We started shipping the current DSP boards, Rev C, approximately March 6th, 2009. Any K3 DSP board Rev C or later will have the extended low end audio frequency response h/w enhancement.
This corresponds approximately to K3 serial number 2800, plus or minus 10-20. Since assembled -Fs and kit K3s flow through different manufacturing paths, there is a slight variance in s/n for the phase-in. If in doubt, check the DSP board Rev as noted above. These changes basically added additional h/w low end frequency response below 300 Hz. You need to also have the latest K3 f/w to take advantage of this. Of course, you can also tailor (and limit) your RX and TX response via the K3's IF Shift and B/W controls and by using the TX and RX Equalizer entries. A picture of the Rev label location on the DSP board and additional info is at: http://www.elecraft.com/K3/mods/dsp_rev_c_information.htm (The 'C', or later, revision letter at the bottom of the label is what is important.) We have added to our parts and mod kits page an option, K3DSPUPGD to swap out your current DSP for one upgraded to the latest Rev C changes. The cost will be $69.00 plus shipping. Order placed via this page will start shipping approximately in 4 weeks, around Nov 9. See: http://www.elecraft.com/order_form_parts.htm#K3%20Parts 73, Eric WA6HHQ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html