- Like many fellow radio amateurs, I own a fairly standard shortwave radio station consisting of a 100W HF transceiver driving a 1kW tube power amplifier. I never chose to spend any money on a kW-rated antenna-tuner. Anyhow, I can tune out VSWRs as high as 3÷1 with the adjustable pi-network of the output filter tank inside my power amplifier.
Thus I set out to design an HF antenna with a VSWR of 3÷1, or less, over the full bandwidth of as many amateur radio HF bands as possible. At the same time, my preference went out to the low- and the non-WARC bands. This design exercise resulted in a new kind of antenna which I dubbed Center-Loaded Off-Center-Fed Dipole Antenna, or CL-OCFD for short.
- In proof of its performance, an EZNEC-calculated VSWR-graph of the CL-OCFD antenna is presented in Figure 2. This antenna works without a tuner over the entire bandwidth of the 80, 40, 30, 20, 15 and 10m-band, simply by adjusting the output-tank of your tube power amplifier. —If your final output stage is a transistor amplifier, you definitely will need an antenna-tuner though.— In such, this antenna is the first described single-wire antenna to be offering these capabilities.
See Full Article: Link
“You may have seen my previous video in which I reviewed the Luiton (Leixen) LT-898UV 10 watt mobile radio. In this episode I build an ultra por... Read more
Amateur Radio’s “vital role” in the 2015 Nepal earthquake response was the topic on June 2 as the City of Santa Clara, California, hosted Sanjeeb Pand... Read more
Description A 5 element Long Boom (2.1m) LFA-Q (Super-rigid Quad-style) Super-Light Quad Style Yagi for 144 – 145MHz The LFA-Q Packs a bigger... Read more
Ver essa foto no Instagram January 19 / 2020 – New complete HF Portable QRP Station on the Palm of the Hand – Yesterday Sund... Read more
IC-9700 Icom Inc. has released more details about the launch of the IC-9700 VHF/UHF/23CM All-Mode SDR Transceiver. Icom plans to release this high-per... Read more
DX Engineering Universal Copper Grounding Clamps DXE-UCGC-Z DX Engineering Universal Copper Grounding Clamps are custom designed to provide a ground r... Read more
Alpha 4510A QRP TO QRO. Our Wattmeters can measure from 200 milliwatts to 5 kilowatts, from 160 meters to 6 meters with no slugs! They displa... Read more
ARRL partner RFinder, the creator of a web and app-based directory of Amateur Radio repeaters worldwide, will supply all data for the 2017-2018 ARRL R... Read more
“With all the low-cost performance SDR available these days, we can have a lot of fun experimenting with it. But we need antenna, with the MFJ-1... Read more