ANTENNA EH 160 mt

Tests (2)

Well, after this test I've tuned the EH for 1.847 (SSB) where, every evening, there 're few italian om in QSO; infact I've noted that outside the EH bandwidth performance goes quickly down (1-2 S point at 30 Khz from center bandwidth);

In the following table you can see how quickly changes performance  outside bandwidth ("*" means bandwidth with 3:1 S.W:R) (test made with Riccardo, IK7FMO).

Here's what happened 25/05/2002:
it's raining and the EH resonance is fully changed (center bandwdth now is at 1.770 Mhz);  on 1.847 I hear the following station:

This time I have the same report with the EH and my 15 mt loop (normally the EH performed better than my 15 mt loop): sure, due to the rain, EH has tuned down;

At this point it was necessary a second antenna to compare with the EH, not a full-size dipole (I've not enought space): a short vertical.
I've build a short vertical for the following reasons:
1) easy to build (1-2 days);
2) same vertical polarization as EH
3) less interdependence (it goes up in the vertical plain...)

My idea was the following: a 10 mt (high) vertical, on 160 mt band, is very short, so it will have same loss respect to the dipole;
the EH antenna should have the same "performance" of a dipole;
if my EH will perform better than my short vertical, then it will be a very useful antenna;
(NOTE: no "absolute" view of the EH performance will derive, but just a practical comparison).

Here's a short description about my short vertical:
it has a first alluminium pipe, then a wire (on a fishing-rod); the vertical size in about 10 mt high; on the top there is a capacitive hat (10 mt).
At the base there's a L-network to adapt the antenna impedance with the 50 ohm coax cable and, on the ground side, 4 variable wire (between 5 and 25 mt);
The vertical is in my garden, on a 8 mt pole;

NOTE: I've added on one of the four ground-wire a 100mt hank wire obtaining a gain of 3-4 dB: interesting.

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73 de iz7ath, Talino Tribuzio