<PAGE>   1

                                                                    EXHIBIT 10.2

                              AMENDMENT NUMBER SIX
                              --------------------
                         TO LOAN AND SECURITY AGREEMENT
                         ------------------------------

         THIS AMENDMENT NUMBER SIX TO LOAN AND SECURITY AGREEMENT (this
"Amendment") dated as of May 1, 2001, is entered into among PHONETEL
TECHNOLOGIES, INC., an Ohio corporation ("Phonetel"), CHEROKEE COMMUNICATIONS,
INC., a Texas corporation ("Cherokee," and together with Phonetel, each a
"Borrower" and collectively, jointly and severally, the "Borrowers"), on the one
hand, and, on the other hand, Agent (as hereinafter defined) and the financial
institutions (collectively, the "Lenders" and individually, a "Lender") that are
signatories to that certain Loan and Security Agreement, dated as of November
17, 1999 (as amended, restated, supplemented, or otherwise modified from time to
time, the "Loan Agreement"), entered into among the Borrowers, Lenders, and
FOOTHILL CAPITAL CORPORATION, a California corporation, as agent for the Lenders
(herein, in such capacity, referred to as "Agent"), in light of the following:

                                    RECITALS
                                    --------

         WHEREAS, Borrowers have requested that the Lenders amend the Loan
Agreement; and

         WHEREAS, Lenders are willing to amend the Loan Agreement under the
terms and conditions set forth in this Amendment.

         NOW, THEREFORE, in consideration of the foregoing and the mutual
covenants herein contained, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereby
agree as follows:




                                      -1-
<PAGE>   2

                                    AGREEMENT
                                    ---------

I.       DEFINITIONS. Capitalized terms not otherwise defined herein shall have
         the meaning ascribed thereto in the Loan Agreement.

II.      AMENDMENTS TO THE LOAN AGREEMENT. Upon the Sixth Amendment Effective
         Date, the parties agree to amend the Loan Agreement as follows:

         2.1      SECTION 1.1 of the Loan Agreement hereby is amended by
                  inserting the following new defined terms in the proper
                  alphanumerical order:

                  "SIXTH AMENDMENT" means that certain Amendment Number Six to
                  Loan and Security Agreement, dated as of May 1, 2001, among
                  Borrowers, Lenders and Agent.

                  "SIXTH AMENDMENT EFFECTIVE DATE" means the date that all
                  conditions set forth in Section 4 of the Sixth Amendment have
                  been satisfied.

         2.2      SECTION 2.6 of the Loan Agreement hereby is amended by
                  inserting the following new subsection (k) thereof:

                  (k) PAYMENT IN KIND OF CERTAIN INTEREST OWING. Notwithstanding
                  the provisions of subsections (c), (h), (i), and (j) above,
                  interest accrued during the month of April, 2001, otherwise
                  due and payable on May 1, 2001, shall instead be added to
                  principal as of May 1, 2001, and shall thereafter accrue
                  interest at the rate then applicable to Advances hereunder.

III.     WAIVER TO THE LOAN AGREEMENT. Upon the Sixth Amendment Effective Date,
         the parties agree to certain waivers as follows:

         3.1      WAIVER OF CERTAIN FINANCIAL COVENANTS FOR THE QUARTER ENDED
                  MARCH 31, 2001. Agent hereby waives any Default or Event of
                  Default solely with respect to Borrower's failure to comply
                  with SECTIONS 7.20(a), 7.20(b), 7.20(c), 7.20(d), and 7.20(e),
                  only for the period ending March 31, 2001.

IV.      CONDITIONS PRECEDENT TO AMENDMENT. The satisfaction of each of the
         following unless waived or deferred by Lenders, in their sole
         discretion, shall constitute conditions precedent to the effectiveness
         of this Amendment and each and every provisions hereof:

         4.1      Agent shall have received this Amendment, in form and
                  substance satisfactory to Agent, duly executed by each party
                  hereto, and in full force and effect;



                                      -2-
<PAGE>   3

         4.2      The representations and warranties in this Amendment, the Loan
                  Agreement as amended by this Amendment, and the other Loan
                  Documents shall be true and correct in all respects on and as
                  of the date hereof, as though made on such date (except to the
                  extent that such representations and warranties relate solely
                  to an earlier date);

         4.3      No Default or Event of Default shall have occurred and be
                  continuing on the date hereof, nor shall result from the
                  consummation of the transactions contemplated herein; and

         4.4      No injunction, writ, restraining order, or other order of any
                  nature prohibiting, directly or indirectly, the consummation
                  of the transactions contemplated herein shall have been issued
                  and remain in force by any Governmental Authority against
                  either of the Borrowers, Agent or any of the Lenders.

V.       REPRESENTATIONS AND WARRANTIES. Each Borrower hereby represents and
         warrants to the Lenders that (a) the execution, delivery, and
         performance of this Amendment and of the Loan Agreement, as amended by
         this Amendment, are within such Borrower's corporate powers, have been
         duly authorized by all necessary corporate action, and are not in
         contravention of any law, rule, or regulation, or any order, judgment,
         decree, writ, injunction, or award of any arbitrator, court, or
         Governmental Authority, or of the terms of its Governing Documents, or
         of any contract or undertaking to which it is a party or by which any
         of its properties may be bound or affected, (b) this Amendment and the
         Loan Agreement, as amended by this Amendment, constitute such
         Borrower's legal, valid, and binding obligation, enforceable against
         such Borrower in accordance with its terms, and (c) this Amendment has
         been duly executed and delivered by such Borrower.

VI.      CHOICE OF LAW. THE VALIDITY OF THIS AMENDMENT, ITS CONSTRUCTION,
         INTERPRETATION AND ENFORCEMENT, THE RIGHTS OF THE PARTIES HEREUNDER,
         SHALL BE DETERMINED UNDER, GOVERNED BY, AND CONSTRUED IN ACCORDANCE
         WITH THE LAWS OF THE STATE OF NEW YORK.

VII.     COUNTERPARTS; TELEFACSIMILE EXECUTION. This Amendment may be executed
         in any number of counterparts and by different parties and separate
         counterparts, each of which when so executed and delivered, shall be
         deemed an original, and all of which, when taken together, shall
         constitute one and the same instrument. Delivery of an executed
         counterpart of a signature page to this Amendment by telefacsimile
         shall be effective as delivery of a manually executed counterpart of
         this Amendment. Any party delivering an executed counterpart of this
         Amendment by telefacsimile also shall deliver a manually executed
         counterpart of this Amendment but the failure to deliver a manually
         executed counterpart shall not affect the validity, enforceability, and
         binding effect of this Amendment.



                                      -3-
<PAGE>   4

VIII.    EFFECT ON LOAN AGREEMENT. The Loan Agreement, as amended hereby, shall
         be and remain in full force and effect in accordance with its
         respective terms and hereby is ratified and confirmed in all respects.
         The execution, delivery, and performance of this Amendment shall not
         operate as a waiver of or, except as expressly set forth herein, as an
         amendment of, any right, power, or remedy of Agent or any Lender under
         the Loan Agreement, as in effect prior to the date hereof.

IX.      FURTHER ASSURANCES. Each Borrower shall execute and deliver all
         agreements, documents, and instruments, in form and substance
         satisfactory to Agent, and take all actions as Agent may reasonably
         request from time to time, to perfect and maintain the perfection and
         priority of Liens in the Collateral held by Agent for the benefit of
         the Lenders and to fully consummate the transactions contemplated under
         this Amendment and the Loan Agreement, as amended by this Amendment.

X.       MISCELLANEOUS.

         10.1     Upon and after the effectiveness of this Amendment, each
                  reference in the Loan Agreement to "this Agreement",
                  "hereunder", "herein", "hereof" or words of like import
                  referring to the Loan Agreement, and each reference in the
                  other Loan Documents to "the Loan Agreement", "thereunder",
                  "therein", "thereof" or words of like import referring to the
                  Loan Agreement, shall mean and be a reference to the Loan
                  Agreement as modified and amended hereby.

         10.2     The Loan Agreement and all other Loan Documents, are and shall
                  continue to be in full force and effect and are hereby in all
                  respects ratified and confirmed and shall constitute the
                  legal, valid, binding and enforceable obligations of each
                  Borrower to Agent and Lenders.

                            [signature page follows]











<PAGE>   5








         IN WITNESS WHEREOF, the parties have entered into this Amendment as of
the date first above written.

                                  PHONETEL TECHNOLOGIES, INC.,
                                  an Ohio corporation

                                  By /s/ John D. Chichester
                                     -------------------------------------
                                  Name: John D. Chichester
                                        ----------------------------------
                                  Title:  Chief Executive Officer
                                          --------------------------------

                                  CHEROKEE COMMUNICATIONS, INC.,
                                  a Texas corporation

                                  By /s/ John D. Chichester
                                     -------------------------------------
                                  Name: John D. Chichester
                                        ----------------------------------
                                  Title:  Chief Executive Officer
                                          --------------------------------

                                  FOOTHILL CAPITAL CORPORATION, a California
                                  corporation, as Agent and a Lender

                                  By /s/ Amy Lam
                                     -------------------------------------
                                  Name: Amy Lam
                                        ----------------------------------
                                  Title:  Vice President
                                          --------------------------------

                                  FOOTHILL PARTNERS III, L.P.,
                                  a Delaware limited partnership, as a Lender

                                  By /s/ Dennis R. Ascher
                                     -------------------------------------
                                  Name: Dennis R. Ascher
                                        ----------------------------------
                                  Title:  Managing General Partner
                                          --------------------------------

                                  ABLECO FINANCE LLC,
                                  a Delaware limited liability company,
                                  as a Lender and as agent for its successors
                                  and assigns

                                  By /s/ Kevin P. Genda
                                     -------------------------------------
                                  Name: Kevin P. Genda
                                        ----------------------------------
                                  Title:  Senior Vice President and
                                          --------------------------------
                                           Chief Credit Officer
                                           -------------------------------