Minutes of the Zeuthen Meeting on Front End Electronics 
   -------------------------------------------------------

    Time:             Monday 15/06/98, 9:30 - 10:50
    Room:             Seminar Room I
    Participants:     K.Berkhan, M.Pohl, U.Uwer, M.Walter


    Agenda:
      1. HV Boards
      2. Test pulse distribution
      3. Tests of Distribution Board
      4. ASD8 note
      5. Analog Readout



   1. HV Boards:
   =============

   1.1 Test procedure
   ------------------
   Sun Hansheng is currently preparing the gas-box for the
   tests. It was decided to start meanwhile with first test
   on  air to gain experience with the test device.

   The need of an additional HV power supply was discussed.
   It was agreed that Mario should order 1 Struck 1-channel 
   HV module. 


   1.2 Varnishing of the HV boards:
   --------------------------------
   Although the paint used for the HV protection of the 
   capacitors showed no out-gazing (M.Capeans) the usage
   of the product demands ina ddition studies of radiation 
   hardness.
   The general feeling is that by careful cleaning and 
   subsequent careful handling of the boards one could
   avoid the usage of any additional protection.


   1.3  Production status and missing components
   ---------------------------------------------
 


    A) HV boards equipped with cables

   
    with cables   | trigger boards | single lay boards|   #channel    
    -----------------------------------------------------------------
    10mm Boards   |                |                  |
                  |                |                  |
     5mm Boards   |   10 (128ch)   |         22       |   2688



    B) HV boards with capacitors

   
    with cables   |   Left compr.  |  Right compr.    |   #channel    
    -----------------------------------------------------------------
    10mm Boards   |   163          |       168        |   10592
                  |                |                  |
     5mm Boards   |   223          |       223        |   28544

 
      
    C) not assembled HV boards


    not used      |  all PCBs      |  =  lc + rc      |   #channel    
    -----------------------------------------------------------------
    10mm Boards   |                |                  |
                  |                |                  |
     5mm Boards   |      200       |    100 + 100     |    12800
 
     
    D) capacitors

    need to assemble remaining boards:  78000
    + 20%(filter,spare)              :  12000

    still available capacitors       :  20000 

    capacitors to order              :  70000

 
       
    The faith of the originally ordered capcitors

        ordered                      : 120,000
        used for coax-boards         :  42,000
        others  (??)                 :  18,000   <<< 42000 DM).



   1.4 HV board cable length 
   -------------------------

   A study by A.Lanoyov has shown that the cable of the HV boards
   must have different cable lengths:

   
   - he finds differences for the cables of one module of up to 5cm (!)
     (the coax cables of one connector have approximately 
      the same lenght, the differences appear between 
      different connectors) 

   - the lengths differences between cables of different modules
     is sometimes even larger (side modules)

 
   A.Lanyov has prepared detailed lists for MC-2 and TC-2.
   Before the cabling can start the calculated cable lenght must be
   checked in the real setup. On important result from the test 
   is also the maximum possible length for the cables.

   Dietrich Pose is currently trying to organize the tests on the
   MC-2 cable-frame. For realistic conditions at least 3 modules
   must be used.

   Taking Sacha's numbers Mike will provide a list of demanded
   lengths for the TC boards which are currently prepared in Zeuthen.


   The cabling of the boards prepared for MC-2 must be checked:
   It seems that the boards produced so fare for MC-2 DO NOT HAVE
   the correct length. Immediate production of the correct boards
   is therefore necessary !!


   1.5 Shipment of HV boards
   -------------------------

   There will be no boards shipped to Hamburg in the next 2 weeks.




   2. Test-pulse distribution board:
   =================================

   5 PCBs (test) are ordered. For the assembling 
   the specification of the Harting connector must be
   found.


    
   3. ASD8 power distribution boards:
   ==================================

   2 boards have been delivered to Hamburg: others 
   will be tested this week.   

   
   
   4. ASD8 order
   =============

   The order of the 7800 ASD8 PCBs is out.
   There was nothing done about the 4000 boards
   we would like to give to an external company.



   5. Analog-Readout:
   ==================

   In total 110 amplifier cards will be produced:

         80 boards with  4 channels each  (= 80 aplifier chips)
         30 boards with 16 channels each  (=120 aplifier chips)

   The amplifier chip is not produced anylonger: Mario negociates
   with colleagues from Hermes to get the needed 200 chips. 
   The delivery of 100 chips is already confirmed.     
   
   For the assembly on the chamber 3 ASD8 positions must be foreseen
   at each half SL:  right, middle, and left position.