QPSK modulator COM-1002 -> Dual D/A converter COM-2001 -> Dual-band 915MHz/2.4GHz modulator COM-4001

This test setup demonstrate the ability to tune to the extreme frequencies:
850 MHz, 1 GHz, 2.050 GHz, 2.5 GHz.
The COM-1002 is only used as a digital sinewave generator. 
Also test the internal versus external frequency reference.

(a) Connect an external 10 MHz frequency reference to the EXT_CLK input of COM-4001.

(b) Power up the assembly. Import the 1002_2001_4001.stn settings into the assembly
using the file | import menu. You may have to turn the power off and then on.

(c) using an oscilloscope, probe the COM-2001 I and Q outputs. The capacitors C3 and C24
are convenient test points. The signals should be 39.062 KHz sinewaves, with amplitude
of 1Vpp.

(d) using a spectrum analyzer, check the COM-4001 output.
The output is an unmodulated carrier at 850 MHz. 
Verify that the level (@849.961 MHz) is typically -2 dBm @ 850MHz.
Verify that the LO leakeage (@850 MHz) is typically -31 dBm.
Verify that the image rejection (@850.039 MHz) is typically -30 dBc.

(f) Frequency selection
Using the ComBlock Control Center, change the control registers to the following values 
and observe the following spectrum outputs:
REG0/1/2/3: 80 F8 A9 32   RF frequency = 850 MHz (REG10 = 05 lower frequency band)
REG0/1/2/3: 00 CA 9A 3B   RF frequency = 1000 MHz (REG10 = 05 lower frequency band)
REG4/5/6/7: 80 84 30 7A   RF frequency = 2050 MHz (REG10 = 07 upper frequency band)
REG4/5/6/7: 00 F9 02 95   RF frequency = 2500 MHz (REG10 = 07 upper frequency band)

Change the spectrum analyzer frequency accordingly.
Verify that the SYNC_LOCK test point is low (locked synthesizer).

(g) Remove the external 10 MHz external frequency reference. 
Modify register REG10 to 06 (internal frequency reference, upper band)
RF center frequency may move by 100 KHz typically.