Connecting A Power Supply; A Word About Grounding; How Is Orion Ii Different From Other High-Performance Hf Transceivers - Ten-Tec ORION II Manual

CONNECTING A POWER SUPPLY

The ORION II transceiver requires a source
of well-filtered and regulated DC voltage.
The supply voltage can range from +12.8 to
+15.0 Vdc but +13.8 Vdc is the optimum
value. The voltage source must be capable
of supplying 22 amperes continuous duty.
We recommend using the included DC
power cable (P/N 86095). We have also
included spare connector pins (P/N 41020)
and a spare 2 pin power connector shell
(P/N 35165) for building your own cable.
The power supply plug will attach in only
one direction to the polarized two-pin DC
connector on the ORION II rear panel. Use
no less than #14 gauge (#12 recommended)
stranded wires for three-foot long
connections to accommodate the required
current demand during transmit. Use
heavier gauge wire for longer power supply
leads.
NOTE: always enable the power source first
and then the transceiver. If a generator or
alternator supports the dc source, always
turn off the transceiver before starting or
shutting off the dc source equipment. These
recharging devices often generate large
voltage spikes that can damage the
transceiver.

A WORD ABOUT GROUNDING

A good ground system is essential for
optimum operation of any HF transmitter.
The best solution is to connect all the station
equipment chassis together using a heavy
gauge of flat ground braid. Use a short
length of braid to connect to a ground rod. If
you are not using a linear amplifier, a less
ideal ground may suffice. A ground
connection to a copper cold water pipe was
often suitable, but that is now a violation of
the National Electrical Code. Be aware that
many modern water connections use plastic
pipe, and are not suitable ground
connections.
Antenna type and its proximity to the station
are also factors in choosing ground
methods. With good resonant antennas
located away from the station, the AC
566 manual
Part #74410
Printed in USA
ground in your house wiring might be
adequate.
HOW IS ORION II DIFFERENT FROM
OTHER HIGH-PERFORMANCE HF
TRANSCEIVERS?
ORION II is different from HF transceivers
that have come before it The original
ORION transceiver pioneered the use of
mode-appropriate selectable crystal roofing
filters at the first I-F stage plus DSP
bandwidth filtering at the third I-F stage.
The ORION II features an even more
advanced roofing filter stage than the
original ORION for optimum receiver
performance.
The mode-appropriate roofing filters used in
the ORION II main receiver are the
centerpiece of the radio's performance. It is
common for radio designers to be able to
produce a receiver that exhibits in excess of
100 dB of available dynamic range. What is
not common is the ability to protect superior
receiver design from being compromised by
real-life on-band factors (i.e. loud close by
signals).
Mode-appropriate roofing filters keep close
by loud signals from having a negative
impact on receiver performance. A typical
high performance HF transceiver is
equipped with a 15 to 20 kHz wide roofing
filter at the first I-F stage. Any signal that
appears under the 15 to 20 kHz roofing filter,
even if you do not hear it in your receiver
passband, has the potential to compromise
receiver performance. Loss of dynamic
range, third-order intercept or the receiver
breaking into non-linearity (distortion) are
possible results.
When dynamic range and third-order
intercept are compromised, the ability to
copy weak signals is also compromised.
The typical 100 dB dynamic range high
performance HF radio, in the presence of
loud signals a few kHz above or a few kHz
below the targeted receiver frequency, could
lose a significant amount of the available
100 dB of range! Why? Because those
loud signals under the 15 to 20 kHz wide
roofing filter have had a negative impact on
the overall performance of the receiver.
Version 4 – October 2006 5