Exhibit 10.29

THIS NOTE HAS NOT BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE  "SECURITIES  ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS AND MAY NOT BE
SOLD OR OTHERWISE  TRANSFERRED OR PLEDGED BY ANY PERSON, UNLESS (1) EITHER (A) A
REGISTRATION  WITH RESPECT  THERETO SHALL BE EFFECTIVE UNDER THE SECURITIES ACT,
OR (B) THE COMPANY SHALL HAVE RECEIVED AN OPINION OF COUNSEL SATISFACTORY TO THE
COMPANY  THAT  AN  EXEMPTION  FROM  REGISTRATION  UNDER  THE  SECURITIES  ACT IS
AVAILABLE,  AND (2) THERE SHALL HAVE BEEN COMPLIANCE  WITH ALL APPLICABLE  STATE
SECURITIES OR "BLUE SKY" LAWS.

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                             DATAMETRICS CORPORATION

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                                                                November 7, 2005

                                                                        $200,000

                             Secured Promissory Note

            DataMetrics  Corporation  ("Borrower"),  for value received,  hereby
promises  to pay to the order of SG DMTI,  LLC,  a  Delaware  limited  liability
company ("Payee"),  the principal sum of TWO HUNDRED THOUSAND DOLLARS ($200,000)
(the "Principal Amount"),  together with interest on the unpaid Principal Amount
due and payable from the date of this Note to December 7, 2005 (1)(the "Maturity
Date"),  at a per annum rate equal to 10 percent  (10%),  in lawful money of the
United States.

      1. Payment Terms.

            A.  Mandatory.  The Principal  Amount of this Note together with any
and all  interest  accrued  and unpaid  thereon  shall be due and payable on the
Maturity Date, or earlier upon the occurrence of an Event of Default  hereunder.
Accrued and unpaid  interest shall commence on the date hereof and be payable on
the Maturity Date. All payments by Borrower  hereunder shall be applied first to
pay any  interest  that is due,  but  unpaid,  and then to reduce the  Principal
Amount.

            B. Optional. This Note can be prepaid, in whole or in part, with the
prior written consent of Payee.

            C. No Right to Set-Off or  Counterclaim.  Each  payment by  Borrower
pursuant to this Note shall be made without set-off or counterclaim and shall be
made in lawful  currency  of the  United  States of America  and in  immediately
available funds.

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(1) 30 days from the date of this Note


<PAGE>

            D. Waiver of  Presentment/Payment of Legal Fees. Borrower (i) waives
presentment,  demand, protest or notice of any kind in connection with this Note
and (ii) agrees to pay to the holder hereof,  on demand,  all costs and expenses
(including  reasonable legal fees and expenses)  incurred in connection with the
preparation, enforcement and collection of this Note.

      2. Interest.

            A. Interest.  The Principal  Amount shall accrue  interest at a rate
equal to ten percent (10 %) per annum.

            B.  Calculation and Payment.  Interest on the Principal Amount shall
be calculated on the basis of a three hundred  sixty-five (365) day year for the
actual number of days elapsed.

            C.  Default Rate of  Interest.  At the election of Payee,  after the
occurrence of an Event of Default and for so long as it continues, the Principal
Amount shall bear interest as set forth in Section 2.A above, plus 8% per annum.

            D. Excess  Interest.  Notwithstanding  anything to the  contrary set
forth herein, the aggregate interest, fees and other amounts required to be paid
by Borrower to Payee are hereby  expressly  limited so that in no contingency or
event whatsoever, whether by reason of acceleration of maturity of the Principal
Amount  or  otherwise,  shall  the  amount  paid or  agreed  to be paid to Payee
hereunder exceed the maximum  permissible under applicable law. If under or from
any circumstances whatsoever, fulfillment of any provision hereunder at the time
of performance of such provision shall be due, shall involve exceeding the limit
permitted by applicable law, then the Principal  Amount shall  automatically  be
reduced to the limit permitted,  and if under or from  circumstances  whatsoever
Payee  should ever receive as interest any amount which would exceed the highest
lawful rate,  the amount of such interest that is excessive  shall be applied to
the reduction of the Principal Amount and not to the payment of interest. In the
event  of a  conflict,  this  provision  shall  control  every  other  provision
hereunder.

      3. Representations of Borrower. Borrower hereby represents to Payee that:

            A. Borrower is a corporation duly organized, validly existing and in
good  standing  under the laws of the State of  Delaware  and has full power and
authority to conduct its business as presently  conducted  and as proposed to be
conducted by it.

            B. Borrower has the corporate  power and capacity to enter into this
Note, and to do all acts and things as are required or contemplated hereunder to
be done,  observed  and  performed  by it.  Borrower  has  taken  all  necessary
corporate action to authorize the execution, delivery and performance of each of
this Note.

            C. The  execution and delivery of this Note and the  performance  by
Borrower  of its  obligations  hereunder  (i) does not and will not  contravene,
breach  or  result  in  any  default  under  (A)  the  articles,  memorandum  of
association,  by-laws, constating documents or other organizational documents of
Borrower, or (B) under any mortgage,  lease,  agreement or other legally binding
instrument, license, permit or applicable law to which Borrower is a party or by
which  Borrower or any of its  properties or assets may be bound,  (ii) will not
oblige Borrower to grant any encumbrance to any person other than to Payee,  and
(iii) will not  result in or permit  the  acceleration  of the  maturity  of any
indebtedness,  liability or  obligation of Borrower  under any mortgage,  lease,
agreement or other legally binding instrument of or affecting Borrower.


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<PAGE>

      4. Events of Default.  Upon the occurrence of any of the following  events
(each an "Event of Default"), the entire unpaid principal of this Note, together
with all accrued interest hereon,  shall become immediately due and payable, and
Payee shall be entitled to pursue all remedies that Payee may have, at law or in
equity, for the enforcement and collection hereof:

            A. The failure of Borrower to make full  payment of all interest and
principal on this Note when due pursuant to Section 1 hereof; or

            B. Borrower  shall make an assignment  for the benefit of creditors,
file a petition in  bankruptcy,  consent to entry of an order for relief against
it in an  involuntary  case, be adjudicated  insolvent or bankrupt,  petition or
apply to any tribunal for the  appointment  of any receiver,  trustee or similar
official for it or a substantial part of its assets, or commence any proceedings
under  any  bankruptcy,  reorganization,   arrangement,  readjustment  of  debt,
dissolution or liquidation  law or statute of any  jurisdiction,  whether now or
hereafter in effect;  there shall occur the appointment of a receiver,  trustee,
assignee, liquidator,  custodian or similar official of it or a substantial part
of  Borrower's  assets;  or there  shall  have been filed any such  petition  or
application or any such proceeding shall have been commenced  against  Borrower,
which remains  undismissed for a period of sixty (60) days or more;  Borrower by
any act or omission  shall indicate its  respective  consent to,  approval of or
acquiescence in any such petition,  application or proceeding or the appointment
of any  trustee  for  it or  any  substantial  part  of  any  of its  respective
properties; or

            C. A court of competent  jurisdiction shall enter an order or decree
under any bankruptcy  law that is for relief against  Borrower in an involuntary
case, appoints a receiver, trustee, assignee,  liquidator or similar official of
Borrower,  or for any  substantial  part of Borrower's  property,  or orders the
liquidation of Borrower;  and the order or decree remains unstayed and in effect
for thirty (30) days.

            D. The  occurrence  of a default in any  covenant  or  agreement  or
breach of any  representation  or warranty under any present or future document,
instrument  or agreement  between  Borrower  and Payee which,  with respect to a
default  of a  covenant  or  agreement,  is not cured  within  the grace  period
applicable thereto, if any, or if no grace period is designated and such default
is capable of cure, remains uncured for more than thirty (30) days following its
occurrence.

            E. A court of  competent  jurisdiction  shall enter into a judgment,
order or decree against Borrower for an amount of $25,000 or more.

      5.  Acceleration.  Upon the occurrence of an Event of Default,  the unpaid
Principal  Amount  and  accrued  interest  thereon  shall  automatically  become
immediately due and payable,  without presentment,  demand,  protest,  notice of
intent to accelerate,  notice of acceleration or other requirements of any kind,
all of which are hereby expressly waived by Borrower.


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<PAGE>

      6. Amendments and Waivers.

            A. The  provisions  of this Note may from  time to time be  amended,
modified or waived, if such amendment,  modification or waiver is in writing and
consented to by Borrower and Payee.

            B. No failure or delay on the part of Payee in exercising  any power
or right under this Note shall operate as a waiver thereof, nor shall any single
or partial  exercise  of any such power or right  preclude  any other or further
exercise  thereof or the  exercise of any other power or right.  No notice to or
demand on  Borrower  in any case  shall  entitle  it to any  notice or demand in
similar or other circumstances.  No waiver or approval by Payee shall, except as
may be otherwise stated in such waiver or approval,  be applicable to subsequent
transactions.  No waiver or  approval  hereunder  shall  require  any similar or
dissimilar waiver or approval thereafter to be granted hereunder.

            C. To the extent that Borrower makes a payment or payments to Payee,
and such payment or payments or any part thereof are subsequently for any reason
invalidated,  set aside and/or  required to be repaid to a trustee,  receiver or
any other party under any bankruptcy  law,  state or federal law,  common law or
equitable  cause,  then to the extent of such  recovery,  the obligation or part
thereof  originally  intended  to be  satisfied,  and all  rights  and  remedies
therefor,  shall be revived  and  continued  in full force and effect as if such
payment had not been made or such enforcement or setoff had not occurred.

      7. Miscellaneous.

            A.  Governing  Law.  This Note shall be governed by and construed in
accordance  with  the laws of the  State  of New  York,  without  regard  to its
principles  of  conflicts  of law.  Sections  5-1401 and  5-1402 of the  General
Obligations  Law of the State of New York shall apply to this Note and  Borrower
hereby waives any right to stay or dismiss on the basis of forum non  conveniens
any  action or  proceeding  brought  before  the courts of the State of New York
sitting in New York County or of the United  States of America for the  Southern
District of New York and hereby submits to the jurisdiction of such courts.

            B.  Notices.  Unless  otherwise  provided,  all notices  required or
permitted  under this Note shall be in writing  and shall be deemed  effectively
given (i) on the day delivered or transmitted to the party to be notified in the
case of notices delivered by hand or by facsimile, (in the event confirmation is
received) (ii) upon confirmed  delivery by Federal  Express or other  nationally
recognized courier service providing  next-business-day delivery, or (iii) three
business days after deposit with the United States Postal Service, by registered
or certified mail, postage prepaid and addressed to the party to be notified, in
each case at the address set forth below, or at such other address as such party
may  designate  by written  notice to the other party  (provided  that notice of
change of  address  shall be  effective  upon  receipt by the party to whom such
notice is addressed).


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<PAGE>

If sent to Payee, notices shall be sent to the following address:
SG Phoenix Ventures LLC
110 East 59th Street, Suite 1901
New York, New York 10022
Attention:  Mr. Andrea Goren
Fax: (212) 202-7565

With a copy to:

Brown Raysman Millstein Felder & Steiner LLP
900 Third Avenue
New York, New York 10022
Attn:  Joel H. Handel, Esq.
Fax: (212) 895-2900

If sent to Borrower, notice shall be sent to the following address:

DataMetrics Corporation
1717 Diplomacy Row
Orlando, FL 32809
Attention:  Daniel Bertram, President
Fax: (407) 251-4588

With a copy to:

McLaughlin & Stern LLP
260 Madison Avenue
New York, New York 10016
Attn: Steven Schuster, Esq.
Fax: (212) 448-0066

            C.  Waiver of Jury  Trial.  PAYEE  AND  BORROWER  HEREBY  KNOWINGLY,
VOLUNTARILY AND INTENTIONALLY  WAIVE ANY RIGHTS THEY MAY HAVE TO A TRIAL BY JURY
IN RESPECT OF ANY  LITIGATION  BASED  HEREON,  OR ARISING OUT OF,  UNDER,  OR IN
CONNECTION  WITH,  THIS NOTE OR ANY OTHER  DOCUMENT OR  INSTRUMENT  EXECUTED AND
DELIVERED IN CONNECTION HEREWITH,  OR ANY COURSE OF CONDUCT,  COURSE OF DEALING,
STATEMENTS  (WHETHER VERBAL OR WRITTEN),  OR ACTIONS OF PAYEE OR BORROWER.  THIS
PROVISION IS A MATERIAL INDUCEMENT FOR PAYEE'S PURCHASING THIS NOTE.

      8. Security.

            A. Creation of Security Interest.  In order to secure the payment of
the  principal  and  interest and all other  obligations  of the Borrower now or
hereafter  owed by the Borrower to the Payee (the  "Secured  Obligations"),  the
Borrower  hereby grants to the Payee (or its designee)  (the "Secured  Party") a
security  interest in all of the personal  property of the  Borrower,  including
without limitation the personal property described below (the "Collateral"):


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<PAGE>

                  (i) all equipment in all of its forms,  wherever located,  now
or hereafter existing, all parts thereof and all accessions thereto;

                  (ii) all inventory in all of its forms,  wherever located, now
or hereafter existing,  including, but not limited to, (A) all raw materials and
work in process therefor, finished goods thereof, and materials used or consumed
in the manufacture or production thereof; (B) goods in which the Borrower has an
interest in mass or a joint or other  interest or right of any kind  (including,
without  limitation,  goods in which the  Borrower  has an  interest or right as
consignee);  and (C) goods which are returned to or  repossessed by the Borrower
and all accessions thereto and products thereof and documents therefor;

                  (iii) all  accounts,  accounts  receivable,  contract  rights,
chattel paper, documents,  instruments,  deposit accounts,  general intangibles,
tax  refunds and other  obligations  of any kind owing to the  Borrower,  now or
hereafter existing, whether or not arising out of or in connection with the sale
or lease of goods or the rendering of services,  and all rights now or hereafter
existing  in  and to all  security  agreements,  leases,  subleases,  and  other
contracts securing or otherwise relating to any such accounts,  contract rights,
chattel paper, documents, instruments, deposit accounts, general intangibles, or
obligations;

                  (iv)  all   intellectual   property  of  any  kind  or  nature
whatsoever,   including  without  limitation   patents,   patent   applications,
copyrights,   copyright   applications,   trademarks   and  service   marks  and
applications therefore, mask works, net lists and trade secrets;

                  (v) all other  general  intangibles,  whether now  existing or
hereafter arising and wherever arising,  including,  but not limited to, all (A)
partnership,  corporate, and other interests in and to any person or entity; (B)
letters  of  authorization,   permits,  licenses,   consents,  contract  rights,
franchises,  documents,  certificates,  records,  customer  lists,  customer and
supplier  contracts,  easements,  variances,  certifications  and  approvals  of
tribunals, bills of lading (negotiable and non-negotiable),  warehouse receipts,
any claim of the Borrower against any lender,  liquidated or  unliquidated,  and
other rights,  privileges and goodwill  obtained or used in connection  with any
property of the Borrower; (C) rights of the Borrower under any equipment leases;
and (D) tax refunds  and other  refunds or rights to receive  payment  from U.S.
federal, state or local governments or foreign governments or other tribunals;

                  (vi) all bank accounts, deposit accounts, and margin accounts,
maintained by the Borrower with financial  institutions,  brokers,  dealers, and
all other  persons  or  entities  relating  to  commodities  and/or  securities,
including all funds held therein and all certificates  and instruments,  if any,
from time to time representing or evidencing such accounts;

                  (vii) all investment  property (as defined in Section 9-115 of
the New York Uniform Commercial Code);

                  (viii) to the  extent  it is  possible  to  create a  security
interest  or perfect a security  interest in such  Collateral  by filing a UCC-1
financing statement centrally,  or in the case of dual filing states,  centrally
and at the county  level,  as  applicable,  all of the  Borrower's  fixtures now
existing or hereafter acquired,  all substitutes and replacements  therefor, all
accessions and attachments  thereto,  and all tools, parts, and equipment now or
hereafter  added to or used in connection with the fixtures on or above all real
property now owned or hereafter acquired by the Borrower;


                                       6
<PAGE>

                  (ix) all records and documents  relating to any and all of the
foregoing,  including,  without limitation,  records of account,  whether in the
form of writing, microfilm, microfiche, tape, or electronic media; and

                  (x)  all  substitutes  and   replacements   for,   accessions,
attachments,  and  other  additions  to  tools,  parts,  and  equipment  used in
connection  with, and all proceeds,  products,  and increases of, any and all of
the foregoing Collateral,  in whatever form, whether cash or noncash;  interest,
premium,  and principal payments,  redemption proceeds and subscription  rights,
and shares or other  proceeds  of  conversions  or splits of any  securities  in
Collateral,  and  returned  or  repossessed  Collateral;  and, to the extent not
otherwise included, all (A) payments under insurance, or any indemnity, warranty
or guaranty, payable by reason of loss or damage to or otherwise with respect to
any of the  foregoing  Collateral,  (B) cash and (C) security for the payment of
any of the Collateral,  and all goods which gave or will give rise to any of the
Collateral or are evidenced, identified, or represented therein or thereby.

            B. Sale or Removal of Collateral Prohibited.  Except for the sale of
inventory in the ordinary course of the Borrower's business,  the Borrower shall
not sell, lease, encumber,  pledge, mortgage,  assign, grant a security interest
in, or otherwise  transfer  the  Collateral  without the written  consent of the
Payee, which consent shall not be unreasonably withheld.

            C.  Uniform  Commercial  Code  Security  Agreement.  This Section is
intended to be a security  agreement pursuant to the Uniform Commercial Code for
any  of the  items  specified  above  as  part  of the  Collateral  that,  under
applicable  law, may be subject to a security  interest  pursuant to the Uniform
Commercial Code, and the Borrower hereby grants the Payee a security interest in
said items. The Borrower agrees that the Payee may file any appropriate document
in the appropriate index as a financing statement for any of the items specified
above as part of the Collateral. In addition, the Borrower agrees to execute and
deliver to the Payee,  upon the Payee's request,  any financing  statements,  as
well as extensions,  renewals and amendments thereof,  and reproductions of this
Note in such form as the Payee may  reasonably  require  to  perfect a  security
interest with respect to said items.  The Borrower shall pay all costs of filing
such financing statements and any extensions, renewals, amendments, and releases
thereof,  and shall pay all reasonable costs and expenses of any record searches
for financing  statements  the Payee may reasonably  require.  Without the prior
written  consent of the  Payee,  the  Borrower  shall not create or suffer to be
created pursuant to the Uniform  Commercial Code any other security  interest in
the Collateral,  other than the Security Interests of Secured Party and existing
secured creditors. Upon the occurrence of an Event of Default, the Secured Party
shall have the  remedies of a holder under the Uniform  Commercial  Code and, at
Secured Party's option, may also invoke the other remedies provided in this Note
as to such items.  In  exercising  any of said  remedies,  the Secured Party may
proceed  against the items of real  property and any items of personal  property
specified  above as part of the  Collateral  separately  or together  and in any
order  whatsoever,  without in any way affecting the availability of the Secured
Party's  remedies  under the Uniform  Commercial  Code or of the other  remedies
provided in this Note.


                                       7
<PAGE>

            D. Rights of Secured Party.

                  (i) Upon an Event of Default,  the  Secured  Party may require
the  Borrower to assemble  the  Collateral  and make it available to the Secured
Party at the place to be  designated  by the  Secured  Party that is  reasonably
convenient  to the  parties.  The Secured  Party may sell all or any part of the
Collateral as a whole or in parcels either by public  auction,  private sale, or
other method of disposition. The Secured Party may bid at any public sale on all
or any  portion  of the  Collateral.  Unless the  Collateral  is  perishable  or
threatens to decline  speedily in value or is of the type  customarily sold on a
recognized market,  the Secured Party shall give the Borrower  reasonable notice
of the time and place of any public  sale or of the time after which any private
sale or other  disposition  of the Collateral is to be made, and notice given at
least  10 days  before  the  time of the  sale or  other  disposition  shall  be
conclusively presumed to be reasonable.

                  (ii)  Notwithstanding  any  provision of this  Agreement,  the
Secured Party shall be under no obligation to offer to sell the  Collateral.  In
the event the Secured  Party offers to sell the  Collateral,  the Secured  Party
will be under no obligation to consummate a sale of the  Collateral if, in their
reasonable  business  judgment,  none of the offers  received by them reasonably
approximates the fair value of the Collateral.

                  (iii) In the event the  Secured  Party  elects not to sell the
Collateral,  the Secured Party may elect to follow the  procedures  set forth in
the Uniform  Commercial Code for retaining the Collateral in satisfaction of the
Borrower's obligation, subject to the Borrower's rights under such procedures.

                  (iv) In addition to the rights  under this  Agreement,  in the
Event of Default by the  Borrower,  the  Secured  Party shall be entitled to the
appointment of a receiver for the Collateral as a matter of right whether or not
the apparent value of the Collateral exceeds the outstanding principal amount of
the Notes and any receiver  appointed may serve without bond.  Employment by the
Secured Party shall not disqualify a person from serving as receiver.

                            [Signature Page Follows]


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<PAGE>

            IN WITNESS  WHEREOF,  Borrower  has caused this Note to be signed in
its name by its duly authorized officer.

                                     DATAMETRICS CORPORATION

                                     By:
                                        ----------------------------------
                                        Name:
                                        Title:


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