[RTTY] Multipath, testing, soundcards

[Bill Turner]

On Thu, 22 Apr 2004 09:57:32 -0500, Tom McDermott wrote:

>A repeating
>pattern (specifically:  RYRYRYRY...) is the worst possible pattern to
>utilize for such test. The pattern should have the most random-like pattern
>of bits. This is because badly-designed modem filters can pass the repeating
>pattern test with good results, yet yield poor copy with more random
>characters.

_________________________________________________________

Could you please explain this further?  It would seem to me that a
filter which only processes one bit at a time would have no *knowledge*
of what came before or what follows afterwards, and therefore would not
be capable of recognizing whether a pattern was repeating or not.  In
other words, would MARK MARK MARK MARK be processed differently than
MARK SPACE MARK SPACE?  Perhaps you are saying that a poorly designed
filter would not handle the transition from MARK to SPACE correctly?

Either way, this could be proven empirically pretty easily I would
think.  

--
Bill, W6WRT
QSLs via LoTW