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I was born in Sinj (Croatia) in 1959, and became ham operator in 1974. I am RF Engineer, with Master's degree from Uni of Zagreb. 

QSL via bureau, direct or LOTW on e-mail request. I have all DXCC countries confirmed. My interests are: antennas, kites,  portable and very fast CW.

Urban environment is very noisy, and DX signals at low angle are heavily attenuated. I seek dominant locations and setup portable station - with big antennas, amplifier and power generator.

I have 50+ kites for antenna lifting, and I know how it feels to run antenna 150 m (500") high.

Spiderbeam poles (I have all sizes) complement kites to quickly setup good antennas.

My gear includes: TS-480, IC-7300, AL-1500, 50+ kites, 7 Spiderbeam poles and 2 push-up masts.

Typical antenna is 3 element vertical yagi - even on 160M. Some of my antenna projects are on dropbox, see link:   https://www.dropbox.com/sh/bvx2jncb1ny9mbl/AADLuyttl6MXs0IOenOjvAaua?dl=0

Portable Low Band Antenna Evolution​

1. I started with Ground Plane (GP) antenna - vertical monopole with 4 elevated radials.

2. Vertical Dipole (VD) is 1.5dB better then GP, good at clearing ground obstacles, and less dependant on good RF ground.

3. Elevated VD by 0.5 wavelengths adds 1-3dB, and is even less dependant on ground RF properties.

4. Vertical Yagi (VY) can add 5dB more on top of elevated VD.

5. Bottom feeding keeps heavy bits (coax, balun) low, and reduces mechanical loads.

6. Using kites to lift antennas very high, combined with Spiderbeam poles.

 

Vertical yagi with bottom feeding is my antenna of choice, 9dB over GP and very independent of ground properties.

Bottom feeding means you keep heavy bits (coax and balun) very low. This reduces mechanical loads, and you can use fibreglass poles instead of towers.

For high bands I use Spiderbeam yagi (remodeled with enamelled copper wire) and 18m push-up pole.

Figure 1: Portable From Car                           Figure 2: Spiderbeam Yagi on 18 m (60') Push-up Mast

 

Figure 3: Kenpro 2700 Suits Windy Places Like Hilltops            Figure 4: QRP is Living in Denial -  Accept Laws of Physics !

 

AL-1500 looks very robust and sleek, with matching tuner MFJ-9982 and external QSK unit.

I use paper log, and send CW by hand - no computer and no microphone. I can receive CW at 50 WPM, but sending fast CW from car is hard. I have to somehow improve mounting for the key.

I fly kite lifted antennas, and have over 50 kites for different wind conditions. Kites enable quick and easy antenna lifting at any location.

 

Figure 6: My favourite team : Jasna and our grandson Sonny

I use Spiderbeam poles to complement kites (2x12m, 3x18m, 1x22m and 1x26m).

I enjoy experimenting with wire antennas, especially bottom feed vertical yagis. Highly unbalanced high impedance feeding is problem with this antenna type. Reducing feedline radiation is a major challenge. Using high power and directional antennas makes it even harder. I have developed high performance tuner / transformer,and multilayer choke baluns for bottom feeding.

Lightning protection is also important when flying 150m high antenna from a hilltop. My coax choke baluns are part of protection system.

My other interests : Rugby Union, Matlab, C++ and Embedded Systems.

 

Example KiteAntenna : bottom fed half wave vertical for 160M band

This vertical is 80m long, radials are not required. Bottom is 16m high, top is 96m high.

Spiderbeam 18m pole holds end fed tuner and coax 16m high. Short fishing rod works very well too.

Figure 7: Portable Antenna For Top Band

Kite lifts vertical antoher 80m above spiderbeam pole. This antenna peaks at 10 degrees elevation (over average ground). Small dot is delta coyne kite used to carry vertical. Antenna wire is copper 0.85mm diameter enameled wire. Copper loss is only 0.15dB, antenna weighs only 370 grams. I use second kite to carry reflector,3rd for director. If wind is slow, I run kites in trains ( 2 to 5 kites on one line).

Home made bottom feed tuner (resonant paralel LC with isolation transformer 49:1) for end feeding at 2400 Ohm. I also make 9:1 balun for 600 Ohm Off-Center-Feed into 75 Ohm coax like RG-6. Tuner adjusts impedance for coax, but antenna is very asymmetrical. I use at least 2 coax-choke baluns in feedline (multilayer resonant coaxial choke design).

Figure 8 : Home Made Bottom Feed Tuner - 2400 to 75 Ohm

 

Figure 9: Our German Wirehaired Pointers: Max and Simba

 

 

7734380 Last modified: 2016-12-02 21:45:42, 6157 bytes

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