- Whenever you choose a coax feedline, the frequency of operation is a very important consideration. Over the operating bandwidth of the coax the VSWR is low, typically 1.2:1 or better. Insertion loss is also an important parameter. It is usually specified in dB/foot and is a linear relationship.
Antenna Selection Made Easy
- This page will help you answer important questions about antenna 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.
Maximum Usable Angle
- We are all familiar with Maximum usable frequency. Maximum usable angle is the other half of the maximum usable frequency equation.
NCDXF/IARU Beacon Project
- The NCDXF, in cooperation with the IARU, constructed and operates a worldwide network of high-frequency radio beacons on 14.100, 18.110, 21.150, 24.930, and 28.200 megaHertz. These beacons help both amateur and commercial high-frequency radio users assess the current condition of the ionosphere
Frequency Calibration for Weak Signal Work
- Accurate calibration of your receiver and sound card is necessary for good results with the weak signal modes in use at LF. Modern receivers with master oscillators that are synthesized to provide all conversion frequencies greatly simplify the process. This article describes a method of making the necessary measurements and adjustments to an ICOM R75 receiver and a sound card, using the ARGO software
The Radio Reference
- RadioReference.com, scanner frequency and radio communications reference source, with complete conventional frequency assignments, trunked radio system information, frequencies, and talkgroups, FCC License assignments and maps, 10-Code Lists, agency maps, files, downloads, links, and detailed agency information for most public safety, military, and local government activities.
- WEaudio was born as a program to record activity on VLF band, it can records audio file on HD as long as you want within prefixed pauses. It can starts record at the hour you want to monitor.
WD6CNF DSP Filter
- Audio Digital Filter, two bandpass filters, three notch filters, two noise filters
graphical setting of filter center frequency and bandwidth Drag vertical lines on top of signal,
Microphone input, speaker output
Mono, 5 kHz bandwidth
- RigResident is a small program for RIG control, which does allow to set and read data of connected tranceiver (frequency, mode etc).
RigResident supports more than 70 TRX models from ICOM, KENWOOD, YAESU and Ten-Tec.
- SpectraScope is a simple Windows interface program allowing your computer to view up to two audio waveforms in either the time or frequency domain. The program is a Windows soft panel operating as a dual channel oscilloscope and spectrum analyzer. The useful frequency of operation is 20 to 10,000 Hz in the time domain and 20 to 20,000 Hz in the frequency domain. The program uses the computer sound card to capture the audio input.
Safety: RF awarness guidelines
- Although Amateur Radio is basically a safe activity, in recent years there has been considerable discussion and concern about
the possible hazards of electromagnetic radiation (EMR), including both RF energy and power frequency (50-60 Hz) electromagnetic fields. This section summarizes what is now known and offers safety precautions based on the research to date.