B A L U N S . . .
15.04.2015: RF Dummy Load
This is a Dummy Load made of thick film resistor on massive heat sink. Resistor value is 50 ohms 250 W, frequency range from DC to 2 GHz. The load is used with low/medium power transmitters.
Download the PDF file: RF load.pdf
Updated 29.03.2015: HF Ferrite Tube Baluns
Here is a short story of magnetic baluns, which we winded using parallel ferrite tubes. These baluns are typically used as impedance transformers with symmetrical, high-impedance HF transmitting antennas, like terminated V-beams, Rhombic's and T2FD's. Test results of 1:9, 1:12 and 1:16 baluns.
Download the PDF file: tube baluns.pdf
27.02.2015: HF Guanella Balun 1:16
This is a wide band current-type balun, used with high impedance balanced transmitter antennas; V-beams, Rhombic's and T2FD's. It is balanced, quad coil, transmission line balun. This balun can handle over 100W transmitter power.
Download the PDF file: balun 1 to 16 Guanella.pdf
29.10.2013: HF Coaxial-Toroid Choke
This is a simple toroid-based coaxial mantel current choke (current balun) to use with low-power transmitters. Device works on 1 to 30 MHz and is able to handle over 100W carrier power.
Download the PDF file: CMC.pdf
07.10.2013: HF Balun 1:4
This is a wide band antenna transformer used with various balanced antennas. It is a traditional Guanella-type current balun. This medium power balun can handle over 100W transmitter power.
Download the PDF file: balun 1 to 4 dual.pdf
Updated 30.03.2015: HF Unun 1:9
These are wide band unbalanced antenna transformers, used with various long-wire antennas, Beveridges and with some vertical antennas. Low power toroid and medium power ferrite tube constructions.
Download the PDF file: unun 1 to 9.pdf
23.09.2013: HF Single Coil Balun 1:16
This is a wide band antenna transformer used with high impedance balanced transmitter antennas; T2FD's and V-beams. It is balanced single coil magnetic voltage transformer. This low power balun can handle up to 100W transmitter power.
Download the PDF file: balun 1 to 16 single.pdf
A N T E N N A S . . .
Updated 25.08.2016: T2FD-NVIS Antenna
Wideband T2FD type suits well for amateur radio stations general purpose antenna. It has low SWR; usually it works without antenna tuner. T2FD is fine listening antenna; it is rather immune to wide-band urban noise. This version is omni-directional NVIS version assembled as inverted-V dipole.
Download the PDF file: T2FD_NVIS.pdf
06.01.2016: Horizontal Loop HF antenna
General purpose, near omni-directional transmitting antenna. Low SWR on some ham frequencies on 3-30 MHz. To be used with antenna tuner or coaxial auto tuner. NEC simulations only.
Download the PDF file: H-Loop.pdf
02.01.2016: Terminated Dipole, HF antenna
This antenna is a Traveling Wave -type omni-directional wide-band HF transmitting antenna with low SWR. It is like the V-Beam, with apex angle of 180°. Typical limited-space monitoring antenna...
Download the PDF file: Terminated Dipole 2016.pdf
17.02.2015: J-wire VHF antenna
Simple and light J-pole replacement antenna for field trips. Narrow band 70MHz prototype.
Download the PDF file: J-wire.pdf
16.02.2015: Coaxial Dipole, Dual Bazooka antenna
Some theory and typical dimensions for HF coaxial dipoles. Antenna type is single band dipole presenting wide band width. Contains measured SWR chart for 40m test antenna.
Download the PDF file: coaxial_dipole.pdf
Updated 03.01.2016: Tests with Longwire antennas
We made some SWR tests with the traditional Longwire Antennas. Test antennas were fed with 1:9 baluns and wire lengths were from 51 to 200 meters at 2,5m to 10m heigth. This document contais also some radiation pattern simulations.
Download the PDF file: longwire.pdf
Updated 03.01.2016: Terminated Vee Beam antenna
We made some simple tests with the Vee Beam antenna. Test antenna was fed with 1:16 balun and had two 400R terminators. Wire length was 33m each and the mast heigth 9m. Document contais also some radiation pattern simulations.
Download the PDF file: veebeam.pdf
OH1AYR is an amateur radio station.
Locator: KP11LC, N 61.0838, E 22.9175.
Operator , license since 1982.
Lazy phone operator: sometimes heard on 3.7 MHz SSB. Favorites: Wire antenna testing, QRP & PSK. Member of SRAL & OH1AL. QSL via eQSL. More info on QRZ.com. Sorry, we do not sell antennas or components.