HP 8340B Manual page 18

4-2. FREQUENCY RANGE AND CW MODE ACCURACY (Cont'd)
c. Using the up arrow key, step the center frequency up to 2.310510 GHz. Check the counter
indication at each step. The counter should indicate the DUT start frequency (CF
GHz) 1 Hz
±
The above steps set the output of the M/N loop to 180 MHz where M
and N
=
the Nth harmonic (N =13) of 180 MHz (180 x 13
output is then 30 MHz. since the AF frequency (1 MHz) is between 0.1 to 5
MHz, the 20/30 MHz frequency is derived from the PLL2 75 to 150 MHz
VCO output divided by 5 (150 MHz / 5
quency is stepped down in 5 kHz steps which steps the 20/30 frequency
from 30 MHz down to 29.990 MHz in 1 kHz steps. Since the M/N fre-
quency remains constant and the HP 8340B/41B output frequency is
mixed with a harmonic (13th) of the M/N signal and the resultant output is
phase compared to the 20/30 output, the DUT output frequency must
increase by 1 kHz/step to satisfy the 20/30 phase lock loop. This checks
the least significant (BCD) N2 programming bits.
To observe the N2 PLL2 VCO frequency changes, repeat the N2 loop
frequency check (Step 6a through 6c) pressing [SHIFT][M3] in step 6b
rather than [SHIFT][Ml]. [SHIFT][M3] will display, from left to right, the
PLL2 VCO frequency and the PLL3 Up Converter frequency (the PLL3 UP
Converter frequency display will be 0 since the PLL3 is not used in the
swept mode).
d. Select a step size of 10 kHz by pressing
center frequency in the [ENTRYDISPLAY]; the
e. Using the up arrow key, step the center frequency up to 2.31 0600 GHz. Check the counter
indication at each step. The counter should indicate the DUT start frequency (CF
GHz) 1 Hz
±
The above steps program the 20/30 frequency from 29.99 MHz to 29.90
MHz in 0.01 MHz steps and checks additional N2 Divider programming
bits.
f. Select a step size of 100 kHz by pressing [SHIFT] [CF] [1] [0] [0]
the center frequency in the
g. Using the up arrow key, step the center frequency up to 2.311S00 GHz. Check the counter
indication at each step. The counter should indicate the DUT start frequency (CF
GHz)
1 Hz
±
The above steps program the 20/30 frequency from 29.9 to 29.0 in 0.1
MHz steps and check additional N2 Divider programming bits.
h. Select a step size of 1 MHz (press [SHIFT][CF] and enter [1] [MHz]).
center frequency in the [ENTRYDISPLAY]. The CF should be at 2.311S00 GHz.
Tests
4-16 Performance
the resolution of the counter.
±
13. The YO start frequency (2310 MHz) is then 20 to 30 MHz below
the resolution of the counter.
±
[ENTRYDISPLAY]. The CF should be at 2.31 0600 GHz.
the resolution of the counter.
±
NOTE
2340). The 20/30 MHz
=
30 MHz). The PLL2 VCO fre-
=
[SHIFT][CF][1][0] [kHz].
display should indicate 2.310S10 GHz.
NOTE
NOTE
0.0005
—
26
=
[CF]
Press to display the
0.0005
—
[kHz].
Press [CF] to display
QOQOS
—
Press [CF] to display the
HP 8340B/41B