2
$\begingroup$

I have one straight horizontal wire antenna 35 meters (114.83 feet) long.

I want to make it work the best on average for the 80, 40, 20 ,15 and 10 meter amateur bands.

Can anyone tell me the best place for the feed point to make it work the best on all the bands ?

I'm happy to use an antenna matcher, can put the feed point anywhere and shorten the antenna but not lengthen it, and can probably remove the 10 m band.

Improve this question
$\endgroup$

2 Answers 2

Reset to default
5
$\begingroup$

I suggest you feed it in the center with open-wire (ladder) line and a balanced antenna tuner. (I have done that for many years). With the right tuner, you can obtain a near-perfect match anywhere on those bands. Also, feeding it in the center eliminates the need for a good RF ground or radial system, as opposed to end-feeding it.

Glenn, W9IQ has a schematic here of a balanced-to-balanced tuner that some may find useful if placed between commonly-available balanced tuners (that use ferrite baluns) and the antenna to increase the impedance range. The tuner I made was different, using link-fed, tapped coils in parallel with a variable capacitor, but Glenn's design appears to cover a much wider range of bands.

You may find that certain lengths of feedline are difficult to match on some bands.

Choose (or build) ladder line with low loss.

Improve this answer
$\endgroup$
2
  • 3
    $\begingroup$ If the ladder line length feeding a 35m dipole is between 15m and 30m, it will be difficult to match on 80m. More information at: w5dxp.com/goodbad/goodbad.htm $\endgroup$
    – Cecil - W5DXP
    Dec 3, 2018 at 4:02
  • 1
    $\begingroup$ A Johnson Matchbox is an excellent balanced tuner for this configuration. If the power level is 100 watts or less, the antenna can be fed with 300-ohm twin lead. $\endgroup$
    – AA6YQ
    Dec 8, 2018 at 8:28
0
$\begingroup$

I have a 23 meter wire antenna strung as an inverted-L. 7m up, the rest horizontal (between 2 trees). Lowest point where the coax is connected about 1m above the ground. I have not done calculations, but have a manual tuner in the shack (with about 12m of coax). A ground pin of 1m deep directly under the inverted L and a counterpoise wire of about 10m length (more wires in many directions would be better but I have no space) looseley covered just under the ground surface. Tunes on all bands: 160m to 6M, including all WARC and 60M. Simple to make and it works - don't expect too much DX but I have worked around the world on it (100W).

Improve this answer
$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .