Elecraft K3S firmware v2.57

MCU 2.57 / DSP 1.94

Major changes and

new features

• SSB POWER CONTROL IMPROVEMENTS: (1) No jumps in power while rotating PWR control during transmit. (2) No upward spike when crossing QRP/QRO boundary. (3) No loss of SSB TX drive level when tapping A/B, changing modes, or doing an ATU TUNE. (4) These improvements may also l​essen the effect of ÒspikingÓ external amplifiers, but further work on the ALC routine is planned.

Note: The SSB drive does still get reinitialized to match the CW level if you do a TUNE (this is desirable). But it also happens if you change bands or recall a memory (that will be fixed in a later release).

• FIRST A>B TAP COPIES MODE (if VFO A and B modes are different). This should greatly reduce the chance of having VFO B in the wrong mode when the operator later goes into SPLIT. (Those who want to do cross-mode split can still set up VFO B differently using BSET mode, and should avoid A>B.) Once the VFO modes are the same, operation of A>B is the same as before:

A single tap copies only the frequency, while a second tap copies everything.

• SPLIT CAN BE USED IN DIVERSITY MODE: See details below.
• PSK31 (PSK D MODE) TRANSMIT IMPROVEMENTS: Eliminated erroneous characters during CW-to-PSK31 transmit when using the keyer paddle. Also greatly improved PSK31 transmit speed by removing all extraneous ÒzerosÓ from the data stream.
• MARS operation now possible on 40 m up to 7550 kHz.

VFO Linking, Sub RX, Diversity Mode, and SPLIT:

• SPLIT CAN BE USED IN DIVERSITY MODE: During SPLIT, VFO B is only the transmit frequency. VFO A controls both receivers. So you now have a choice when using SPLIT with the sub receiver: diversity receive, or listening to both your RX (main) and TX (sub) frequencies simultaneously. Also see BSET note below.
• VFO A-B LINKING: This is now indicated by slowly flashing the VFO B kHz decimal point.
• A/B and REV CAN NOW BE USED IN DIVERSITY MODE. In both cases, the VFOs are swapped, allowing you to listen in diversity mode on VFO Bs frequency.
• BSET IN DIVERSITY MODE: If you use BSET in diversity mode, youll now hear the main RX in the left ear and sub RX in the right. This is useful when using SPLIT with diversity, as it allows you to override diversity mode temporarily and listen to both your RX and TX frequencies.
• VFO B NOT LOCKED WHEN LINKED TO VFO A: This means the VFOs can be linked but at different frequencies. A fixed offset can be established using VFO B, and will be maintained as you tune VFO A.
• VFOs NOT LINKED IN DIVERSITY MODE: VFO A is used to update both synthesizers (main and sub), but VFO B is now free to be used as a SPLIT TX frequency (see below). In DIVERSITY mode, the VFO A kHz decimal point slowly flashes, as before.

Miscellaneous:

• MESSAGE PLAY FIXES: There were a few issues with CW and DATA message buffer playback, including occasional truncated characters when chaining in CW mode, and inconsistent behavior when chaining.
• MORE ACCURATE AM-MODE POWER LEVEL. Also slightly higher modulation percentage.
• INTERNAL 2-TONE TEST GENERATOR now works with 2.7 as well as 2.8 kHz crystal filters, and the tones are now correct when used with both LSB and USB.
• KEY OUT disabled sooner on power-up: Previously, KEY OUT was active for about 3 to 4 seconds on power-up. This has been reduced to under one second.

In any case, no RF is present during this period. For Software Developers (see K3 Programmers Reference, rev B14):

• ÒDSÓ (VFO A DISPLAY READ): This command now correctly handles all of the RX EQ / TX EQ Òmini-bar graphÓ levels as displayed in the main menu. The bar graph level 1 character, if it appears in the ÒDSÓ response string, is now converted to an underscore rather than a semicolon. This preserves the semicolon as strictly a command terminator.
• "DT" COMMAND ADDED (VFO A DATA sub-mode read/set). "MD" is still used t​o set norm/rev.
• "IF" COMMAND INCLUDES DATA SUB-MODE (K31 must be in effect).
• "IC" COMMAND ADDED (ICON and MISC STATUS): Provides state information on many functions, including BSET, TX TEST, VFO linking, diversity mode, sub RX antenna, full/semi QSK, dual-passband CW, dual-tone FSK filtering, ESSB, nose gate, FM PL tone on/off, etc.
• ÒLK$Ó COMMAND ADDED (VFO B LOCK).
• ÒTQÓ (TRANSMIT STATUS QUERY) now returns 1 consistently when the K3 is in transmit mode.
• MORE MENU ENTRIES ACCESSIBLE WITH ÒMPÓ COMMAND: KAT3, VCO MD, and AGC THR are now available. See MN command table for details.
• KY (keying) remote control command now handles CR, LF, TAB and other ASCII characters including: [ ] ^ _ ` All of these characters are useful in PSK D mode. Theyre ignored in other modes, except that '_' becomes an "AA" prosign in CW mode.
• Prosign mapping (e.g., Ò=Ó conversion to ÒBTÓ) is now disabled in PSK D and FSK D modes. This allows all ASCII characters to be transmitted normally.

(Prosigns can always be sent using the alphabetic characters themselves in these modes.)