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Antenna
The antenna is a most critical part of the complete radio installation. It must accept
the output power from the transmitter, radiate that power with minimum loss and in
the receive mode, accept weak signals for input to the receiver.
Incorrect antenna installations will yield poor system performance and are often the
cause of complaints of poor transceiver performance.
A range of antennas is available from Barrett to suit most small fixed stations.
Detailed instructions are included with each antenna.
912 Single Wire Broadband Dipoles
- Barrett P/N BC91201
Barrett 912 single wire broadband dipoles are ideal for base stations that require
operation on multiple frequencies throughout the HF spectrum using a single
antenna.
The 912 antenna can be mounted either in a horizontal or inverted 'V' configuration
as illustrated in the following diagrams. In the horizontal configuration the major
radiation direction is broadside to the antenna. When mounted in the inverted 'V'
configuration the antenna becomes fairly Omni-directional. In the horizontal
configuration the minimum distance between the masts is 49 metres and the
recommended mast height is 15 metres. In the inverted 'V' configuration the
recommended mast height is 15 metres and
at this height the 2 metre stub masts are each installed at a minimum of 19 metres
from the mast base. In locations with limited space the antenna can be mounted
with the ends past the load resistors drooped down towards the ground. White
nylon supports located just past the load resistors are provided to attach halyards
for this configuration. In this configuration the minimum distance between masts is
reduced to 33 metres. Support towers may be either lattice masts as illustrated,
tubular telomasts or other support structures that may be available locally. It is
recommended that the halyards used to support the antenna be either UV stabilised
Dacron cord or wire rope and that pulleys should be of stainless steel construction.
Содержание 2050
Страница 31: ...31 of 285 then press the key ...
Страница 66: ...66 of 285 then press the key type in your messages using the alpha numeric keys then press the key ...
Страница 91: ...91 of 285 use the Scroll keys to select Yes to erase the address book entry then press the key ...
Страница 93: ...93 of 285 enter the telephone number using the numeric keys up to 16 digits then press the key ...
Страница 99: ...99 of 285 then press key to save the new alias ...
Страница 110: ...110 of 285 Add an Entry press the key type in a new label using the Alpha keys then press the key ...
Страница 118: ...118 of 285 Upload pack See section Cloning programming from another transceiver ...
Страница 134: ...134 of 285 then press the key Change the Selcall format associated with the ID if required then press the key ...
Страница 172: ...172 of 285 If the operator attempts to change channels while linked the following screen is shown ...
Страница 175: ...175 of 285 If the operator attempts to change channels while linked the following screen is shown ...
Страница 186: ...186 of 285 Press the key and the first address that matches or the closest match the prefix entered is selected ...
Страница 189: ...189 of 285 Pressing the key displays the link status Or if you already have a link established ...
Страница 224: ...224 of 285 Fitting the 2050 Into the 2040 Manpack Adaptor Removing the Battery Cartridge ...