Antenna experiments
My first loop
The pictures show my naive attempt to build a magnetic loop from RG58 coax cable I bought 15 years ago for an Ethernet network. The shielding is rather thin and fragile, but I gave it a try anyway. Note the capacitor, unsuitable for high power. According to the math, this loop should tune from 28MHz to 14MHz. I noticed a tuning effect on 20m, but the SWR never went below 1:3. I dumped the antenna after an hour of testing.
A 10m Bazooka
With the remaining RG58, I was able to build a 10m Bazooka. I would have prefered a 20m version, but that would have taken more cable than I had readily available. I obtain a 1:1 SWR on 29.5MHz which increases to 1:2.5 on 28.5MHz. Unfortunately, the 10m band is noisy and dead. However, with my TS450SAT, I am able to tune the antenna to 20m, and obtained immediate results on my first attempt with YU, YO and IZ. If this antenna is able to get me there, I am eager to know what can be accomplished with a 20m dipole on the roof.
A short dipole
With 10m of thin wire, I built a short dipole as my first external antenna. It lacks end isolators, and I was unable to tune it to 10m, but it got me my first european contacts on 40m. Of course, most of the 100W I fed into this dipole got lost. I find the results nonetheless encouraging.
70cm ground-plane
Since I am experiencing difficulties to open the Echolink repeater F6GLS at Paris-Montparnasse, I built the AG4RQ coat-hanger groundplane for 70cm. The first results are quite good, and I might build a mechanically more robust permanently installed version.
Short inverted V
I turned the short dipole into an inverted V, this time with end isolators. The antenna is fed by RG58 coax, for the time being without balun. I made my first DX with this antenna, but it's always hard to tell if the success is due to propagation conditions or an improved antenna.
