ANTENTOP- 01- 2005, # 007

Balcony Antenna

FEEDING THE ANTENNA (5) & (9)

Feed the antenna with 50 ohm coaxial cable, braid connected to the bracket (5) and the center conductor connected to an aligator clip. Select the band using the aligator clip (9):-

0 turns = 14 MHz (20 meter band) (VSWR - almost 1:1)

2 turns = 10 MHz (30 meter band) (VSWR - almost 1:1)

6 turns = 7 MHz (40 meter band) (VSWR - about 1.1:1)

51 turns = 3.8 MHz (80 meter band) (VSWR - about 1.4:1)

53 turns = 3.7 MHz (80 meter band) (VSWR - about 1.4:1)

55 turns = 3.6 MHz (80 meter band) (VSWR - about 1.4:1)

57 turns = 3.5 MHz (80 meter band) (VSWR - about 1.4:1)

Here is a photograph of one of the prototypes in my balcony. In the background you can just make out another one of these antennas, but with a bigger (63 turn) coil.

OTHER INFORMATION

The mounting is very rubust, yet the wind resistance is rather low. Both my antennas have stood up to gale force winds; they hardly wobble!! You do not have

to use 5.35 meters of for item (1) if you want to work on other bands, such as 18 MHz.

If you intend to use more than 10 watts, then make sure you have a good

1 cm, or more, of insulation between the aluminium pole (1) and the bracket (6).

Have fun with this project. Regards from Harry - SM0VPO

-73!-

by Harry Lythall - SM0VPO

mailto: sm0vpo@telia.com

Credit Line: http://web.telia.com/~u85920178/antennas/balcant2.htm

You may have already seen my HF Balcony Antenna which was designed solely for 14MHz, then a coil was added to cover all the lower HF bands (10, 7 and 3.5MHz). Following an article in RadCom I have now extended this antenna to cover all bands from 3.5MHz through to 30MHz without any switching or tuning. The antenna functions using both Fractal and Meander principles. The height of one turn of the loop gives coverage of the 10-meter band, the old balcony antenna covers 20-meters, an extra element covers 17-meters and the 40-meter long meander gives

coverage on the 80-meter band. Here is the measured range of the complete prototype antenna:

Band---Range (MHz)---Worst VSWR----Center VSWR

80 m---3.55 - 3.70-----------3:1--------------------1.1:1

40 m----7.00 - 7.10-----------2.2:1-----------------2.2:1

30 m-----10.10 - 10.15-------2.3:1-----------------2.3:1

20 m-----14.00 - 14.35-------1.1:1-----------------1:1

17 m-----18.07 - 18.17-------1.2:1-----------------1.2:1

15 m------21.00 - 21.45------2.8:1-----------------2.5:1

12 m-------24.89 - 24.99------2.1:1----------------2.1:1

10 m-------28.00 - 29.20--------3:1-----------------1.1:1

As you can see, the VSWR rises on some of these bands but the antenna is still 100% useable on all

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