Hi Steve, There are AIR CORE filament choke designs, too, BTW...
How extensive is your collection of QST magazines? Have a look at those pieces that featured monoband 160 circuits, and you might hit paydirt. I KNOW that I saw one either there, or in one of the ARRL HANDBOOKS. There ARE always options! ~73~ Eddy VE3CUI - VE3XZ ******************************* ----- Original Message ----- From: "rbethman" <[email protected]> To: "Discussion of AM Radio in the Amateur Service" <[email protected]> Sent: Wednesday, April 29, 2009 2:47 PM Subject: Re: [AMRadio] Filament choke > From reading past messages from 2007, the FC-30 by B&W doesn't have > enough inductance for 160M. The specs are from 3.5MHz and up. > > You'd be better off checking some of Orr's Handbooks for the correct > ferrite rod and wind your own. > > I know I have a home-wound one here, BUT - I don't know if it would work > for 160M. I didn't build it. > > Bob - N0DGN > > [email protected] wrote: > > I'm building a 160m grounded-grid amp around the GI-7B tube > > (it worked so well in my SB-230 retrofit project: > > http://www.wd8das.net/SB230.html ) > > > > Anyone know of a source for a filament choke appropriate for this tube? > > The filament draws only 2 amps, so the 30-amp ones I see available > > online are really overkill (and awfully large). But for 160m I'm > > thinking that a somewhat higher inductance than might normally be used > > for 80-10m amps might be in order. Say >50 uH?. Bifilar-wound would > > be best, but two separate chokes would probably work too. > > > > Should I not find a ready-made source, then I guess I could make one if > > I find some ferrite rod suitable for use at 1.9 MHz. > > > > Thanks... > > > > Steve WD8DAS > > > > [email protected] > > http://www.wd8das.net/ > > --------------------------------------------------------- > > Radio is your best entertainment value. > > --------------------------------------------------------- > > ______________________________________________________________ > > 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 > > > > > > -- > Bob - NØDGN > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
