5
The Amateur Radio Dilemma and the DX Engineering RTR-2 Solution
The benefits of using separate receiving antennas for “low-band” HF operations have been known
for many years. Low band enthusiasts know that typical transmitting antennas collect too much
noise for reception, especially for DXing on the 160 and 80 meter bands. But, affordable HF
transceivers have been designed without any provision for a receive antenna connection. Otherwise
very capable transceivers, even brand new models, lack a built-in receive antenna port and relay
system. Unfortunately, only the most expensive HF transceivers have a separate receive antenna
input. Even many “high-end” radios do not provide adequate switching between the receive antenna
and the default transmit antenna, or they do not interrupt the receive antenna input during transmit.
To obtain a separate receive antenna input, certain models required optional equipment or modules
which are no longer available.
Now, with the
DXE-RTR-2
Receive Transmit Interface, the joy of low-noise, low-band reception
with a separate receive antenna is available to all transceiver and receiver owners. This unit offers a
special receive antenna connection solution, with RF overload protection and improved
preamplification, which incorporates safeguards and switching flexibility. Typical homebrew and
commercial transmit/receive (T/R) relays and other receive switching solutions offer little or no
protection to the receive antenna equipment. The
DXE-RTR-2
allows instantaneous receive
comparisons between the receive antenna and the transmit antenna, with a convenient three-position
front panel switch. Multi-color Status LEDs on the front panel allow the user to determine at a
glance if the unit is connected to power, turned on, if the keying cable is properly connected, when a
receive or transmit antenna is selected for reception and when the unit is keyed for transmission.
RTR-2 Technical Description and Functions
The DX Engineering
RTR-2
Modular Receive Transmit Interface is an indispensable accessory for
the radio enthusiast and is useful for any Amateur to expand the capabilities of their transceiver or
receiver. It is a specialized multi-port relay unit with one RF transmit capable input and output and
one receive antenna input, and a special purpose output. Here is a detailed description of specific
technical aspects and functions of the
RTR-2
.
Internal Option Slots
The BNC and F connectors at
RX ANT IN
are in parallel and are connected directly to the
RTR-2
Option Slots. Bypass Plug-In boards are in place to carry input RF directly to the RTR relay. The
DX Engineering Plug-In Modules function exclusively for the receive antenna input operational
protection and enhancements. There are three slots for the following order of option installation:
Option 1
– the top slot is intended for the 75 to 50 ohm Impedance
Transformer (
DXE-IT-PM
) when the receive antenna 75 ohm feedline
is connected to either the F connector or the BNC connector
RX ANT
IN
.
Without the transformer, either input is 50 ohms, which is the
internal impedance of the RTR-2.
