44ft doublet with folded legs
PA6A in PACC contest
As a temporarily solution I have used a commercially available antenna for CB as a non-resonant antenna for 10 thru 40 meters. Tuning was done with a remote ATU (CG-3000) at the base of the antenna. My goals were to achieve an antenna with a low take-off angle on 20 and 30 meters, respectable efficiency and only two elevated radials.
- Isolated mount of the antenna on the mast. I used ex. military fiberglass chain link poles.
- Physical length of the antenna between 5/8λ on 10m and 3/16λ on 40m.
- Two sloping radials in opposite direction and of the same length as the monopole
- ATU mounted at the feed point of the antenna.
- Avoid lengths close to a half wavelength
- Take off angle <20 degrees
Modeling this antenna in both MMana and EZNEC resulted in a length of 7.8m (26') with the goals set above.
I have used this antenna over a year and it worked like a charm. Receiving on this type of antenna was a bit noisy.
Note: Make sure that the physical height of the CB antenna is > 5/8λ and extend this length at the base with a wire to get the total length of 7.8m.