On December 8, 2018, XYL and I traveled to Puerto de Mogan on Gran Canaria. As usual, I brought my FT-817nd. We stayed at Cordial Mogan Playa Hotel, a few hundred meters up the ravine from the village. It was easy to predict that the QTH was not the best with high mountains all around except to the South-West. I checked the take-off angle using http://www.heywhatsthat.com/profiler.html and estimated it to 10 degrees. I judged that it would be possible to work from the bottom of the ravine after all. Once in place, the angle from the balcony to the surrounding mountain ridges were measured to 35 degrees to the west and approximately 60 degrees to the east. Against Europe, the angle was slightly lower than 35 degrees.

The fishing rod with 5 meters of antenna wire alongside was mounted on the balcony in the southwest direction and pointed upwards at 45 degrees. As a counterweight, the balcony’s steel rail was used. The ATU could match the antenna from the 30 to the 15 meter bands.

It turned out that all amateur bands from 20m upwards were completely dead. There was not even any atmospheric noise.

However, contacts were possible daily with Europe on 30 and 40 m from an hour before sunset for about 20 minutes. That was from about 1710 to 1730 local time and equal to GMT. The sunset was around 1810. It shows that the radiation angle at that time was very high. The signals probably entered at an angle of 30 degrees above the horizon or more. A very good indicator was the German weather station at 10100 kHz. It went from S0 on the meter to S8 for a few minutes and then quickly fell back again.

To be able to use 40 m, a 5 meter long extension of the antenna wire was connected from the tip of the fishing rod wire back to the other end of the balcony. It became a fairly pointed angle, but the ATU could match the extended antenna on 40, 30 and 20m.

Only EU stations were worked. PY stations were often heard, but they were weak.

Effective Isotropic Radiated Power (e.i.r.p). What is it?

e.i.r.p. = Pout (from TX) – losses (in antenna and feeder etc) in dB + antenna gain in dBi.

The regulations for 5 MHz in Sweden with max 15 W e.i.r.p. will have some strange consequences:

An inverted vee dipole with apex at 13 m has a gain of 6.7 dBi. If losses in tuner and feedline amount to 1 dB, Pout should be 5.7 dBs lower than 15 W or 4 W. It holds for an antenna over even ground with average conductivity.

For a vertical ¼ wave GP with 2 to 4 radials at 2 m Pout max is rather 30W.

Click on the image for a better view.

Inv vee dipole at right angle to the antenna plane:                           Vertical:

Over the last couple of days for SM to ZL on 40m (please click on the image):

And using WSPR on 20m (please click on the image):

The DL-1000, which is the defense’s telephone wire, consists of 7 strands. 4 from copper and 3 galvanized steel wires and an insulating coating. It is popular as antenna wire. The question is how it stands against copper wire regarding losses on short wave.

The MMANA simulation program allows you to select materials in the antenna conductors. The difference in material losses between copper and steel wire amounts to more than 3 dB for a 20m dipole.

To make a practical measurement, a dipole for 14 MHz was mounted with the center 7 meters above ground and the ends one meter lower. A MINI VNA was connected to the 37 meter long RG 213 coaxial cable and the length was retracted. However, the cable is simulated as loss-free.

In addition to 1.5 square mm copper, 1 mm plastic coated soft steel wire was used, which is used in the garden.

The feed impedance was measured at the resonance point when it was pure resistive.

Results:

Impedance ohm

Copper         53

DL 1000        64.7

Steel wire     74.2

Thus, an additional loss resistance of 11.7 ohm for DL ​​1000 and 21.2 ohm for steel wire. This corresponds to 18% or 0.85 dB extra power loss for DL ​​1000 and 28.6% or 2.3 dB for the steel wire.

Additional information:

The DC resistance of a strand of DL1000 is 7 ohms/100m.

I have simulated what happens with an LW of 100 meters at 14 MHz:

When I measured a dipole, the feed impedance increased by about 12 ohms when I used the DL1000 instead of the FK 1.5. This means that a 12 ohm loss resistor is in series with the copper wire feed impedance. For steel wire, the corresponding loss resistance was 21 ohms.   I then put the corresponding loss resistance in all the current maxima on the long wire. One can see it as 10 series-connected half-wave dipoles.   The result was that a 100 meter long wire of 14 MHz with the DL1000 had 1.6 dB of lower gain than an LW of copper! For a half-wave dipole, the corresponding losses were 0.85 and 2.3 dB, respectively. The longer the antenna is, the more important with good material in the wire (and, of course, low losses in the ground).   In figures: Gain Cu = 10.7 dBi, Gain DL1000 = 9.13 dBi and Gain steel wire = 8.44 dBi. The latter result does not correspond to what you get if you choose steel as material in the antenna wire in MMANA. Then Gain = 7.1 dBi ie 3.63 dB worse than with copper. The same goes for half-wave dipoles.   By comparison, a 3 element monoband has a gain of about 12 to 13 dBi.    

If the antenna length is increased to 200 meters, the gain increases:
Gain Cu = 12.16 dBi, Gain DL1000 = 10.18 dBi ie an additional 1.43 (Cu) and 1.05 dB (DL1000) respectively. For steel wire the gain is then 8.1 dBi.

Below a 10 wavelength long wire 1 wavelength up on 14 MHz.
With Copper Line:

With (a half from) DL1000:

With steel wire:

There are four bevs:

1. A 190 m terminated wire in 290 dgs. Works great for North America.

2. A 185 m teminated wire in 240 dgs.

3. A 130 m terminated wire in 60 dgs. Just a little bit better than number 2. Discriminates signals from SW with about 2 S-units. A bit disappointing.

4. A 120 m unterminated wire in 355 dgs.

I’ve been a bit sceptical about the balance of the military telephone cable called DL1000 in Sweden. It almost looks as if one wire is wound around the other rather than two twisted wires. So I made a measurement as outlined in the sketch below while listening on strong signals:

As reference I connected both wires in parallel connected directly to the measurement receiver.

The results were:

Frequency     Common mode rejection

7 MHz            25 dB

3.5 MHz         40 dB

There was no difference with and without the load resistor R.

So the telephone line is OK as a feeder for receiving antennas on 80 and below as regards to common mode pick up but doubtful on 40m.

I was using a 50m length of DL1000 telephone cable with a transformer with binocular BN73-202 at each end with a turn’s ratio of 2:3. There was a MINI VNA Pro used in transmission mode connected to the transformers.

Attenuation in the transformers:

Attenuation in transformers plus 50 m of DL1000 telephone cable: