4-2.
FREQUENCY RANGE AND CW MODE ACCURACY (Cont’d)
i.Using the up arrow key, step the center frequency up to 2.320500 GHz. Check the counter
indication at each step. The counter should indicate the DUT start frequency (CF — 0.0005
GHz) ±1 Hz ±the resolution of the counter.
NOTE
The above steps program the 20/30 frequency from 29.0 MHz to 21.0 MHz
in 1 MHz steps. The last CF step programs the 20/30 to 30 MHz and the
M/N frequency to 180.769231 MHz. This checks the remaining N2 Divider
programming bits.
j.
If a significant frequency error is evident, note the conditions under which the error occurred
and continue this procedure to determine if any other conditions produce an error.
7. Check the 20/30 MHz Ni loop frequencies as follows:
a. Press [INSTR
PRESET]. Select a step size of 10 kHz by pressing [SHIFT]
[CF][1][0][kHz].
Press [CW]and enter [2][3][1][9][.][9][7][MHz].
b. Press [SHIFT]
[Ml]to display, from left to right, the M divide number, the N divide number, the
M/N Output frequency, and the 20/30 Output frequency.
c. Using the down arrow key, step the CW frequency down to 2 319.870000 MHz. Check the
counter indication at each step. The counter should indicate the DUT CW frequency ±1 Hz ±
the resolution of the counter.
NOTE
The above steps set the output of the M/N loop to 180 MHz where M=26
and N =13. The PLL1 VCO frequency is stepped up in 100 kHz steps. This
steps the 20/30 frequency up from 20.03 MHz in 10 kHz steps to 20.13
MHz. The M/N frequency remains constant and the YO frequency is
mixed with a harmonic (13th) of the M/N signal. The resultant output is
phase compared to the 20/30 output. The DUT output frequency must
decrease by 10 kHz/step to satisfy the YO phase lock loop. This checks
the least significant Ni programming bits.
d. Select a step size of 100 kHz by pressing [SHIFT]
[CF][1][0][0][kHz].Press the [CW]key to
view the CW frequency in the [ENTRYDISPLAY]. The CW frequency should be at 2
319.870000 MHz.
e. Using the down arrow key, step the CW frequency down to 2 318.970000 MHz. Check the
counter indication at each step. The counter should indicate the DUT CW frequency ±1 Hz ±
the resolution of the counter.
NOTE
The above steps program the 20/30 frequency from 20.13 up to 21.03 in
0.1 MHz steps and checks additional Ni Divider programming bits.
HP 8340B/41B
Performance Tests
4-17