• 6 Febbraio 2023 14:23

IK1TTD

An Italian Radioamateur Station

ANTENNA ANALISYS

Along the years, I always try to have a better setup for my DX Pedition ! Some year ago I found the Rybacov Antenna, a very common antenna used from a lot of people… if you google it, you will find tons of project; my Rybacov it is differnt from the mass model that everybody has; he has not ferrite or toroid, just a coil wound in air, and 3 radials.. you find all specifics here.

But the Rybacov, as every vertical, has the noise problem sometime… it is happened during some DXpedition to have very high noise, and I experienced lot of trouble to “hear” people calling me…

I would find a valid alternative to the Rybacov, which is still my favourite as is the only antenna the “WORKS” on ALL BAND “, and when I say “works” it is really so…

Anyway, actually I ‘m testing the Endfed Antenna, total different antenna, with some limitations, for example do not works on all band.. or may be I can say you can tune it on every band, but will not give you a good performance. As portability it is very flexible, as could be placed in 3 different configuration: vertical, sloop and inverted V. You can see my construction of this antenna right here.

I have ran 1 test in RX and 3 test in TX:

RX – Rybacov VS Endfed Vert Config

TX 1 – Rybacov VS Endfed Vert Config

TX 2 – Rybacov VS Endfed Sloop Config

TX 3 – Rybacov VS Endfed Inverted Vee

TEST RX – In the RX I have compared the two antenna in the same vertical configuration.Here below some result of the RX TEST, so results are empiric, considering smeter and human sensations.

In RX test (RX 1 in the morning, RX 2 in the afternoon) the the Rybacov was overall the winner, in general signal was higher of 1-2 s-points; in the second RX test run in the afternoon, the Endfed gained a winning point offering some better results. The overall impressions is that the RX on the Endfed is more comfortable, lower noise level; but on very weak signal, the Rybacov was winning… some small signal was readable on the Rybacov and not anymore on the Endfed. So I can say that on very weak signal the Rybacov is more noisy but still better on Endfed

SEE THE RESULT OF THIS TEST


TEST TX 1 Rybacov VS Enfed Vertical config – For Test TX 1 I have used the REVERSE BEACON, analyzing the signal of the 2 antennas on the same beacon (value of the signal is in DB over qrm). The Rybacov win over the Endfed on all band except 10 and 20 meter . Also some DX Beacons replied just to the Enfed and not to the Rybacov.

SEE THE RESULT OF THIS TEST


TEST TX 2 Rybacov VS Enfed Sloop config – For Test TX 2, still using the beacons reply, I have change configuration of the Endfed, putting in sloop 10 meters… I am trying to compare compact configuration antenna, considering to have a small space in a ipotetic outdoor spot or dx pedition or activation. Seems that also in this case the Enfded is winning just on 20-17-30 meters…. other bands I got better results with Rybacov

SEE THE RESULT OF THIS TEST


TEST TX 3 Rybacov VS Enfed Inverted V – For Test TX 2, again using the beacons reply, I have change again configuration of the Endfed, now using an Inverte Vee configuration… This time the Endfed is a bit better and win over the Rybacov.

SEE THE RESULT OF THIS TEST


CONCLUSION

Talking about portable antenna, the size is always a big matter… during outdoor traffic some time, or I should say almost every time, there is no space enough for big antennas; so this test is born to understand if I should change my Rybacov, which follow me since several years. I will say the Enfed could be an alternative for 20 meters, which at the end seems to be a bit more performing: so if you plan to make activity JUST on 20 meters, and if you are sure you can hang at least 10 meters long wire, then use Enfed… instead, if you plan to make activity on every band will be open ( I ALWAYS do that !) the Rybacov will be your best companion.

During the morning, I got higher report on TX TEST with Rybacov, in RX the Enfed offers less QR; in the evening, the difference between the two antennas is going to be reduced; I amde also a test reducing the power to 20 watt, and in this case on 20 meter I got a better result with Rybacov. At the end of everything I found as follow:

  • Overall use – RYBACOV
  • Less QRM – ENDFED
  • Higher signal – RYBACOV
  • More configuration – ENDFED
  • Less space needed – RYBACOV
  • Longest DX – ENDFED (just 1 in the whole test)
  • Using with less power – RYBACOV
  • Better SSB rx – RYBACOV
  • Better CW rx – ENDFED

As conclusion, I consider the ENDFED a good antenna for outdoor, to works good should be built in configuration sloop 20 meters, or Inverted Vee 20 meters, but I still prefer the RYBACOV; it is the best solution when you have small place to install like a small balcony (see my report from 3A here). I do a lot of activity from small Island, so also in this case building up a vertical is a winning.

I have to thank you my friend Riccardo IU1OPK beacause he inspired me to build this antenna as alternatives, the antenna design and datas are from him.

SEE THE FINAL RESUL OF THE TEST HERE

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