DX Engineering DXE-RBS-1P User manual

Reversible Beverage System
DXE-RBS-1P
DXE-RBS-1P-INS Rev 2
© DX Engineering 2009
P.O. Box 1491 · Akron, OH 44309-1491
Phone: [phone] · Tech Support and International: [phone]
Fax: [phone] · E-mail: [email protected]

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Table of Contents
Introduction 3
Features 3
Specifications 3
Typical Reverse Beverage System Layout - Figure 1 4
Additional Parts Required 5
Hardware 5
Ground Rods 5
Feedline 5
Antenna Wire 6
Power Supply 6
Installation 6
Site Selection 6
Proximity to Transmitting Antennas 7
Lightning Protection 7
Adding #26 Wire - Figure 2 7
Grounding 7
Antenna 8
Antenna Performance Chart - Table 1 8
Feedline 9
75 Ohm Termination - Figure 3 9
Mounting 9
Feed point and Reflection Units 9
Antenna Ladder Line 9
450 Ohm Ladder Line Insulated Support - Figure 4 10
Connections 10
Antenna 10
Polarity of Feedline - Figure 5 10
Feedline 11
Reversible Beverage System - Figure 6 11
Operation and Configuration 12
Control Voltage 12
Troubleshooting 12
Additional Applications 14
Directional Beverage Layout - 4 Directions - Figure 7 14
Directional Beverage Layout 15
Port Selection Control Voltage Matrix - Table 2 15
Optional Items 16
Technical Support and Warranty 20

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Introduction
The DXE-RBS-1P allows two Beverage antennas receiving in opposing directions to share the
same space. With the DXE-RBS-1P, you can build a 2-wire reversible Beverage antenna system
with superior signal-to-noise ratio, most useful on the 40, 80 and 160m bands. The W8JI design
consists of a DXE-RBS-1FP Feed Point System and a DXE-RBS-1RT Reflection Transformer.
You can operate and even confirm the F/R ratio of this antenna at any time from the operating
position.
This system is immune to strong signal overload and core saturation common in multi-transmitter
contesting environments, and is used by winning contest stations and low-band DXers.
The DXE-RBS-1P has two 75 antenna ports that use type F connectors. This allows the use of
DX Engineering DXE-F6-CTL/1000 high quality, low loss F-6 flooded coaxial cable as the
feedline.
The standard configuration of the DXE-RBS-1P uses the AWAY port for receiving and directional
control. The TOWARD port is terminated (termination included).
Applying negative 10 to 18 Vdc (or AC) to the feedline reverses the direction of reception. For
simultaneous reception from opposing directions, feed lines from both ports can be connected to
separate receivers. Having both feed lines available at the operating position also allows the use of a
noise canceling device.
While the DXE-RBS-1P is optimized to use DXE-LL-450-5C/-1K high quality multi-strand
copper 16 gage 450 ladder line for the antenna element, the system will work with any 300-600
two-wire line.
Features:
•Broad operating range, 0.2 to 30 MHz
•Fully isolated grounds used to prevent common-mode noise and unwanted signals
•Wide foil traces and air gaps for increased lightning protection
•75 design enables the use of high quality, low cost RG-6 coaxial feedline
•Stainless Steel chassis used for shielding and improved life
Specifications
•Operating Range: 0.2 to 30 MHz
•Reversing voltage (Required for remote direction switching):
•9 to 12 Vac or negative 10 to 15 Vdc at 80 mA max.
•Antenna Impedance: 450 nominal (accepts 300 to 600 balanced line)
•Feedline Impedance: 50 to 75 (75 recommended)

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Figure 1 depicts a typical
DXE-RBS-1P system
layout. A DX Engineering
DXE-FVC-1 is used to
provide the switching
voltage on the feedline
required for the DXE-RBS-
1P system to reverse
directions.
Figure 1 - Typical Reverse
Beverage System Layout

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Additional Parts Required But Not Supplied
Hardware
Supports and insulators for mounting the DXE-RBS-1FP Feed Point unit, the DXE-RBS-1RT
reflection transformer and the antenna wire.
For the antenna run, non-conductive supports are best, however metal tubing can be used if the
antenna line is kept a couple of inches away from the metal supports using non-conductive spacers.
This prevents any degradation of system performance due to mutual coupling. DX Engineering
offers a very convenient insulator (See Figure 4) for securing the 450 ladder line to wood
supports. They also lock the line in place. Part number DXE-LL-INS includes 25 insulators.
The use of a non-conductive mounting configuration for the DXE-RBS-1FP and DXE-RBS-1RT
is also highly recommended. Use pressure treated posts or perhaps a handy tree. If mounting these
units on conductive supports (i.e., a metal fence post or pipe) keep the feedline a couple of inches
away from the support using non-conductive spacers as well. If a pipe is used to mount the DXE-
RBS-1FP Feed Point unit, use a V-Saddle clamp, part number DXE-CAVS-1P, that accepts pipe
sizes from 1/2” to 1-3/4”. The DXE-RBS-1RT reflection unit is flanged for mounting and requires
two wood or metal screws.
To enhance weather resistance of the DXE-RBS-1RT, it may be useful to put a bead of non
corrosive, marine grade silicone, like DX Engineering DXE-RTV598335,along the seams where
the two halves of the cases meet. Leave a small opening in the seams at their lowest point to allow
any condensation to drain. Silicone which contains acetic acid, which has a vinegar-like smell, is
corrosive to aluminum and should be avoided.
Ground Rods
A minimum of two, 5 foot, 3/4 inch OD or larger copper ground rods and clamps are required. One
rod is needed for each end of the antenna. In poor soil, adding an additional ground rod to each end
may improve performance. As an alternative, 3/4 inch OD copper water pipe works well.
Feedline
Use 75 coaxial cable with F-type coaxial cable connectors from the feed point unit to the
operating position. We recommend using a high quality 75 “flooded” RG-6 type coax such as DX
Engineering DXE-F6-SPL. Flooded style cables have the distinct advantage of automatically
sealing small accidental cuts or lacerations of the jacket. Flooding also prevents shield
contamination and the coaxial cable can be direct-buried. This coaxial cable is available with F-
Connectors installed and in any desired custom length from DX Engineering.
Preparing flooded F-6 cable for connectors not difficult with the correct tools. DX Engineering
offers an inexpensive stripping tool, part number DXE-CPT-659, that strips the F-6 coaxial cable in
one operation and the tool includes an extra cutting cartridge.
It is essential that the feedline connections are of high quality and weather resistant. The feedline is
used not only for the received signal, but also carries the voltage used for directional control. For

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this reason, we recommend the use of Snap-N-Seal type F connectors. DX Engineering part number
DXE-SNS6-25 contains 25 Snap-N-Seal connectors.
The Snap-N-Seal connectors cannot be installed with normal crimping tools or pliers. An
installation tool like the DXE-SNS-CT1, available from DX Engineering, and is essential for proper
F type Snap-N-Seal connector installation.
Antenna Wire
A suitable length of balanced ladder or open wire line with an impedance between 300 and 600 .
See Table 1 for suggested lengths. The line that most closely approximates 450 impedance is #18
gauge. Ladder line constructed of #16 gauge wire, with standard 1-inch spacing, has about 420 
impedance, but is considerably stronger, can use fewer supports and is less likely to break during
weather events. DX Engineering offers the #16 gauge ladder-line, part number DXE-LL450 in both
500 and 1000 foot spools.
Power Supply
Applying 9 to 12 Vac or negative 10 to 15 Vdc at 80 mA to the coaxial feedline will cause the
antenna to reverse receiving direction. The DX Engineering DXE-FVC-1 Feedline Voltage Coupler
which includes the required 12 Vac wall transformer can be used.
If using a Bias Tee, since a negative voltage is required for direction change, do not use a DC
source that is used for other station equipment; a separate wall transformer is recommended. The
source should be current limited or fused for no more than 1 amp. The DX Engineering DXE-PSW-
12D1A AC Adapter, 12Vdc 1000 mA Wall Transformer may be used, with the appropriate fusing
and polarity reversal handled before connection to a bias tee.
Installation
Site Selection
Like any antenna, the DXE-RBS-1 will couple to everything around it. This system should be
located more than a wavelength from other large metallic structures, such as towers or noise sources
like power lines, electric fence wires and neighbors’ houses in order to achieve peak performance.
Most installations involve compromise of some sort, so do the best you can.
The DXE-RBS-1 antenna is versatile in that you can make reasonable height changes, drape it over
tree branches (insulated balanced line only!), and deviate its path from a straight line by about 10
degrees without significantly degrading performance. Avoid placing the antenna near transmitting
antennas, power lines, large metal fences, or over buried cables. Install the balanced line 5 to 8 feet
above the ground. It is not necessary to strictly follow the contour of the land because small hills,
ravines and ditches generally will not affect the performance of the antenna.
While the impedance of the antenna is affected by its height above ground, the effect on
performance is minimal. A perfectly level (with respect to the ground) antenna looks better but is
not absolutely necessary!

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Contrary to popular belief, a gradual slope of the antenna as it approaches its feed and termination
points does not improve performance. Simply bring the ends down to the termination and feed
boxes at any convenient angle, even if it is perfectly vertical. In the worst case the vertical portion
will be only a few feet. Signal reception in the few feet of wire comprising the vertical ends is
insignificant when compared to the signal reception from the entire length of the antenna. Unless
the antenna is more than 0.05-wavelength high, the vertical ends will not compromise antenna
performance.
Proximity to Transmitting Antennas
This system will not be damaged by a transmitted signal as long as it is more than 1/2-wavelength
from the transmitting antenna, and the power is not more than 1500 watts.
Do not transmit directly into this antenna with more than 10 watts.
Lightning Protection
This system features small air gaps and wide foil trace areas, as well as entrance gaps at all terminal
feed-throughs. The gaps act as safe, short paths for lightning. The DXE-RBS-1P is normally
immune to nearby lightning, although a direct strike might cause significant damage.
Figure 2
For additional lightning protection, use a 1-foot length of #26 wire between the antenna terminals
and each side of the balanced line, at both ends of the antenna as shown in Figure 2.
Grounding
The antenna GROUND terminals on both the feed and reflection units are intentionally insulated
from the metal enclosure and whatever the enclosure is mounted to. This isolation prevents the
feedline from becoming an unintentional ground path and introducing unwanted signals and noise
into the antenna system via a common feedline and antenna ground.
The shields of both the AWAY and TOWARD coaxial feedline connectors are common to the
DXE-RBS-1FP enclosure. Do not connect the DXE-RBS-1FP enclosure to the ground terminal,
since that would connect the feedline shields to the antenna ground and possibly increase noise or

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reduce the front-to-back ratio. If you want to ground the metal housing, it should be grounded to its
own separate ground rod. That rod should be two to five feet from the nearest antenna ground.
Connect the ground terminal only to earth ground using at least one copper ground rod. Use a large
diameter ground rod when possible. We recommend using 3/4 inch OD or larger rigid copper water
pipe if possible, although conventional copper coated steel rods will also work. Avoid small
diameter ground rods. A good ground system improves performance and enhances lightning
survivability.
In poor conductivity soils, better performance may be realized with multiple ground rods spaced a
few feet apart. Remember that increasing ground rod depth beyond five feet rarely improves RF
grounding because skin effect in the soil prevents current from flowing deep in the soil.
Follow national and local wiring codes for grounding where cables enter a building.
Antenna
You will need at least 3/8-wavelength of a nominal 450 balanced ladder line for the antenna.
Ideally, the entire antenna run should be of the same type balanced line such as DXE-LL450-1K
450 Ladder Line. Mixing two similar appearing, but different impedance lines can compromise
system performance.
The performance difference between the various 450 lines is generally negligible, especially for
lengths near a multiple of 240 feet (73.1 meters) on the 160 Meter band, a multiple of 120 feet (36.5
meters) on the 80 meter band, or a multiple of 60 feet (18.2 meters) on the 40 Meter band. It is
possible to use home-made parallel line, although close spacing should be used.
The following combinations are examples of relative performance for various antenna lengths. The
antenna can be any length between 3/8-wavelength through multiple wavelengths. The DXE-RBS-
1P performance is excellent even when it is not cut to the ideal length.
Antenna Performance Based on Band / Length
Antenna Length 160 Meters 80 Meters 40 Meters 20 Meters
120 feet (36.5 meters) Too short Marginal Good Good
240 feet (73.1 meters) Marginal Good Best Good
360 feet (109.7 meters) Fair Best Best Good
480 feet (146.3 meters) Good Best Good Good
600 feet (182.9 meters) Better Good Good Good to Marginal
720 feet (219.4 meters) Best Good Good Marginal
Table 1 - Antenna Performance Chart
The DXE-RBS-1P is forgiving in many installation parameters. Nevertheless, attention to detail
will yield better performance.

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Feedline
75 coaxial feedline from the DXE-RBS-1FP to the control voltage coupler and station is strongly
preferred, but any impedance from 50 to 75 ohms unbalanced is acceptable. We recommend using a
high quality 75 “flooded” RG-6 type coax such as DX Engineering part number DXE-F6-SPL.
Bury this feedline a few inches deep for 10 feet or more approaching the DXE-BS-1FP. Grounding
the feedline shield to a separate ground rod near the feedpoint may also be done, but is not
necessary. Use a 5-foot ground rod, but not the same ground rod used for the ground terminal on the
DXE-RBS-1FP. These two ground rods should be spaced a minimum of three to four feet apart.
If you use a single feedline, be sure the unused
port is terminated with the supplied termination
as shown in Figure 3. Failure to terminate the
unused port will significantly reduce the antenna
system's front-to-back ratio.
Figure3
Mounting
Feed Point and Reflection Units
The DXE-RBS-1FP feed point and DXE-RBS-1RT reflection units can be mounted on trees,
pressure treated lumber, or landscaping timbers. Pressure treated wood posts or landscaping timbers
are a convenient way to mount the units and also support and attach the ends of the antenna wire.
When setting end-posts, a power auger or post-hole digger works well. Line the hole with copper
flashing which will become part or all of the feed point (and termination) ground connection. If you
choose to use a metal pipe for mounting, use a DXE-CAVS-1P V-saddle clamp or other suitable
hardware. Do not use the metal mounting pipe for the antenna ground. Use a separate ground rod
placed at least two or more feet away from the base of the metal pipe. The DXE-RBS-1FP and the
DXE-RBS-1RT cases do not require grounding.
You may orient the feed point unit so the connectors labeled AWAY and TOWARD are at the
bottom and the antenna connections are at the top, but it is better if all connectors face downward.
Never mount this unit with the connectors facing up. The far-end reflection unit is normally
mounted with the two antenna terminals toward the top.
Antenna Ladder Line
The only requirement for the antenna wire support is it must hold the antenna up, and it can not
connect the antenna to ground. A metal pole with a small PVC stub for an insulator is every bit as
good as a full non-metallic pole. Trees make good supports, especially if you use electric-fence
insulators for use with wooden posts.
The support shown in Figure 4 can be nailed or screwed to either wood or plastic. The window in
the ladder line fits over the support and then a plastic pin locks it in place, while allowing it to float
horizontally. These DXE-LL-INS supports are available from DX Engineering, in packages of 25
insulators. The ladder line used for the RBS system may require more supports than a single wire

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Beverage because of the limited tension you can apply to the wire, mainly due to the size of the
window in the line. The ladder line need not be perfectly parallel to the ground along its length, and
a half twist every 20 to 30 feet in the line will help maintain balance in the antenna.
Figure 4 - 450 ΩLadder Line Insulated Support
Connections
Antenna
The antenna ladder-line is connected between the feed point and reflection units observing the
polarity between the units. The + side of the ladder line on the feed point unit should be connected
to the +side of the reflection unit, refer to Figure 5. Since you may be twisting the ladder line
multiple times along its length, correct polarity should be verified using a meter. An incorrect
connection will result in poor front-to-back ratio or sensitivity.
Figure 5
Note: The antenna connection wing nuts on the units should be
hand tightened only, do not use any sort of pliers or other
tool as this places excessive force on the terminals.