> HKT511\x00\x00
>
> This can be easily fixed by checking for both ident strings or by
> shorting the string to just 7 characters.
>
> When this is done, CHIRP starts the download process, but then the
> clone process is ended with 'Unexpected respose'.

Well, you need to read all eight bytes, but make sure that the first
seven are right. Maybe even just stick to the first six?

    if not ident.startswith('HKT511'):
        raise ...