OCF: Proprer type of balun (transformer)
ve2pid wrote:
On 15 fév, 19:22, Roy Lewallen wrote:
Sometimes the radiation from the feedline, mains wiring, and stuff in
the shack can be beneficial -- it might, for instance, fill in deep
nulls in the main antenna's pattern and result in a spectacular signal
strength improvement in particular directions.
I am slightly OT here, but the same argumentation could be used about
non-resonant antennas like the G5RV. Yes, ATU needed, but L-type
autotuners for example have very small insertion loss.
I am wondering about the real advantage of a razor cut dipole
(resonant anyway on a small region around a freq) versus a multi-band
dipole using a length of feed line matching section like the G5RV or
ZS6BKW/G0GSF Antenna System...
73 de Pierre VE2PID
No, the phenomenon I'm talking about is feedline radiation, which is
very difficult to prevent with a non-symmetrical antenna like an OCF
dipole because of their asymmetry. It has nothing to do with resonance
or non-resonance, or wideband or narrowband characteristics. You can, of
course, cause feedlines of symmetrical antennas to radiate by imbalanced
feeding. But this is as true of a resonant dipole as a random length
symmetrical antenna.
Roy Lewallen, W7EL
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