[Elecraft] 2.2 kHz filter for #1107

[Allen Ward]

I finally got around to changing the capacitors in my K2's SSB module to match those in the current version as originally described by John KI6WX.  I had changed all the crystals some time ago (with most of the available mods) and that had made a big difference.  For some time I have thought that the audio quality of the K2 was superior to my other tranceivers (TS-830, TenTec Corsair, and Heath HW-5400 I am not including my S-Line because that is a whole different deal). The bandwidth was increased about 200 Hertz, the passband ripple was decreased.  I was surprised to find that the change actually improved the quality and enhanced the DSP operation.  Quite an improvement for $2.14!!  Great work John.  I reccomend to anyone with an older K2 and the original crystals to change ALL the crystals, add the 2nd filter mod., the BFO mod and change the capacitors in the SSB module (and do any other mods). It is worth the cost and effort.  Thanks to Wayne and Eric for a great transceiver and making it possible to have a three or four year old rig that is absolutely current.
A big tip of the hat to all concerned.
73 Allen KA5N