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SERVICE INFORMATION FROM HEWLET-PACKARD
1st Quarter 1994
The Optical Spectrum Analyzer = Part 3
;
'
Sensitivity
Mike LevernierlHmlett-Packard
tical spectrum analyzers, see the pre- sitivity. Sensitivity is coupled directly
vious issue of Bench Briefs.) Figure 1 to video bandwidth, as shown in
shows the display of a signal that has Figure 2. As the sensitivity level is
an amplitude equal to the sensitivity lowered, the video bandwidth is de-
setting of the optical spectrumanalyzer. creased (or the transimpedance
amplifier gain is increased), which re-
Single monochromators typically sults in a longer sweep time, since the
have sensitivity about 10 to 15 dB bet- sweep time is inversely proportional
ter than that of double monochroma- to the video bandwidth. The sweep
Introduction tors due to the additional loss of the time can be optimized because the
r In the previous issue of Bench Briefs
Richard Ogg explained the optical
spectrum analyzer in terms of signal
second diffraction grating in double
monochromators. The double-pass
monochromator has the same high
video bandwidth is continuously vari-
able and just enough video filtering
can be performed. This avoids the
sensitivity of single monochromators problem of small increases in sensitiv-
processing, various operating modes, even though the light strikes the dif- ity causing large increases in sweep
noise generation, and the control of fraction grating twice. The high sen- time, which can occur when only a
noise through filtering schemes. In sitivity is made possible by the half- few video bandwidths are available
this issue, Mike Levemier describes wave plate and the use of a smaller in fairly large steps.
OSA sensitivity through Hewlett- photodetector that has a lower noise
Packard's patented way of allowing equivalent power (NEP).
the user to directly enter the required Tuning Speed
sensitivity level - what HP calls a Sensitivity can be set directly on
"sensitivity function." For more de- Hewlett-Packard optical spectrum Sweep-Time Limits
tailed information on optical spec- analyzers, which then automatically For fast sweeps, sweep time is limited
trum analysis basics, order Applica- adjust to optimize the sweep time, by the maximum tuning rate of the
tion Note 1550-4, Optical Spectrum while maintaining the desired sen- monochromator. The direct-drive-
Analysis, HP Pub. No. 5091-3054E
from your local HP sales/serviceoffice.
Sensitivity - Directly Settable
%3
!8
- 08 dBn
'1 by the User
I
1 Sensitivity is defined as the minimum
detectable signal or, more specifically,
six times the rms noise level of the
instrument. Sensitivity is not Sensitivity = -80 dBm-
specified as the average noise level,
as it is for RF and microwave spec-
c- trum analyzers, because the average
noise level of optical spectrum analyz-
ers is 0 watts (or minues infinity RB E 1 nn UE 208 H z S SI-950 i ~ e c
dBm). (For more information on the
differences between electrical and op- Figure 1. Display of signal with amplitude equal to sensitivity level.
Pub. No. 5952-3465 0 1994 Hewlett-Packard
WWW.HPARCHIVE.COM
SENS - 8 2 dBm
5.00 d8lOlU
Video BW
300 H-
z
S T R R T 1 1 5 0 . 0 nm S T O P 1 1 5 0 . 0 nn
* R E 1 nm x U B 3 8 HZ S * S T 18 s e c
Figure 2. Video bandwidth directly affects sensitivity. Figure 3. Improved sweep times, even for
high sensitivity measurements that tradi-
tionally result in slow sweeps. This plot
shows the normalizedoutput of an erbium
amplifier filter that was stimulated by a
white-light source.
motor system allows faster sweep response. The purpose of this filter is changed to reposition the signal in the
rates when compared with optical to attenuate light at the pump wave- measurement range of the analyzer's
spectrum analyzers that use gear-re- length, while passing the amplified internal circuitry, and the sweep con-
duction systems to rotate the diffrac- laser output of 1550 nm. Due to the tinues. This repositioning explains
tion grating. low power level of white-light the pause that can occasionally be
sources, this measurement requires seen in a sweep with a wide measure-
For high-sensitivity sweeps that tend great sensitivity, which traditionally ment range.
to be slower, the small photodetector
and continuously variable digital
has resulted in long sweep times.
Chopper Mode
"1
video bandwidths allow faster sweep Autoranging Mode The main purpose of the chopper
times. The small photodetector re- Autoranging mode is activated auto- mode is to provide stable sensitivity
duces the sweep time because it has matically for sweeps with amplitude levels for long sweep times, which
a lower NEP than the large photo- ranges greater than about 50 dB. The could otherwise be affected by drift
detectors used in other optical spec- amplitude range is determined by the of the electronic circuitry. The desired
trum analyzers. Lower NEP means top of the screen and the sensitivity stability is achieved by automatically
that for a given sensitivity level, a level set by the user. With the auto- chopping the light to stabilize elec-
wider video bandwidth can be used, ranging mode activated, when the tronic drift in sweeps of 40 seconds
which results in a faster sweep. signal amplitude crosses a threshold or greater. The effect is to sample the
(Sweep time is inversely proportional level, the sweep pauses, the trans- noise and stray light before each trace
to the video bandwidth for a given impedance amplifier's gain is point and subtract them from the
span and resolution bandwidth.) (See 'optical Spectrum Analyzer," page 8)
The continuously variable digital
video bandwidths improve the sweep
time for high-sensitivity sweeps in
two ways. First, the implementation
of digital video filtering is faster than
the response time required by narrow
analog filters during autoranging.
Second, since the video bandwidth
can be selected with great resolution,
just enough video filtering can be
used, resulting in no unnecessary
sweep-time penalty due to using a
narrower video bandwidth than is re- -
quired. Figure 3 shows a 20 second
filter-response measurement. This fil-
ter, for an erbium amplifier, was
- Non-Chopper Mode
Chopper Mode (ST = 41 Sec)
1
stimulated by a white-light source
and the figure shows the normalized Figure 4. Dynamic range improvement from chopper mode.
2 BENCH BRIEFS 1ST QUARTER 1994
WWW.HPARCHIVE.COM
tract numbers for provisioned prod-
1994 ucts, and recommends replacements
Logistics for discontinued products. The com-
panion microfiche lists NSNs for
Data Book product components and can be re-
quested with postage-paid cards in-
cluded in the data books.
John CloutierIHmlett-Packard
If your work requires U.S. Govern- To obtain a free copy of the 1994
ment National Stock Numbers Logistics Data Book, contact your
(NSNs) for HP products and their nearest HP office, or:
components, HP's annual Logistic
Data Book and its companion micro-
fiche are must-have resources. John Cloutier
Hewlett-Packard Company
The data book cross references HP Federal Support Services
product numbers to National Stock MS 51U-TH
Numbers (NSNs) and Joint Electronic P.O. Box 58059
Type Designators (JETDs), lists con- Santa Clara, CA 95052-8059 0
on the rear of the E1401A Mainframe.
Safety-Related If a hazardous AC Voltage is present
(greater than 30 VAC RMS, or 42 VAC
Service Notes peak), your unit is hazardous.
r Service Notes from Hewlett-Packard
relating to personal safety and pos-
A new power supply must be in-
stalled. Order Safety Service Note
sible equipment damage are of vital E1401A-02-S (document ID number
importance to our customers. To 5758 on the HP FIRST system) for
make you more aware of these impor- more information.
tant notes, they are printed on paper High voltage applied to the connector
with a red border, and the service E3910A/B PT500 Protocol Tester module plane or connector module
note number as an "-S" suffix. In Serial Numbers Affected handle could cause the existing
order to make you immediately aware 08-0000 I CA33350292 ground path to open, resulting in a
of any potential safety problems, we possible shock hazard to the user.
are highlighting safety-related service E3939A/B PT500 Protocol Tester
notes here with a brief description of Serial Numbers Affected Affected units must be retrofitted
each problem. Also, in order to draw CA32220000 I CA33300023 with grounding wires to rectify the
your attention to safety-related ser- problem. Contact your local HP sales1
vice notes in the service note index, E4093A/B PT500 Protocol Tester service office and your unit will be
each safety-related service note is Serial Numbers Affected repaired free of charge.
highlighted with a contrasting color. 02-0000 I CA33320025
For more information, order the fol-
HP E1401A VXI C-Size High-Power E4095A/B PT500 Protocol Tester lowing Product Safety Service Notes
Mainframe Serial Numbers Affected using the HP FIRST FAX system.
Serial Numbers Affected 03-0000 I CA33330209
3227A00165 I 3227A00207
L Product Safety HP FIRST
E4100B PT500 Protocol Tester Service Note Doc. ID No.
Build-up of surface contamination in- Serial Numbers Affected
side the E1401A power supply plus a CA33130001 I CA33150006 E391ONB-02-S 5961
jumper wire with damaged insulation E3939NB-02-S 5962
may cause a shock hazard to exist on IDAC-M-XPE PT500 Protocol Tester E4093NB-02-S 5063
an externally-accessible pin on the Serial Numbers Affected
p rear panel of the E1401A. CA32090001 I CA33010010
E4095NB-02-S
E4100B-024
IDAC-M-XPE-02-S
5064
5065
5066
Check your unit as follows: Connect IDAC-MPT PT500 Protocol Tester IDAC-MPT-024 5067
a voltmeter between chassis ground Serial Numbers Affected
and pin #23 on the Sub-D connector 01-0000 101-9999 0
1ST QUARTER 1994 BENCH BRIEFS 3
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How is the Recommended Calibration Cycle Determined?
Jim SteadlHewlett-Packard 90% did not require any adjustments). and AM bandwidth calibration that
fall into the user calibration category.
/I
Introduction New Circuit Designs
For T&M products, HP usually indi- Mechanical Wear
cates in the manual a recommended Design improvements are also used
calibration cycle. For many micro- to justify extended calibration cycles. Sometimes the instrument or system
wave instruments this is typically a Reduced parts count and fewer environment has a large influence on
one-year recommendation. With hardware adjustments mean there is the long-term stability of the product.
calibration costs rapidly increasing, less chance for drift or aging to have A good example is the HI' 8510 sys- \
longer calibration cycles are required an effect on the calibration. In addi- tem. Normal usage of a network 4
to maintain a reasonable cost of own- tion, newer circuit designs may pro- analyzer requires that devices be con- 1'
ership. Following is an explanation of vide better stability. When compared nected and disconnected to make
some of the steps involved in deter- to the HP 8340A, the HP 8360 series measurements. Over an extended
mining how an extended cycle can be has about one-third fewer compo- time period this results in the connec-
justified. nents and about 25% of the HP 8340A tors being subjected to wear and/or
hardware adjustments. Long-term damage. For this reason, the HP 8510
ALC stability was also improved recommended calibration cycle is li-
Past Experiences through the use of a Planar-Doped- mited to one year and will probably
Barrier (PDB) diode as the leveling never be extended.
Most companies maintain a database detector.
on past calibrations and can easily de-
termine what percentage of instru- Conclusions
ments required adjustments. This User vs. Self Adjustments
data is then used to appropriately The recommended calibration cycle is
change the calibration cycle. HP Periodic adjustments are sometimes just that; a recommendation. Operat-
maintains such a database for instru- required for optimum performance. ing environment and the user's appli-
ments used in our microwave instru- To maintain an extended calibration cation are variables that cannot be
ment production facility. As an cycle, it is important that these adjust- included in the manufacturer's
example, when the HP 8360 was in-
troduced we looked at the data for a
ments are either done automatically
by the instrument, or set up as user
recommendation. The published
cycle should be used by the customer
'7
similar product, the HP 8340A. The adjustments. Both the HP 8340A/B to help determine an initial calibration
data indicated that under normal and HP 8360 series use auto tracking cycle. Then an ongoing data collection
operating conditions the recom- to maintain maximum RF output process should be initiated to deter-
mended one-year calibration cycle for power. In addition, the HP 8360 series mine the best calibration cycle for the
the HP 8340A was conservative (Le./ has both frequency span calibration customer's application.
1994 Bench Briefs' Instrument
Service Note Index
HP FIRST (208)344-4809
T & M Section - Press 4
Password Section - Press 3
Password - 76683 '/
t
SN SN Abstract HP FIRST ?
4
Type No. Document ID No.
MA 3324A-03 New firmware must be installed with new A6 Signal Source Board 5708
IO 3456A-25
MR 3457A-17
Clarification of product specifications and calibration cycle
Modification prevents shorting of multiple channels
5706
5985
3
IO 35653-07 Reprogramming required for use with HP 35630A/B VISTA software 5977
IO 3577A-17 Source harmonic distn spec changed from -30 dBc to -25 dBc 5978
IO 3577B-07 Source harmonic distn spec changed from -30dBc to -25 dBc 5979
4 BENCH BRIEFS WWW.HPARCHIVE.COM 1ST QUARTER 1994
~~
SN SN Abstract HP FIRST
Type No. Document ID No.
MR 3589A-03 C1405A/B keyboard incompatibility with HP 3589A 5937
IO 3784A-03 Mod optimizes the HP 3784A for burst mode operation 5692
IO 3784A-04 Instructions to retrofit Opt 002 to a standard instrument 5693
MA 3784A-05 Mod to housing for pwr supply caps C1 and C2 5694
MA 3785A-25 Mod ensures conformance to performance test 5695
MR 4155A-01 Updating the preliminary ROMs with formal-releasedROMs 5994
MR 4156A-01 Updating the preliminary ROMs with formal-released ROMs 5995
MR 4291A-01 New A3A3 assembly improves osc level (self-test 15) 5968
IO 4396A-08 New key cap for power line switch 5917
MR 4396A-09 New A3A3 assembly improves RF output level (self-test 16) 5969
MR 4396A-10 Modification prevents rubber key from sticking 5970
MR 4396A-11 Mod corrects PHASE LOCKED LOOP UNLOCKED error at high temp 5996
IO 4396A-12 Option upgrade procedures 5997
MA 4957A-01C Available option allows high speed option retrofitting 5014
MR 4980A-11 LED board mod allows greater range of brightness adjustment 5929
MR 4981A-11 LED board mod allows greater range of brightness adjustment 5930
MR 4982A-11 LED board mod allows greater range of brightness adjustment 5931
IO 5071A-01 Unusual power-up seq can cause pseudo "Fatal Error" message 5719
IO 5071A-02 HP 5071A performance test 5720
IO 5529A-01A List of software revision A.01.13 anomalies 5900
IO 5529V-01A List of software revision A.01.13 anomalies 5901
MR 6060B-02 Safety compliance of RFI filter cap discharge time constant 5761
MR 6063B-02 Safety compliance of RFI filter cap discharge time constant 5762
IO 6651A-03 Mod reduces radiated RFI when replacing A2 HPIB board 5944
IO 6652A-03 Mod rcduces radiated RFI when replacing A2 HPIB board 5945
IO 6653A-03 Mod reduces radiated RFI when replacing A2 HPIB board 5946
IO 6654A-03 Mod reduces radiated RFI when rcplacing A2 HPIB board 5947
IO 6655A-03 Mod reduces radiated RFI when replacing A2 HPIB board 5948
IO 8130A-03 List of differences in mechanical/electrical major parts 5949
MR 8560A-26C Recommended replaccment of 5-volt regulators 5739
IO 8560A-27 Incorrect manual procedure cannot measure resol B/W accuracy 5714
MA 8560A-28 Diodes w/higher breakdown voltage improves focus reliability 5950
MR 8560E-02C Recommended replacement of 5-volt regulators 5740
MA 8560E-06 Diodes whigher breakdown voltage improves focus reliability 5951
MR 8560E-07 5-volt regulator reliability improvement on A6 PC board 5923
MR 8561B-25C Recommended replacement of 5-volt regulators 5741
IO 8561B-27 Incorrect manual procedure cannot measure resol B/W accuracy 5715
MR 8561E-01C Recommended replacement of 5-volt regulators 5742
MA 8561E-05 Diodes whigher breakdown voltage improves focus reliability 5952
MR 8561E-06 5-volt regulator reliability improvement on A6 PC board 5924
MR 8562A-67C Recommended replacement of 5-volt regulators 5743
MA 8562A-68 Diodes whigher breakdown voltage improves focus reliability 5953
IO 8562A-69 YTF adjustment procedure 5938
MR 8563A-20C Recommended replacement of 5-volt regulators 5744
IO 8563A-21 Incorrect manual procedure cannot measure resol B/W accuracy 5716
MA 8563A-22 Diodes w/higher breakdown voltage improves focus reliability 5954
MR 8563E-02C Recommended replacement of 5-volt regulators 5745
MA 8563E-07 Diodes with higher breakdown voltage improves focus reliability 5975
MR 8563E-08 5-volt regulator reliability improvement on A6 PC board 5925
IO 8566B-10B Option 462 6 dB resolution bandwidths 5955
MA 8566B-19A RF attenuator with calibration ROM replacement 5688
MA 8567A-03A RF attenuator retrofit kit, HP P/N 85680-60228 5689
MA 8568A-37B RF attenuator with calibration ROM replacement 5690
MA 8568B-08A RF attenuator with calibration ROM replacement 5691
IO 8568B-10B Option 462 6 dB resolution bandwidths 5956
1ST QUARTER 1994 BENCH BRIEFS 5
WWW.HPARCHIVE.COM
SN SN Abstract HP FIRST
Type No. Document ID No.
IO
IO
8593E-01
8593E-03
Additional equipment required during Option 012 calibration
List of specific test equipment reqd for Opt 151,163 calib
5763
5988
f
Y
IO 8594E-01 Additional equipment required during Option 012 calibration 5764
IO 8594E-03 List of specific test equipment reqd for Opt 151,163 calib 5989
IO 8595E-01 Additional equipment required during Option 012 calibration 5765
IO 8595E-03 List of specific test equipment reqd for Opt 151,163 calib 5990
IO 8596E-01 Additional equipment required during Option 012 calibration 5766
IO 8596E-03 List of specific test equipment reqd for Opt 151,163 calib 5991
MA 8643A-01 RPP Module modification reduces noise floor of RF output 5721
IO 8643A-02 Jitter is normal for internal modulation source 5722
IO 8643A-03 Cable replacement and identification 5767
MA 8644A-01 RPP Module modification reduces noise floor of RF output 5723
IO 8644A-02 Jitter is normal for internal modulation source 5724
IO 8644A-03 Cable replacement and identification 5768
MA 8644B-01 RPP Module modification reduces noise floor of RF output 5725
IO 8644B-02 Jitter is normal for internal modulation source 5726
IO 8644B-03 Cable replacement and identification 5769
MA 8645A-02 RPP Module modification reduces noise floor of RF output 5727
IO 8645A-03 Jitter is normal for internal modulation source 5728
IO 8645A-04 Cable replacement and identification 5770
IO 8664A-02 Jitter is normal for internal modulation source 5729
MR 8664A-03 Recommended replacement Reverse Power Protection assembly 5747
IO 8664A-04 Cable replacement and identification 5771
IO 8665A-03 Jitter is normal for internal modulation source 5730
MR 8665A-04 Recommended replacement Reverse Power Protection assembly 5748
IO
IO
IO
8665A-05
8665B-02
8665B-03
Cable replacement and identification
Jitter is normal for internal modulation source
Cable replacement and identification
5772
5731
5773
c
IO 8683A-03 Field support kit and assembly obsolescence 5700
IO 8683B-04 Field support kit and assembly obsolescence 5701
IO 8683D-04 Field support kit and assembly obsolescence 5702
IO 8684A-05 Field support kit and assembly obsolescence 5703
IO 8684B-07 Field support kit and assembly obsolescence 5704
IO 8684D-05 Field support kit and assembly obsolescence 5705
MR 8711A-02 Cable replacement corrects display instability problem 5717
MR 8711A-03 Incorrect part in service kithcorrect procedure in manual 5718
MR 875114-17 Modification fmes unexpected spurious problem 5736
MR 8751A-22 Mod prevents hang ups or unexpected resets 5737
IO 8751A-24 New key cap for power line switch 5918
IO 8920A-07 Instructions for replacing the motherboard 5699
MR 8920A-08 Incorrect RF diagnostics results (Option 007) 5774
MR 8920D-01 Early units require FW upgrade for use with HP 11807A Opt 009 5958
MR 8920DTS-01 Early instuments require hardware and firmware upgrades 5959
MR 8921A-01 H/W and F/W upgrade required for 83201A compatibility 5749
MR 8921D-01 Early units require FW upgrade for use with HP 11807A Opt 009 5960
IO 899OA-01 Save A1 control board assembly top and bottom shields 5939
IO 8991A-01 Save A1 control board assembly top and bottom shields 5940
IO 8991A-02 Part number correction for the A1 control board assembly 5941
IO 8992A-01 Save A1 control board assembly top and bottom shields 5942
MA E1222M-09 Upgrade address space for error map to 1Mbyte 5760
MR
MR
E1300A-02
E1301A-03
New time-delay fuse corrects intermittent fuse failure
New time-delay fuse corrects intermittent fuse failure
5756
5757
f
SA E1401A-02-S Recommended modification to prevent possible shock hazard 5758
MR E1446A-01 New fuse prevents output from sticking at +24 or -24Vdc rail 5759
MR E1672A-01 Mod reduces Trig output levels when loaded with 50 ohms 5936
6 BENCH BRIEFS 1ST QUARTER 1994
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SN SN Abstract HP FIRST
Type No. Document ID No.
IO E2500B-08 Changes to performance test software for pulse on/off tests 5752
10 E2505A-01 New table provides correct ref designators during test 3xx 5753
IO E2505A-02 Changes to performance test software for pulse ordoff tests 5754
MR E2550A-01 Mod corrects synchronization problems in parallel operation 5935
MR E2550A-02 New firmware improves performance 5984
MR E2755A-01 Mod improves reset and futes crosstalk on FG60 control board 5986
MR E3611A-03 Elimination of RF oscillation for lightly loaded supply 5998
MR E3614A-01 New fuse eliminates intermittent blowing (Opt OE3) 5971
MR E3615A-01 New fuse eliminates intermittent blowing (Opt OE3) 5972
MR E3616A-01 New fuse eliminates intermittent blowing (Opt OE3) 5973
MR E3617A-01 New fuse eliminates intermittent blowing (Opt OE3) 5974
PS E3910AIB-02-S Inadequate ground may cause possible shock hazard 5%1
IO E3910B-01 Fan speed regulator no longer required 5912
PS E3939AIB-02-S Inadequate ground may cause possible shock hazard 5962
IO E3939B-01 Fan speed regulator no longer required 5913
PS E4093A/B-02-S Inadequate ground may cause possible shock hazard 5963
IO E4093B-01 Fan speed regulator no longer required 5914
PS E4095A/B-02-S Inadequate ground may cause possible shock hazard 5964
IO E4095B-01 Fan speed regulator no longer required 5915
PS E4100B-02-S Inadequate ground may cause possible shock hazard 5965
IO E4240B-01 Fan speed regulator no longer required 5916
PS IDAC-M-XPE-02-S Inadequate ground may cause possible shock hazard 5966
PS IDAC-MPT-02-S Inadequate ground may cause possible shock hazard 5967
MR J2213A-03 LED board mod allows greater range of brightness adjustment 5932
MR J2219A-02 LED board mod allows greater range of brightness adjustment 5933
MR 11612A/B-01 Mod corrects open DC force path caused by incorrect wiring 5982
MA 16092A-01 New metal clips improve contact repeatability 5919
MA 16099A-01 New flat-head mounting screws improve test fuRure mounting 5920
MR 16339A-02 New miniature banana-plug cable wire eliminates breakage 5709
IO 16500B-01 170MB hard disk drive update for 16500B mainframe 5993
IO 18281A-01B Country specific firmware is available 5222
MR 18281A-02 Mod remove PS3 to prevent network crashes 5934
MR 34401A-03 Mod improves time stability of DC current ranges (1OmA/100 mA) 6001
10 34401A-04 Explanation of indicated calibration failure of AC current 6002
MR 35280A-01 Repositioningint gnding lock washer elimis source sig probs 5999
MR 35650A-01 CR1 on ps brd fails due to excessive tightening of heat sink 6000
IO 35650B-01 Shield reduces magnetic emissions when fan assy replaced 5980
MR 35650B-02 Mod for use with 35659A Opt AMV or H 0 1 5987
MR 35652AIB-01 Mod improves reliability of microdot connector 5981
MR 35665A-02A Mod corrects C1405A/B Keyboard failures 5922
IO 37704A-01 Instructions to retrofit Opt 001 to a standard instrument 56%
IO 37741A-01 Installation of HP 15850A Opt H03 5697
MR 37743A-01 Mod corrects incorrectly loaded capacitor on transmitter brd 5698
SM 53310-0194-01 Installing Option 001 into an HP 53310A 5976
MR 66oooA-02 New resistor values for ac line input prevents failure 5957
MA 70001A-17A New reset programmable array logic (PAL) integrated circuit 5983
MA 70004A-13 New PAL circuit allows MODRST line on A4 to be bi-directional 5992
IO 70301A-03 New 20 dB attenuator has longer semi-rigid cable 5707
MA 70320A-01 RPP Module modification reduces noise floor of RF output 5732
IO 70320A-02 Jitter is normal for internal modulation source 5733
IO 70320A-03 Cable replacement and identification 5775
IO 70322A-02 Jitter is normal for internal modulation source 5734
IO 70322A-03 Cable replacement and identification 5776
IO 70700A-01C Information on new firmware 5293
MA 7082OA-02 Firmware revision 1.1increases trace capability 5750
1ST QUARTER 1994 BENCH BRIEFS 7
WWW.HPARCHIVE.COM
SN SN Abstract HP FIRST
Type No. Document ID No.
MR 70908A-07 Mod reduces n x 300 MHz residual responses 5751 f-
T
MR 85032B-01 Corrections to spec errors in O/S manual and customer letter 5926
IO 85620A-04 Module hangup is caused by improper programming 5746
IO 85620A-05 Downloadable programs may not be compat w/earlier modules 5943
MR 85644A-02 Mod eliminates 1MHz osc on output of tracking source 5927
MR 85645A-02 Mod eliminates 1MHz osc on output of tracking source 5928
IO 86791A-01 Service manual update, part number 86791-90004 5735
IO 86793A-01 New table provides correct ref designators during test 3xx 5755
MR 87510A-05 Modification fmes unexpected spurious problem 5738
IO 87510A-08 New key cap for power line switch 5921
MR S9410A-OlC New FW fuces calibration timing problem 5710
MR 89410A-02 New analog motherboard improves channel match 5711
MR 89440A-01C New FW fmes calibration timing problem 5712
MR 89440A-02 New analog motherboard improves channel match 5713
Service Note Types
IO Information Only MA Modification Available
MR Modification Recommended SA Safety
PS Priority Safety Shl Interoffice Service Memo (IOSM)
rOptical Spectrum Analyzer,"continued from page 2)
trace point reading. In all modes of range possible, some improvement the chopper mode.
operation, Hewlett-Packard optical can be obtained with the use of the
spectrum analyzers zero the detector chopper mode. While this mode does This concludes the series on optical
circuitry before each sweep. improve dynamic range, it is not re- spectntm analyzers. Bench Briefs
quired for the analyzers to meet their wants to thank Richard Ogg, Carla
dynamic range specifications. McCarter, and Mike Levemier of the
Improved dynamic range is another Hewlett-Packard Microwave Tech-
benefit of sampling the stray light be- nology DivisioniLightwave Opera-
fore each trace point. For measure- Figure 4 shows the improved tion for their contributions to this
ments requiring the greatest dynamic dynamic range obtained by activating series. 0
Bulk Rate
US. Postage
San Jose, CA
Permit No.
Volume 34 Number 1
Service information from
Hewlett-Packard Company
To obtain a qualification form for a free
Subscription, send your request to the
above address.
Reader comments or technical article
contributions are welcomed.
Please send them to the
Bench Briefs Editor at the above address. f
Editor: Jim Bechtold
Hewlett-Packard
All righls reserved Permission to reprinl Bench Briels granted upon wrillen request to the Editor Printed in U.S.A.
8 BENCH BRIEFS 1ST QUARTER 1994
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