designing for MF and LF communications When radio began, it started with low frequency communications, which it was thought was the answer to long distance communications. Since then we have seen the development of sky wave communications on HF frequencies, followed by the proliferation of communications system using the VHF and UHF direct wave and…
Category: Articles
Here you can find articles I’ve cached, that are no more available in the net or are very rare to be found. Where possible credit will be given to authors.
Feeder Radiation
When you connect centre fed antennas, like dipoles, Vs, triangles, yagis, rhombics, loops and so on, to coaxial cable, unless care is taken, it is not difficult to end up with feeder radiation.
Folding the Dipole Antenna
About folded dipole antennas
Magnetic Longwire Baluns
Do these things do exactly what they say they do – or are they total hogwash? Have you seen the ads? This device will match your long wire to your receivers 50 ohm input? Firstly a long wire on HF would be on 28 MHz longer than 120 foot and on the lower bands it just…
160m Antenna – Inverted L
Another antenna added from the antenna plan is a 160 meter ¼ wavelength inverted L. A 130 foot length of 12 gauge PVC covered stranded wire slopes up from the ground system to the 40 foot level of the 45 foot tall fiberglass flagpole (about 60 feet of wire length) and then proceeds about 70…
The gamma match
The Gamma match is the most used matching device used for yagi beams. What it does is: A Yagi almost never has an impedance of 50 ohms. In other chapters i told that Gain, bandwith, F/B etc. all relate to eachother these figures are never all high at one point. A well designed yagi has…
Kenwood KPG-46 programming cable
Kenwood KPG-46 Programming Cable Suitable for the following radios: Kenwood TK-71 TK-81 serie Kenwood TK-7302 / TK-8302 NX-700 de Kenwood / NX-800 Series Kenwood TM-271E Component List: C1 470?f 16v. C2 47?f 16v. C3 a C6 10?f 16v. IC1 MAX 232. REG1 78L05.
Windom Antenna 10-80
A windom antenna for 10 to 80 meters band – a design by PU1LHP
A 40m Vertical Antenna
A Vertical Antenna for 7 HMz
DX Century Club First post-WWII Countries List
Postwar Countries List Official List for ARRL DX Contest and the Postwar DXCC From QST, February 1947, pp. 49 – 50 MANY of the DX men have been at a loss to appraise accurately their postwar DX accomplishments because the last revised Countries List was made up back in 1939 and, since that time, many…