RFX900 Filters

GNU Radio
1

Hi all,

Does anybody know if the ISM filter on the RFX900 board affects both the
Rx
and Tx paths or only the Rx?
Is there a easy way to disable it?

Thanks for your help!

2

Wireless Monster wrote:

Hi all,

Does anybody know if the ISM filter on the RFX900 board affects both
the Rx and Tx paths or only the Rx?
Is there a easy way to disable it?

The filter affects both TX and RX, but not the auxiliary RX path (RX2).
If you just want to receive, use the 2nd SMA port and make sure to set
that in the software. If you want to bypass the filter for transmit,
you will need to put a cap of about 50 to 200 pF in the path, and cut
the traces to the filter.

Matt

3

Hi Matt,

Thank you for your help.
Can you point me to the board schematics to see where I should ‘cut’ :slight_smile:

Rgds,

4

Wireless Monster wrote:

Hi Matt,

Thank you for your help.
Can you point me to the board schematics to see where I should ‘cut’ :slight_smile:

Look on the board. You want to cut the filter out of the path, but you
don’t want to cut the main signal path.

Matt