HP 8559A User Manual

ADJUSTMENTS
5 - 19. LOG AMPLIFIER LOG AND LINEAR ADJUSTMENT (SERIAL PREFIX 22O8A) (Cont'd)
12. Set step attenuator to 0 dB. Digital voltmeter should indicate 800 mV, plus offset (algebraic sum) * 1 mV.
If DVM reading is not within limits, adjust A14R2 LOG LIN adjustment for a digital voltmeter reading of
800
mV, plus offset minus 50 percent of overshoot. (Example: if DVM indicates 767 mV and should be
indicating 777
mV ( - 10 mV overshoot), adjust A14R2 for a DVM reading of 777 mV minus - 5 mV, or
782
ml)
13. Repeat steps 10, 11, and 12 until the digital voltmeter indicates 800 mV plus offset f 1 mV with no further
adjustment of
Al4R2 in step 12.
14. Set the step attenuator to the positions shown in Table 5
- 7 and record DVM reading for each setting.
Correct the DVM readings by algebraically adding the offset (recorded in step 9).
TABLE 5-7. LOG FIDELITY CHECK
Max. (mV) 1
Step Attenuator
Setting
(dB)
15. Readjust A14R2 if necessary to meet the limits in Table 5 - 7.
DVM Reading
DVM Reading Corrected for
(mV)
Min. (mV) Actual (mV)
16. Set step attenuator to 0 dB and set output level of signal generator for a digital voltmeter reading of 800
mV plus offset (recorded in step 9) f 1 mV.
17. Set Amplitude Scale to LIN. The digital voltmeter should indicate the reading set in step 16 *25 mV. If it
does, go to step 19. If it does not, or if log fidelity is not within limits, go to step 18 and select
A14R16*.
18. Select A14R16* to obtain an output in step 17 within f 25 mV of the reading set in step 16. Decreasing
A14R16* 10 percent will increase the DVM reading approximately 30 mV in step 17.
NOTE
Log fidelity must
be considered when selecting A14R16*. That is, if the
DVM READING CORRECTED FOR OFFSET in Table
5-7 is greater than 100
mV for a STEP ATTENUATOR SETTING of 70 dB, A14R16* should be
selected for a DVM reading greater than the reading set in step 16.
If the
READING CORRECTED FOR OFFSET is less than 100
mV, A14R16* should
be selected for DVM reading less than the reading set in step 16.

HP 8559A Specifications

General

Brand	HP
Model	8559A
Category	Measuring Instruments
Language	English