python3 - udpclient.py error

I'm seeing this error:

```
./udpclient.py freq 92800000
Traceback (most recent call last):
  File "./udpclient.py", line 48, in <module>
    s.send(buf)
TypeError: 'str' does not support the buffer interface
```

I'm not a Python programmer and my attempts to make this work with Python 3.x have failed.
