Hi Jim,
Thanks for the detailed reply. I have never tried JT65 of any flavor so I have
no basis for comparison and accept your conclusions.
Since I'm more of a DXer than a contester, I don't often use N1MM or any of the
other programs that support 2Tone. I use DXBase for general logging and AXETTY
(an MMTTY variant) on RTTY. AXETTY, by Joe, WA6AXE, speaks to DXBase. I asked
Joe whether he would port to 2Tone, but he's not interested. In my (very)
limited use of N1MM on RTTY I have used multiple decode windows. It appears to
me that 2Tone might be superior once it locks to the signal, but on quick
exchanges that doesn't seem to happen. Maybe something I'm doing wrong.
Nevertheless, not a big issue for my style of operating.
Although licensed in 1958 I was never on RTTY until I got the K3 about 4 1/2
years ago. The passing of my wife three years ago took a big hunk out of that
time. Even so, with very modest antennas I've now worked 210 countries on RTTY
and it's become my favorite mode. Maybe I should give JT65 a try, except as a
former "copy-by-ear" EMEer I think it's "cheating" on that mode :-)
73,
Wes N7WS
On 5/9/2014 2:00 PM, Jim Brown wrote:
On 5/9/2014 1:26 PM, Wes (N7WS) wrote:
Likewise, after your glowing recommendation of the US100, I bought one.
Hi Wes,
I did my testing with JT65HF on he HF bands, with the K3 output feeding both
one Thinkpad internal sound card and the Tascam feeding a second Thinkpad. I
did the same comparison between the Numark and internal, then between the
Tascam and the Numark. My criteria was the number of good decodes for each 1
minute pass. The Tascam and Numark boxes consistently decoded twice as many
signals per 1 minute pass. The internal sound card rarely decoded a signal
weaker than an indicated -12, whereas the Tascam and Numark regularly decoded
additional signals down to -20, with occasional -22 decodes. I attribute that
to better performance near the bottom of the A/D. When comparing the two USB
boxes to each other, roughly once in ten passes, one would decode a signal
that the other would not, but neither was better than the other -- on one pass
the Tascam would miss a station that the Numark copied, then 5-10 minutes
later the Numark would miss a station that the Tascam copied. This was quite
extensive -- in addition to watching the nigher bands, I even let them run
overnight on 160, then compare decodes the next morning.
I found performance "a bit better" with RTTY, but did no equivalent testing to
substantiate that, because I found the JT65 results far more quantifiable and
repeatable. So for RTTY contesting, the Tascam is on one rig feeding one
laptop, and the Numark is on the other rig, feeding the other laptop. Now that
we have 2Tone as an alternative to MMTTY, I've been running three decode
windows per radio, and the most I can say to describe the result is that they
are about equally good, but on almost every pass, one of the windows will copy
something that one of both of the others missed, not no consistent advantage
I've been able to discern to one over the other. The real advantage is that
you have three looks at the same signal, so you tend to ask for far fewer
repeats, AND I have changed to not repeating the exchange. I notice W0YK doing
the same.
73, Jim K9YC
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