Eval board configuration

You have to make two potential changes. The ac-coupling cap on the eval board (C3) is 1nF. With the RF input impedance being 50 ohms, this gives you an input high pass corner frequency of 3.1 MHz. You would generally want this frequency to be at least one tenth of your minimum operating frequency. So as-is, the board is good for operation down to 31 MHz. If you need to go lower, then increase C3 (I's also set C4 to the same value). 

You may also need to adjust the corner frequency of the internal offset control loop by changing the value of the COFS cap connected to pins 9 and 10 (C6). The default value is 1nF. That gives you a loop bandwidth for the cancellation loop of 220 KHz (see Table 4 on page 25). That setting would be good for frequencies down to around ten times this (2.2 MHz). So again depending on your target minimum input frequency, you should set the loop bandwidth to be lower by at least one tenth. The trade off of setting this loop bandwidth very low is slower response time. 

Ok, closing out this case.