Hi Alan, thank you for replying.

I use the included dualconversion xtals and the included HFD-08RD with the optic 6 transmitter.
I did suspect the plane at first, after all an electric powered hotliner with long servo extension cables to both tail and wingtips can be tricky.
So the first thing I did after the failed rangecheck was to check the receiver, servo's and so on outside ot the plane instead. I ask a friend to hold the transmitter while I myself walk away with the receiver, a receiver batterypack (no power switch inbetween battery/receiver and tried different batterypacks) ) and a servo or two (tried different servos).

The old laser 6 system uses the supplied rcd 3500 dualconversion receiver and supplied original xtals.
So ofcourse I tested swapping xtals, receivers, and batterypacks between these two systems. and everything seems to work fine except for the optic 6 transmitter. It has a very short range nomatter what I try. While the the Laser 6 has an equally good range with both par of xtals and the HFD-08RD receiver.

But I agree it seems very strange that two new Optic 6 systems should suffer from short range.
So I've been trying to think of something I did wrong, like having the transmitter turned on without extending the antenna. Wich caused something to overheat. Or perhaps using a better quality and higher capacity 8 cell nimh transmitter pack was a bad idea as fully charged it has a marginally higher voltage than the supplied no-name pack, And so mabe it overloaded something.
perhaps I accidentally kinked the receiver antenna cable, but no the receiver works fine with the laser 6 transmitter.

Just can't think of anything else to try or check,