Matching SHORT Balanced Antennas
Matching very short antennas is difficult and prone to very high power loss in the antenna tuner. This is especially true when trying to match very short 160m antennas such as the short 600 Ohm Ladder-Line-fed 14m (46 ft.) long dipole described here.
Most commercial antenna tuners cannot match such antennas at all on 160m, and the few that can have very high loss.
German amateur radio operators living in the most densely populated country in Europe are challenged to erect effective 160m antennas on their "postage stamp" size yards.
As they say, Necessity is the Mother of Invention!
One Germany 'ham' has researched
matching short antennas for a dozen or more years and created several interesting, purpose-designed antenna tuners. However, none of his efficient tuners are able to match 160m + all HF bands. He uses different tuners for different bands.
This page compares Alfred's 'first' 160m Link-Coupled tuner to 5 other tuners.
Feedline Length: 5.5m (~18 ft.), 600 Ohm Ladder-Line Height (AGL): about 10m (~33 ft.)
6 Antenna Matchboxes Tested on 160m
These were the only antenna tuners Alfred had available in 2011 when he conducted his test.
MEASURED RESULTS:
Footnotes:
- No 160m foreseen
- Unable to find a match on 160m
- The Annecke is an improved J.V. tuner.
Results Comments:
- The Heathkit and SA-2060A and DF2BC's home-brew 160m Parallel Coupler were the only two tuners that could match the antenna on 160m.
- The home-brew 160m link-coupled tuner transferred twice as much current to the feedline as the 2060A. This equates to 4x as much power!
- The 2061A tuner was converting at least 3/4 of the transmitter's power to HEAT!
- The Annecke Symmetrical Coupler is an improved version of the Johnson Viking Matchbox. Specifically, it has an improved circuit on the TX side of the link coils. See this link for a description: https://www.dj0ip.de/antenna-matchboxes/symmetrical-matchboxes/viking-vs-annecke/
The DF2BC Link-Coupled 160m Tuner:
Note: You will find detailed d-i-y instructions for building this 160m tuner on my other web site, here:
https://www.dj0ip.de/open-wire-fed-ant/short-antennas/short-160m-antenna/
Alfred's full test comparing these 6 antenna tuners on all HF bands is posted on my other web site, here:
https://www.dj0ip.de/open-wire-fed-ant/matching-o-w-f-antennas/tech-shoot-out/
Alfred's Matchbox Shootout was published in the May, 2011 issue of the DARC's "CQDL" magazine, on pages 332 & 333. The information posted here and on my other web site (https://www.dj0ip.de/) is posted with permission of "DARC Verlag GmbH" and Alfred Kluss (DF2BC).