Archive for October, 2017

Many hams equate frequencies and bands with colloquial usage. Therefore VHF is 2 meters, specifically 144 to 148 MHz, and HF is 160 through 6 meters, just like on our HF radios. Oops. VHF refers to Very High Frequency, and is a chunk of radio spectrum from 30 to 300 MHz- all inclusive. That places […]

Many amateur radio projects use fiberglass tubing and there are some precautions you should take when handling it. When the tubing arrives – before you open the box – be prepared. There may be fiberglass dust, slivers or particles present when the fiberglass parts were manufactured. Your best bet is to open the box outside, […]

An antenna analyzer is a useful tool for adjusting commercial as well as homemade antennas. The primary use of an antenna analyzer is to determine the current resonant frequency of an antenna to allow adjustment to the desired frequency; however antenna analyzers can also be used for other tasks, including: * SWR, Complex Impedance, Vector Impedance measurement * Return Loss, Inductive Reactance, Capacitive reactance * Electrical length of a section of coaxial Cable (Select models) * Feedline loss of a length of Coaxial cable * Frequency Counter and signal generation * Graphing display (Select Models) * Memory for storing graphs (Select models) * Multi language display (Select models) * Frequency range scanning (Select models) A table of Antenna Analyzers and available features can be found at the following link: caa500markii_it.pdf Selection of an appropriate analyzer is primarily based on the range of RF frequencies that you need to measure. Secondary consideration would be the need for features that are available only on certain analyzers. In general, HF only analyzers are less expensive than those that also include VHF,UHF and microwave capabilities. Some analyzers can handle reference impedance SWR measurements for standard impedances other than 50 ohms, such as 25, 75 and 100 ohms. Depending on the analyzer, the RF connector may be BNC, PL-259 or N connector; some include N to PL-259 adapters. Some analyzers have memories and the ability to connect to a USB port on your computer to download memorized measurements for later reference and analysis. This can be very useful for “what has changed” investigation.