Posts by LZ1JH

    Hi,

    Two antennas best fit with 75 ohms feeder pieces. However, in order to obtain polarization, it will be necessary to have 1/4 lambda spread. If not to work with the transformer. This is very well explained here: https://www.qsl.net/sv1bsx/antenna-pol/polarization.html

    This feed seems to me better than a helix one because I think it's a little overshadowed by the LNB at 10 Ghz. Helix is right ahead LNB. And yagi are around him. But I think so I can be wrong ;).

    73 Rumen LZ1JH

    Hello Hans-Jochen,

    The individual antennas are made directly from the feeder RG 141-50. The elements are made of copper wire with a diameter of 1,5 mm. The director has a length of 51 mm and a reflector with a length of 61 mm. The distance between them is 30 mm. Fiders must have the same lengths. They gather at a point where the impedance is 12,5 ohms. To match 50 ohms lines, a 25 ohms 1/4 lambda transformer is needed . This is very easy with two pieces of RG 141-50 tailored to the shortening coefficient. For this cable is 0.7. The most important thing is to properly connect dipoles to get LHCP. I showed it on the attached picture. For proper connection, LZ2US helped me a lot. The best SWR I received is about 1,2.


    73 Rumen LZ1JH


    Hello All ,

    On the idea of ON7WP Pedro I designed this dual feed. After a few mistakes I finally managed to get LHCP and after reporting RHCP. The two horizontal yagi's are on the Y/4 in front of the two verticals. The antenna is 80 cm offset. With a power of about 2 watts from a SG labs transverter, a 10 meter feeder at a transponder level of -72dB provided a signal level of -64db. So I have already done more than 20 QSO.

    73 Rumen LZ1JH