[Elecraft] k3S usb software silenced sidetone and no rf out

[Don Wilhelm]

For those who have a K3S or a K3 that has been upgraded with the KIO3B 
option, the "fix" for the problem of the computer 'wiggling' the DTR and 
RTS lines when the computer is turned on is to download MCU 5.33 or higher.

There is a SAFE MODE to prevent just that - read the Firmware Release 
Notes for MCU 5.33.

73,
Don W3FPR

On 3/18/2018 11:54 AM, Rick WA6NHC wrote:
> With the homebrew circuit (opto-isolator X 3, one each for PTT, Data/FSK 
> and CW) I'm using, I chose to take the CW keying directly to the key 
> port of the K3 (in parallel with the hand key, plus there are paddles). 
> That allows me to leave Config: PTT Off-Off.
> 
> This has worked really well, except the OS wake up still keys the 
> transmitter during the discovery phase of boot up.  That apparently 
> can't be avoided (so I put the TX in test mode, if I'm in the shack).  I 
> use real serial ports as USB has more problems in QRO RF.
>