Currently using an Alinco DJ-X3... replaced the stock with a Diamond
SRH701 which is giving me pretty decent performance. However, after
replacing with a Diamond SRH771 (looks the same design as the
now-obsolete RH77CA), reception actually seems to be slightly worse
than before (would just pick up an ATIS broadcast from an airbase
about 20km away before, now it picks up nothing).

Any recommendations? The Diamond SRH999 is also not an improvement
despite it being 3 times the price of the SRH771...

As you probably have guessed already, I can only get Diamond stuff
locally... heard only good things about the Watson WSMA-881, but I
have to order that overseas... trying to avoid that.

Thanks in advance..