Minutes of the HV Boards Meeting:
        ---------------------------------

    Date:        15/09/98
    Participants: P.Krizan, S.Korpar (part time) , M.Staric, U.Uwer
   

   1. Cross Talk Measurements:
   ---------------------------

   Marco Reported on cross talks studies: 
  (see 
   http://www-hera-b.desy.de/subgroup/detector/tracker/outer
                              /electronics/hv/tests.html    
   for the details)

   A first prototype was built with the aim to provide 
   realistic cross talks numbers for the case where the HV capacitors
   are very close to each other. The measured cross talk was 
   about 3% which must be compared to 1.5% for the old board.

   -> cross talk is 2times higher than for the old one. 
      But is this worrisome ?


  2. Adapter Board to hold the HV board:
  --------------------------------------

  The first proposal is using an adapter board on the chamber 
  providing  a row of pins to connect the HV board to. 
  This proposal is not suitable since:

      - it does not allow to have different HV on the two 
        different single layers 

      - the row of pins  hardly fits in the available module height
        of 12.5 mm

  
  The alternative is to plug the HV board directly to the module.
  This requires to have a separate board for the lower and upper
  single layer.

  
  3. The two-parts HV board:
  --------------------------

  The two parts of the HV boards are plugged directly to the module:

  - in case of the new end-plugs where a pin is available this 
    is no problem
 
  - to be compatible for the old-style modules an adapter board
    would be necessary. The space is very limited.

  
  The space limitations for this board type was discussed.
  It turns out  that any gas-many-fold can not be larger than 
  6x7mm^2. We must check if this is sufficient. 
  Samo stressed to need of getting "solid" numbers on the 
  dimension of the gas-many-fold. He also would like to get 
  the 1mm nylon tubes.
  
   
  4. Next meeting: 
  ----------------
  Next meeting was fixed to be either Tuesday or Wednesday at 15:00.