Krohn-Hite 7008 User manual

Model 7008
Remote Programmable
Up to 8 Channel Low Noise
Differential Preamplifier
Operating Manual

Service and Warranty
Krohn-Hite Instruments are designed and manufactured in accordance with sound engineering
practices and should give long trouble-free service under normal operating conditions. If your
instrument fails to provide satisfactory service and you are unable to locate the source of trouble
contact our Service Department at [phone] giving all the information available concerning
the failure.
DO NOT return the instrument without our written or verbal authorization to do so. After contacting
us we will issue a Return Authorization Number which should be referenced on the packing slip and
purchase order. In most cases we will be able to supply you with the information necessary to
repair the instrument avoiding any transportation problems and costs. When it becomes necessary
to return the instrument to the factory kindly pack it carefully and ship it to us prepaid.
All Krohn-Hite products are warranted against defective materials and workmanship. This warranty
applies for a period of one year from the date of delivery to the Original Purchaser. Any instrument
that is found within the one year warranty period not to meet these standards will be repaired or
replaced. This warranty does not apply to fuses or batteries. No other warranty is expressed or
implied.
Krohn-Hite Corporation reserves the right to make design changes at any time without incurring any
obligation to incorporate these changes in instruments previously purchased.
Modifications to this instrument must not be made without the written consent of an authorized
employee of Krohn-Hite Corporation.

Model 7008
Remote Programmable 8 Channel
Low Noise Differential Preamplifier
OPERATING MANUAL
Unit 4 15 Jonathan Drive Brockton MA 02301
-
5566
Tel: [phone]; Fax: [phone]
E-mail: [email protected]; Web: www.krohn-hite.com
7008ManRev2.docx
V2.0 Dated: 02/14
Copyright© 2014 Krohn-Hite Corporation. All rights reserved. No part of this publication may be
reproduced stored in a retrieval system or transmitted in any form by any means electronic
mechanical photocopying recording or otherwise without the prior written permission of Krohn-
Hite Corporation.

Model 7008 8 Channel Low Noise Differential Preamplifier

i
TABLE OF CONTENTS
GENERAL INFORMATION ...................................................................................................................... iv
Certification ................................................................................................................................. iv
Warranty. ..................................................................................................................................... iv
Safety and Preparation for Use. .................................................................................................. iv
Line Voltage. ................................................................................................................................ iv
Line Fuse. ..................................................................................................................................... iv
Line Cord. ..................................................................................................................................... iv
Warranty Service. ........................................................................................................................ iv
Service.......................................................................................................................................... iv
Repackaging for Shipment. .......................................................................................................... iv
Definitions. ................................................................................................................................... iv
SECTION 1 - GENERAL DESCRIPTION ..................................................................................................... 5
1.1 INTRODUCTION............................................................................................................................. 5
1.2 SPECIFICATIONS ............................................................................................................................ 5
1.2.1 INPUT .................................................................................................................................. 5
1.2.2 OUTPUT ............................................................................................................................... 6
1.2.3 100kHz FILTER ..................................................................................................................... 7
1.2.4 FRONT PANEL ...................................................................................................................... 7
1.2.5 GENERAL ............................................................................................................................. 7
1.2.6 OPTIONS .............................................................................................................................. 7
1.2.7 ACCESSORIES ....................................................................................................................... 8
SECTION 2 - OPERATION ........................................................................................................................ 9
2.1 INTRODUCTION............................................................................................................................. 9
2.2 POWER REQUIREMENTS ............................................................................................................... 9
2.3 TURN-ON PROCEDURE.................................................................................................................. 9
2.4 FRONT PANEL DISPLAY AND CONTROLS ..................................................................................... 10
2.4.1 MODE ................................................................................................................................ 10
2.4.1.1 LCL (local mode) ............................................................................................... 10
2.4.1.2 EDIT (edit mode) ............................................................................................... 10
2.4.1.3 REMOTE (remote mode) .................................................................................. 11
2.4.2 CHANNEL UP CHANNEL DOWN CONTROL ....................................................................... 12
2.4.3 SETTING PARAMETERS ...................................................................................................... 13
2.4.3.1 INPUT CONFIGURATION ................................................................................... 13

ii
2.4.3.2 100kHz LOW-PASS FILTER ................................................................................. 15
2.4.3.3 INPUT COUPLING .............................................................................................. 15
2.4.3.4 GAIN .................................................................................................................. 16
2.4.3.5 SHUNT (OHMS) ................................................................................................. 17
2.4.4 DC OFFSET ......................................................................................................................... 19
2.4.5 INPUT + AND - BNC CONNECTORS .................................................................................... 19
SECTION - INCOMING ACCEPTANCE ................................................................................................. 21
3.1 INTRODUCTION ........................................................................................................................... 21
3.2 TEST EQUIPMENT REQUIRED ...................................................................................................... 21
3.3 GAIN ACCURACY ......................................................................................................................... 21
3.4 NOISE CHECK............................................................................................................................... 22
3.5 COMMON MODE REJECTION...................................................................................................... 22
3.6 DISTORTION CHECK .................................................................................................................... 22
3.7 AC/DC COUPLING CHECK ............................................................................................................ 22
SECTION 4 - USB-COM OPTION (for Remote Programming) ............................................................... 24
4.1 INTRODUCTION ........................................................................................................................... 24
4.2 USB-COM OPTION ...................................................................................................................... 24
4.2.1 INSTALLING THE DRIVERS ................................................................................................. 25
4.2.2 DRIVER INSTALLATION SEQUENCE ON A WINDOW XP™ S ............................................... 25
4.2.2 HOW TO SET-UP/RUN WINDOWS™ HYPER-TERMINAL ON WINDOWS XP™ SYSTEM ...... 27
4.2.3 AN ALTERNATE TO HYPER-TERMINAL OPERATION .......................................................... 31
4.3 MODEL 7008 PROGRAMMING COMMANDS .............................................................................. 33
4.3.1 TABLE OF COMMANDS ..................................................................................................... 34
4.3.2 COMMAND STRING EXAMPLES ........................................................................................ 34
4.3.3 REPSONSE TO A COMMAND STRING ................................................................................ 35
SECTION 5 - LAN-COM OPTION (for Remote Programming) ............................................................... 36
5.1 INTRODUCTION ........................................................................................................................... 36
5.1.1 SITE LANs AND PRIVATE LANs ........................................................................................... 36
5.1.2 CONNECTING THROUGH A NETWORK .............................................................................. 36
5.1.3 CONNECTING DIRECTLY TO THE MODEL 7008 (no network) ........................................... 36
5.1.4 HOW TO FIND THE CURRENT IP ADDRESS ........................................................................ 36
5.1.5 SETTING A FIXED IP ADDRESS ........................................................................................... 38
5.1.6 LAN and HyperTerminal Setup .......................................................................................... 41
5.1.7 How to Set-Up and Run Windows™ HyperTerminal ......................................................... 41

iii
SECTION 6 - REMOVING AND INSTALLING PREAMPLIFIER CARDS ..................................................... 44
6.1 INTRODUCTION........................................................................................................................... 44
6.2 REMOVING A MODEL 700 PREAMPLIFIER CARD ........................................................................ 44
6.3 INSTALLING THE MODEL 700 PREAMPLIFIER CARD ................................................................... 46

iv
GENERAL INFORMATION
Certification - Krohn-Hite certifies that this product meets published specifications at the time of
shipment.
Warranty - This Krohn-Hite Corporation product is warranted against defects in materials and
workmanship for a period of one (1) year from the date of shipment.
Safety and Preparation for Use - Dangerous voltages capable of causing injury or death are present
in this instrument.
Warning! Use extreme caution whenever the instrument covers are removed. Do not remove the
covers while the unit is plugged into a live outlet.
Line Voltage - The Model 7008 accommodates any voltage in the range 105Vac to 132Vac or 210Vac
to 264Vac with a frequency in the range 50Hz to 60Hz.
Line Fuse - The line fuse is located on the rear of the 7008. The fuse is a 3/4A slow-blow for 120V
applications and a 3/8A slow-blow for 240V applications.
Line Cord - The Model 7008 has a detachable three-wire power cord for connection to the power
source and to a protective ground. The exposed metal parts of the instrument are connected to the
outlet ground to protect against electrical shock. Always use an outlet which has a properly
connected protective ground.
Warranty Service - For warranty or repair service this product must be returned to a Krohn-Hite
Corporation authorized service facility or to Krohn-Hite directly. Contact must be made with Krohn-
Hite Corporation or an authorized representative to receive a Return Authorization before returning
this product for repair.
Service - Do not attempt to service or adjust this instrument unless another person capable of
providing first aid or resuscitation is present. Do not install substitute parts or perform any
unauthorized modifications to this instrument. Contact the factory for instructions on how to return
the instrument for authorized service and adjustment. The Model 7008 is not intended for hot-
swapping applications. Be certain to switch power off before inserting or removing plug-in cards in
the chassis.
Repackaging for Shipment - The original packing materials should be saved for reshipment of the
Model 7008 if needed. If the original packing materials are not available wrap the instrument in
polyethylene sheeting or equivalent and place in a strong box cushioning it on all sides by at least
three inches of high-density foam or other filler material.
Definitions - A Bracket set [ ] indicates a button.

Section 2 – Operation
________________________________________________________________________________
5
SECTION 1
GENERAL DESCRIPTION
1.1 INTRODUCTION
The Krohn-Hite Model 7008 is a two to eight channel Differential Preamplifier providing low noise
and high gain amplification to 1MHz. The output of the 7008 is derived from using a very low noise
FET instrumentation amplifier. Noise referred to input is 7nV√Hz and common mode rejection is
>100dB at 1kHz. The Model 7008 has fixed gain settings of x1 (0dB) x10 (20dB) x100 (40dB) and
x1000 (60dB).
The 7008 provides momentary pushbutton switches that control input coupling 100kHz filtering
(std) gain channel selection shunt resistor for low level signal applications input configuration and
local/remote/edit selections. BNC connectors are provided for single-ended and differential input
configurations and for the amplified output. All settings can be edited and monitored with the 16
character 2-line front panel display.
Optional USB or LAN remote control is available for the 7008. All front panel functions with the
exception of power on can be controlled remotely with either option. See Section 3 for
programming information.
The 7008 is an excellent preamp for amplifying low level input signals to oscilloscopes or other
devices. The 7008 is also very useful for troubleshooting sources of noise amplifiers power supplies
and various other electronic circuits.
1.2 SPECIFICATIONS
1.2.1 INPUT
Configurations: Single-ended and differential selectable.
Coupling: AC (0.16Hz 0.16mHz with option 10 installed) and DC selectable.
Impedance: 1M ohm (1G ohm with option 10 installed) shunted by 40pF. Each input may be
independently enabled or grounded.
Input Shunt Resistor: 50 500 5k and 50k ohm ±0.3% and open selectable.
Resistor Value
(1/4W ohms)
Maximum
Current
(amps)
Maximum
Voltage
Maximum Power
Across Shunt
Resistor
(watts)
50
0.05
2.5
0.125
500
0.016
8
0.128
5 000 (5k)
0.002
10*
0.020
50 000 (50k)
0.0002
10*
0.002
*Maximum power limited by maximum voltage of 10V.

Section 2 – Operation
_________________________________________________________________________________
6
Maximum Input Voltage: 10V peak with gain set to x1.
Max Safe Voltage: Any continuous voltage between ±30V (for 7008-10 option: ±15V).
Gains: x1 (0dB) x10 (20dB) x100 (40dB) x1000 (60dB) selectable.
Accuracy: ±0.3dB.
Stability: 200ppm/°C.
Bias Current: ±5pA typical 50pA max.
CMMR:
Freq
G
ain
= 1
G
ain
= 10 to 1k
50Hz
>90dB
>10
2
dB
10kHz
>75dB
>
87
dB
50kHz
>60dB
>7
2
dB
1.2.2 OUTPUT
Maximum Output Voltage: 10V peak.
Frequency Response:
Wideband Noise (Referred to input 2MHz Bandwidth Detector)
GAIN
100kHz
FILTER OFF
(µVrms)
100kHz
FILTER ON
(µVrms)
Option 11
400Hz Filter
(µVrms)
1
120
90
40
10
14
9
4
100
10
3.2
0.85
1k
10
3.2
0.85
Noise Density (x1k gain setting filter off): 7nV/√Hz typical.
Impedance: 50 ohms single-ended.
Distortion: 0.005% (-85dB) at 1kHz.
Offset Voltage: Adjustable to zero.