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> Yes, however, I use the 40 meter element which is > "closer" to 30, than the 20m element. I do not use > the internal tuner of my 1000D, leave it OFF. I use > an external tuner, with the output C element at maximum > capacitance. This insures highest efficiency in this > situation. I have a separate feedline up to the > EF-140S 40 meter rotating element. > > The tuner input capacitor is meshed only about 20%, > 70 pf, and the inductor is set to about 0.6 uhy. Please note that the above tuner settings are required to match the Z seen at the end of my coax here in the shack; it contains a very low real part, R. That is why the output capacitor is set to max, or 350 pF. This should always be the case when the R part of the Z at the shack end is below, say around 25 ohms or lower to keep the power transfer efficiency as high as possible. Best that you actually measure the Z input to the line that is seen in your shack; the end of the line you will connect to the tuner output. Use an MFJ-259B, or something similar to learn this impedance; then you' can set your tuner properly. To really to it correctly, go the the University of Chicago Tuner Simulator site, enter your measure line input Z, and the component values of your tuner, if you know them (see the tuner manual, for example). The T-network simulator, by W9CF, will immediately tell you how the tuner components should be set for lowest swr and highest operating efficiency. The simulator site URL is: http://fermi.la.asu.edu/w9cf/tuner/tuner.html 73, Jim, KH7M -------------------------------------------- Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. Force 12 Web site: http://www.qth.com/force12 Submissions: send to Force12Talk@qth.com To unsubscribe: send a blank e-mail to Force12Talk-leave@qth.com Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk For problems with the list, contact n4zr@qth.com |
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