I have small Short wave receiver for the 7 broadcast bands. (49,41,31,22,19 and 16 meters) What Modulation do they use in this? The radio is a small grundig mini 300 world band reciever.
All "short wave" public broadcast I have ever listened to were plain old AM.
You will find some SSB (single side band) and OOK (on/off keying) interspersed in various bands between the "short wave" stations. Those require different demodulation techniques to recover the signal. A regenerative receiver can demodulate AM and OOK easily, and SSB sortof if very carefully tuned. For most practical purposes, you need a receiver specifically intended for SSB to properly receive it.
In general, something called a "short wave radio" is little different from a AM radio except in the range of frequencies it can be tuned to.
Here is what wikipedia say.
and here's the table of frequencies: -
Specifically wiki says "Most international broadcasters use amplitude modulation with 5 kHz steps between channels; a few use single sideband modulation."