Describing and demonstrating an end-fed multiband antenna for portable use.
It’s a full-sized half wave on 20 metres and a loaded half wave on 40 metres. The antenna also works on 10 metres. It’s not recommended for use on other bands.
A broadband transformer replaces the antenna coupler. While it’s likely less efficient than an L-match antenna coupler this arrangement allows instant band changing. Its only disadvantage is that its bandwidth on 40 metres is somewhat narrow (150kHz approx) when used with the loaded half wave wire described.
Similar to the Par Endfedz design this transformer will work on other bands with a half wave wire. With 10m of wire I could get low SWR (as indicated by the FT-817’s indicator) on 20 and 10m. 20m of wire gave those two bands plus 40 and 15m. Some variation of the trimmer will however be necessary so it’s worth carrying a small screwdriver, preferably attached to the transformer unit to prevent loss.
There’s a bit of cut and try in construction. Those wanting a premade unit should investigate either the Dutch HyEndFed or the American Par Endfedz 40/20/10m end-fed models. Both have received good reviews on eham.net .
Check these links for further info:
The USA contacts included were on 20 metres, made in the morning. Good contacts have also been made within VK on 40 metres.
The International Amateur Radio Union (IARU) Region 1 Monitoring System (IARUMS) August newsletter reports that Radio France International was active... Read more
This video illustrates how RF (radio frequency) standing waves are created in transmission lines – through the addition of the forward (t... Read more
This high ruggedness device, MRF1K50H, is designed for use in high VSWR industrial, scientific and medical applications, as well as radio and VHF TV b... Read more
How to Receive Beautiful Images of the Earth Directly From Space | GOES-15,16,17 and Himawari 8 HRIT
“In the fall of 2016 I saw my first rocket launch and little did I know that the satellite on that rocket would come to shape and fill my though... Read more
A post on the D4C Facebook page says: On May 6, 2015 history was made on contact across the Atlantic on VHF bands on the W-E path: The new D4C... Read more
Amateur Radio on the International Space Station (ARISS) has announced a “notable contribution” from the Quarter Century Wireless Association (QCWA) t... Read more
In light if the coronavirus pandemic, the ARRL Public Relations Committee has extended the nomination deadline for the Philip J. McGan Memorial Silver... Read more
Storm Storm Comes & How Starlink Fell | Space Weather Briefing 02.09.2022 Read more
Available for PC, Mac, smart phones, tablets or Kindle devices A comprehensive guide to the RTL2832U RTL-SDR software defined radio by the authors of... Read more
Warning: file_get_contents(https://plusone.google.com/_/+1/fastbutton?url=https%3A%2F%2Fqrznow.com%2Ftriband-end-fed-half-wave-antenna-for-portable-use%2F): failed to open stream: HTTP request failed! HTTP/1.0 404 Not Found in /home/qrznow/public_html/wp-content/themes/goodnews5/framework/functions/posts_share.php on line 151