Page 10
RPA-1 User Manual
Maintenance
The RPA-1 requires virtually no maintenance as long as the unit is not exposed to direct sunlight,
moisture, or extreme temperatures. But as with any electrical device, lightning is a concern.
Lightning
While most amateur radio operators rarely suffer damage from lightning (even though they never
disconnect their equipment), the best protection is to disconnect electrical devices during storms.
The key to proper lightning survival is proper grounding of feedlines and equipment, and
maintaining integrity of shield connections. A proper installation improves lightning protection
and enhances weak-signal receiving performance. Consult lightning protection and station
grounding information in the ARRL handbooks, the NAB Broadcast Handbook or other reliable
sources.
Figure 3.
Circuit board illustrates how to reduce the gain and power the unit through the coax.
To reduce gain, sol-
der a 1500
Ω
resistor
in parallel with R1
and
another with R6.
See page 9.
To reduce gain, sol-
der a 1500
Ω
resistor
in parallel with R1
and
another with R6.
See page 9.
To reduce gain, cut a
lead from C3
and
C6.
See page 9.
To reduce gain, cut a
lead from C6
and
C3.
See page 9.
Unsolder RFC1 lead that con-
nects to power jack, and then
reconnect to center pin of the
RF output jack. See page 9.
Page 3
RPA-1 User Manual
Introduction
ongratulations on your purchase of the RPA-1 receiver preamplifier. Its unique
combination of push-pull design and robust components provides significantly better
performance than other preamplifiers on the market, so we know you are anxious to get
started. Before
you install the RPA-1, take a few minutes to read this brief user guide and
familiarize yourself with the installation, operation and safety procedures. We are confident that
you will find this preamp easy to use and that it will reward you with years of faithful service.
Additional Requirements
Please note you will need the following items (not included in this package) to install and operate
the RPA-1 receiver preamplifier:
Power Source
The RPA-1 requires a negative ground, 10-18 Vdc @200mA min power
source that is not included. Depending on the supply current, you might also need an
inline fuse. Powering the RPA-1 through the coax feedline requires a voltage injector
circuit or a DX Engineering FVI-1 Voltage Injector that includes a power supply. Refer to
Connecting the Power Supply
on page 9 for details.
Sealant
If you opt to mount the unit outdoors, you will also need a silicon-based sealant,
such as 100% pure silicone RTV (DX Engineering part number RTV598335). Refer to
Installation and Maintenance
at the top of page 8 for complete information.
1
C
