never mind, I had 88uH instead of mH. But that still gives 1200Hz, not 380... Chuck, K1OM
On Sat, Jul 26, 2008 at 7:44 PM, Chuck Grandgent <[EMAIL PROTECTED]> wrote: > what am I doing wrong ? > 1/(2*pi * square root of (LC)) (from memory), with those values I get > 12000hz > > Chuck, K1OM > > > On Sun, Jul 20, 2008 at 2:25 PM, EP Swynar <[EMAIL PROTECTED]> wrote: > >> Hi All, >> >> Saving --- and READING! --- past issues of old radio magazines can be >> certainly worth the space and effort... >> >> To-day, in the October 1970 issue of HAM RADIO (pp. 44 - 46), I stumbled >> upon a short piece by W4NVK entitled, "The Simplest Audio Filter". >> >> And simple it is, indeed...! >> >> Following the parameters therein for a 380-Hz CW audio frequency, I >> connected an 88-mH torroid coil in series with a 2-ufd. capacitor in the >> speaker lead of my Drake R-4 receiver...the results are REALLY quite >> amazing, and surprisingly effective. >> >> There are parameters given for CW frequencies of 1200-Hz, down to 380-Hz, >> but my ear prefers the lower tones, so I stuck with those particular values. >> >> If you have a spare 88-mH toroid laying about, along with some extra >> capacitors, this is a GREAT, easy-to-add-on adjunct that will only enhance >> the CW performance of your vintage commercial rig, or homebrewed >> creation...and it's OH SO EASY! >> >> ~73~ Eddy VE3CUI - VE3XZ >> > >
