UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13D/A

Under the Securities Exchange Act of 1934

(Amendment No. 11)^*

TESSCO Technologies Incorporated

(Name of Issuer)

Common Stock

(Title of Class of Securities)

872386107

(CUSIP Number)

Eric R. Smith

Venable LLP

750 East Pratt Street, Suite 900, Baltimore, MD 21202 (410)244-7400

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

November 17, 2020

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box. ¨

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D/A

Explanatory Note

This Amendment No. 11 amends, supplements and to the extent inconsistent with, supersedes the Schedule 13D filed on February 15, 2007, as amended by Amendment No. 1 filed on February 18, 2009, Amendment No. 2 filed on February 24, 2012, Amendment No. 3 filed on August 26, 2016, Amendment No. 4 filed on March 20, 2020, Amendment No. 5 filed on July 22, 2020, Amendment No. 6 filed on August 3, 2020, Amendment No. 7 filed on September 25, 2020, Amendment No. 8 filed on October 20, 2020, Amendment No. 9 filed on October 30, 2020 and Amendment No. 10 filed on November 6, 2020 (as amended, the “Schedule 13D”) by Mr. Robert B. Barnhill, Jr. (the “Reporting Person”).

Item 4 is hereby amended and supplemented as follows:

The Reporting Person is soliciting shareholders’ consents (the “Consent Solicitation”) to (i) reconstitute the Issuer’s Board of Directors (the “Board”) by removing John D. Beletic, Jay G. Baitler, Paul J. Gaffney, Dennis J. Shaughnessy, and Morton F. Zifferer, Jr. (collectively, the “Subject Directors”) (and any other person(s) elected, appointed or designated by the Board (or any committee thereof) to fill any vacancy or newly created directorship on or after September 25, 2020 and prior to the conclusion of the Consent Solicitation) and replacing them with four highly qualified, independent director candidates — J. Timothy Bryan, John Diercksen, Emily Kellum (Kelly) Boss and Kathleen McLean and (ii) amend the Issuer’s Sixth Amended and Restated By-Laws (the “Bylaws”) to (a) repeal any provision adopted after August 7, 2020 without the approval of shareholders and (b) reduce the percentage of shareholders required to call a special meeting to 25% of the aggregate number of votes held by the shares of stock of all classes then outstanding and entitled to vote at a special meeting (which was the standard before the Subject Directors and other complicit Board members further entrenched themselves by recently amending the Bylaws without shareholder approval to increase the threshold to 50%).

On November 16, 2020, the Reporting Person, in his capacity as founder and largest shareholder of the Issuer, issued a press release (the “Press Release”) in response to the two recent and dubiously-timed additions to the Board. In the Press Release, the Reporting Person noted, among other things, that he believes the recent addition of the two new directors, Cathy-Ann Martine-Dolecki and Ronald D. McCray, to the Board without shareholder approval in the middle of a consent solicitation process is rash and reactionary and a failure of good corporate governance.

The Reporting Person believes that the additions of Ms. Martine-Dolecki and Mr. McCray to the Board were effectively replacements for two of the Subject Directors: Dennis J. Shaughnessy, who resigned from the Board, effective November 9, 2020, and Morton F. Zifferer, Jr. (together with Mr. Shaughnessy, the “Substituted Directors”), who announced that he will step down from the Board effective upon the conclusion of the Consent Solicitation. Proposal 1 of the Consent Solicitation provides that a consent for the removal of any of the Subject Directors also constitutes a consent to remove any other person(s) elected, appointed or designated by the Board to fill any vacancy or newly created directorship between September 25, 2020 and the conclusion of the Consent Solicitation.

As a result, the removal of any Subject Director in connection with the Consent Solicitation will also result in the removal of Ms. Martine-Dolecki and Mr. McCray. The Press Release describes the Reporting Person’s plans to recommend to the reconstituted Board that it interview Ms. Martine-Dolecki and Mr. McCray for possible reappointment to the Board if they are removed. As additional context, when evaluating Ms. Martine-Dolecki and Mr. McCray, who effectively recently replaced the Substituted Directors, the Reporting Person plans to heavily weigh, among other things, the Consent Solicitation results related to the Substituted Directors when determining whether to recommend that the reconstituted Board reappoint Ms. Martine-Dolecki and Mr. McCray. Moreover, the Reporting Person intends to recommend to the reconstituted Board that it engage in shareholder outreach to solicit views on Ms. Martine-Dolecki and Mr. McCray.

The Reporting Person contemplated revising his form of consent to allow shareholders to individually consent to remove the Substituted Directors. However, he believes that this would (i) serve to disenfranchise shareholders that have already cast their consent during the first 35 days of the Consent Solicitation and (ii) result in many shareholders not having their voices heard during the 60-day consent solicitation process due to the delays associated with the mailing of a new consent card to and from shareholders. The Substituted Directors were added 45 days after the Reporting Person’s preliminary consent solicitation statement was filed and 27 days after the Reporting Person’s first consent was delivered to the Issuer, almost halfway through the 60-day consent solicitation process. The Board had the opportunity to disclose the potential addition of the Substituted Directors at any point earlier in the process and if the Board had done so within fourteen days of the Reporting Person filing his solicitation statement, the Reporting Person could have revised his form of consent, allowing shareholders the ability to individually consent to the Substituted Directors. However, the Reporting Person believes that these directors were merely added at this specific time to confuse the process and game the system and further believes that, even if the consent card were updated now, the Board may choose to add yet another director to further the confusion. The Reporting Person has promoted numerous governance enhancements in the Consent Solicitation, including (a) reducing the recently changed threshold to call a special meeting of shareholders from 50% to 25%, (b) the addition of two directors to the Board that are proposed by shareholders owning at least 5% of the outstanding shares and (c) increasing Board diversity.

The Reporting Person notes that, as part of the his discussions with shareholders during the Consent Solicitation, not a single shareholder has told the Reporting Person that the Issuer had vetted Ms. Martine-Dolecki and Mr. McCray with them ahead of their appointment. Additionally, the Reporting Person, unlike the current Board, has designed a mechanism for shareholders to propose directors to the Board. If any shareholder with 5% or more of the outstanding shares would like to add either Ms. Martine-Dolecki or Mr. McCray, the Reporting Person would press for this initiative as well. The Reporting Person believes that he is aligned with shareholders and the Board is trying to obfuscate the process to protect three incumbent directors.

The description of the Press Release does not purport to be complete and is qualified in its entirety by reference to the full text of the Press Release, which is filed as Exhibit 99.1 to the Schedule 13D and incorporated by reference herein.

The Reporting Person intends to continue to engage in discussions with the Issuer’s Board and management, the Issuer’s other shareholders, potential investors in the Issuer and/or other parties regarding, or take actions concerning, the Issuer’s business, operations, governance, management, strategy, capitalization and/or Board composition. These discussions and/or actions will relate to, and may result in, any matter set forth in paragraphs (a) through (j) of Item 4 of Schedule 13D, including strategic transactions potentially impacting ownership and control of the Issuer.

Signature.

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

DATE: November 17, 2020

Exhibit 99.1

Robert Barnhill, Jr. Reminds Shareholders of Their Right to

Remove TESSCO Directors Hastily Appointed Last Week Without Shareholder Approval

Submitting a WHITE Consent Card FOR the Removal of Any of John D. Beletic, Jay G. Baitler, Paul J. Gaffney, Morton F. Zifferer, Jr. or Dennis J. Shaughnessy Constitutes a Consent to Remove Cathy-Ann Martine-Dolecki, Ronald D. McCray and Any Other Directors Appointed to the Board Prior to the Conclusion of the Consent Solicitation

Consent to the Election of Robert Barnhill Jr.’s

Highly-Qualified Independent Candidates to the TESSCO Board

HUNT VALLEY, Md./PRNewswire/ On November 16, 2020, Robert B. Barnhill, Jr., founder and largest shareholder of TESSCO Technologies, Incorporated (NASDAQ: TESS) (“TESSCO” or the “Company”), issued the following press release in response to the dubiously-timed additions to the Company’s Board of Directors (the “Board”):

Last week, the Board took what Mr. Barnhill deems an extraordinarily reactionary and defensive tactic to further entrench the majority influence held by incumbent directors, John D, Beletic, Jay G. Baitler and Paul J. Gaffney over a captive Board. We believe that the recent addition of two new directors to the Board without shareholder approval (“Unilateral Board Appointments”) in the middle of a consent solicitation process is rash and reactionary and a failure of good corporate governance. In our view, a slight Board compositional change effected without shareholder approval is not sufficient to remedy the enormous issues facing the Company. Based on the Company’s annual meeting results from 2019 and 2020, we believe it is clear the Board lacked a mandate from shareholders to undertake this exercise, particularly on the eve of its meetings with proxy advisory firms and institutional shareholders.

Fortunately, Mr. Barnhill’s definitive consent solicitation statement (the “Solicitation Statement”) and accompanying WHITE consent card contemplated the possibility of the Unilateral Board Appointments.

As a result, removal of any Subject Director¹ by the affirmative consent of holders of a majority of shares of the Company’s common stock (“Common Stock”) as of the October 13, 2020 record date will result in the removal of all directors appointed or designated by the Board on or after September 25, 2020 and prior to the completion of the Consent Solicitation, including Ms. Martine-Dolecki and Mr. McCray.

We believe the Unilateral Board Appointments to be a direct entrenchment tactic and a blatant attempt to confuse shareholders during the Consent Solicitation. We do not believe that the Subject Directors, who have lost shareholder support, should be able to frustrate the will of the shareholders by unilaterally appointing new directors without shareholder approval during a consent solicitation. However, consistent with shareholders’ best interest, following the Consent Solicitation, Mr. Barnhill plans to recommend to the reconstituted Board that it interview Ms. Martine-Dolecki and Mr. McCray for possible directorships, while also taking shareholder feedback into account.

At your earliest convenience, please consent to remove the Subject Directors (which will also result in the removal of Ms. Martine-Dolecki and Mr. McCray, the two directors recently appointed as a result of the Unilateral Board Appointments), and replace them with our four highly-qualified independent candidates—J. Timothy Bryan, John W. Diercksen, Emily Kellum (Kelly) Boss and Kathleen McLean.

TAKE ACTION TODAY!

Consent and Consent Revocation Procedures

We urge you to consent to all four proposals on the WHITE consent card and return it in your postage-paid envelope provided prior to December 11, 2020. An executed consent card may be revoked at any time by marking, dating, signing and delivering a written revocation before the time that the action authorized by the executed consent becomes effective. A revocation may be in any written form validly signed by the record holder as long as it clearly states that the consent previously given is no longer effective. The delivery of a subsequently dated consent card that is properly completed will constitute a revocation of any earlier consent. The revocation may be delivered to Harkins Kovler, LLC at the address set forth below. If you hold your share in “street” name with a brokerage firm, bank, dealer, trust company or other nominee, please consult such nominee for instructions on how to consent or revoke your consent.

If you have any questions about the Consent Solicitation or need assistance executing the WHITE consent card, please contact:

Harkins Kovler, LLC

3 Columbus Circle, 15th Floor

New York, NY 10019

Telephone: +1 (212) 468-5380

Toll-Free: +1 (800) 257-3995

Email: SaveTESSCO@harkinskovler.com

¹ Mr. Shaughnessy was originally a Subject Director targeted for removal by the Consent Solicitation. However, he retired in connection with the Unilateral Board Appointments. Therefore, shareholder approval of the removal of Mr. Shaughnessy will only have the effect of removing all directors appointed or designated by the Board on or after September 25, 2020 and prior to the completion of the Consent Solicitation.

Important Additional Information

Mr. Barnhill, Ms. McLean, Ms. Boss, Mr. Bryan, Mr. Diercksen, UA 6-9-2016 Robert B. Barnhill, Jr. Rev Trust, RBB-TRB LLC, a Maryland limited liability company (“RBB-TRB”), RBB-CRB LLC, a Maryland limited liability company (“RBB-CRB”), Robert B Barnhill Jr & Janet W Barnhill Tr FBO Durkin Slattery Barnhill Trust, Janet W Barnhill Tr UA 6 9 2016 Janet W Barnhill Rev Trust, Winston Foundation, Incorporated, a Maryland corporation, and Donald Manley (the “Participants” or “We”) are participants in the solicitation of consents from the Company’s shareholders to remove the Subject Directors (and any other person or persons, other than those elected by the Consent Solicitation, elected, appointed or designated by the Board (or any committee thereof) to fill any vacancy or newly created directorship on or after September 25, 2020 and prior to the time that any of the actions proposed to be taken by the Consent Solicitation become effective) and elect Ms. McLean, Ms. Boss, Mr. Bryan and Mr. Diercksen to fill four of the resulting vacancies (as well as to amend the Company’s Sixth Amended and Restated By-Laws proposed in connection therewith). We have filed the Solicitation Statement and a WHITE consent card with the Securities and Exchange Commission (the “SEC”) in connection with any such solicitation of proxies from the Company’s shareholders.

SHAREHOLDERS OF THE COMPANY ARE STRONGLY ENCOURAGED TO READ THE SOLICITATION STATEMENT, ACCOMPANYING WHITE CONSENT CARD AND ALL OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY AS THEY CONTAIN IMPORTANT INFORMATION. UPDATED INFORMATION REGARDING THE IDENTITY OF POTENTIAL PARTICIPANTS AND THEIR DIRECT OR INDIRECT INTERESTS, BY SECURITY HOLDINGS OR OTHERWISE, IS SET FORTH IN THE SOLICITATION STATEMENT AND OTHER MATERIALS FILED WITH THE SEC. Shareholders can obtain the Solicitation Statement and any amendments or supplements to the Solicitation Statement filed by the Participants with the SEC at no charge at the SEC’s website at www.sec.gov. Copies will also be available, without charge, on request from the Participants’ proxy solicitor, Harkins Kovler, LLC at +1 (800) 257-3995 or via email at SaveTESSCO@HarkinsKovler.com.

Certain Information Regarding the Participants

Mr. Barnhill is the founder, former Chairman of the Board and the largest shareholder of the Company.

Mr. Barnhill beneficially owns 1,620,387 shares of the Common Stock (approximately 18.5% of the outstanding shares), which includes 11,503.5 shares that Mr. Barnhill owns directly and the shares owned by the following Participants: UA 6-9-2016 Robert B. Barnhill, Jr. Rev Trust owns 1,265,882 shares of Common Stock, RBB-TRB, LLC owns 109,125 shares of Common Stock, RBB-CRB, LLC owns 109,125 shares of Common Stock, Robert B Barnhill Jr & Janet W Barnhill Tr FBO Durkin Slattery Barnhill Trust, owns 30,750 shares of Common Stock, Janet W Barnhill Tr UA 6 9 2016 Janet W Barnhill Rev Trust owns 67,500 shares of Common Stock, and the Winston Foundation, Incorporated owns 26,500 shares of Common Stock. Mr. Barnhill is the sole manager of RBB-TRB and RBB-CRB, a trustee of the UA 6-9-2016 Robert B. Barnhill, Jr. Rev Trust and the Robert B Barnhill Jr & Janet W Barnhill Tr FBO Durkin Slattery Barnhill Trust and a director of the Winston Foundation, Incorporated. Mr. Barnhill’s spouse is a trustee of the Janet W Barnhill Tr UA 6 9 2016 Janet W Barnhill Rev Trust. The percentage of Mr. Barnhill’s stock ownership is based on the 8,760,562 shares of Common Stock outstanding as of October 13, 2020, as reported in the Company’s Consent Revocation Statement on Schedule 14A, filed with the SEC on October 15, 2020. Christopher Barnhill may be considered a Participant in the solicitation but is no longer providing any assistance with respect to the solicitation and does not currently beneficially, directly or indirectly own any securities of the Company.

None of the Participants (other than Mr. Barnhill) currently beneficially, directly or indirectly own any securities of the Company.