Hi Geoff I didn't know that about small cores, but, if I were to take on this idea, I would use the biggest I could get in there, which is around 45mm.
There's a local radio station on medium wave which has given me grief in the past, (pre K3 mind you) and I could change it into a high pass filter just for that. Come to think of it, I wonder if I could make such a filter for use with the MFJ259; that might be a better idea. David G3UNA > David, > > A Low Pass filter cutting off above 6m is useful here, because our not so > local FM BC station operates just above 100 MHz. > > I suggest that if you do convert a LPF, do not use small toroidal > inductors (unless "air wound") if the filter is to be used between a > receiver and an antenna feeder. Small cores can create IMD problems ftom > BC stations etc, which is one reason why the solenoid type of inductor is > used. > > 73, > > Geoff > GM4ESD > > > David Cutter wrote on Friday, June 18, 2010 9:27 AM: > >> I was idly wondering if I should convert them to something useful, >> perhaps >> to a band pass filter. There's room to fit small toroid inductors >> instead >> of the solenoid types. Then again, with the Elecraft line up I probably >> wouldn't benefit much, but it would be an interesting project. > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
