HRD no audio in CW TX mode

CW is not an audio transmit mode. It is generated by turning the transmitter, which is generating a pure un-modulated carrier, on and off, commonly called "keying". In the Flex 6500 this is accomplished by plugging a key or paddle into the front panel KEY jack. The radio accepts either a straight key (or external keyer) input, or a paddle to use the internal keyer. This generates dots when one side is closed and dashes when the other side is closed.

Using a Windows program to generate CW is not the best way, as the timing in Windows is not guaranteed and keying timing may get messed up.

Most of us use an external keyer, such as WinKey, The WinKey has a USB port and will interface to most logging software to generate perfect CW. It will convert text from the PC to CW, or can be used manually with a paddle.

The Flex also has CWX built in, which can use Macros to send canned messages, or keyboard input for real-time message generation.

But, there is no audio input for transmitting with CW.