Elecraft KX3 Programmers Reference - Manual (Page 11)

11
FW $ (Filter Bandwidth and Number; GET/SET)
NOTE: FW is a legacy K2 command with side-effects based on the K3x and K2x meta command settings.
For the KX3 and K3, use BW if possible. Also use BW in switch macros.
K3 Extended SET/RSP format (K31): FWxxxx; where xxxx is 0-9999, the bandwidth in 10-Hz units. May be
quantized and/or range limited based on the present operating mode.
Basic and K2 Extended formats: See KIO2 Programmer’s Reference (K2). In K22 mode, direct selection of
crystal filters is possible by adding a 5
th digit (K2 and K3 only). However, K31 must not be in effect, or it will
override the legacy K2 behavior and only allow direct bandwidth selection. For example, you could send
K30;K22;FW00003;K20;K31; to select filter #3 and then restore the original K2x and K3x command modes
(yours may be different).
Notes: (1) In AI2/3 modes, moving the physical WIDTH control results in both FW and IS responses (width and
shift). (2) In diversity mode, FW matches the sub receiver’s filter bandwidth to the main receiver’s, which may
result in the generation of FA/FB/FR/FT responses. (3) Both FW and FW$ can be used in BSET mode (one
exception: at present, FW/FW$ SET can’t be used in BSET mode with diversity receive in effect). (4) In K22
mode, a legacy 6
th digit is added to the response. It is always 0. In the K2, it indicated audio filter on/off status.
GT (AGC Time Constant; GET/SET)
Basic SET/RSP format: GTnnn; where n is 002 for fast AGC and 004 for slow AGC.
K2 Extended SET/RSP format (K22): GTnnnx; where x is 0 (AGC off) or 1 (AGC on).
Note: AGC time constant is stored per-mode in the K3, as is AGC on/off and VFO tuning rate.