On 1/8/2014 3:24 AM, Martin Storli - LA8OKA wrote:
The OCF antennas are know to cause RF in the shack, and RF in the shack quite often result in strange behaviour from the radio equipment.
Correct. Because they are badly unbalanced, they also pick up lots of RX noise.
A choke balun may work, but a current balun with ferrite is far better.
A ferrite choke is far more effective at solving both the noise and the RF in the shack. BUT off-center fed antennas, because they are badly unbalanced, establish very high common mode voltages across the choke. As a result, there is a high mortality rate with chokes on off-center-fed antennas. In other words, a ferrite choke on an OCF antenna is quite likely to fry with power.
OCF antennas are an old idea whose time has passed. They should be avoided, unless, of course, you happen to live in an alternate universe where RX noise and RF in the shack are not a problem. :)
73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
