A Shortened 7 mHz Dipole

The shortened dipole for 7 mHz was described by Ken GM4JMU in Sprat 74. It is made from insulated wire - Ken used 24/0076. The coils are wound on 40mm ferrite as above, with 40 turns of the same wire on 1.5 ins PVC tube and may be water proofed if required. The balun at the centre is wound with miniature coax (RG174U). Tuning is best done in the clear and the preferred method of adjusting to resonance employed..

The same idea can be used to provide a mult-band doublet, by substituting tuned feeder for the coax.

The dipole described would be useful for the amateur with limited space and also for portable use.

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