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Off centre fed (ocf) dipole with dual core balun
40/20/10m Off Centre Fed Dipole (NO TUNER REQUIRED)
This is a new Off Centre Fed (OCF) Dipole antenna which is BRAND NEW and ready to depoly in minutes. The antenna is able to operate over the whole of the 40m, 20m and 10m bands without a tuner and has a VSWR less than 1.5:1 over the bands with a typical minimum VSWR of 1.2:1. The antenna is supplied with a TZ-250D-4m, dual core 4:1 toroidal balun for excellent performance and exceptional impedance to braid current at the feed point. No more radiation from the feedline using this balun!
The bandwidth of this antenna is nothing short of spectacular, covering over 1000kHz on 40m with the VSWR less than 2.0:1. The bandwidth on 20m and 10m is just as impressive, and there is no need for a tuner for any part of these bands. Operate CW or the top end of the phone band without needing to retune. With such a low VSWR, transmission line losses are as low as they can possibly be.
Of course, as the antenna is designed with a high impedance input and a 4:1 matching transformer, the antenna can also be used on other bands with slightly degraded performance and a little additional loss in the feeder. The antenna presents a VSWR of approximately 2.5:1 on 15m which can be handled by most if not all inbuilt transceiver ATUs, external automatic tuners or manual tuners. The antenna can also be used on the WARC bands with a tuner and a near perfect match can always be obtained on 12m, 17m and 30m. Operation on 80m is also possible with a good tuner but the performance on 80m will be noticeably degraded when compared to a full size dipole. However, for those with restricted space or just wanting an antennas that is light, small and easy to string-up at a field day or portable operation, this antenna is for you.
The antenna is very light weight and is 20m long, so not much room is required. It is recommended that the antenna be mounted at least 25-30ft off the ground and full performance can be achieved when the antenna is mounted above 36ft (10m). At 15m, you'll get some great DX on 20m and 40m. "Ol sol" (the sun) has finally re-emerged from its slumber, (THE SUNSPOT NUMBER HAS HIT 30) and this antenna can provide some great high gain lobes on 10m...or 11m for that matter. GOOD NEWS - Finally an active sunspot from cycle 24 is visible on the sun's earth facing disc. HF conditions should improve in the coming months so be sure to have your station ready with a nice easy multi-band, efficient antenna.
See the photos or look at the specs in greater detail at .au
* Gain dBi (maximum, when mounted @ 15m)
* 10m : 9.39 dBi (10 deg elevation at 55 deg off broadside)
* 20m : 8.35 dBi (19 deg elevation at 37 deg off broadside)
* 40m : 6.8 dBi (40 deg elevation at broadside)
For more information on Rippletech products and this type of antenna see:
