The construction details for this antenna are taken from Rothammels Antennenbuch (A.Krischke). It is the 'classical' design using two wires of 15.60 m each and a 450 ohms ladderline, 9.30 m long. The correct adaption to the 50 ohms coax at the end is not yet clear to me, for the first version I followed the instructions using a kind of air-core choke balun (described here) with 10 turns.
After some tests with this antenna setup as inverted-V, I was using it mainly during my LU/DC2IP activity in november 2007. There it was put horizontally at a height of approx. 8 m.

I have produced another one, foreseen for to replace the 5-ele on my houses roof. During adjustment of the radiator length, this antenna shows a jump in the SWR, looking like some loose contact. This is not yet fixed. More to come...

SWR was better than 1:1.2 from the very beginning (not yet sealed). Experience will be reported later when antenna is more tested and used.

This antenna had a SWR of better than 1:1.2 from the very beginning. When I sealed all the patch cables etc. the SWR got worse, about 1:1.5 which then by shortening the dipole by 1-2 mm on each side was turned back to the original value.
For my holidays activity from 9A I built a second one, well I just constructed a new antenna boom which consists of 3 parts and fits nicely in the car. For the elements I used the elements of the previously build yagi. Mounting this antenna is rather time consuming then and it turned out, that for some /p activities 6mm element diameter might be too thin (I broke one).

The construction details for this antenna are taken from an article of the German magzine Funkamateur. It consists either of a vertical element of (2n+1) * Lambda/4 and a single radial or of a vertical element of 2n * Lamda/4 = n * Lambda/2 plus a transformation line plus a closed stub or of a vertical element of 5/8 * Lambda plus all of the above. This table gives the lengths of the active wires, the radials ad the additional coax cable pieces for impedance transformation.

After shortening the dipol by approx. 3 mm on each side the SWR was roughly 1:1.1 when the antenna was mounted 3m above ground. However, 1m above the roof of my house (there are some reasons to keep it so close) the SWR is depending on the antenna direction between 1:1.4 and 1:1.8.
So this antenna design seems to be very sensitive to the mounting height (or to the distance to other objects). Nevertheless, when testing the antenna for the first time on the roof, I had a QSO with DC6BB in JO33UK, QRB= 480km, not bad.
Plan: Replace this antenna by 6 or 7 ele of less sensitive 28Ohm design (most probably I will use 6ele, this looks most like a TV antenna).