On Wed, 16 Jul 2003 17:58:47 -0700 "Bruce Sawyer" <n6nt@arrl.net> writes:
> I can now switch back and forth between the MMTY and
> Rttyrite
> engines in one keystroke, so it's painfully obvious now that I'm
> getting
> much better copy out of Rttyrite. MMTY is working OK, but it
> generates a
> lot more decode errors than Rttyrite. What happened?
Bruce,
MMTTY copies a lot better than Rttyrite on my P200. I have two
copies of Rttyrite running for so2r, and have adequate computer
resources.
Try running the Windows resource meter to see if your computer has
adequate cpu resources while running WL/MMTTY. If the resource meter
flat-tops at 100%, maybe you can do a ctrl-alt-delete to see what else
is running, and turn some of it off.
You can connect headphones to your sound card's audio output to see
if there is some gross distortion or noise in the loop. In the playback
audio controls, "microphone" or "line input" needs to be selected,
depending on which one you are using for the sound card input.
Try restarting the computer to maximize resource availability.
With 500 Hz filters or narrower, you should be able to verify
that the receiver's passband is centered on the MMTTY demodulator.
The MMTTY spectral display should be max around the mark/space,
and fall off at both edges. You can tweak it with the hi/lo cut
or passband tuning on the rig. Make sure the correct mark/space
tones are selected in MMTTY. Make sure afc is off, and stays off.
After you turn it off, verify that the mark/space frequencies are
still correct. They change themselves when afc is on.
Hope something here helps.
Dave Hachadorian, K6LL
Big Bear Lake, CA
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