Forum Post: CC1120 vs. CC1101 setting and RSSI

I am trying to set up communication with the following parameters:

Data Rate:         76.8 kbps
TX Deviation:        19.3 kHz
Channel Spacing:    200 kHz
Modulation:        2-FSK
Carrier frequency:    917.6 MHz

I have two CC1120 Smart RF studio boards and two CC1101 boards.
I set one CC1120 and one CC1101 as receivers and another CC1120 and CC1101 as transmitters.
The related setup XML files and screen shots are in the ZIP file.

While there seem to be not much of a problem to transmit from CC1101 or  CC1120 to CC1101 the CC1120 receives quite poorly (59 out of 100 sent from CC1101 and only 28 when sent from CC1120).
See the attached screen shots:
uslpc1_txcc1101.JPG is when CC1101 is the transmitter, uslpc1_txcc1120.JPG is when CC1120 is the transmitter.

Moreover, there is a significant difference when I set CC1120 and CC1101 both for "Continous RX" and just monitor the background:
CC1120 records RSSI around -50 dBm while CC1101 is around -113 dBm.

See uslpc1_cntnsRXcc1120_vs_cc1101.JPG.

When I set both CC1120 and CC1101 to:
Data Rate:        4.8 kbps
TX Deviation:        1.2 kHz
Channel Spacing:    25 kHz
Modulation:        2-FSK (same as above)
Carrier frequency:    917.6 MHz (same as above)
    both CC1120 and CC1101 record similar RSSI numbers.

The goal is to have a setup in which CC1120 can receive and transmit from and to CC1101 node with similar packet error rates ...1% or better ...
This clearly is not working such way ...

Any idea what I may be doing wrong?

Thank you,
    Bogdan.