[gentoo-user] [OT] How to copy text from hex editor

[Mick]

This may be simple, but I don't know how to do it:

I have opened a file I captured with tcpflow using hexdump and also tried 
okteta.  With either applications I can select the plain text, but 
corresponding hexadecimal characters are also selected at the same time.

Is there a way of copying and pasting the plain text portion of the file 
content only, or are there some clever incantations that hexdump will take to 
only show the plain text portion of the file? 
-- 
Regards,
Mick