DX Engineering DXE-RBSA-1P Instructions manual

Reversible Beverage System

DXE-RBSA-1P

DXE-RBSA-1P-INS Rev 4b

© DX Engineering 2021

1200 Southeast Ave. - Tallmadge, OH 44278 USA

Phone: [phone] ∙ Tech Support and International: [phone]

Fax: [phone] ∙ E-mail: [e-mail]

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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

Basic 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

Detailed System Troubleshooting

15

Technical Support and Warranty

20

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Introduction

The DXE-RBSA-1P allows two Beverage antennas receiving in opposing directions to share the
same space. With the DXE-RBSA-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-RBSA-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-RBSA-1P has two 75Ω 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-RBSA-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-RBSA-1P is optimized to use DXE-LL-450-5C/-1K high quality multi-strand
copper 16 gage 450Ω ladder line for the antenna element, the system will work with any 300-600Ω
two-wire line.

The DXE-RBSA-1P chassis is custom made from stainless steel and has a special UV resistant
cover with an integral RF Shield coating applied to the inside surfaces.

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
 75Ω design enables the use of high quality, low cost RG-6 coaxial feedline
 RF Shielded Weatherproof Housing - unique protection

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: 450Ω nominal (accepts 300Ω to 600Ω balanced line)
 Feedline Impedance: 50Ω to 75Ω (75Ω recommended)

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

Figure 1 - Typical Reversible

Beverage System Layout

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Additional Parts Required But Not Supplied

Hardware

Supports and insulators for mounting the DXE-RBSA-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 450Ω 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-RBSA-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-
RBSA-1FP Feed Point unit, use a Stainless Steel V-Clamp, part number DXE-SSVC-2P, that
accepts pipe sizes from 1/2” to 2”. The DXE-RBS-1RT reflection unit is flanged for mounting and
requires two wood or metal screws.

Ground Rods

A minimum of two, 5 foot by 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 75Ω coaxial cable with F-type coaxial cable connectors from the feed point unit to the
operating position. We recommend using a high quality 75Ω “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 F­Connectors 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
this reason, we recommend the use of compression type F connectors.

The compression 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 compression connector installation.

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Antenna Wire

Antenna wire is a suitable length of balanced ladder or open wire line with impedance between 300
and 600Ω. See Table 1 for suggested lengths. The line that most closely approximates 450Ω
impedance is #18 gauge. Ladder line constructed of #16 gauge wire, with standard 1-inch spacing,
has about 420Ω 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-RBSA-1P 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-RBSA-1P 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!

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.