This is important for such ladderlines which shall be used as a TRAVELLING WAVES FEEDER. The distance between the two wires are responsible for the line-impedance. Such application is to find in MONOBAND-SYSTEMS.

For STANDING WAVES FEEDERS, the typical impedance figures have no importance. The other reasons for different spreaders are as follows:

1. In salty atmospheres near the coastlines, the longer spreader is the better solution for minimizing RF-loss due to salt-water depositing to the spreader surface.

2. QRO-Friends may use the longer ones. In case of a kilowatts power, the RF-Voltage becomes very high and this requires a good distance between the line-wires.

3. The typical LINE RADIATION AND RECEPTION depends from the line wire distance. If the main activities are concentrated from 6 to 15m, the SP-50 is the right choice, for all the other bands, SP-120, SP-150 and SP-200 are ok!

4. For friends of a 4-wire-feeder-system, the models SP-150 and SP-200 are prepared for it.

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