Yes, it can be done, Mike. Remember that the 4:1 balun will be happiest seeing an impedance around 200-300 ohms, though. The 4:1 ratio really only holds when the impedances are correct. Once you throw in a mixed load that is well away from this value, plus an unknown amount of reactance, the ratio changes and losses can mount. Not a serious concern at QRP power levels, but at 100w it could cook a balun that is seriusly mismatched.
The best way to use baluns is to adjust your balanced feedline length on a given band to give very little reactance, regardless of the resistive part of the load impedance. The ATU will have an easier time matching a resistive load than one with combined reactance and resistance. The baluns will work best when the loads are resistive, even if the wrong value. When you mix in reactance, the balun will have unpredictable ratios and losses. Good luck and 73 Bob N6WG The Little Station with Attitude -----Original Message----- From: Mike W [mailto:[EMAIL PROTECTED] Sent: Sunday, August 21, 2005 4:03 PM To: Robert Tellefsen; elecraft@mailman.qth.net Subject: RE: [Elecraft] Antenna question - Balun On 21 Aug 2005 at 8:40, Robert Tellefsen wrote: > Two things will make matching easier. Get two > baluns, 1:1 and 4:1. Put them on the two > antenna ports of the ATU Looking at the two versions of the BL1 for 1:1 and 4:1 Can you not use a 2pco ( dpdt ) switch or relay to change between the two ?. Commons to the two inner windings ( see BL1.pdf ). Short them for interconnect on the NO connections for 4:1 Parallel them on the NC connections for 1:1. _______________________________________________ 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
