Hello David: Wayne asked me to reply since I prepared the application note. Only two resistors are needed, so if you've done the mod using the daughter board locations Wayne originally mentioned, you're all set.
The version shown in the app note mimics what Aptos is doing as they modify the boards in inventory. The resistors are in the same place electrically, but they chose to put them on the main KIO3 board instead. We followed that in the application note so it'd be easy to tell if the modification has been made either in the field or at the factory. Ron AC7AC -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of David Pratt Sent: Wednesday, January 14, 2009 1:10 PM To: wayne burdick Cc: Elecraft List Subject: Re: [Elecraft] K3 Caution when using an external monaural speaker In a recent message, wayne burdick <[email protected]> wrote ... >The short version is: put 1/8-W (or larger), 470-ohm resistors from >each speaker output to ground. (The actual value isn't critical; >anything from 330 to 1000 ohms would probably work just as well.) This >can be done conveniently on the KIO3's audio daughter board, at its >single-row, right-angle male connector. I see that the AF mod application note at http://www.elecraft.com/K3/mods/AF_Output_Mod_Rev_A.pdf is somewhat different to what you describe, Wayne. The 470 ohm resistors appear to be in different places of the circuit. Does this come to the same thing, or are the two resistors from each speaker output to ground also necessary? 73 -- David G4DMP Leeds, England, UK ------ _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
