<\/p>\n
For a long time I had the idea to use UTP (Unshielded Twisted Pair) cable for my receive antenna, the K9AY or anything else. Advantages is that there are 4 pairs of twisted cable available in one cable and therefore there is no need for a control cable. Even switching the preamp can be done via the same cable.\u00a0 Or use the remaining pairs for an RS485 communication to switch antennas, attenuators or preamps.<\/p>\n
This cable is available cheap in the computer networking business.<\/p>\n
For a long time nothing happened until in the German magazine Funkamateur, DK7ZB published a balun for a delta loop. I recalculated the balun for a smaller toroid. I used a FT50-43. The balun was build on a piece of copper clad PCB board. I terminated the balun with a 100 Ohm resistor and measured the return loss.<\/p>\n
The return loss was very good. On 10 MHz the return loss was still 20 dB and below 5 MHz even better than 25 dB.<\/p>\n See the plot below:<\/p>\n Next try was to make 2 baluns and test a piece of UTP cable. A length of 30M was found in the cable box.\u00a0Losses were still very acceptable. The plot below shows the losses from 0-10 MHz. On 1.8MHz, my main interest, the cable and the 2 baluns had a loss of 2.5dB<\/p>\n![](\"https:\/\/pa3csg.nl\/wp-content\/uploads\/2015\/06\/torroid.jpg\" "\\"\\"")
<\/a><\/p>\n<\/a><\/p>\n