Online SDRs: Is it possible to find the Center Frequency?

[K5KNT]

A few questions regarding online SDRs and the Center Frequency:

Is knowing the center frequency necessary or important?

If so, is it possible to determine the center frequency?

If yes, how would this be accomplished?

Thanks,

K5KNT

[KaySeeks]

The center frequency of the signal you are receiving?

[K5KNT]

I"m not sure. In Appendix B of the Harvester User manual it says:

Determine the centre frequency of your receiver. This is particularly important
when receiving OOK or FSK signals and enabled [sic] you to accurately establish the
correct transmitter frequency.

I'm not actually using this software, but I found the User Manual interesting.

[Josh]

In that case they refer to the cf, or center of intelligence of the given signal. If the mark of a 1000hz shift fsk sig is at 22.490 and the space is at 22.491. the cf is 22.490.5.
For a cw sig, if using a sdr, just look at the carrier and note the freq at the peak it occupies. For a non sdr rig you either add or subtract the beat note from the dial freq to get the cf, depending on if your bfo is above or below the cw.

[K5KNT]

Thank you.