BARRETT 2030 HF SSB TRANSCEIVER
Helical dipoles are manufactured to specific frequencies, but may require fine
tuning after installation. To enable this the dipole elements have an adjustable
length tip to allow fine tuning for optimum VSWR during installation. Install the
antenna in its final position and check the VSWR on each of the frequencies that
the antenna was manufactured for. Should the VSWR be greater than 1.5:1 the
antenna will require adjustment. If a tunable transmitter is available, determine on
each frequency the helical dipole was manufactured for, at what frequency the best
VSWR is obtained. If this occurs at a frequency below the required frequency then
the tips will have to be shortened on the pair of elements corresponding to that
frequency. If the best VSWR occurs on a frequency higher than the required
frequency then the tips will have to be lengthened. Adjust both ends by an equal
amount and repeat the above sequence until an optimum VSWR is obtained. If a
tunable transmitter is not available use a method of trial and error to adjust the
length of the tips, a little at a time, until an optimum VSWR is obtained. Remember
always adjust each pair of elements by the same amount at each adjustment.
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