=== Calibrating Your Radio

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=== Reference Spectrum

WSJT-X provides a tool that can be used to determine the detailed
shape of your receiver's passband.  Disconnect your antenna or tune to
a quiet frequency with no signals.  With WSJT-X running in one of the
slow modes, select *Measure reference spectrum* from the *File* menu.
Wait for about a minute and then hit the *Stop* button.  A file named
`refspec.dat` should appear in your log directory.  

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