use real part at common.dumps()

amodem/common.py

@@ -47,7 +47,7 @@ def loads(data):
 
 
 def dumps(sym, n=1):
-    sym = sym.imag * scaling
+    sym = sym.real * scaling
     sym = sym.astype('int16')
     data = sym.tostring()
     return data * n

amodem/sampling.py

@@ -76,5 +76,5 @@ if __name__ == '__main__':
     sampler = Sampler(x, Interpolator())
     sampler.freq += df
     y = np.array(list(sampler))
-    y = common.dumps(y*1j)
+    y = common.dumps(y)
     sys.stdout.write(y)

tests/test_common.py

@@ -49,5 +49,5 @@ def test_icapture():
 
 def test_dumps_loads():
     x = np.array([.1, .4, .2, .6, .3, .5])
-    y = common.loads(common.dumps(x * 1j))
+    y = common.loads(common.dumps(x))
     assert all(x == y)

tests/test_full.py

@@ -29,7 +29,7 @@ def run(size, chan):
     data = tx_audio.getvalue()
     data = common.loads(data)
     data = chan(data)
-    data = common.dumps(data * 1j)
+    data = common.dumps(data)
     rx_audio = BytesIO(data)
 
     rx_data = BytesIO()