ground Rod Ground Rod
Ham Shack
Terminator Unit Terminator UnitFeed Unit
Ant
Rev
Ant
Fwd
A OUT B OUT
RX
Forward
Reverse
BevFlex-4X Block Diagram - Beverage On Ground (BOG) Configuration
RG-6 feed lines to shack
Any length, do not need
to be the same length
Typical BOG length: 100 ft to 300 ft, on ground or buried 1-2" deep
FWD IN REV IN
Feed unit may be placed at
any point between terminators
REV END FWD END
Direction refers to direction
of main receive lobe.
Terminal
2 to GND
Terminal
2 to GND
Installation of this antenna configuration is similar to the classic, above ground Beverage described above except
different studs on the termination units are used to connect to the ground rods. See Figure-12 above for details.
The Terminal Units come factory configured for Beverages and Beverage on Ground. See Table-3, and Figure-19 and
Figure-20 for more information on setting the internal jumpers.
3 dB Beam-width: 98.6°
Front to Back Ratio: 15.1 dB
Elevation Angle 35.0 deg.
Outer Ring -21.6 dB ref.
NEC-4 EZNEC Pro/4

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4. EWE Antenna
The inverted EWE antenna was first described by Floyd Koontz, WA2WVL, and documented in the February 1995 edition
of QST. It is, by far, the smallest of the four receiving antenna variations possible with the BevFlex-4X system. The EWE
consists of a single wire element in an upside down “U” configuration, as shown below. The EWE is not a traveling wave
antenna like the Beverage and BOG, but is really a phased array of two, short, vertical, antennas that are top coupled by
the horizontal wire. The EWE antenna is a good performing, low frequency, receiving, reversible, antenna you can deploy
in a very small space. Each end of the EWE is fed back to the operating position with RG-6 coax. Like the Beverage and
the BOG, a four ft. ground rod must be installed at each end of the EWE.
The Terminator Unit internal jumpers must be configured for EWE use. The factory setting is for Beverage type antennas.
See Table-3 and Figure-19 and Figure 20 for more information on configuring the jumpers in the Termination Units
If the ground conductivity is poor, an additional wire connected between the ground rods and buried just beneath the
ground may help the performance of the EWE antenna. The box normally used as a “feed point unit” for Beverage and
BOG installations is now used as an isolation transformer to maintain balance and eliminate ground loops. Note that the
coaxial feed-line connections to the switching control unit are reversed from the Beverage connections when the BevFlex-
4X is configured as a EWE or FLAG antenna system.
Figure-13 Typical Antenna Pattern for a 40 ft. x 10 ft. EWE (1.9 MHz)
Figure-14 EWE Antenna Block Diagram
3 dB Beam-width: 149.2°
Front to Back Ratio: 23.9 dB
Elevation Angle 32.0 deg.
Outer Ring -24.3 dB ref.
NEC-4 EZNEC Pro/4

Page-17 BevFlex-4X Installation Manual Rev 2.23 November 2019
Receiver
Control Unit
Coax
RG-6 Coax
RG-6 Coax
Ground Rod Ground Rod
Ham Shack
Terminator Unit Terminator Unit
Feed Unit
Ant
Rev
Ant
Fwd
B OUT
FWD IN
A OUT
REV IN
RX
Forward
Reverse
BevFlex-4X Block Diagram - EWE Configuration
RG-6 feed lines to shack
Any length, do not need
to be the same length
Directions
#12 Antenna Wire, 30 ft to 40 ft typical length
Top wire elevated at 10'
REV END FWD END
Note: Feed line connections
are reversed for EWE, Flag,
and VE3DO configurations.
Directions indicate direction
of main receive lobe.
Terminal 1
Terminal 2 Terminal 2
Terminal 1

Page-18 BevFlex-4X Installation Manual Rev 2.23 November 2019
5. Flag Antenna
The Flag antenna is a rectangular, single wire element with dimensions of approximately 34 ft. wide x 16 ft. high and is
typically installed 10 to 25 ft. above ground. The Flag, like the EWE, is not a traveling wave antenna like the Beverage
and BOG, but is really a phased array of two, short, vertical, antennas that are top coupled by the horizontal wires. It may
also be thought of as a pair of back-to-back EWE antennas mounted above ground. Details of Flag operation theory and
performance are widely available on-line.
Figure-15 Typical Antenna Pattern for a 34 ft. x 16 ft. Flag @ 10 ft. (1.9 MHz)
Figure-16 below shows a typical Flag antenna installation.
3 dB Beam-width: 150.8°
Front to Back Ratio: 33.2 dB
Elevation Angle 31.0 deg.
Outer Ring -29.7 dB ref.
NEC-4 EZNEC Pro/4

Page-19 BevFlex-4X Installation Manual Rev 2.23 November 2019
Figure-16 Flag Antenna Block Diagram
Receiver
Control Unit
Coax
RG-6 Coax
Ham Shack
Terminator Unit Terminator Unit
Feed Unit
Ant
Rev
Ant
Fwd
B OUT
FWD IN
A OUT
REV IN
RX
Forward
Reverse
BevFlex-4X Block Diagram - Flag Configuration
RG-6 feed lines to shack
Any length, do not need
to be the same length
Directions
#12 Antenna wire
#12 Antenna wire
Lower wire 10' above ground
34' Typical
flag horizontal length
8' Typical
8' Typical
RG-6 Coax
Direction indicates direction
of main receive lobe.
Note: Feed line connections
are reversed for Flag, EWE,
and VE3DO configurations.
FWD END
REV END
Terminal 1 Terminal 1
Terminal 2 Terminal 2
Like the EWE, the Flag has a feed point on one vertical element (forward direction) and a termination point on the other
vertical element (reverse direction). By selecting the appropriate taps on the BevFlex-4X universal termination units, the
Flag now is reversible with individual RG-6 coax feed lines connected via the termination unit to each of the two vertical
elements, as shown. The box normally used as a “feed point unit” in Beverage and BOG installations is now used as an
isolation transformer to maintain balance and eliminate ground loops in the system. Note that the coaxial feed-line
connections to the switching control unit are reversed from the Beverage connections when the BevFlex-4X is configured
as a Flag or EWE antenna system. The major advantage of the Flag antenna is retention of reasonable low frequency,
low noise performance with a much smaller real estate requirement than either the Beverage or BOG. Figure-15 shows a
typical Flag antenna pattern.
The Terminal Unit internal jumpers must be reconfigured for Flag antenna use. The factory setting is for Beverage type
antennas. See Table-3 and Figure-19 and Figure-20 for more information on configuring the jumpers in the Termination
Units.

Page-20 BevFlex-4X Installation Manual Rev 2.23 November 2019
6. VE3DO Antenna
The VE3DO antenna is similar in configuration to the EWE antenna except for the vertical ends of the antenna wire, which
are folded back parallel to the ground to the center of the horizontal part of the antenna where the two end Terminator
Units share a single ground rod. The horizontal bottom wires are suspended about 18” above ground level. More
information about the VE3DO antenna is available at the following link:
http://audiosystemsgroup.com/VE3DO.pdf
The Terminal Unit internal jumpers must be configured for VE3DO use. The factory setting is for Beverage and BOG type
antennas. See Table-3, and Figure-19 and Figure-20 for more information about configuring the Termination Units for the
VE3DO antenna.
Figure-17 Typical Antenna Pattern for a VE3DO (1.825 MHz)
3 dB Beam-width: 144.6°
Front to Back Ratio: 20.35 dB
Elevation Angle 33.0 deg.
Outer Ring -29.6 dB ref.
NEC-4 EZNEC Pro/4