20m delta looppop
- This antenna is fed for vertical polarisation, to give a low angle of radiation for DX and also a nearly omni-directional radiation pattern
- The Cedevita-20 is a hybrid monoband antenna, the result of merging the radiator of a shortened vertical with one element of a dipole. It fits on most balconies and must be hung from the ceiling.
By ik1zyw Paolo Cravero
EH antennas and CFA antenna
- Many antennas function because of common mode currents, rather than working in spite of them. Two popular examples are CFA and EH antennas. Another recent example, appearing in Antennex's compact antenna articles, is a thick stub "vertical" with no counterpoise.
G5RV multi-band antenna
- Multi-band centre-fed antenna capable of very efficient operation on all HF bands, specifically designed with dimensions which allow it to be installed in gardens and other open spaces which accommodate a reasonably-straight run of 31.1m (102 ft) for the flat-top standard model.
The G5RV Antenna System Re-Visited
- The original G5RV antenna system consists of a center-fed horizontal 102' wire plus a 34' length of open-wire 525-Ohm feeder. Louis Varney, the antenna system's developer, intended two other features. Learn more at Cebik website
Antenna Polarization notes
- Antenna polarization is a very important consideration when choosing and installing an antenna. Most communications systems use either vertical, horizontal or circular polarization. Knowing the difference between polarizations and how to maximize their benefit is very important to the antenna user.
RadioExam.org Amateur Radio Exams
- Exams on this site are for Amateur Radio licenses issued by the US Federal Communications Commission, and are only valid in the United States and any other locations under FCC jurisdiction
KVK Antenna Systems
- The manufacturer of the NuBeam, Vipole, and the multi-band Quad-Folded-Dipole (or QFD for short) antenna. Also have a unique multiband vertical which can combine operation on multiple HF frequencies as well as provide high gain on 50, 144 and 438MHz in a single antenna.
WD6CNF DSP Filter
- Audio Digital Filter, two bandpass filters, three notch filters, two noise filters
graphical setting of filter center frequency and bandwidth Drag vertical lines on top of signal,
Microphone input, speaker output
Mono, 5 kHz bandwidth
Assessing unknown Ferrite Toroids
- Ok so you have had a good day at the Rally and you have come back with a carrier bag full of ferrite toroids that "just might be useful for something". How do you find out what they are? Very few seem to be stamped with any indication of their properties, and some are 'painted' garish colours which presumably means something.
QRM and noise reductionPriority listing
- You will find on these pages my experiences and results on antennas and local/non-local QRM/noise reduction. Using a broadband vertical active magnetic loop and a home made / designed broadband amplifier. Two vertical magnetic Alford loops are used in an array.
Analog and Digital Signal Processing and a dual phase coherent Software Defined Radio (SDR) are used. By PA0SIM