Also the redundancy of the FEC treatment in MT-63 allows it to give 100% accuracy with 25% loss of data. In actual use, Olivia will do better under worse conditions at a large loss of speed. Contestia attempts to bridge the gap, but MT-63 gives the highest accurate through put at the highest speed before going to an ARQ protocol. David KD4NUE
-----Original Message----- From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com] On Behalf Of Tony Sent: Saturday, March 21, 2009 3:41 AM To: digitalradio@yahoogroups.com Subject: [digitalradio] Re: KV9U - MT63 Rick, > You have done the tests and found that MT-63 is not very good at > handling weak signals compared with other modes. It is less sensitive than others, but some of the most sensitive modes are not necessarily the best performers when conditions deteriorate. I think it's reasonably sensitive though. > Is you recent on air testing to determine that or some other parameters, such as > ability to handle interference, etc.? Not really. I pretty much know what to expect with MT63 because I've been using it since IZ8BLY first released it a long time ago. The most impressive thing about MT63 is how it seems to resist heavy static crashes. I made a few recordings with short segments of the signal removed to simulate this type of QRN and there was little effect on copy. It seems to withstand a lot more QRM than most and will usually print well with a good chunk of it's signal obliterated. There's a short video on this reflector in the file section showing how MT63 resists a combination of Pactor QRM and some fairly deep selective fading. > By the way copying both you near noise level, and Skip, KH6TY, a bit > stronger at S3-4. Tried to decode an earlier narrower mode but no luck. > Was it MFSK8? That was DominoEX4. Please give us a call next time Rick! Tony -K2MO
