Itty bitty RXs with servos?

pressalltheknobs

Posted a thousand or more times
There's a replacement

https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMAS6410L

also this one
https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMAS6410NBL
https://www.horizonhobby.com/as6410nbl-dsmx-6ch-as3x-receiver-with-bl-esc-spmas6410nbl

which works with these
https://www.horizonhobby.com/23-gram-performance-linear-long-throw-servo-spmsa2030l
https://www.horizonhobby.com/23-gram-linear-long-throw-offset-servo-spmsa2030lo

you can get the mechanics separately
https://www.horizonhobby.com/replacement-servo-mechanics:-23-gram-2030l-spm6836

There are some similar non spektrum type parts around that you might find at the usual on-line warehouse stores...hobbyking, banggood etc. I think hobbyking used to make a DSM2 compatible part. There are some "bricks" for other protocols.