AOR AR8000, Руководство по эксплуатации

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AR8000 operating manual
108
Long wire aerials
For shortwave reception a random length of long wire approximately 10 to 20
metres in length forms a good compromise. The wire should be connected to
the centre pin of a BNC plug then connected to the BNC aerial input on the top
of the AR8000.
If possible try to locate the receiver close to a window so that the wire has the
shortest and most direct run from the rear of the receiver to the outside World.
Never attach the wire aerial directly to a support or wall. Instead attach a
small length (one metre) of insulating material such as nylon to each support
(house or tree for example) and then onto the aerial wire. Allow the wire aerial
to drop diagonally into the window and receiver rather than straight down the
wall.
Keeping the aerial away from supports and building will reduce the loss of
signal from the wire aerial and prevent unwanted noise from entering the aerial
system.
Magnetic balun long wire aerials are becoming very popular as they allow
coaxial cable to be used as the down-lead from the wire aerial into the receiver.
The balun transforms the impedance to a low level suitable for 50 OHM coaxial
cable. In this instance the path of feeder is unimportant and chances of noise
entering the aerial system reduced. The 50 OHM BNC aerial input of the
AR8000 is ideally suited for connection of a magnetic balun.
Dipoles
For the very best results you should consider a dedicated aerial such as a
single or multi-band dipole or similar aerial. The problem with a wide coverage
receiver like the AR8000 is that for the ultimate results many dedicated aerials
are required to cover the whole spectrum. This may involve complex aerial
switching and reduces the ability to quickly monitor many bands.