If you have a feedpoint impedance of 32 ohms on an inverted "L" for 1.8 mhz, can anyone venture a guess as to what the impedance would be of the same antenna at 3.5 mhz ?? thanks, Bill ______________
Several hundred ohms most likely. Many factors come into play, such as radiator diameter and objects within it's field that are coupling into the antenna. 73, Gerald K5GW In a message dated 11/6/2010
An EZNEC model of an Inverted-L with 60ft vertical and 77ft horizontal gave me a resonant feedpoint resistance of 32 Ohms at 1.8MHz when the ground loss resistance was 13 Ohms. That same antenna at 3
It is going to have a pretty high impedance, just how high is hard to predict but the 50ohm swr is likely higher than 10. So an "open wire feeder" and a matching section is called for. For something
how did you determine the ground loss resistance of 13 ohms at 1.8 mhz & what would be the ground loss resistance at 3.5 mhz? k7puc _______________________________________________ ___________________
How is any of this relevant the question about his Inverted-L ? Steve G3TXQ _______________________________________________ _______________________________________________ TowerTalk mailing list Towe
I needed 13 Ohms ground loss to get to his measured resistance of 32 Ohms. But it doesn't matter whether that is right or wrong, nor what the value is on 80m, because compared to the Resistive compon
Why use an open wire feeder? You can tune the antenna at the base and run coax. You can even have a relay to bypass the tuning section when using it on 160m. Another option would be a relay or trap o
If you have a feedpoint impedance of 32 ohms on an inverted "L" for 1.8 mhz, can anyone venture a guess as to what the impedance would be of the same antenna at 3.5 mhz ?? thanks, Bill ______________
VERY high -- if it's 32 ohms on 160M, it's close to a quarter wave, which would make it close to a half wave long wire on 80M. WAG about 10K ohms. A good compromise is to make it a bit shorter (or lo