Working of channel in limesdr-usb

Hello,while doing dvb-t to check the transmitter side we tried transmitting from CH-B from limesdr and received it using airspy and witnessed the frequency spectrum everything was fine,we got peak at the point which we transmit DVB-T, but when we are doing the same using CH-A we are not able to get the peak at the frequency spectrum (which is received using an airspy)does it mean that it has issues with the channel or the band or the connector is not mated properly??Suggestions are highly recommended.
thanks in advance,
Soma Sundaram Ravindran