开云体育

After all these years sometimes I get to forget!

You have a carrier frequency which you send to a mixer then mix it with some audio
then you end up with one central carrier and two side bands of audio content.

The carrier is a waste of your power so you take it out and so also the other side band
energy which is a mirror. So your xtal filter does the job and selects one side band.

When this signal is received by you then you need to re-insert the carrier (BFO)
back to make the incoming signal intelligible in audio.

And if you vary your BFO frequency the incoming signal may sound tinny or bassy
depending where your BFO is!

Hope that helps!
---
Raj vu2zap