Steve, Your amps are a bit different from Bitx. We ktow, that in BitX they are termination sensitife - and it is abt 50/500 ohm. with characteristic impedance abt 180 ohm.
What is in Your (pnp/npn) case?
I've read that it's about 200/200, but I rather think, that is similar case like in BitX (output impedance depends of input)
Did you ever chceck it?