Now this method is a bit convoluted, but you could put extra long leads on an ohm meter that will measure low ohms. Start at the feedpoint with one lead, and experimentally tap onto the antenna where you think the 55 foot point is. If you have found the center, you will have the resistance of 55 feet of wire indicated on your meter. You likely know the gauge of your wire, thus, you can use a wire table to predict what 55 feet of that wires should measure on the resistance scale. You will have to zero out the extra long test leads you make to reach to the far side of the loop. The easiest way is to make a test lead of 55 feet and then have short lead and the meter with you as you seek the center on the far side.
Other means of accomplishing the same thing, are to find equal capacitance point on far side to each side of the feed point insulator, or equal inductance. However both of those methods may suffer from incidental coupling within the attic. The low ohms method is done at DC to overcome those disadvantages. -Stuart K5KVH _______________________________________________ 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
