On Fri, Mar 9, 2012 at 3:50 PM, Bill <[email protected]> wrote: > I have found the easiest single antenna to utilize is the OCF... ============ The OCF has advantages and can work very well. I have had good success with several versions, and in fact published an article in QST about one such setup (March 2006). It's important to note that any OCF antenna will have common-mode current flowing on the feedline, which will produce RF in the shack. With modest power this is usually not a problem, but as power goes up, the effects get worse.
If the antenna is coax-fed, the common-mode RF can be choked off with a 1:1 balun or an isolator. If it's fed with balanced line, it should go to a balun and thence to a coax link to the transmitter, and that coax should have provisions for choking the RF. The cold side of the isolator should be grounded to a good RF ground (i.e. not just a ground rod or water pipe -- ideally, a counterpoise or radial system, or other really good RF sink). The feedline will radiate, and this should be included in your EZNEC or other model when determining the radiation pattern. Tony KT0NY -- http://www.isb.edu/faculty/facultydir.aspx?ddlFaculty=352 ______________________________________________________________ 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
