COM1019 DSSS modulator -> COM2001 Dual D/A converter (baseband) -> COM4003 L-band 
[1500 - 1740 MHz] RF quadrature modulator

Direct sequence spread-spectrum
19.9 Mchip/s QPSK
Spreading code: Barker, length 13
Data rate: 3.06 Mbps.
No noise. 
PRBS-11 sequence is being transmitted.
Modulated signal centered at 1.5 GHz.

(a) Connect a serial cable to the COM1019 (leftmost ComBlock).
Connect an external 10 MHz frequency reference to the COM-4003 EXT_CLK port.
Turn power on. 
Enumerate the ComBlocks from the ComBlock Control Center.
Import the configuration settings 1019_2001_4003.stn

(b) With an oscilloscope, check the baseband signal at test points C3 and C24 of
the COM-2001 dual D/A converter. These test points are located close to the SMA
output connectors. The I & Q baseband signals should be 1 Vpp, 0.85V mean, 
filtered (no sharp transition). 

(c) With an oscilloscope, check that the COM-4003 frequency synthesizer is locked:
The SYNC_LOCK test point should be low.

(d) With a spectrum analyzer, check the RF output signal at the RF-OUT SMA connector.
The signal should be a 19.9 MHz wide (-6 dB) modulated signal centered at 1.5 GHz.
The total output power is TBD dBm.
The 1st sidelobe power density is -39 dB lower than the main lobe (i.e. -77 dBc in a
3 KHz band).