ADDvantage Technologies Group, Inc.

(Name of Issuer)

Common Stock, $0.01 par value per share

(Title of Class of Securities)

006743306 

(CUSIP Number)

May 12, 2006

(Date of Event Which Requires Filing of this Statement)

CUSIP No. 006743306

SCHEDULE 13G

Page 3 of 8 Pages

1

NAME OF REPORTING PERSON

     Highland Park Partners

S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)

      20-4630745

2

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                                                                                            (a) o
                                                                                                                                            (b) x

3

SEC USE ONLY

4

CITIZENSHIP OR PLACE OF ORGANIZATION

       Illinois

NUMBER OF
SHARES
BENEFICIALLY

5

SOLE VOTING POWER

     133,275

OWNED BY
EACH
REPORTING

6

SHARED VOTING POWER

     0

PERSON
WITH

7

SOLE DISPOSITIVE POWER

     133,275

8

SHARED DISPOSITIVE POWER

     0

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       1.31%

10

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
                                                                                                                                          o

11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

      1.31%

12

TYPE OF REPORTING PERSON*

       PN

Schedule 13G

Page 4 of 8 Pages

Item 1(a).

Name of Issuer:

ADDvantage Technologies Group, Inc.

Item 1(b).

Address of Issuer's Principal Executive Offices:

1221 E. Houston

Broken Arrow, Oklahoma

Item 2(a).

Name of Persons Filing:

(i)   Millennium Group LLC

(ii)  Highland Park Partners

Item 2(b).

Address of Principal Business Office or, if None, Residence:

Item 2(c).

Citizenship:

(i)   Millennium Group LLC - Illinois

(ii)  Highland Park Partners - Illinois

Item 2(d).

Title of Class of Securities:

Common Stock, $0.01 par value per share

Item 2(e).

CUSIP Number:

006743306

Item 3.

If this statement is filed pursuant to ss.ss. 240.13d-1(b), or 240.13d-2(b) or (c), check whether the person filing is a:

(a)o

Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o)

(b)o

Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c)

(c)o

Insurance Company as defined in Section 3(a)(19) of the Act (15 U.S.C. 78c)

(d)o

Investment Company registered under Section 8 of the Investment Company Act of 1940
(15 U.S.C. 80a-8)

(e)o

(g)o

Parent Holding Company or control person in accordance with ss. 240.13d-1(b)(ii)(G),

(h)o

Saving Association as defined in ss. 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813)

(i)o

Church plan that is excluded from the definition of an investment company under ss. 3(c)(15) of the Investment Company Act of 1940 (15 U.S.C. 80a-3)

(j)o

Group, in accordance with ss. 240.13d-1(b)(ii)(J)

Item 4.

Ownership.

Millennium Group LLC

(b)  Percent of Class:  3.93%  /(1)

(c)  Number of shares as to which such person has:

(i)   Sole power to vote or to direct the vote:  398,475

(ii)  Shared power to vote or to direct the vote:  0

(iii) Sole power to dispose or to direct the disposition of:  398,475

(iv) Shared power to dispose or to direct the disposition of:  0

 /(1)

Percentages are based on 10,142,247 of Common Stock outstanding as of May 5, 2006 (as set forth on the Issuer's Form 10-Q, filed on May 15, 2006 with the Securities and Exchange Commission).
 

Page 6 of 8 Pages

 /(2)

Item 8.

Identification and Classification of Members of the Group.

Not applicable.

Item 9.

Notice of Dissolution of a Group.

Not applicable.

Item 10.

Certification.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having such purpose or effect.