antentopSince2 July

Ham Spirit
Free Choice



Free Antentop Amateur Open Book
Antentop Album
Antentop Survey




Antentop is FREE e-magazine devoted to Antennas and Amateur Radio an

Special page devoted to

Multirange Vertical Antennas

Custom Search


ANTENTOP- 03- 2003, # 004 Multirange Vertical Antennas




Igor Grigorov, RK3ZK



A combined three-band antenna


Three band antenna fundamentals: At a lack of the place for installation of a separate vertical antenna for each of three upper HF ranges it is possible to use a combined three-band antenna that works at the ranges itself. Figure 1 shows schematic of a combined three-band antenna.


Figure 1 A combined three-band antenna



The antenna consists of from three quarter-wave verticals that are resonated for each of working ranges. The verticals are connected in the bottom together. Two quarter-wave counterpoises should be use for each operation range of the antenna A coaxial cable with 50-Ohm characteristic impedance will do well for the antenna. A coaxial cable with 75-Ohm characteristic impedance also would be work with the antenna, but a SWR in the coax will be higher compare to 50-Ohm coaxial cable. Table 1 shows the combination of ranges where a mutual influence of vibrators against each other is minimum.


Design of the Antenna: Three various designs of the three- range antenna are shown below. Figure 2 shows a simple design suitable for 6 - to 15-M. The three vibrators are placed on a small distance from


each other. The distances between the vibrators are fixed with the help of small plastic insulators. The design has very strong mutual influence for every vibrator against each other.


Figure 2 Simple design of a three ranges antenna

Page 42


42 43 44



QRP Transceivers and PA from Accessible Parts IP for QRP Antentop Book Radio Antenna Engineering Book Antentop Printed and e- magazines



Just for Fun:

Map IP Address

Thanks for your time!

Last Updated:

February 26, 2020 22:08

Antentop Home Page

Free Antentop Open Book