QM5 Yagi for 2 meters band
- The QM5 antenna is a simple 5 elements Yagi with 1.88 m boom length for the lower 144 MHz SSB/MGM band, I used it mainly for Sporadic-E and MS contacts. It exhibits a forward gain of 9.17 dBd; i.e. 11.3 dB forward gain over the isotropic radiator, while the F/R is about 11.5 dB. Elements
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QM7 7 elements 144 MHz Yagi-Uda Antenna
- The QM7 antenna is a simple 7 elements Yagi with 3.70 m boom length for the lower 144 MHz SSB/MGM band, used it mainly for Sporadic-E and MS contacts. It exhibits a forward gain of 11.35 dBd; i.e. 13.5 dB forward gain over the isotropic radiator, while the F/R is about 12.5 dB
A magnetic loop antenna for HFpop
- Able to cover all frequencies between 3.5 and about 10 MHz, the loop described here is directional, does not require a radial system, and stands just 1.8 metres tall. Most parts needed can be purchased at a hardware shop. The antenna can be put together in an afternoon and requires only hand tools to assemble. It should cost less than sixty dollars to build.
by Peter Parker VK3YE ex VK1PK
Understanding Standing Wave Ratios SWR
- We worry a lot about Standing Wave Ratio (SWR) in amateur radio since SWR is one indication of how well our antenna system is working. Most HF transceivers and antenna tuners have built in SWR meters. SWR is a measure of a transceiverís output power verses the portion of that power reflected by the antenna system By Ken Larson KJ6RZ
Thinking about Ideal Loops
- Loop antennae have been used from ELF to UHF since the beginning of radiocommunications. At low frequencies, the main problem for loop antennae is to have enough sensitivity; the antenna being very small respect to the wavelength the collected energy is also small. To increase the output level the loop may be made resonant, so loosing it%u2019s intrinsic aperiodic characteristics.
A two dollar helical hf portable antenna
- Hereís an easily transportable vertical antenna for 20 meters collapsible to 4 feet that costs about $2.00 to make.
This was created as a fun project to demonstrate how to enjoy operating HF in the field with a home-made portable antenna without spending a ton of money.
Bev AH6NF (YL) made this antenna, tuned and ready to operate in less than one hour
Antennas : theory and designs
- Thierry LOMBRY, ON4SKY, develops in several long articles all you need to know aboutantennas, their design and performance, for both amateurs and SWL
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Antenna Selection Made Easy
- This page will help you answer important questions aboutantenna selection before you talk to a supplier. After reading this paper, you should be able to better determine the most important parameters you need to know for your antenna selection criteria.
- Signal Engineering technologically advanced antennas with modern design and construction technique. Up to date information about current line of high performance 10 and 11 meters antennas.
HF Antennas for restricted space
- Arrl document about invisible antennas and indoor systems. It is important to consider that few compromise antennas are capable of delivering the performance one can expect from the full-size variety. But the patient and skillful operator can often do as well as some fellows who are equipped with high power and full-size antennas. The "cliff-dweller" may not be able to "bore a hole" in the band as often, and as easily, but DX can be worked successfully when band conditions are suitable.
- A full featured, graphical, user friendly program that performs structural analysis on horizontally polarized yagi antennas constructed from round tubing. YS can work in Imperial or Metric Units, and is likely to tell you more about a yagi antenna than you ever thought you needed to know. YS has been used by commercial manufacturers and premier station builders for over a decade by Kurt Andress, NI6W