EXHIBIT 10.4e


                   Amendment to Securities Purchase Agreement


         This  Amendment  is made as of August 7,  1997,  by and among  American
Tower Systems, Inc, a Delaware corporation ("ATS"), Diablo Communications, Inc.,
a  California  corporation  ("Diablo"),  and Diablo  Communications  of Southern
California, Inc., a California corporation ("DCSC").

                               W I T N E S E T H:


         WHEREAS,  ATS and Diablo,  and ATS and DCSC have,  heretofore,  entered
into separate  Securities  Purchase  Agreements  dated as of March 20, 1997 (the
"Securities Purchase  Agreements") and separate Assets Purchase Agreements dated
as of July 8, 1997 ("Purchase Agreements"); and

         WHEREAS,  ATS,  Diablo and DCSC are  desirous of amending the terms and
conditions of the Securities Purchase Agreements;

         NOW, THEREFORE,  in consideration of the sum of One Dollar ($1.00), and
other good and valuable consideration,  the receipt, adequacy and sufficiency of
which are hereby acknowledge, the parties hereto, intending to be legally bound,
do covenant and agree as follows:

1.       Definitions.  Terms not  otherwise  defined  shall have the  respective
         meaning prescribed  therefor in the Securities  Purchase Agreements and
         Purchase Agreements.

2.       Referenced  Documents.  The Securities Purchase Agreements and Purchase
         Agreements are incorporated herein by reference.

3.       Advances  to  Date.  Pursuant  to the term of the  Securities  Purchase
         Agreement  between  ATS and  DCSC,  the  sum of  $248,751.00  has  been
         advanced to DCSC by ATS as of the date of this amendment.  No sums have
         been advanced to date under the Securities  Purchase  Agreement between
         ATS and Diablo.

4.       Amendment of Securities Purchase Agreements.  Notwithstanding  anything
         to the  contrary  in the  Securities  Purchase  Agreements  and/or  the
         Purchase  Agreements,  any and all advances made by ATS to Diablo or by
         ATS to DCSC pursuant to the Securities  Purchase  Agreements,  from and
         after  the date of this  Amendment,  shall be  deemed  advances  of the
         purchase price under the respective  Purchase  Agreement and shall be a
         credit against the purchase  price at close of the Purchase  Agreement.
         Any  and all  such  advances  made  from  and  after  the  date of this
         Amendment shall not be subject to additional compensation  certificates
         nor shall they  accrue any  interest,  except as  provided  below.  All
         advances  made  from  and  after  the date of this  Amendment  shall be
         utilized by Diablo and/or DCSC for completion of construction  projects
         and site development  projects and such expenditures  shall be included
         in the Interim  Adjustment  referred to in Section 2.3 of the  Purchase
         Agreements.  The  maximum  amounts to be  advanced by ATS to Diablo and
         DCSC in the  aggregate  pursuant to this  Amendment is the sum of three
         hundred thousand dollars ($300,000).

                                                        
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5.       Conversion  to Loan.  In the event that the Purchase  Agreements do not
         close,  any and all  advances  made  pursuant to this  Amendment  shall
         automatically  become loans made by ATS to Diablo  and/or DCSC,  as the
         case  may be.  Such  loans  shall  be in the  principal  amount  of all
         advances made under this Amendment to Diablo and or DCSC, respectively,
         shall  bear  interest  and  be  due  and  payable  as  provided  in the
         applicable Securities Purchase Agreement,  but ATS shall not, except as
         provided in the next sentence,  be entitled to Additional  Compensation
         Certificates  with respect  thereto.  Upon  termination of the Purchase
         Agreement or Agreements,  Diablo and/or DCSC, as applicable, will issue
         a note  evidencing the loan or loans in a form,  which,  except for any
         provisions in this Amendment to the contrary,  will be the form of note
         attached as Exhibit A to the  Securities  Purchase  Agreements,  except
         that, if the reason for such  termination  was the default or breach of
         Diablo  and/or  DCSC,  such notes  shall be dated as of the date of the
         respective   advances  pursuant  hereto  and  the  provisions  of  this
         Amendment shall not apply.

6.       Prior  Agreements.  Except  as  specifically  provided  herein  to  the
         contrary,   the  terms  and  conditions  of  the  Securities   Purchase
         Agreements and the Purchase  Agreements  shall remain in full force and
         effect.

         IN WITNESS WHEREOF,  ATS, Diablo and DCSC have caused this Amendment to
be  executed as of the date first  written  above by their  respective  officers
thereunto duly authorized.

                          American Tower Systems, Inc.

                          By:______________________
                          Name: Justin D. Benincasa
                          Title: Vice President


                          Diablo Communications, Inc.

                          By:________________________
                          Name:_____________________
                          Title:______________________


                          Diablo Communications of Southern California, Inc.

                          By:_________________________
                          Name:_______________________
                          Title:________________________



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