Hi Tom - I don't think you mentioned what bands you intend to use the antenna for. If just 40M, then you may do as well with coax and not need the tuner. If you use it for an all band doublet, the tuner may have difficulty on some bands depending on the impedence and the lenght of the feedline. Without the balun, you may have radiation from the feedline, which may not be a problem or it may cause problems in the shack with RF getting into equipment or noise on receive if the source is near the rig. I use a doublet but I increased the lenght to 88 ft and the k2 handles it well on most bands. I plan to increase the lenght to 100 ft to get better efficiency on 80 meters. I use a 1 to 1 balun. A 4 to 1 balun may work better on some frequencies but would likely give less efficiency on 80 meters due to low radiation resistance. Finally, changing the lenght of the feed line can improve the match on some bands with a possible worse match on others. Multiband antennas are always a compromise and experimenting may be required. Rick - K7MW Original Message ----- From: "Tom McCulloch" <[EMAIL PROTECTED]> To: <elecraft@mailman.qth.net> Sent: Saturday, August 20, 2005 6:57 PM Subject: [Elecraft] Antenna question
> Hi all, > I'm considering putting up a 40 meter dipole fed with a 450 ladder line. > I have a K2 which I run at about 5 to watts (I do not have the 100 watt > amp). The K2 also has the internal ATU. > > I have always used 50 ohm coax up until now. Is there anything I should > know about using the K2 with 450 ohm feedline? (Will I need a balun, or can > I just feed the ladderline directly to the K2's ATU and that will take care > of the match. > > Thanks for your help. > > Tom, WB2QDG > > K2 1103 > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
