R/C Tech Forums - View Single Post - New Sanwa MT-44 4-channel 2.4GHz radio system
Old 12-31-2016, 11:29 PM
  #82  
Nezil
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I have some updates as promised...

Unfortunately I wasn't able to race on Friday, but I did get about 2 hours of solid practice in, which is probably longer run-time than if I'd been racing, so it's still an interesting touch point.

The battery (3 x 750mAh AAA Panasonic Eneloops) voltage dropped from 4.2v to 3.8v during the course of the run, but didn't go below that. 3.8v is actually still higher than the nominal 3 x 1.2v of 3 x NiMH, and if I remember correctly, the discharge curve of NiMH should be reasonably flat. The battery gauge on the MT-44 currently indicates about 75% remaining. If that is true, then you'd get about 8 hours out of AAAs, and probably double that out of the optional LiPo. It's too early to say if that's accurate or not, and I'll try and post back as I learn more.

I also got a chance to take some additional PPM / Response measurements of M12S and MT-4S, and here are the results (original results also shown again for completeness; new data in bold):
  • Sanwa MX-V: 63Hz / 15.9ms
  • Sanwa MT-4 (Normal Mode): 90Hz / 11.1ms
  • Sanwa MT-4 (SHR Mode): 192Hz / 5.2ms
  • Sanwa MT-4 (SSR Mode - Narrow Pulse): 191Hz / 5.2ms
  • Sanwa MT-4S (FH4T Normal Mode): 93Hz / 10.8ms
  • Sanwa MT-4S (FH4T SHR Mode): 383Hz / 2.6ms
  • Sanwa MT-4S (FH4T SSR Mode - Narrow Pulse): 383Hz / 2.6ms
  • Sanwa MT-4S (FH3 Normal Mode): 110Hz / 9.1ms
  • Sanwa MT-4S (FH3 SHR Mode): 332Hz / 3.0ms
  • Sanwa MT-S (FH4T Normal Mode): 95Hz / 10.5ms
  • Sanwa MT-S (FH4T SHR Mode): 384Hz / 2.6ms
  • Sanwa MT-S (FH4T SSR Mode - Narrow Pulse): 191Hz / 5.2ms
  • Sanwa MT-S (FH3 Normal Mode): 83Hz / 12.0ms
  • Sanwa MT-S (FH3 SHR Mode): 332Hz / 3.0ms
  • Sanwa MT-44 (FH4T Normal Mode): 95Hz / 10.5ms
  • Sanwa MT-44 (FH4T SHR Mode): 383Hz / 2.6ms
  • Sanwa MT-44 (FH4T SSR Mode - Narrow Pulse): 383Hz / 2.6ms
  • Sanwa MT-44 (FH3 Normal Mode): 83Hz / 12.0ms
  • Sanwa MT-44 (FH3 SHR Mode): 332Hz / 3.0ms
  • Sanwa M12S (FH4T Normal Mode): 95Hz / 10.5ms
  • Sanwa M12S (FH4T SHR Mode): 383Hz / 2.6ms
  • Sanwa M12S (FH4T SSR Mode - Narrow Pulse): 383Hz / 2.6ms
  • Sanwa M12S (FH3 Normal Mode): 110Hz / 9.1ms
  • Sanwa M12S (FH3 SHR Mode): 332Hz / 3.0ms

This data shows that the MT-4S is identical to the M12S in terms of latency. This is interesting, because the MT-4S was billed as being 'As fast as the M12', and the M12S as being '20% faster than the M12'. Perhaps there is some un-known latency in the processing before transmission, but I'd be surprised...

Also interesting is that the MT-44 is slower in FH3 Normal mode, not that this is particularly important; I'm not sure why you'd use that mode.

One other thing I noticed when playing with the MT-4S and M12S, was that the spring tension, for the steering in particular, was much lighter on the M12S and MT-44 than the MT-4S and MT-S. Of course this is adjustable on all of these radios, but it seems that if you attempt to make the MT-S and MT-4S as low tension as the M12S and MT-44, they won't center correctly; something is different about the action of the MT-44 and M12S, and in a good way.
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