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                                                                   EXHIBIT 10.53

                                   PCTEL, INC.

                                MARTIN H. SINGER
               AMENDED AND RESTATED MANAGEMENT RETENTION AGREEMENT

      This Amended and Restated Management Retention Agreement (the "Agreement")
is made and entered into by and between MARTIN H. SINGER (the "Executive") and
PCTEL, INC. (the "Company"), effective as January 6, 2006 (the "Effective
Date"). This Agreement shall supersede the Management Retention Agreement dated
as of November 15, 2001 between Executive and the Company and the Amendment to
the Management Retention Agreement dated September 30, 2003. This Agreement
together with the other agreements identified in Section 10(c) below, shall
represent the entire agreement and understanding between the parties as to the
subject matter herein.

                                    RECITALS

      A. It is expected that the Company from time to time may consider a Change
of Control (as defined below). The Board of Directors of the Company (the
"Board") recognizes that such consideration can be a distraction to Executive
and can cause Executive to consider alternative employment opportunities. The
Board has determined that it is in the best interests of the Company and its
stockholders to assure that the Company will have the continued dedication and
objectivity of Executive, notwithstanding the possibility, threat or occurrence
of a Change of Control of the Company.

      B. The Board believes that it is in the best interests of the Company and
its stockholders to provide Executive with an incentive to continue his
employment and to motivate Executive to maximize the value of the Company upon a
Change of Control for the benefit of its stockholders.

      C. The Board believes that it is imperative to provide Executive with
severance benefits upon Executive's termination of employment following a Change
of Control which provides Executive with enhanced financial security and
incentive and encouragement to remain with the Company notwithstanding the
possibility of a Change of Control.

      D. Certain capitalized terms used in this Agreement are defined in Section
4 below.

      The parties hereto agree as follows:

      1. Term of Agreement. This Agreement shall terminate upon the date that
all obligations of the parties hereto with respect to this Agreement have been
satisfied.

      2. At-Will Employment. It is intended that the employment arrangement
contemplated by this Agreement and Executive's Amended and Restated Employment
Agreement (the "Employment Agreement") shall continue until June 30, 2008 (such
period of employment being referred to herein as the "Employment Term").
Notwithstanding the foregoing, the parties agree that neither this Agreement,
the Employment Agreement, nor any provision herein is intended to guarantee the
continuation of Executive's employment for the duration of the Employment Term.
If

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Executive's employment terminates for any reason, including (without limitation)
any termination prior to a Change of Control, Executive shall not be entitled to
any payments, benefits, damages, awards or compensation other than as provided
by this Agreement and the Employment Agreement, or as may otherwise be available
in accordance with the Company's established employee plans or pursuant to other
written agreements with the Company.

      3. Change of Control Severance Benefits.

            (a) Involuntary Termination other than for Cause, Death or
Disability or Voluntary Termination for Good Reason Following a Change of
Control. If, within twelve (12) months following a Change of Control,
Executive's employment is terminated (i) involuntarily by the Company other than
for Cause, death or Disability or (ii) by Executive pursuant to a Voluntary
Termination for Good Reason, then, subject to Executive entering into a standard
form of mutual release or claims with the Company, the Company shall provide
Executive with the following benefits upon such termination:

                  (i) Severance Payment. Executive shall be entitled to receive
a lump-sum cash payment in an amount equal to two hundred percent (200%) of
Executive's Annual Compensation. Such severance payment will be made within ten
(10) days of the date of Executive's termination of employment, unless the
Company reasonably determines that Section 409A of the Internal Revenue Code of
1986, as amended (the "Code"), will result in the imposition of additional tax
to an earlier payment of the severance payment, in which case the severance
payment will be payable on the date that is six (6) months and one (1) day
following the date of the Executive's termination of employment.

                  (ii) Continued Executive Benefits. The Company will reimburse
Executive for the cost of Executive's health, dental, vision, long-term
disability and life insurance coverage at the same level of coverage as was
provided to Executive immediately prior to the Change of Control and at the same
ratio of Company premium payment to Executive premium payment as was in effect
immediately prior to the Change of Control (the "Company-Paid Coverage"). If
such coverage included Executive's dependents immediately prior to the Change of
Control, such dependents shall also be covered at Company expense. Company-Paid
Coverage shall continue until the earlier of (A) one (1) year from the date of
termination, or (B) the date upon which Executive and his dependents become
covered under another employer's group health, dental, vision, long-term
disability and life insurance plans that provide Executive and his dependents
with comparable benefits and levels of coverage. For purposes of Title X of the
Consolidated Budget Reconciliation Act of 1985 ("COBRA"), the date of the
"qualifying event" for Executive and his or her dependents shall be the date
upon which the Company-Paid Coverage commences, and each month of Company-Paid
Coverage provided hereunder shall offset a month of continuation coverage
otherwise due under COBRA.

                  (iii) Pro-Rated Bonus Payment. Executive shall be entitled to
receive a lump-sum cash payment equal to one hundred percent (100%) of the
higher of (A) Executive's Target Bonus as in effect for the fiscal year in which
the Change of Control occurs or (B) Executive's Target Bonus as in effect for
the fiscal year in which Executive's termination occurs. Such higher amount will
be pro-rated by multiplying such bonus amount in clause (A) or (B), as

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applicable, by a fraction, the numerator of which shall be the number of days
prior to Executive's termination during such fiscal year, and the denominator of
which shall be three-hundred and sixty-five (365). Such severance payment will
be made within ten (10) days of the date of Executive's termination of
employment, unless the Company reasonably determines that Section 409A of the
Internal Revenue Code of 1986, as amended, in which case the severance payment
will be payable on the date that is six (6) months and one (1) day following the
date of the Executive's termination of employment.

                  (iv) Equity Compensation Accelerated Vesting. One Hundred
percent (100%) of the unvested portion of any stock, option, restricted stock or
other Company equity compensation held by or granted to Executive shall be
automatically accelerated in full so as to become completely vested.

            (b) Voluntary Resignation. If Executive's employment terminates by
reason of Executive's voluntary resignation (and is not a Voluntary Termination
for Good Reason), then Executive shall not be entitled to receive severance or
other benefits except for those (if any) as may then be established under the
Company's then existing severance and benefits plans or pursuant to other
written agreements with the Company.

            (c) Disability; Death. If Executive's employment with the Company
terminates as a result of Executive's Disability, or if Executive's employment
is terminated due to the death of Executive, then Executive shall not be
entitled to receive severance or other benefits except for those (if any) as may
then be established under the Company's then existing severance and benefits
plans or pursuant to other written agreements with the Company.

            (d) Termination for Cause. If Executive is terminated for Cause,
then Executive shall not be entitled to receive severance or other benefits.

            (e) Termination Apart from Change of Control. In the event
Executive's employment is terminated for any reason, either prior to the
occurrence of a Change of Control or after the twelve (12) month period
following a Change of Control, then Executive shall be entitled to receive
severance and any other benefits only as may then be established under the
Employment Agreement and the Company's then existing severance and benefits
plans or pursuant to other written agreements with the Company.

      4. Definition of Terms. The following terms referred to in this Agreement
shall have the following meanings:

            (a) Annual Compensation. "Annual Compensation" shall mean an amount
equal to Executive's Company annual base salary.

            (b) Target Bonus. "Target Bonus" shall mean Executive's annual
bonus, assuming one hundred percent (100%) "on target" satisfaction of any
performance milestones.

            (c) Cause. "Cause" shall mean:

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                  (i) An act of personal dishonesty taken by Executive in
connection with his responsibilities as an employee and intended to result in
substantial personal enrichment of Executive;

                  (ii) Executive being convicted of, or a plea of nolo
contendere to, a felony;

                  (iii) A willful act by Executive which constitutes gross
misconduct and which is injurious to the Company; or

                  (iv) Following delivery to Executive of a written demand for
performance from the Company which describes the basis for the Company's
reasonable belief that Executive has not substantially performed his duties,
continued violations by Executive of Executive's obligations to the Company
which are demonstrably willful and deliberate on Executive's part.

            (d) Change of Control. "Change of Control" means the occurrence of
any of the following events:

                  (i) Any "person" (as such term is used in Sections 13(d) and
14(d) of the Securities Exchange Act of 1934, as amended) becomes the
"beneficial owner" (as defined in Rule 13d-3 under said Act), directly or
indirectly, of securities of the Company representing fifty percent (50%) or
more of the total voting power represented by the Company's then outstanding
voting securities who is not already such as of the Effective Date of this
Agreement; or

                  (ii) The consummation of the sale or disposition by the
Company of all or substantially all the Company's assets; or

                  (iii) The consummation of a merger or consolidation of the
Company with any other corporation, other than a merger or consolidation which
would result in the voting securities of the Company outstanding immediately
prior thereto continuing to represent (either by remaining outstanding or by
being converted into voting securities of the surviving entity or its parent) at
least fifty percent (50%) of the total voting power represented by the voting
securities of the Company or such surviving entity or its parent outstanding
immediately after such merger or consolidation; or

                  (iv) A change in the composition of the Board occurring within
a two (2)-year period, as a result of which fewer than a majority of the
directors arc Incumbent Directors. "Incumbent Directors" shall mean directors
who either (A) are directors of the Company as of the date upon which this
Agreement was entered into, or (B) are elected, or nominated for election, to
the Board with the affirmative votes of at least a majority of those directors
whose election or nomination was not in connection with any transaction
described in subsections (i), (ii), or (iii) above, or in connection with an
actual or threatened proxy contest relating to the election of directors to the
Company.

            (e) Disability. "Disability" shall mean that Executive has been
unable to perform his Company duties as the result of his incapacity due to
physical or menial illness, and such inability, at least twenty-six (26) weeks
after its commencement, is determined to be total and

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permanent by a physician selected by the Company or its insurers and acceptable
to Executive or Executive's legal representative (such Agreement as to
acceptability not to be unreasonably withheld). Termination resulting from
Disability may only be effected after at least thirty (30) days' written notice
by the Company of its intention to terminate Executive's employment. In the
event that Executive resumes the performance of substantially all of his duties
hereunder before the termination of his employment becomes effective, the notice
of intent to terminate shall automatically be deemed to have been revoked.

            (f) Voluntary Termination for Good Reason. "Voluntary Termination
for Good Reason" shall mean Executive voluntarily resigns after the occurrence
of any of the following:

                  (i) Without Executive's express written consent, a material
reduction of Executive's duties, title, authority or responsibilities, relative
to Executive's duties, title, authority or responsibilities as in effect
immediately prior to such reduction, or the assignment to Executive of such
reduced duties, title, authority or responsibilities; provided, however, that a
reduction in duties, title, authority or responsibilities solely by virtue of
the Company being acquired and made part of a larger entity (as, for example,
when the senior vice-president of a business unit of the Company remains as such
following a Change of Control) shall not by itself constitute grounds for a
"Voluntary Termination for Good Reason;

                  (ii) Without Executive's express written consent, a material
reduction, without good business reasons, of the facilities and perquisites
(including office space and location) available to Executive immediately prior
to such reduction;

                  (iii) A reduction by the Company in the base salary of
Executive as in effect immediately prior to such reduction;

                  (iv) A material reduction by the Company in the aggregate
level of employee benefits, including bonuses, to which Executive was entitled
immediately prior to such reduction with the result that Executive's aggregate
benefits package is materially reduced (other than a reduction that generally
applies to Company employees);

                  (v) The failure of the Company to obtain the assumption of
this agreement by any successors contemplated in Section 8(a) below; or

                  (vi) Any act or set of facts or circumstances which would,
under Illinois case law or statute constitute a constructive termination of
Executive.

      5. Conditional Nature of Severance Payments.

            (a) Noncompete. Executive acknowledges that the nature of the
Company's business is such that if Executive were to become employed by, or
substantially involved in, the business of a competitor of the Company during
the twenty-four (24) months following the termination of Executive's employment
(the "Restricted Period") with the Company for any reason (whether during the
Employment Term or subsequent to the end of such period), it would be very
difficult for Executive not to rely on or use the Company's trade secrets and
confidential

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information. Thus, to avoid the inevitable disclosure of the Company's trade
secrets and confidential information, Executive agrees and acknowledges that
Executive's right to receive the severance payments set forth in Section 3 (to
the extent Executive is otherwise entitled to such payments) shall be
conditioned upon Executive not directly or indirectly engaging in (whether as an
employee, consultant, agent, proprietor, principal, partner, stockholder,
corporate officer, director or otherwise), nor having any ownership interest in
or participating in the financing, operation, management or control of, any
person, firm, corporation or business that competes in the markets for the
Restricted Business; provided, however, that nothing in this Section 5(a) shall
prevent Executive from owning as a passive investment less than one percent (1%)
of the outstanding shares of the capital stock of a publicly-held company if (A)
such shares are actively traded on the New York Stock Exchange or the Nasdaq
National Market and (B) Executive is not otherwise associated with such company
or any of its affiliates. The "Restricted Business" for purposes of this
Agreement is one which is engaged in the design, development, manufacture,
production, marketing, sale, licensing or servicing of any products, or the
provision of any services, that are the same as or similar to those of the
Company during the Restricted Period. Upon any breach of this section, all
severance payments and benefits pursuant to this Agreement shall immediately
cease.

            (b) Non-Solicitation. During the twenty-four (24) months following
the termination of Executive's employment with the Company for any reason
(whether during or after the Employment Term), Executive agrees and acknowledges
that Executive's right to receive the severance payments set forth in Section 3
(to the extent Executive is otherwise entitled to such payments) shall be
conditioned upon Executive not either directly or indirectly soliciting,
inducing, attempting to hire, recruiting, encouraging, taking away, hiring any
employee of the Company or causing an employee to leave his or her employment
either for Executive or for any other entity or person.

            (c) Understanding of Covenants. Executive represents that he (i) is
familiar with the foregoing covenants not to compete and not to solicit, and
(ii) is fully aware of his obligations hereunder, including, without limitation,
the reasonableness of the length of time, scope and geographic coverage of these
covenants.

      6. Section 280G. In the event that the severance and other benefits
provided for in this Agreement or otherwise payable to Executive (i) constitute
"parachute payments" within the meaning of Section 280G of the Code and (ii) but
for this Section, would be subject to the excise tax imposed by Section 4999 of
the Code, then Executive's severance benefits under this Agreement shall be
payable either

                  (i) in full, or

                  (ii) as to such lesser amount which would result in no portion
of such severance benefits being subject to excise tax under Section 4999 of the
Code, whichever of the foregoing amounts, taking into account the applicable
federal, state and local income taxes and the excise tax imposed by Section
4999, results in the receipt by Executive on an after-tax basis, of the greatest
amount of severance benefits under this Agreement, notwithstanding that all or
some portion of such severance benefits may be taxable under Section 4999 of the
Code. Unless the Company and Executive otherwise agree in writing, any
determination required under this Section shall be

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made in writing, by the Company's independent public accountants (the
"Accountants"), whose determination shall be conclusive and binding upon
Executive and the Company for all purposes. For purposes of making the
calculations required by this Section, the Accountants may make reasonable
assumptions and approximations concerning applicable taxes and may rely on
reasonable, good faith interpretations concerning the application of Sections
280G and 4999 of the Code. The Company and Executive shall furnish to the
Accountants such information and documents as the Accountants may reasonably
request in order to make a determination under this Section. The Company shall
bear all costs the Accountants may reasonably incur in connection with any
calculations contemplated by this Section.

      7. Section 409A.

            (a) Section 409A Compliance. This Agreement will be deemed amended
to the extent necessary to avoid imposition of any additional tax or income
recognition prior to actual payment to Executive under Section 409A of the Code
and any temporary, proposed or final Treasury Regulations and guidance
promulgated thereunder and the parties agree to cooperate with each other and to
take reasonably necessary steps in this regard.

            (b) Board Discretion. Notwithstanding the provisions set forth in
this Agreement, the Board of Directors or the Committee may in its sole
discretion at any time amend the timing of payments or benefits set forth under
Section 3 for the benefit of Executive, to the extent such amended timing can be
effected in compliance with Section 409A of the Code and any temporary, proposed
or final Treasury Regulations and guidance promulgated thereunder.

      8. Successors.

            (a) Company's Successor. Any successor to the Company (whether
direct or indirect and whether by purchase, merger, consolidation, liquidation
or otherwise) to all or substantially all of the Company's business and/or
assets shall assume the obligations under this Agreement and agree expressly to
perform the obligations under this Agreement in the same manner and to the same
extent as the Company would be required to perform such obligations in the
absence of a succession. For all purposes under this Agreement, the term
"Company" shall include any such successor to the Company which executes and
delivers the assumption agreement described in this Section 8(a) or which
becomes bound by the terms of this Agreement by operation of law.

            (b) Executive's Successors. The terms of this Agreement and all
rights of Executive hereunder shall inure to the benefit of, and be enforceable
by, Executive's personal or legal representatives, executors, administrators,
successors, heirs, distributees, devisees and legatees.

      9. Notice.

            (a) General. Notices and all other communications contemplated by
this Agreement shall be in writing and shall be deemed to have been duly given
when personally delivered or one day following mailing via Federal Express or
similar overnight courier service. In the case of Executive, mailed notices
shall be addressed to him at the home address which he most recently
communicated to the Company in writing. In the case of the Company, mailed
notices shall

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be addressed to its corporate headquarters, and all notices shall be directed to
the attention of its Secretary.

            (b) Notice of Termination. Any termination by the Company for Cause
or by Executive pursuant to a Voluntary Termination for Good Reason shall be
communicated by a notice of termination to the other party hereto given in
accordance with Section 9(a) of this Agreement. Such notice shall indicate the
specific termination provision in this Agreement relied upon, shall set forth in
reasonable detail the facts and circumstances claimed to provide a basis for
termination under the provision so indicated, and shall specify the termination
date (which shall be not more than 30 days after the giving of such notice). The
failure by Executive to include in the notice any fact or circumstance which
contributes to a showing of Voluntary Termination for Good Reason shall not
waive any right of executive hereunder or preclude Executive from asserting such
fact or circumstance in enforcing his rights hereunder.

      10. Miscellaneous Provisions.

            (a) No Duty to Mitigate. Executive shall not be required to mitigate
the value of any benefits contemplated by this Agreement, nor shall nay such
benefits be reduced by any earnings or benefits that Executive may receive from
any other source.

            (b) Waiver. No provision of this Agreement shall be modified, waived
or discharged unless the modification, waiver or discharge is agreed to in
writing and signed by Executive and by two authorized officers of the Company
(other than Executive). No waiver by either party of any breach of, or of
compliance with, any condition or provision of this Agreement by the other party
shall be considered a waiver of any other condition or provision or of the same
condition or provision at another time.

            (c) Integration. This Agreement, together with the Employment
Agreement, the Company's 1997 Stock Plan (the "Option Plan"), Executive's option
agreements and restricted stock agreements, Company's Deferred Compensation
Plans (the "Deferred Compensation Plan"), the Confidential Information
Agreement, and the equity awards that have previously been issued to Executive,
represents the entire agreement and understanding between the parties as to the
subject matter herein and supersedes all prior or contemporaneous agreements
whether written or oral. No waiver, alteration, or modification of any of the
provisions of this Agreement will be binding unless in writing and signed by
duly authorized representatives of the parties hereto (except that the Option
Plan and the Deferred Compensation Plans may be revised or modified in
accordance with their terms).

            (d) Choice of Law. The validity, interpretation, construction and
performance of this Agreement shall be governed by the laws or the State of
Illinois.

            (e) Severability. The invalidity or unenforceability of any
provision or provisions of this Agreement shall not affect the validity or
enforceability of any other provision hereof, which shall remain in full force
and effect.

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            (f) Counterparts. This Agreement may be executed in counterparts,
each of which shall be deemed an original, but all of which together will
constitute one and the same instrument.

      IN WITNESS WHEREOF, each of the parties has executed this Agreement, in
the case of the Company by its duly authorized officer, as of the day and year
set forth below.

COMPANY:

PCTEL, INC.

By: /s/ Richard C. Alberding                        Date: January 6, 2006
    ------------------------------------

Name: Richard C. Alberding

Title: Chair of the Compensation Committee of the Board of Directors

EXECUTIVE:

/s/ Martin H. Singer                                Date: January 6, 2006
----------------------------------------
Martin H. Singer

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                          Amendment to Award Agreements

         This agreement (the "Agreement") is entered into as of December 30,
2005 by Nuveen Investments, Inc. ("Nuveen") and Timothy R. Schwertfeger (the
"Executive").

         WHEREAS, Nuveen and the Executive are parties to various award
agreements identified hereafter (collectively, the "Award Agreements") which
among other provisions grant Executive (1) the right and option to purchase
shares of Nuveen's Class A Common Stock (hereinafter, the "Stock") at specified
prices, and (2) the right to receive restricted Stock. The Award Agreements are
as follows: Restricted Stock Award and Agreement dated June 13, 2002, made
effective June 10, 2002; Restricted Stock Award and Agreement dated January 25,
2005, made effective January 14, 2005; Non-Qualified Stock Option Agreement
dated January 24, 2005, made effective January 14, 2005; Long Term Equity
Performance Award Agreement - Stock Options dated January 31, 2005, made
effective January 14, 2005; and Long Term Equity Performance Award Agreement -
Restricted Stock dated January 31, 2005, made effective January 14, 2005; and

         WHEREAS, the Award Agreements identified above were made in respect
where applicable of the following equity incentive plans: the Second Amendment
and Restatement of The John Nuveen Company Equity Incentive Award Plan, and the
Nuveen Investments, Inc. 2005 Equity Incentive Plan (collectively, the "Plans");
and

         WHEREAS, the parties desire to amend each of the Award Agreements to
provide that the term "Retirement" as used in each the Award Agreements shall be
defined as follows: "Retirement means the retirement of a Participant from the
employment of Nuveen or a Nuveen subsidiary at (i) such Participant's normal
retirement upon reaching age 65, or (ii) such Participant's early retirement
with the approval of the Committee;"

         NOW THEREFORE, in consideration in part of the other compensation
granted to the Executive, Nuveen and the Executive have agreed as follows,

         1. Amendment of Award Agreements. Notwithstanding any other definition
of the term "Retirement" in any of the above-noted Plans or Award Agreements,
each of the Award Agreements is amended to provide as follows: "Retirement means
the retirement of a Participant from the employment of Nuveen or a Nuveen
subsidiary at (i) such Participant's normal retirement upon reaching age 65, or
(ii) such Participant's early retirement with the approval of the Committee."

         2. Waiver. Executive irrevocably waives any and all rights which he
would otherwise have under the Plans and the Award Agreements in the absence of
the amendment of the definition of "Retirement" in the Award Agreements
contained in the Agreement.

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         IN WITNESS WHEREOF, the parties have entered into this Agreement as of
December 30, 2005.

         EXECUTIVE:

         /s/ Timothy R. Schwertfeger
         ----------------------------
         Name: Timothy R. Schwertfeger

         NUVEEN INVESTMENTS, INC.

         By:  /s/ Alan G. Berkshire
              -----------------------
         Its: Senior Vice President

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