SiChip: This may suit publication ?
Clones of the cheap,popular and versatile Chinese HC-12 UHF FSK data transceivers have shown problems when used together with earlier HC-12 modules. Compatibility issues seem to relate to clones "30.000 MHz" crystal producing 400 kHz spaced channels that are 37kHz above the correct frequencies. In contrast,original HC-12 modules using "T300" crystals very closely match stated channel specifications (433.400 MHz, 433.800 Mhz, 434.200 MHz etc ) .
Mix and matching classic and clone modules should hence be avoided, as clone off spec. transmissions may fall outside receiver pass bands. These HC-12 clones seem to otherwise work OK,although signals at some channels may fall beyond legal band limits.
Identification seems best made from a close inspection of the module's canned crystal. Maker markings may also be present,along with subtle silk screening & masking differences. A spectrum analyser or UHF scanner could further show the actual transmitter frequencies.
View thread =>
http://www.thebackshed.com/forum/forum_posts.asp?TID=10443&PN=1&TPN=1
Regards - "Manuka" (Stan. SWAN - Wellington,NZ)