One way to make an under-sized filament choke (from an inductance point-of-view) work is to parallel-resonate it at the desired frequency of operation with a capacitor. Practically, you can do this by adding the required capacitance to the input tuned circuit. On the two GG amps I built I use switched low-Q pi-nets on the input, so that meant for 160M the capacitor on the filament side of the pi-net "grew" in value, over what it would have otherwise been. Also works for parallel-resonant input nets, of course.
I got the idea from Rich Measure's web pages; he explains it in detail there. 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 Post: [email protected] To unsubscribe, send an email to [email protected] with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
