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Old 02-01-2021, 01:10 PM   #4 (permalink)
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The SPM4651T has better "diversity" than the SPM4649T.
But its still not good. I wouldn't fly a heli bigger than a 300-size with either one as the one and only receiver.

The SPM46XX receivers were geared towards the quadcopter market.
At least the SPM4651T has both antenna are soldered on and a hard-case. As for "diversity"? Well, IDK.

The SPM4649T was a disaster when it first came out. That receiver didn't have the "quick start" reboot after a brown out and the "diversity" was that if one antenna whisker fell off, there was a 2nd (until that one fell off).
But the topper was that while it was spec'ed at 8.4v (2S LiPo), I literally caught the first two on fire when I plugged them into a 2S LiPo that was only 7.8v at the time. We had to use a BEC set to 7.4v from that point on.

I still use either the SPM4649T or the SPM4651T on my 5 heli with the Brain2.
But, the big difference is that the Brain2 / iKON2 supports the SPM46XXT + 1 or 2 standard DMSX sats directly plugged into the flight controller for a total of 3 active receivers all working a the same time.
I use the SPM4651T + 1 standard Spektrum DSMX sat on my Goblin 380 (the Trex 470 is a little smaller than the G380) and I use the SPM4651T (or SPM4649T) with 2 standard DSMX Spektrum sats on my two Goblin 570, Goblin 700 Nitro and Protos 700 Nitro.
This is less about signal loss or radio interference and more about sat / SRXL cables that get frayed, broken or bad connections. I think the wires and connectors failing on the receivers is probably the most common cause of crashes. The more receivers there are working together, the less impact the failure of one of them causes.

I don't think the MicroBeast Plus supports both a SRXL2 + 1 sat plugged directly into its SRXL2 and sat port.
In that case, the only way to get multiple receivers working together (for redundancy and reliability) is to use an external AR-series receiver with a sat plugged into that.
IMHO: That's a big hole for the MicroBeast Plus.

Before MSH Electronics perfected the use of SRXL + Sats on the Brain2 / iKON2, I used an AR9030T with 3 Spektrum DSMX sats and connected it to my Brain2 with SRXL on my Trex 700N and 600N/E. That was mostly for peace of mind and getting some telemetry.

As for the AR6100 / AR6100e - they are both DSM2 only.
I think that the receivers that use DSM2 exclusively are going to have a limited future.
Additionally, the AR6100T does not support a serial interface, so you loose 2 channels into the flight controller. Using the serial interface (SRXL / SRXL2) into the flight controller will present all the channels that the transmitter supports. That could mean you cannot do "bank switching" or some other feature the MicroBeast Plus would support if there were 8 channels.
IMHO: If you want to play with telemetry, you should get DSMX anyway.

If I had the MicroBeast Plus, I'd use the SPM4651T as the one and only receiver on a mini-size heli like the Trex 470.
The SPM4651T is better than a single DSMX Spektrum sat (which is the only other option for directly connecting a receiver to the MicroBeast Plus).
But, if you are in the EU, the SPM4651T may need to have a firmware update. They were shipping with 2.37.0 and the latest is 2.40.02. They messed up something to do with using the receivers in the EU, so that is something you should consider.
To upgrade it, you need the "SRXL2 Update Cable, Rx-Servo Male & Female-Female" (SPMA3066) adapter cable, the "TX/RX USB Programming Cable" (SPMA3065) programming cable and the "Spektrum Updater" (v1.3) program. But, the cables all work with the new AR-series receivers for updates and AS3X programming.
For AS3X programming, you need the Spektrum Programmer program. It also does the firmware updates too.

And, with a small heli like the T470, it gives you neat wiring and and a compact installation.
Like I said, when the SPM4651T does crap out no one dies. People may get hurt, but no one dies.
"Those who can make you believe absurdities can make you commit atrocities." (Voltaire)
Watch out: There are a lot of absurdities being thrown around lately.
+ > RIP: John Lewis

Last edited by ticedoff8; 02-01-2021 at 01:36 PM..
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