Identical to complex scope, except has magnitude block before scope sink (which is now of the float type).
In the following example, a Mode S transmission can be seen. Mode S uses Pulse Position Modulation (PPM), for which the first demodulation step is treating it as an AM signal (i.e. take magnitude of complex stream and ignore phase).
Grab it from gr-baz.
Although this version still works, it will no longer be maintained: