http://nucwiki.org/wiki/index.php?action=history&feed=atom&title=LeCroy_2228A 2026-05-27T01:37:18Z Revision history for this page on the wiki MediaWiki 1.31.1 http://nucwiki.org/wiki/index.php?title=LeCroy_2228A&diff=233&oldid=prev 2019-03-09T06:44:32Z

<p>Created page with &quot;= External = <a href="/wiki/index.php/File:Mcmaster_lecroy_2228a_ext_front.jpg" title="File:Mcmaster lecroy 2228a ext front.jpg">300 px</a> LeCroy 2228A TDC COM STOP COM START STOP 0 1 2 3 4 5 6 7 CLEAR 63348 F...&quot;</p> <p><b>New page</b></p><div>= External =<br /> <br /> [[File:mcmaster_lecroy_2228a_ext_front.jpg|300 px]]<br /> <br /> LeCroy<br /> 2228A<br /> TDC<br /> <br /> COM STOP<br /> COM START<br /> STOP<br /> 0<br /> 1<br /> 2<br /> 3<br /> 4<br /> 5<br /> 6<br /> 7<br /> CLEAR<br /> 63348<br /> <br /> [[File:mcmaster_lecroy_2228a_ext_top.jpg|300 px]]<br /> <br /> FULL SCALE COUNT<br /> TEST POINT<br /> <br /> PICOSEC./COUNT SELECT<br /> 250<br /> 100<br /> 50<br /> <br /> LeCroy<br /> MODEL 2228A<br /> CURRENTS<br /> -6V 550 mA<br /> +6V 600 mA<br /> -24V 140 mA<br /> +24V 25 mA<br /> LeCroy RESEARCH SYSTEMS<br /> <br /> LAM SELECT<br /> END OF CONVERSION (EOC)<br /> EOC AND ADDRESSED CHANNEL VALID<br /> OC AND ANY CHANNEL VALID<br /> OFF<br /> <br /> Q SELECT<br /> EOC<br /> EOC AND ADDRESSED CHANNEL VALID<br /> EOC AND ANY CHANNEL VALID<br /> <br /> CAUTION<br /> CRATE POWER SHOULD BE TURNED OFF DURING INSERTION AND REMOVAL OF UNIT<br /> TO AVOID POSSIBLE DAMAGE CAUSED BY MOMENTARY MISALIGNMENT OF CONTACTS<br /> <br /> [[File:mcmaster_lecroy_2228a_ext_btm.jpg|300 px]]<br /> <br /> <br /> = Internal =<br /> <br /> [[File:mcmaster_lecroy_2228a_int_top.jpg|300 px]]<br /> <br /> [[File:mcmaster_lecroy_2228a_int_btm.jpg|300 px]]<br /> <br /> Key ICs:<br /> * MOTOROLA MC10102P: input quad 2 input NOR gate<br /> * mixes test trigger?<br /> * RCA CA3046: NPN transistor array<br /> * NE NE521N: dual differential comparator / sense amp<br /> * LeCroy SC100: ADC?<br /> <br /> = 2015-06-04 repair =<br /> <br /> 11 bit ADC (0x600 full range) but values were as follows for the two units I tested:<br /> <br /> Slot 9 (broken knob)<br /> CH0: 0x000632<br /> CH1: 0x000644<br /> CH2: 0x000632<br /> CH3: 0x000358<br /> CH4: 0x000637<br /> CH5: 0x000525<br /> CH6: 0x00062A<br /> CH7: 0x00063A<br /> <br /> Slot 11 (good knob)<br /> CH0: 0x000699<br /> CH1: 0x000691<br /> CH2: 0x00069D<br /> CH3: 0x000353<br /> CH4: 0x000696<br /> CH5: 0x00069F<br /> CH6: 0x00068C<br /> CH7: 0x000686<br /> <br /> Both units seem to have constant offset errors, possibly the test pattern generator. Also, CH3 is flaky on both units...coincidence?<br /> <br /> Ran a 14 hour burn in test in test mode (slot 11 / good knob):<br /> <br /> [[File:mcmaster_lecroy_2228a_2015-06-04_n11_cal_all.png|300 px]]<br /> <br /> You can see considerable drift on channel 3 (yellow), the channel with a bad reading. Other channels were pretty stable, within +/- 1 DN over the entire period. Swapped some ICs around and issue seems to have gone away.<br /> <br /> More measurements after swapping:<br /> <br /> [[File:mcmaster_lecroy_2228a_2015-06-04_n11_03_cal_all.png|300 px]]<br /> <br /> Took about 1200 seconds (20 min) to settle.<br /> <br /> Test code: https://github.com/JohnDMcMaster/uvscada/blob/master/lecroy_6010/2228a_cal.py</div>

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