ANTENNA
EH 160 mt
Tests (1)
Note:
in the second prototype, I've make a mistake in the network assembly obtaining
the following configuration:
Using my MFJ259B I found
R=50
ohm X=0 ohm with 1:1 S.W.R. at 1.835;
with this network, during the contest on 160, I've contacted the following
stations (160mt SSB):
Date | Time | Call | RST given | RST Received | NOTE |
30/03/2002 | 19:15 | S57M | 59+ | 1 S point over the Noise | Noise at S7 |
30/03/2002 | 19:28 | YT1R | 59+ | 58 | - |
30/03/2002 | 19:29 | 9A2AJ | 59+ | 59* | - |
31/03/2002 | 18:00 | YT6A | 59+ | 59* | - |
31/03/2002 | 18:18 | II8A | 59 | 57 | with a 20 dB attenuator |
31/03/2002 | 18:18 | IZ7BAR | 59 | 59+20 | - |
31/03/2002 | 18:18 | IZ7BAR | 58 | 57 | Now I'm not using the EH but a 15 mt tuned-loop |
a "*" means I've
not asked an exact report (it was a contest, so an usual 59 was expected);
Contact were very hard (notwithstanding there were not other station calling at
the same time);
I've heard also station over 1000 Km (HA,OZ,ON) but they were lower and was not
possible make QSO;
but I must admit in the past year, also using a 80 mt "tuned-dipole"
(note a dipole for 80 mt, not a 80 mt long dipole), I never went over 50 Km.
After remaking the network with the standard configuration (as in picture),
I've made same other
test; with a local station (Riccardo, ik7fmo, 50 km far to me), there are a 1 S
point difference between EH in high position (8 mt high, free) and EH in low
position (4mt high, with same obstacle) (see picture); resonance has moved down only 5
Khz;
The EH was so tuned:
MHZ | Resistance | Reactance | - |
1.750 | 10 | 10 | - |
1.760 | 12 | 9 | - |
1.770 | 17 | 6 | - |
1.780 | 23 | 11 | * |
1.790 | 38 | 19 | * |
1.800 | 60 | 0 | * |
1.810 | 56 | 30 | * |
1.820 | 34 | 40 | * |
1.830 | 18 | 35 | - |
1.840 | 11 | 30 | - |
1.850 | 8 | 25 | - |
1.860 | 5 | 22 | - |
1.870 | 3 | 19 | - |
1.880 | 2 | 17 | - |
1.890 | 1 | 16 | - |
1.900 | 1 | 14 | - |
The "*" marks
the 3:1 S.W.R. bandwidth.
As you can see, it's about 30-40 KHz;
inside this bandwidth Riccardo (IK7FMO) gave me a S9 report, outside (1.850 Mhz)
he gave me S7-8 and only S6 at 1.890 MHZ.
Antenna in low position (left) and high position (right)
EH in low position
73 de iz7ath, Talino Tribuzio