Hi Friedrich,
the antenna in my post is basically an off-centre fed dipole, so it can be set up in any configuration that you would normally set up an OCFD. I personally use it with a 10m fibreglass mast as I like to get as big a signal out as possible when I’m on a day trip. I set up as an inverted vee, but straight, vertical, inverted L etc, will all work. You trim the antenna down much the same as any dipole: a few centimetres at a time. An antenna analyser is required for this, I use a SARK 110. I occasionally connect the BNC directly to the KX2, but I usually take 2-3 m of DXW-174, so that I can get the balun higher up off the ground in a tree if possible. Remember to use adhesive lined heatshrink between the centre conductor of the RG178 and the wire section, that centre conductor is very fragile.
I’ve heard it said that a counterpoise often improves performance with an endfed antenna close to a building, perhaps this is happening in your case. However, as the design I use is basically a dipole, I don’t think a counterpoise is appropriate. In an ideal world, there needs to be little or no current on the feedline, otherwise the antenna will appear longer than the resonant dipole it is intended to be. At home, I certainly have the coax earthed at the connection point on the roof and at the transceiver.
I notice the EARC did particularly badly in the WSPR tests:
But again, that was away from buildings and maybe was missing the all important counterpoise.
73 de OE6FEG / M0FEU
Matt