Xbee pro 900HP 200K not communicating

Hi ,

I just bought two Xbee Pro (S3B) 900 HP 200K modules with RP-SMA connectors. For the time being I am just trying to communicate between the two Xbees without any antenna using X-CTU . However, they are unable to receive any data when I send it from the other Xbee. What can be the issue? I have checked the Channel Mask, Preamble ID and Network ID and none of them seems to be an issue. Are antennas necessary to communicate if there are connectors on the modules?

Kindly help,

Thanks in advance.

As a general rule, you should never use a transmitter without a load (antenna) as it will burn out the final amplifier. The digi radios seem to be fine with this, but the short answer to your question is: YES