how does a circuit can be modulator and demodulator at the same time?

[mohamis288]

Hi,
I am studying MC1496 datasheet. one of the test circuit has been shown in datasheet named "balanced modulator and demodulator". I have uploaded the image in the attachment. anyway, I have two question:
1) how does a circuit can be modulator and demodulator at the same time?
2) this does not determine whether it is SSB modulator and demodulator, DSB modulator and demodulator, AM modulator and demodulator and ... ? what does it mean?

 

[Aussie Susan]

The image you attach looks similar to the one that I could in the data sheet at https://www.egr.msu.edu/eceshop/Parts_Inventory/datasheets/mc1496p.pdf except that it was labelled Figure 27.
Have you read the description related to that figure? In the version I linked to it clearly called it an 'AM Modulator'.
I suspect that the chip can be used for a number of different purposes, one of which is a modulator and another is a demodulator.
Also have you looked at the application note mentioned in the first paragraph of the data sheet?
Susan