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Next generation of pa0fri antenna


Frits, pa0fri describes the new generation of its wire antenna. The article about new pa0fri wire centerfed antenna (yet under construction in english) is here:  http://pa0fri.home.xs4all.nl/Ant/PA0FRI%20Antenna/pa0fri%20antenna%20eng.htm

The main idea was simple and good matching for coax fed of the antenna in 80 meter band.

My experiences

The antenna gives good results on 3.576 MHz (tested on JT65 mode). The important dimensions are:

1. Length of dipole L = 2 x 16.5 meter.
2. Configuration: INV V.
3. Height of instalation in feed point: H = 10 meter.
4. Length of ladder line 570 Ohm: LL = 12 meter.
5. Pass trough the wall is realised with two coaxials (2 x 0.5 meter), the pass trough the wall reduces the required length of ladder line.
6. Was used only one serial capacitor from koax (coax type is RG 58, length in my instalation is l = 2530 mm, C = ca 200 pF).
7. No baluns are required, tested for short coaxial H155 (3 meter) and also for ca 20 meter long cable.

Schematics of antenna

Matching in Smith chart on 3.556 kHz


The antenna gives good results and excellent matching on one of frequencies of 80 meter band (for JT65 segment was VSWR below 1:1.2 after adjustment of coax capacitor). The antenna can be easily matched with the automatic unbalanced tuner on all bands from 80 meter to 10 meter.


© 2014  Míra Šídlo, ok1ufc, datum poslední úpravy:03.01.2015