Last night I had a chance to play some more with this. Perusing the junquebox yielded a 3-section, 400pF/section broadcast band air variable and a piece of air-wound coil stock about 2" diameter and about 2.5" long, #16 tinned wire, with spacing between turns about equal to the wire diameter. The coil looked about right for an 80M tank coil for a single 807 or 6146, etc.
I wired them in parallel and put the parallel combination is series with the antenna lead. MUCH better - I could still null out the 1500Kc interference, but signals a few 100KHz from 1500Kc were much stronger compare with the earlier network of 200µH in parallel with 56pF. The new component values are 1000pF (measured) and 11.26µH (calculated), which approximates a series reactance of 92 ohms inductive (ignoring the capacitor's presence) at 1.2MHz and 88 ohms capacitive at 1.8 MHz (ignoring the inductor's contribution). WBZ at 1.13MHz was, within my ability to read the S-meter of questionable calibration and with QSB, 2 S-units down with the filter in, compared to what it is with the filter shorted out. On the 80M band there is no noticeable attenuation from the filter. I can live with this; I'm calling it good and moving on. Thanks to all the helpful suggestions and comments. 73, -Larry/NE1S ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected] To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
