Quadrafilar Helix antenna for 436 Mhz
- This is an antenna that author just built. Was intend for receiving the AO-27 downlink (at 436.800 +/- doppler). It is built with right hand circular polarization, and the gain is supposed to be in the neighborhood of 3 DB.
440 Mhz J-Pole Antenna plans
- Here is a 70cm (440 Mhz) J-Pole antenna that is inexpensive, and easy to build. Author use 1/2 inch copper pipe, and the associated fittings necessary. The dimensions arenít typical however, this is what it took to get its SWR low.
Super J-Pole for 435MHz
- The Super J Pole antenna is a co-linear vertical consisting of a number of half wave length vertical elements separated with half-wave length stubs (Tuning stub) feed with a folded matching stub by vk6ysf
An Unusual Magnetic Antenna
- This article by OK1FOU describes how to build a relatively small loop antenna which can be placed for instance at the balcony. It is especially suitable for a two band antenna covering two adjacent amateur radio bands (10/14 MHz, 14/18, etc.)
The G3BGR Magnetic Loop
- This ia a home built Magnetic loop antenna which was used by G3BGR, indoors on 7,10 and 14Mhz. The basic idea was in Radcom 1986
- Multiplatoform freeware DSP software. Linrad has its origin in software that was developed for 144 MHz EME CW but it is quite general and should be seen more like a kit for designing a receiver that a receiver for some particular usage.
It can be used as a CW receiver with a small time delay and a fast waterfall graph. A dsp for conventional receiver to imporve signals readability, a spectrum analyzer.