Jim, You might like to view this page of my site where I detail changes to KSB2 capacitor values to reduce the excessive LF response.
http://homepages.nildram.co.uk/~baker/K2_SSB_Mods_Overview.html 73 Stewart G3RXQ On Sun, 28 Aug 2005 09:47:05 -0500, Jim Brown wrote: > On Sat, 27 Aug 2005 10:26:57 -0500, Jim Brown wrote: > >> The mods are quite simple. First, change R14 from 1K to 2K. Second, >> change C34 to 0.22 uF. Third, add 2.2uF in series with R15. >> > A correction to one of my suggested mods by Don, W3FPR, who understands the K2 > in far more detail than I do, and emailed me to discuss it. The cap in series > with R15 is a bad idea, for several reasons, based on the control logic for > the compressor. If a cap were to be added there, it ought to be in parallel > with R15, not in series, and it ought to be smaller -- perhaps about 1 uF. > > What both caps do is reduce modulation from breath pops and low frequency > noise in your shack. Popping and low frequency boost is a common problem with > directional mics used close up. Even in pro applications, we use a lot of low > cut on these mics, and it is even more important to do so in communications > circuits. > > Jim > > > _______________________________________________ > 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
