200
BARRETT 4050 HF SDR TRANSCEIVER - OPERATING AND INSTALLATION MANUAL
:RRGHQRUÀEUHJODVVYHVVHOVSUHVHQWPRUHRIDSUREOHPWRJURXQG,GHDOO\WKH
YHVVHOVKRXOGEHÀWWHGZLWKDQH[WHUQDOFRSSHUJURXQGVKHHWFRQQHFWHGWRWKH
interior of the vessel by suitable stud or an earth plate (“E” plate Barrett P/N
BCA91700)
,IWKHYHVVHOLV\HWWREHFRQVWUXFWHGWKHQLQWKHFDVHRIÀEUHJODVVYHVVHOVDWKLQ
copper sheet with an area of not less than 4 square metres should be moulded
into the hull during lamination. A suitable heavy strap should be connected to
the sheet and left free for earth connection.
Should neither of these methods be available it will be necessary to bond as
many large metallic objects, such as the engine and propeller shaft, together to
form a ground.
Whichever method is used the ground run from the ground system to the
antenna tuner should be as short as possible and use copper strap at least
50 mm wide (wider if available). Consideration must always be given to the
problem of electrolysis. Severe structural damage may occur if electrolysis is
present.
Corrosion
All connections in marine situations are subject to corrosion and oxidation.
To minimise this all joints should be cleaned and have silicon grease applied
before assembly. Under severe conditions joints should be protected with self
vulcanising rubber tape.
Electrical Checkout
After mechanical installation is complete, select the highest frequency to be
used on the Transceiver. A directional watt-meter such as a Bird Model 43
should be inserted in the coaxial transmission line between the Transceiver
and the tuner. The tune mode on the Transceiver is then energised (refer to the
Transceiver user manual). Upon application of RF energy, the tuner should start
to tune, indicated by the ‘clattering’ of the tuner relays. After a few seconds
the relay noise will cease. The Transceiver should indicate a successful tune and
WKHZDWWPHWHUUHÁHFWHGSRZHUVKRXOGLQGLFDWHDORZYDOXHFRQVLVWHQWZLWKD
VSWR of better than 2:1. If the cover of the tuner is removed, the PCB mounted
‘tuned’ LED should be illuminated. Now select the lowest desired frequency on
the Transceiver and repeat the above procedure. The result should be the same,
except that the tune cycle may take longer. If the above procedure does not
give the results as indicated, check that the antenna length and connections
are correct and re-check all ground (earth) connections.
Содержание 4050 HF SDR
Страница 218: ......