[Elecraft] K3 Beta Firmware, Rev. 2.23 (ESSB; LSB/USB transmit gain balance)

[wayne burdick]

K3 beta firmware rev. 2.23 is now available. (Details appear below.) 
Several K3 owners successfully tested the ESSB feature (Extended Single 
Sideband).

For instructions on how to load beta firmware, please see:

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

73,
Wayne
N6KR

* * *

MCU 2.23, 7-31-08

* LSB/USB TRANSMIT EQUALIZATION (experimental): Improved gain balance 
between LSB and USB. A 1 to 3 dB difference between the two had been 
reported with the 2.7 kHz (5-pole) filter. The passband should also be 
slightly flatter.

* ESSB (EXTENDED SINGLE SIDEBAND) ADDED:  Allows the K3 to transmit in 
SSB modes at a bandwidth of up to about 4 kHz. Requires a 6 kHz crystal 
filter on the RF board. Note: ESSB receive is obtained just by 
adjusting the WIDTH control.

To enable ESSB transmit:

(1) Make sure the 6 kHz filter is configured correctly for AM transmit; 
switch to AM mode, then specify this filter using CONFIG:FLTX AM. (A 
future firmware release should allow use of the FM filter for SSB as 
well, pending lab tests.)

(2) Locate CONFIG:TX ESSB. Select the desired extended bandwidth for 
SSB transmit (3.0 to 4.0 kHz) using VFO A. Then tap ‘1’ on the keypad 
to turn ESSB on/off. When on, the “+” icon in the mode area will turn 
on. (If you turn ESSB on/off frequently, you might want to assign the 
TX ESSB menu entry to a programmable function switch.)


---

http://www.elecraft.com