hf propagation

A portable 2-element VHF yagi  ^pop - Build a portable VHF yagi antenna for 2 meters. All you need is two rabbit ear antennas from Radio Shack, two CATV baluns, four feet of 3/4 CPVC pipe with one tee.

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.

HF Receiving Loop Antenna - HF receiving loop antenna, an easy-to-make receiving loop antenna for HF

Effective HF Mobile Antennas - Effective HF Mobile Antennas Keith WB2VUO, explains difficulties on gaining antennas efficiency on lower bands with mobile antennas.

9 band vertical HF antenna by RW3XA  ^pop - Simple vertical radiator with matching box. No traps, no tuner required.

Transmitting Antennas For HF Broadcasting - This paper discusses a number of common used HF transmitting antenna systems and corresponding reference antenna codes. The latter was developed in close consultation with regional coordination groups ABU-HFC, HFCC-ABSU.

How create simple dipoles - How to create a simple but effective half wave dipole, illustrated instrucions on how to build wire antennas

GDXF - German DX Foundation - The German DX Foundation (GDXF), founded in 1996, was established to support HF DX activities - on all bands or modes - to rare countries all over the world

Ham Radio HF Nets - Amateur radio HF nets

Ontario Emergency Communications - Assisting in relaying information to local authorities in Ontario in the event of an emergency.

Auckland ATV Group - The ATV User's Group is a subgroup of the Auckland VHF Group, Club call ZL1BQ, compromising of persons interested in the transmission and reception of Amateur Television

AF2CW - DX, CW, Propagation, Licensing, Boat Anchors

IC-PCR 1000 in Germany on-line receiver - Icom PCR 1000 HF/VHF/UHF Antenna VHF/UHF Diamond X 50N HF W3D22 80m/40m 34m (111,54 feet) long based in Germany Hamburg JO43XO.

OM Power - HF Amplifier - Strong RF HF power amplifiers made in europe ! Output 2,5KW 4KW PEP, 160m to 10m.

Autotena - Antenna manufacturer in Taiwan, products range are RF communication antennas ( CB, VHF, UHF, Dual band, Base Station, Marine, GPS,GSM, PCS, Cellular, DVB-T ) , Amplifiers , Mounting Kit ,Accessories & Related products.

The reflected W beam - Hexagonal wire beams for all hf bands, technical resource, EZNEC files, tools for antenna modeling and documentation. You can also order parts to build your own antenna.

Yaesu FT-817 Portable QRP Transceiver - The FT-817 is a small 5W MF/HF/VHF/UHF transceiver with internal batteries. Here is an assortment of technical information K6XX put together about this rig that might interest you.

ACARS VHF Data - The first of a series of articles that provide an introduction to the latest ICAO defined digital communication modes, including VDL modes 2, 3 and 4. In this edition we begin with the current ACARS application then bring this up to date with AOA.

Sydney Scanner Frequencies - One of the best compilations of frequencies in Sydney particularly SW. Include Police, other emergency people, Marine, the entire aircraft list for Sydney, RAAF squadron frequencies, UHF CB frequencies as well as a heap of miscellaneous frequencies like security, shoppin malls etc.

Long Beach California Frequencies - A complete list on Long Beach Frequencies. Long Beach Police Penal Codes, and Police 10 Codes

PC-HFDL - Freeware acars deconding software for windows.

RAUMUF - MUF Calculator by G7RAU ( upload updated 31 August 2002) for calculating the possible e MUF on VHF during es season.

G7RAU Live MUF V7 - Live MUF is a DXC (cluster) telnet client which attempts to resolve propagation modes from spots and also attempts to calculate sporadic e possibilities purely based on incoming data from the cluster

Satpro - SATPRO is an earth satellite tracking software package for the IBM-PC and compatible class of microcomputers running MS-DOS. The forte' of SATPRO over other software packages is the accuracy of ephemerides produced and the number of simultaneous propagations that can be accomplished

Kenwood TS-950S RF gain mod - The Kenwood TS-950S and TS-950SD HF transceivers are fine radios. However, many, if not all, of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF