End-Fed Halfwave Antennapop
- The end-fed halfwave antenna is a resonant half wavelength long antenna like a dipole antenna except for it is fed at its end rather then in the center. This antenna is as old as radio and is probably best known as the Zepp Antenna
A $20 HF mobile antenna
- A few hours of fun with PVC and wire and
you’ve got yourself a respectable road radiator. The antenna consists of little more than some PVC pipe topped by a RadioShack replacement whip antenna and a couple of coils made from a small roll of #14 house wire.
- The SoftRock-40 is a small, low-cost, good-performing "software defined radio" receiver that plugs into a computer USB port and delivers I-Q audio signals to the computer's sound card. It was designed by Tony Parks, KB9YIG and Bill Tracey, KD5TFD as an "SDR sampler project" for hams everywhere to easily try out software defined radio.
- In the VLF portion of the spectrum it is easy to listen to the emissions created by the Earth itself. These emissions are generated by many different mechanisms and are often beautiful to listen to. Coverage on LF and MF frequencies
- MFSK is an easy-to-use chat mode for real-time amateur contacts, nets and bulletin transmissions, but not intended for contesting or Bulletin Board System (BBS) use. It is a half-duplex non-Automatic Repeat ReQuest (ARQ) forward-error-correcting (FEC) mode. It performs well on long-path fading conditions and in the presence of interference
A low power 3.5MHz ARDF transmitter
- This low power transmitter is developed for ARDF exercising purposes but of course can be used as super QRP transmitter either. With 1 or 2 meter wire as antenna and a ARDF receiver with ferrite-rod antenna the range is about 100m but with better antennas and a 'real' receiver the range is probably much larger.
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.
Wavefront CompactPCI (CPCI) RF converter
- The Wavefront CompactPCI (CPCI) RF converter provides a complete half-duplex radio front-end in an industry-standard 6U format. The architecture consists of dedicated receive and
transmit channels that share a common RF interface.