[ARCHIVED THREAD] - MT63 (Page 1 of 2)
Posted: 8/18/2014 7:09:44 AM EDT
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Anyone here use MT63? It looks like a good digital mode with decent throughput and good error correction. I see that it's used by MARS. I'd be interested in trying an MT63-1000 QSO tonight if anyone is game. Some links: |
Let's try this:
If there is QRM or someone else on 14.066, QSY to 14.068. I'll call CQ ARFCOM. My call is KB3***. If this time or freq is no good for you please post an alternative. |
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I'd love to join you guys but I'm not sure I'll be around at 1930. MT63 is one of my all time favorite modes and I have a lot of experience working it. Nobody uses it anymore except MARS, though.
I would strongly recommend you use long interleave. The extensive FEC is the entire point of MT63. A few MT63 pointers for you: Most important--be patient and wait a full 12 seconds (for long interleave) for decode to start. MT63 is not like other modes. If you fiddle with the tuning knob, thinking that that is the reason you don't have decode, then decode starts over again each time you touch the knob and you'll never get any decode. So just be patient and trust it. Use looooooooooong CQ calls. MT63-1000L is very, very fast. You need the transmission to go out for at least 30 seconds so that people can tune it, wait the 12 seconds and get some decode. Don't be surprised if you need 20 lines of CQ ARFCOM de WXXX in the buffer! Even though the documents say you only need to be within 100Hz, don't believe it. Within 50Hz is really where you need to be to get good, reliable decode. On a 100W rig set your power between 25 and 35W average. You can push a little more but because of the high PAPR on MT63 you start to distort the signal very quickly and then nobody can decode you. If I don't make it make sure to post an AAR! |
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Quoted: I'd love to join you guys but I'm not sure I'll be around at 1930. MT63 is one of my all time favorite modes and I have a lot of experience working it. Nobody uses it anymore except MARS, though. I would strongly recommend you use long interleave. The extensive FEC is the entire point of MT63. A few MT63 pointers for you: Most important--be patient and wait a full 12 seconds (for long interleave) for decode to start. MT63 is not like other modes. If you fiddle with the tuning knob, thinking that that is the reason you don't have decode, then decode starts over again each time you touch the knob and you'll never get any decode. So just be patient and trust it. Use looooooooooong CQ calls. MT63-1000L is very, very fast. You need the transmission to go out for at least 30 seconds so that people can tune it, wait the 12 seconds and get some decode. Don't be surprised if you need 20 lines of CQ ARFCOM de WXXX in the buffer! Even though the documents say you only need to be within 100Hz, don't believe it. Within 50Hz is really where you need to be to get good, reliable decode. On a 100W rig set your power between 25 and 35W average. You can push a little more but because of the high PAPR on MT63 you start to distort the signal very quickly and then nobody can decode you. If I don't make it make sure to post an AAR! Thanks. I've changed my suggested settings to MT63-1000L per your suggestion.
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I use MT63-2000L all the time on VHF FM nets for RACES in my area. The nice thing about it, is it's very robust, and you don't even need a proper interface. As long as the computer's mic can hear the radio, it'll decode it. And vice-versa with the radio's mic and pc speakers. Been using it since 2009 or so with FLDigi. You'll notice a few second delay in the transmission, that's the FEC (forward error correction) making sure it got the data correct. Never tried the narrower versions on HF, though. |
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OK, I'm seeing TXs with lower edges at 14066.5, 14066.625, and 14067.
Frostbite is on 14066.625. Y'all might want to put your center freq on 14067.5 or your lower edge at 14067, which will be 14066 on the dial + 1500. Edit listening 40M 7112 (7113.5 center) now, I'll mentioned if I see anything but way early for the band here in AZ. |
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Quoted: Saw your signal but could not decode you. Very bad conditions on 40M also. Quoted: Quoted: I just saw WU** on 40M and replied. w00t! Saw your signal but could not decode you. Very bad conditions on 40M also. You're coming in here 599. I just called CQ and asked for a relay to you. Maybe someone else will drop in.
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I did mention how this mode is more sensitive to freq. accuracy than others 
Everyone might try zero beating their rig against WWV to see how far off they are. Seriously. I know I'm spot on because Seek2 heard me and he is always spot on
I actually just checked my calibration against WWV and I was about 20Hz off. Well within the MT63 tolerance but I've since corrected that to <5Hz off. eta...and BigDaddy is also always spot on
Sitting on 40M guard but going away from the radio for a while. |