antentopSince2 July






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

Special page devoted to

R3PIN Experimenters with UA6AGW Antenna

Custom Search


ANTENTOP- 01- 2015 # 019

R3PIN Experimenters with UA6AGW Antenna




Figure 3 Coupling Loop at UA6AGW Antenna


Data for the Antenna


Dimension of the antenna were too big for the 2- meter band. Antenna with help of C1 and C2 may be tuned across 18- 56- MHz. Test of the antenna was made at 10- meter band at frequency 28.850- MHz. Antenna was tested at position showed at Figure 1. Antenna had SWR 1.0: 1.0. C2 had maximum capacitance. Antenna was tuned to the 28.850- MHz by C1.



Figure 4 Whiskers and Capacitors


Antenna had Diagram Directivity similar to classical UA6AGW Antenna, i.e. the DD was ellipse sitting along whiskers of the antenna. Side suppression of the antenna was near minus15- dB. It was possible to make local QSOs when the antenna was placed at a table or windowsill. Experimenters with the antenna was loaded to Youtube at:


Experiment # 2


Design of the Antenna


Second antenna made by R3PIN is shown at Figure 5.The antenna was made as a table design. Dimensions of the antenna were decreased compare to antenna from first experiment. Loop of the antenna has diameter 5.5- cm. It was a copper tube in 4.7- mm OD. To make a "copper tube coaxial cable" inside of the tube was inserted Teflon insulated wire in 0.27- mm diameter. Whiskers of the antenna had length 10- cm.

The whiskers made from strand tinned wire. Capacitors C1 and C2 were ceramic dielectric with capacitance 6- 25- pF. Coupling loop was completely different from the counterpoint of antenna shown at Figure 2.


The coupling loop was placed athwart to radiation loop. Coupling loop had two turns of copper wire in 1.2- mm diameter (17-AWG). Gap between the turns was 5- mm. Coaxial cable was soldered directly to the coupling loop.



Two ferrite rings, one at the coupling loop another one at the connector side of the cable, were placed on to the coaxial cable. Figure 6 shows the coupling loop. With help a fixture (similar to the clock hand) the loop could move along the radiation loop. Figure 7 shows the fixture.




Page- 51


50 51 52




Just for Fun:

Map IP Address

Thanks for your time!

Last Updated:

January 5, 2020 16:19