hf propagation

Active HF antenna - An active HF receiving antenna circuit by G7BCJ

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 transceiver’s output power verses the portion of that power reflected by the antenna system By Ken Larson KJ6RZ

Mobile Helix Antennas for HF - Normal mode helix antennas for HF mobile. Photos andn plan for a 20 meters mobile helix antenna by N2MH

Copper J-Pole Antennas - Conejo Valley Amateur Radio Club, article edited by Rory Eikland, KG6HCU and Ken Larson, KJ6RZ, they have had excellent experience building and using J-Pole antennas, and share their experience on planning VHF and UHF Jpole antennas.

Remote antenna tuner controller - Software to remotely tune an HF antenna, included in help a principle hardware picture, by M.Recchia IK0VVE

VHF/UHF Yagi Antenna Design  ^{updated  pop} - Design your vhf yagi antenna online, a JavaScript enhanced web page that implements the design of an antenna in the VHF, UHF by K7MEM

New HF antenna HB9ABX  ^pop - A new, revolutionary design allows the construction of small HF antennas, which provide the same efficiency as large antennas. This antenna can be built for all HF bands, from 10 to 80 m.

G0GJV VHFLog - VHF contest logging program, run in DOS mode

10 Meters - European beacons map - Map in png format of european beacons transmitting on 10 meters band by Ari Catanzaro

New York Hudson Falls live scanner - Live feed from Warren county fire dep. radio

Spider Antennas - Compact HF antennas for home and mobile use, compact HF maritime antennas, manufactured by multi-band antennas

Ciro Mazzoni Antennas - HF Antennas, magnetic loop antenna, based in Italy

Alpha Delta Communications - Manufacturers and distributors of coaxial surge protectors, coaxial switches, HF fixed wire antennas

GLA Systems - Texas BugCatcher antenna manufacturers. Mobile antenna for hf bands. The serious HF Mobile Antenna by Henry Allen, K5BUG

About digital modes - The digital modes provide a wonderful opportunity for those of us who would like to work on the HF bands but find CW too difficult and SSB phone prohibitive because of interference problems. The digital modes are easy to set up and get operating, require low power and a narrow band.

Let's Go T-Hunting - An introduction to RDF contesting in southern California, updated from a paper originally submitted for Proceedings of the 1992 West Coast VHF/UHF Conference.

Topband - 160 meter Radio Propagation - Here you will find a variety of tools which will hopefully help you improve your chances of succeeding at Topband (160 meter) DX.

HF Radio wave propagation - Radiowave propagation in the medium and high frequency spectrum in DOC format

Yaesu FL-2100Z Linear HF Amplifier Mods - Two usefull modifications of the FL 2100

FTBVR5K VR-5000 Radio control - Memory management programming software for the Yaesu VR-5000 receiver

Propfire Firefox propagation extension - Propfire is an extension to the Firefox web brower that displays current propagation information by N0HR

FTBCAT Cat radio control software  ^pop - Free CAT control software for Yaesu FT-100, FT-100D, FT-817, FT-817ND, FT-847, FT-857, FT-857D, FT-897, FT-897D, FT-920, FT-1000MP Mark V, VR-5000 and FRG-100 transceivers.

FTB60 radio control - Memory management program for the FT-60R/E FM handheld.

Programming VHF/UHF Radios - Programming a new VHF/UHF radio usually proves to be a frustrating experience for most new amateur radio operators. A new radio must first be programmed for simplex and repeater operation before it can be used to communicate with local hams.

A 80/40m Direct Conversion HF Receiver with DDS VFO - Juha (OH2NLT) and Matti (OH7SV) have designed JUMA-RX1, an award winning 80/40m direct conversion HF receiver with highly accurate direct digital synthesis VFO. The receiver is very compact, because it constructed using surface mount components. No coils need to be wound to construct this receiver!