ANTENTOP- 01- 2008, # 010

Simple Weekend Antenna for 145-MHz

Trip Variant of the Antenna

A bit later, I made a kit of the antenna suitable for my mountain trip. Testing of the antenna in the mountains shows, that my YAGI is compared to collinear in 3- 5 meters long on distance up to 50 kms and beats the antennas up to 90 kms and more.

Photos below shows kit of my trip YAGI. Only 30 seconds are needed to install the antenna. Boom for the YAGI was made from a plastic water pipe in 510- millimeters length and 21- millimeters in diameters. Transformer 12.5-Ohms/50-Ohms is placed inside the plastic tube. The antenna is good fit to rucksack and may be easy repaired in the trip.

50-Ohms YAGI

For those who do not want cut length oh matching transformer was calculated antenna having 50- Ohms input impedance. So coaxial cable may be directly to connected to antenna terminals. View of the antenna is almost the same, however, simple RF-Choke near antenna terminal (0ne- three turns around a ferrite ring is recommended for the design. Distance between reflector and director should be chosen (415- 440 millimeters) for minimum SWR. The antenna has gain near 4,3 dbd.

New Year Pictures from UA6HJQ

http://www.antentop.org/

Page 48