Table of Contents
Tube Repair, High and Low Voltage, Preamp cards
Tube Geometrical Specs
Preamp Cards
Broken Cards
The attached excel file is a list of broken cards that have been looked at. With most of these cards at least one bad component or connection had been identified. Bad components have also been marked with tape. The cards are in a box labled “PREAMPS TO BE FIXED”
broken_preamp_cards_updated_jul_28_2011_.xls
Channel Schematic
The following is a schematic of a SINGLE CHANNEL on a preamp card. Each preamp has two channels. The LS221 and SN75183 chips are each dual packaged so there is only one of each per card.
Low Voltage Connector
The P ground is the applied ground from the 15 pin low voltage connector. The S ground are the traces that run to the screw holes on the outside of the card and would normally be connected to the aluminum on the shield.
When looking at the preamp card with the 15 pin low voltage connector on the top the pinout is
____card end_____ | SSTTTTTGGGGGG77 | | |
where S and T represent +5S and +5T respectively, G represents ground and 7 represents -7
Charge Injection Test
Scope screenshot below is of test with 250mV negative going pulse at 200khz repetition rate
Top trace is nput to TEST pin
Second trace shows signal at pin 3 of LM311
Third trace is +OUT
Fourth trace is -OUT
Datasheets for the major components
Low Voltage Distribution System
Below is a schematic of the low voltage distribution system for a given crate.
The original schematic file which can be edited is posted in the vetoshield ELOG https://fireplace.soudan.umn.edu:8082/Shield/ in entry # 486.
Breakout Box
Below is a more detailed representation of the breakout boxes being used
and some photos
