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BARRETT PRC-4090 TACTICAL HF SDR TRANSCEIVER - INSTALLATION
Site Selection Recommendations
The success of every HF Radio system is primarily measured by its ability to
receive weak signals and to transmit
RF power efficiently. A number of impor
-
tant factors need to be considered to achieve success. These include: frequency
selection, time of day and ambient noise at the receiver site. Frequency and
time of day are factors which can be used to calculate the maximum usable
frequency (MUF) and lowest usable frequency (LUF) using prediction software
freely available on the internet. A typical example of this is VOACAP, http://
www.voacap.com/prediction.html
Site selection and system design go hand in hand and should be considered
before any equipment is purchased. Forcing the radio system into an unsuitable
site will undoubtedly result in disappointing if not unworkable performance of
the system. Little can be done to improve an installed system if, for example,
the ambient RF noise is unacceptably high.
It is recommended that site evaluation be done before any system designs are
finalised to avoid system performance disappointment.
The following should be considered when choosing a position for the trans-
ceiver:
Operating Convenience
The transceiver should be placed so that the operator is comfortable and any
required facilities are easily accessible.
Air Circulation
The PRC-4090 relies on air flow around cooling fins to dissipate heat generated
by the transmitter. The mounting position must allow free air flow around these
fins.
Proximity of Transceiver to Antenna
When using RG-58 coaxial cable from the transceiver to the antenna, a cable
length of no more than 30 metres is recommended. Should a run of more than
30 metres be required, it is recommended that a low loss coax such as RG-213
or RG-8 be used.
It is recommended that the transceiver chassis is connected to ground (earth)
using the post on the rear panel to stop pick-up of unwanted noise from local
power supplies and electrical equipment.
