RaDAR – End Fed Half Wave Antennas

From numerous experiments done during the last year or two while practicing RaDAR, Ihave come to believe that the best HF antenna for rapid deployment and re-deployment is the End Fed Half Wave Antenna or EFHWA. Various designs have been tried with excellent results. The latest experiment was building and testing the well known Fuchs end fed antenna tuner. This is a very versatile tuner and by using a 21 meter length of antenna wire, any bands from 40m through to 10m, including all the WARC bands, can be tuned very effectively. With a longer wire, around 41 to 42 meters, 80m can also be catered for. Antenna deployment time – FAST!

So what is the Fuchs tuner? The following diagram sums it up quite nicely.

FuchsCCT

Winding the toroids may look difficult but really are quite simple to do. L3 should take the following form when complete.

L3

Various combinations of control settings have been tried and tested. The authors results were as follows:

21m long wire (No radials or earth)
40m Coupling 3/4 L3 3, Cap 60% SWR Good
30m Coupling 2, L3 2, Cap 100% SWR Good
20m Coupling 3/4 L3 2, Cap 33% SWR Good
17m Coupling 2 L3 1, Cap 90% SWR Good
15m Coupling 3/4 L3 2, Cap 25% SWR Good
12m Coupling 3 L3 1, Cap 50% SWR Good
10m Coupling 1 L3 1, Cap 25% SWR Good

41m long wire (No radials or earth)
80m Coupling 6 L3 4, Cap 90% SWR Fair

4 thoughts on “RaDAR – End Fed Half Wave Antennas

  1. Hi!,
    I have also built the Fuchs tuner, and it seems like we have similar results – good SWR on 40m an up, while “fair” SWR on 80m with a 41m wire. I tried to get a good SWR on 80m but failed. Have you any idea on how to decrease the SWR (on 80m with a 41m wire?)
    regards,
    SM5 OCI Per

  2. Hello

    I did get swr better on 80m just adding one turn between “lower sw” pins 5 and 6… there is now 7 turns total..

    Nice blog here, thanks!

    73 de OH6TX Jari

    • Ah! Exactly what I had in mind. I did a test with a transformer between the TRX and the Fuch, but the test did not yield a good result. Your idea is what I had in mind to test next. Time for experiments has been scarce for a couple of months, but I hope to be able to test this soon.

      Thanks,
      SM5OCI Per

      • It’s worth to test it and relative easy to undo if nessessary.

        I have swr 1.0 on 80m now with that 7 turns in primary.. measured just with swr meter of FT817 and 41m wire instelled in inverted v configuration.

        Good luck Jari

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