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Exhibit 24-a


POWER OF ATTORNEY

    KNOW ALL BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints each of William J. Cadogan, Robert E. Switz and Jeffrey D. Pflaum, with full power to each to act without the other, his or her true and lawful attorney-in-fact and agent with full power of substitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign the Annual Report on Form 10-K of ADC Telecommunications, Inc. (the "Company") for the Company's fiscal year ended October 31, 1999, and any or all amendments to said Annual Report, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, and to file the same with such other authorities as necessary, granting unto each such attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that each such attorney-in-fact and agent, or his substitute, may lawfully do or cause to be done by virtue hereof.

    IN WITNESS WHEREOF, this Power of Attorney has been signed on this 30th day of December, 1999, by the following persons.

 
   
/s/ John A. Blanchard III
John A. Blanchard III
  /s/ John J. Boyle III
John J. Boyle III
 
/s/ William J. Cadogan

William J. Cadogan
 
 
 
/s/ James C. Castle, Ph.D.

James C. Castle, Ph.D.
 
 
/s/ Thomas E. Holloran

Thomas E. Holloran
 
 
 
 
 
/s/ B. Kristine Johnson

B. Kristine Johnson
 
 
/s/ Alan E. Ross

Alan E. Ross
 
 
 
 
 
/s/ Jean-Pierre Rosso

Jean-Pierre Rosso
 
 
/s/ John W. Sidgmore

John W. Sidgmore
 
 
 
 
 
/s/ John D. Wunsch

John D. Wunsch
 
 
    

Charles D. Yost
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Exhibit 24-a
POWER OF ATTORNEY