Amateur radio station since 1993






























































































































Experimental Tri Band yagi for 14/21/28 MHz Bands

- Turning radius only 4,5 m

- Boom only 3,4 m

- Gain on 14 MHz 6,4 dBi

- Gain on 21 MHz 5,8 dBi

- Gain on 28 MHz 6 dBi

- Gain about 11 dBi for setting 10 m height

MMANA Model WDK222.maa

Radiation pattern of TriBander on 14 MHz for optimal height 10 m
Radiation pattern of TriBander on 21 MHz for optimal height 7 m
Radiation pattern of TriBander on 28 MHz for optimal height 5 m

OptiYagi Tubes+Wire TriBander 14/21/28 (3 el for 28 MHz)


New antenna (Jule 2016) FiveBander 14-18-21-24-28 MHz


" If you want a thing well done, do it yourself " .... Doing RF switch !


Insertion loss between Port - Input

Insertion loss between Port - Port


The Lighting Protection for Rotors

      I hope you thinking about protection your antenna rotors and station. How many HAMs ground or disconnect their rotor cables?
      So much information has been posted on lightning protection for Rotor in Internet, but not many HAMs used those recomendations. Is not good idea !     

     Static charging (include snow storm and wind) , nearby lightning can be give damage controller of rotor.

     How we can solving this problem? Look here a turnkey solution ! Download description of LPR

     Alex K6VHF introduces a tunkey solution and calls attention to assembled and tested board of LPR.

The Lightning Protection for Rotors support :

Yeasu-G 250/450/600/800/1000/2800/550/5500

Kenpro- KR-400/500/600, complete list look here


     Easy to install, have TVS-diode/Gas tube Arrestor and relay for disconnect your RIG.

     TVS diode shunts RF currents and voltages over 18V, Gas tube Arrestor shunt voltages over 80v.      Relay connect your rotor only for work time.

  Amateur equipment should be single point ground (better outside of hourse/shack).
You must connect ground wire from Lightning Protection for Rotors to ground point.

Lightning protection systems do not always prevent damage to Rotor or Radio. You should still unplug such devices during thunderstorms to ensure sufficient protection !

My Yagi Antenna Construction with Elevation for EME



Modification mini-actuator 12`` Golden Inerstar

More info about actuators :

(This page will try to inform you of the actuator's secrets) Thanks SV1BSX

My simple idea, but heavy-duty for elevation system :

Bolt diam. 14 mm ! Steel plate 4 mm !

90 mm homebrew bearing wishout rollers !

.... my system to put on weight about 2,5 kg


You can use very easy Manual Rotator Control for Azimut or Elevation for DC motor

Duble Band antenna for FM , 145 and 433 MHz , only 1 coaxial feeder 50 Om

You can download : contructions , SWR , MMANA file model. Many Ham use this antenna in Russia and Ukraine with good result for local and Tropo QSO . Easy constructions and good gain : 2,8 dbd in 2 meter band and 5,2 dbd in 70 cm band. I use this antenna for SAT QSO via VO52 with good result .

You can see this antenna use for R3 repiter 145/433 in KO80 near Kharkov

UB9MAR Alexander has sent me photo his realisation of this antenna



Dual band FeedHorn for 1296 and 5760 MHz

Ham`s who work on SHF band from field condition or with small setup know many reason to have a multiband antenna system. Dish is very effective antennas for 23 cm band and above. Many Ham`s use one dish for some bands by change feed horn or antenna module. For example i also use two changing modules of 6 and 3 cm band for small offset TV SAT dish .

DL4EMA Guenter[1] made loop feed of 23 cm band for prime focuse dish and RA3AQ Dmitrij [2] made some different design of loop and diameter of reflector.

1. Parabolic Dish Ring Feed (1998) DL4MEA
2. Ring Feed for Field day (2008) RA3AQ

The main advantage of a loop feed is very simple mechanical configuration and good performance of antenna system for Field days and QSO by TROPO propogation.
I made dual band feed horn with loop feed of 23 cm and additional horn of 6 cm band. This configuration is also simple and has necessary radiation pattern for illumination dish with 0,3-0,42 F/D. The dual feed horn has separate input for both band. The small horn of 6 cm is located inside and behind reflector of loop feed. Part of feed horn of 6 cm using axial choke at the open end of the waveguide and has not influence for part of 23 cm.
The radiation pattern in Figure below shows that the main lobe for 23 cm band has beam width about 130 degress and for 6 cm - about 110 degress. The radiation aperture such as the open end of a rectangular waveguide and loop has near of equal beam width pattern in E and H plane . The backward radiation of this feeds has good suppress and level sidelobe is low .

Pattern for 5760 MHz

Feedhorn for 1296 MHz has been made by RA3AQ and later I added feedhorn for 5760 MHz .

Pattern for 1296 MHz

Measured radiation pattern

Victor UA9YLU made this Dual Band Horn for his Dish SVEC 1,8 m . He got ratio Noise from Sun / Cold Sky - 7 db for 1296 MHz and 4,5 db for 5760 MHz

Vladimir R3GC made this Dual Horn. He used saucepan for reflector of element 1296 MHz.

Alexander UA3OW made this Dual Band Horn.



Horn for 10 GHz with angle of 110 degrees for illuminating Dish F/D 0,35-0,5

Description of S11 for horn with angle of 110 degrees:


Feed horn 10368 MHz , SWR <1.1

Click for large image :

Other Horn for best illuminate offset dish (80 degr) , aperture size 45x30mm , waveguide size 23x10mm


Horn 5760 Mhz for offset dish (80-85 degr.) , click for full size image



Dual Mode Horn 5,7 GHz optimise for 75 degr. offset TVS Dish and Horn for 80 degr offset TVS Dish

click for full size image

Measured radiation pattern Horn for 80degr offset TVS Dish


Dual Mode Horn 24 GHz optimise for 85 degr. offset TVS Dish


click for full size image

SWR < 1,5 23-26 GHz







Compromise Short Horn 5760 MHz for 85 degr. offset TVS Dish

SWR < 1,2 5760 MHz

Measured radiation pattern of Compromise Short Horn for offset TVS Dish

Modification horn for TV SAT dish in 10368 MHz band

Increase in internal diameter to 20 mm !!!


Horn for F/D 0,6-0,7


Modification Horn from SAT LNB - increase diameter to 18,5 ìì inside

"Cold" horn for measurement Noise factor of LNA on 5,7 Ghz and 10 Ghz



Multi Mode Horn with Bi- Orthogonal polarization for Offset dish, 5,1-5,6 GHz for Wi-Fi.


You can download simple calculator for Dish CalcDish.xls (russian)

OK1TEH Matej translated to Calcdish_en.xls



My proect micro yagi in sungle boom for 432 MHz and 1296 MHz band ("LazyYagi")