I am trying to help someone set up an S-Bus system using an R2008SB receiver and SBD-1 decoders.

I have set the channels (1 – 3) on a decoder and everything works correctly when I test it with my own R7008SB receiver. When the decoder is connected to the R2008SB receiver the servos still respond to the correct controls but oscillate violently.

An S-Bus servo plugged directly into the S-Bus port on theR2008SB responds correctly without any buzzing or oscillation.

We have experimented with two different R2008SB receivers and three different SDD-1 decoders but always with the same result.

Is there a compatibility issue between the R2008SB and theSBD-1 decoder? If not, have you any other suggestions?

Thank you

We checked this on the bench. When an R2008SB receiver is used with an SBD-1 and analog servos the servos act exactly as you mention, but if we put in digital servos everything works correctly.

When an R7008SB receiver is used with an SBD-1 and analog servos everything works correctly.

The higher frame rate of the R2008SB w/SBD-1 vs. the R7008SB w/SBD-1 is the reason.

R2008SB w/SBD-1 – 6.7ms frame rate
R7008SB w/SBD-1 – 15ms frame rate

Thank you. That provides a solution, albeit the more expensive one of using digital servos. More importantly, it reassures me that I am not going completely mad.