[Elecraft] K3 rev 4.22 Beta Release: Improved APF (CW); all SSB anomalies fixed

[Wayne Burdick]

K3 beta-test firmware revision 4.22 (with DSP rev. 2.70) is now  
available. This release includes our new APF (audio peaking filter)  
for CW mode. APF pitch is now tunable in 5-Hz steps, and the entire  
200-1000 Hz pitch range is usable.

For voice modes, the "Fast Monitor" and improved TX Noise Gate are now  
fully functional. All known issues with SSB power level have been  
corrected.

See detailed release notes below.

Please send any questions to k3support at elecraft.com. For instructions  
on how to load beta firmware, see:

      http://www.elecraft.com/K3/k3_software.htm

73,
Wayne
N6KR

* * *

MCU 4.22/DSP 2.70/FPF 1.14, 11-15-2010

NOTE: Be sure to install all firmware files for this release,
including FPF 1.14. Otherwise your menu text will be incorrect.

* APF (AUDIO PEAKING FILTER) ADDED: APF provides enhanced
copy of weak signals in CW mode, and is especially useful when
signals are at the noise level. The K3’s APF is patterned after
the most successful analog APF implementations, and is equally
effective in user tests. To use APF, make sure CONFIG:DUAL PB
is set to APF. (This is the default. “NOR” restores the original DUAL PB
function.) Then hold DUAL PB to turn APF on/off. A special DSP
graphic display is used to show that APF is in effect. At the time
APF is activated, the regular I.F. SHIFT setting, if any,  is “frozen,”
and SHIFT then controls the center pitch of the APF filter in 5-Hz
steps. APF is independent for the main and sub receivers, as well
as for presets I and II. Switching between these two presets is a
convenient way of turning APF on/off quickly.

* ADDED VOICE TX “FAST MONITOR”: Normally the voice
monitor includes a ~20-ms delay, which is necessary to hear how your
on-air signal will sound (with compression, etc.). If you prefer to not
hear any delay in the voice monitor, set CONFIG:TX MON to FAST.
Note: You’ll still hear the delayed and processed monitor if you
adjust the MIC, CMP, TX EQ or TX GATE settings while transmitting.

* TX NOISE GATE IMPROVEMENT: The Noise Gate/Downward
Expander for voice modes has smoother response and much
improved performance near the threshold.

* NARROW AF FILTER IMPROVEMENT: Adjusting SHIFT and
WIDTH when using very narrow DSP filters no longer causes
‘pop’ artifacts.

* SSB reduced power level bug fixed: Error was introduced
in DSP 2.65.

* FSK-D & PSK-D bug fixed: In DSP 2.69, there was no monitor
for these modes if CONFIG:TX MON was set to FAST.