[Discuss-gnuradio] Switching On and Off the Power Amplifier in python

[sri ram]

Hi all,
        I am trying to perform On
Off Keying and I figured out that the way actual chips (TI-Chipcon
1000) do it is by turning on and off the power amplifier. 
I found out that when I just modify the transmit constellation and use
benchmark_tx.py the received power does not go down to 0 when the
transmitted symbol is 0+0i. As pointed out by some of you, I found that
the stream of symbols have a DC component which results in a beat
frequency at the receiver.
My question now is, can I just shutdown and power up the (transmit)
power amplifier depending on the transmitted symbol to perform On Off
Keying. I think, I will not have the DC problem then because the power
amplifier would now see only one symbol either 1 or 0 instead of a
stream of symbols which have a DC component. In my understanding, the
code currently sets auto_tr to true meaning that whenever it is not
transmitting/ done transmitting a packet it goes to the receive state
and so the power amplifier is off.

Is it possible to set the power amplifier On/OFF in Python ? Where can
I find the code that performs this or is relevant to this?

Thanks,
Sri