[Discuss-gnuradio] Re: BasicRX/BasicTX faq?

[Matt Ettus]

> They share a common ground but there is also a transformer in the mix, does
> this mean that they can go down to DC?

Since the inputs and outputs on the BasicTX and BasicRX are transformer-coupled,
you can not pass DC.  The low end is about 100 kHz.  You can make it much lower
by replacing the transformers with other minicircuits parts which go down to 10
kHz or so.

If you need DC, you would need to remove the transformers and put a differential
to single-ended opamp circuit in there.  Look at the AD8132 for examples of how
to do this.

Matt