2Tone vs. MMTTY - AA5AU QSO with 9U4U on 2/20/2013
Saw the Packetcluster spot for 9U4U on 7040 kHz AT 0344z ON 2/2/2013, but the spot did not say RTTY. I went there anyway and he was there. I could not copy anything for a long time with a solid carrier very near his Mark frequency, but I could hear him. I had N1MM Logger already opened so when the QRM cleared I started calling. He then disappeared for a few minutes then came back slightly higher in frequency. He was working up about 2 kHz. I had him on 7039.883 kHz on my PRO III and saw him work N6SS at 7042.218, so I went there and made the contact.
The screenshot below is my contact at 0315Z. His signal was below the noise level of S5. I was using my 40M inverted vee with apex at 40' which was better than the Pixel Loop on the other tower. IF bandwidth was set to 500 Hz, with the Twin Peak Filter enabled and 6db attenuator on. I had no copy without the TPF. I had the RF gain backed off where the S-meter was showing 20db. I was using an AGC setting of SLOW in the radio. I was running 500 watts output. His transmission is circled in red in all four RTTY windows.
The top window is MMTTY using the Fluttered FIR profile with AFC off with Dual Peak Filter in MMTTY enabled. I got a piece of my call but not fully.
The next 2nd window is 2Tone using the Narrow/Normal mode. My callsign printed correctly once, the nearly a second time when AA2AU printed. This 2Tone combination of Narrow/Normal has been consistently the best over the period of time I have been using 2Tone.
The 3rd window is 2Tone using the Wide/Flutter mode that did not copy anything resembling a transmission from him. This setting in 2Tone has not been very productive other than with Fluttered signals. That makes sense. In my excitement to make the contact I forgot to turn Flutter off. I normally like the setting of Normal/Wide in this window.
The 4th window is MMTTY using the Standard profile with AFC on. I got my call perfectly once and got my suffix once. That is pretty good.
I'd say the 2nd window wins in this one but barely. The standard profile MMTTY window (4th window) was pretty good too under these conditions.
Just another example of how good 2Tone is, but the MMTTY standard profile was nearly as good on this one contact. I think this example shows the importance of multiple decoders when you may only get one shot at getting it right!
73, Don AA5AU