If there is one antenna that has grown considerably in popularity in recent years, it is the Cobweb antenna. The Cobweb is so popular because of various reasons, like its small size, only 2.8 x 2.8 m for a version with the 20 meter band, as its longest wavelength. In addition, the fact that this antenna is a multiband version that can cover up to 7 bands. And… perhaps also the shape as a clothesline that makes the acceptance within a ham’s family higher than normal, hi!
Like any antenna, the advantages are also balanced by disadvantages. I have listed them for you below, noting that it is not a scientific study, but my own personal findings.
- Because of its relatively small size, it is easy to place in many places.
- Close to omnidirectional (+/- 1 dB), so no rotor needed.
- Up to 7 amateur bands can be covered and fed with one coax cable. Designs from 20 to 4 meters and from 40 to 10 meters.
- Build it yourself is certainly possible and not too complicated.
- Limited bandwidth in which you can operate without a tuner on 40, 20, 15, 10 and 6 meters.
- Up to 2 dB less gain than a stretched dipole.
- Interaction between the elements can make tuning difficult.
- Relatively high windload (but depends on spreaders diameter).
Cobweb vs. vertical
I see the Cobweb antenna as a direct competitor to the multiband vertical. The question on the minds of interested parties is which one now performs better with DX. I am currently investigating this on the bands 20 meters to 10 meters. As “representative” on behalf of all verticals, I have chosen the so-called Rybakov vertical. This is a 7.7m vertical that has relatively favorable radiation pattern for DX on several bands.
The Rybakov I deployed has a aluminium whip, multiple radials of a ¼ length of the longest wavelength used. Tuning by means of a CG-3000 automatic tuner, right at the feed point.