U.S. Special Land Stations: 1913-1921 Recap

Thomas H. White -- October 7, 2000

Effective December 13, 1912, U.S. radio stations were generally required to have government-issued licences in order to operate, and were also assigned unique callsigns, under the provisions of the Act to Regulate Radio Communication. Within the new licencing scheme, Special Land stations was an umbrella term comprising three separate licence categories -- Experimental, Technical and Training School, and Special Amateur. (The requirements for the three classifications are spelled out in the 1914 edition of Radio Communication Laws of the United States. A general overview of these stations appears in U.S. Special Land Stations: Overview.) When the first official list of licenced stations appeared on July 1, 1913, it included 22 Special Land station entries, consisting of 12 Experimental, 7 Technical and Training, and 3 Special Amateur stations.

The first letter in a Special Land station's callsign identified its licence class -- X for Experimental, Y was Technical and Training School, and Z meant Special Amateur. (A-W initial letters were assigned to regular amateur stations, which were in a completely separate licence category.) In addition, the leading number in a station's callsign designated the Radio Inspection District in which it was located. Thus, 1XE was a 1st district Experimental station (AMRAD, Medford, Massachusetts), 3YG was a 3rd district Technical and Training School station (Philadelphia School of Wireless Telegraphy), and 5ZA was a 5th district Special Amateur station (Louis Falconi in Roswell, New Mexico). If a station's licence category changed it also got a new callsign, for example, the switch from 9YN to 9XN for the University of North Dakota indicated that the licence had changed from Technical and Training School to Experimental. Also, as stations were deleted, their old callsigns were often reassigned to new stations. During World War One, all the outstanding licences expired, so all the stations had to get new ones when licencing was restored after the war. Most relicenced stations were given the same call which they had had before the war.

The Commerce Department issued an annual station list, Radio Stations of the United States, from 1913 through 1916. Publication was suspended during World War One, then restarted beginning in 1919. Quarterly supplements to the annual lists were issued through the end of 1914, then, beginning on January 1, 1915, the quarterly supplements were replaced by updates included in the Commerce Department's newly launched Radio Service Bulletin, which was issued monthly. (The Radio Service Bulletin also suspended publication during the war, following the March, 1917 issue. It restarted in August, 1919.)

The list below is a recap of basic information published about Special Land station additions, deletions, and major changes, as reported by the annual Radio Stations of the United States and supplements, plus the Radio Service Bulletin, for the period from July 1, 1913 though the end of 1921.

NOTE: Online scanned copies of Radio Service Bulletins 1 through 183 (January, 1915 through June, 1932) are available at the Federal Communication Commission's Radio Service Bulletins page.
 
LICENCING  BEGINS
7/1/1913 edition of Radio Stations of the United States
                            INITIAL "SPECIAL LAND STATION" LIST
9YI  Ames, IA               Iowa State Coll. of Agri. & Mechanic Arts
1XA  Amesbury, MA           Wireless Specialty Apparatus Co.                DEL 8/1915
8XA  Ann Arbor, MI          University of Michigan
4XG  Atlanta, GA            Georgia School of Technology                    DEL 7/1916
9XB  Beloit, WI             Beloit College
6XR  Berkeley, CA           Frank Rieber
1XB  Boston, MA             Wireless Specialty Apparatus Co.                DEL 12/1915
1XH  Boston, MA             Holtzer-Cabot Electric Co.                      DEL 10/1915
1YH  Cambridge, MA          Harvard University
1XP  Cambridge, MA          George W. Pierce
1XC  Chelsea, MA            Wm. J. Murdock Co.
8YD  Detroit, MI            Wm. J. Meisenheimer                             DEL 8/1915
9YN  Grand Forks, ND        University of North Dakota (later 9XN)
3XR  Hyattsville, MD        J. Harris Rogers
6YL  Los Angeles, CA        High School
2YN  New York, NY           Alfred Goldsmith (College City of NY) (later 2XN)
2ZH  Nutley, NJ             Arthur A. Hebert
3XC  Philadelphia, PA       Frank B. Chambers
3XJ  Philadelphia, PA       Saint Joseph's College
3ZS  Saint Davids, PA       Chas. H. Stewart
9YC  Saint Louis, MO        Christian Brothers College (later 9XC)          DEL 3/1917
3ZH  Washington, DC         H. B. DeGroot

10/1/1913: Supplement No. 1 to the 7/1/1913 Radio Stations of the United States
                            ADDITIONS
6XS  Alameda, CA            Hugh R. Sprado                                  DEL 5/1916
1XW  Watchaug Pond, RI      Ralph C. Watrous                                DEL 1/1917

1/1/1914: Supplement No. 2 to the 7/1/1913 Radio Stations of the United States
                            ADDITIONS
3ZR  Baltimore, MD          Thos. L. Richardson (later Quarantine, Curtis Bay, MD)
4YC  Charleston, SC         The Citadel Military Institute
1XI  Gloucester, MA         John Hays Hammond, Jr.
9XH  Kansas City, MO (port) Harry D. Betz
4XA  Key West, FL           Geo. W. Almour                                  DEL 2/1917
6XL  Los Angeles, CA        Y. M. C. A.
5ZD  Memphis, TN            C. B. De La Hunt
9ZE  Minneapolis, MN        Philip E. Edelman (later 9XF)
1ZO  New Bedford, MA        Lester I. Jenkins                               DEL 2/1916
2XH  New York, NY           Walter G. Hudson                                DEL 9/1916
6XC  Oakland, CA            Lewis Mason Clement                             DEL 9/1916
6XT  Oakland, CA            Howard H. Tremble                               DEL 9/1916
6YE  Oakland, CA            Ellery W. Stone                                 DEL 1/1915
3ZD  Riverdale, MD          Frank A. DeGroot
6YS  San Diego, CA          Southern Electrical Co.                         DEL 11/1916
4XL  Savannah, GA           Claude A. Lewis and Manning White
2XD  Slingerlands, NY       Burr V. Deitz
9XD  Valparaiso, IN         Dodge's Institute of Telegraphy
                            CHANGES
2XN  New York, NY -- Call changed from 2YN (Alfred Goldsmith [College City of NY])

4/1/1914: Supplement No. 3 to the 7/1/1913 Radio Stations of the United States
                            ADDITIONS
6XB  Berkeley, CA           University of California
5XC  Memphis, TN            Christian Brothers College                      DEL 9/1916
1XG  Pittsfield, MA         General Electric Co.
6XA  San Francisco, CA      Howard G. Aylsworth
6XH  San Francisco, CA      William W. Hanscom
3XB  Tacoma Park, MD        Bliss Electrical School

7/1/1914 edition of Radio Stations of the United States
                            ADDITIONS
3ZF  Friendship Heights, MD John V. Purssell
2XM  New York, NY           John H. Morecroft (Columbia University)
2XT  Steamship "Tyler"      D. G. McCaa                                     DEL 9/1916
2XW  Summit, NJ             Frank N. Waterman
                            CHANGES
3ZR  Quarantine, Curtis Bay, MD -- City changed from Baltimore (Thomas L. Richardson)

10/1/1914: Supplement No. 1 to the 7/1/1914 Radio Stations of the United States
NOTE: I have not been able to track down a copy of this supplement. 8ZS is listed below
      because is the only station, included in the 1915 edition of Radio Stations of the
      United States, that was not reported in any issue of the Radio Service Bulletin. 
                            ADDITIONS
8ZS  Wilkes-Barre, PA       John H. Stenger, Jr.

1/1915 Radio Service Bulletin #1 (updates to the 7/1/1914 list)
                            ADDITIONS
5ZI  Montgomery, AL         Wm. H. Amerine (Signal Corps, Ala. Nat. Guard)
6ZB  Pacific Grove, CA      Howard S. Bunting
3ZK  Richmond, VA           Frank S. Splatt (Signal Corps, Va. Nat. Guard)  DEL 11/1916
2XA  Schenectady, NY        E. M. Kinney
                            CHANGES
9XN  Grand Forks, ND -- Call changed from 9YN (University of North Dakota)
6YE  Oakland, CA -- DELETED (Ellery W. Stone)

2/1915 Radio Service Bulletin #2 (updates to the 7/1/1914 list)
                            ADDITIONS
1ZC  Hartford, CT           Harry E. Chapman                                DEL 7/1916
9XK  Kansas City, MO        Robert R. Moore
1ZD  Lexington, MA          Samuel Winthrop Dean
1ZP  Penikese, MA           James A. B. Thomas                              DEL 3/1915
9ZS  Springfield, IL        Illinois Watch Co.
9XV  Saint Louis, MO        Washington University
                            CHANGES
2XD  Slingerlands, NY -- Owner now C. F. & B. V. Deitz (Was Burr V. Deitz)

3/1915 Radio Service Bulletin #3 (updates to the 7/1/1914 list)
                            ADDITIONS
9YG  Agricultural Coll., ND North Dakota Agricultural College
8ZX  Canal Dover, OH        Harry S. Weber
8ZF  Cincinnati, OH         Henry M. Rubel, Jr.
8YO  Columbus, OH           Ohio State University
1ZZ  Farmington, CT         David Lyon Moore                                DEL 9/1916
8ZU  Hamilton, OH           Doron Bros. Electric Co.
1ZM  Hartford, CT           Hiram Percy Maxim
9ZK  Illiopolis, IL         Harry J. E. Knotts (State-Center Record)        DEL 2/1916
2XU  New York, NY           Peter Cooper Hewitt
1ZL  Northampton, MA        Dean A. Lewis (later Dean Lewis & G. C. Sabin)  DEL 3/1917
8ZM  Springfield, OH        Ross McGregor
9YR  Saint Louis, MO        Saint Louis University (later 9XY)
8ZW  Wheeling, WV           John C. Stroebel, Jr.
                            CHANGES
1ZP  Penikese, MA -- DELETED (James A. B. Thomas)
9XC  Saint Louis, MO -- Call changed from 9YC (Christian Brothers College)

4/1915 Radio Service Bulletin #4 (updates to the 7/1/1914 list)
                            ADDITIONS
8YA  Auburn, NY             Edward L. Colby (Colby's Telegraph School)
5ZN  Beeville, TX           Ed. Nettelton
8ZB  Buffalo, NY            Nelson E. Holt
9XL  Burlington, IA         Leslie W. Lyon (later Wm. Peters [Burlington H.S.])
9YA  Iowa City, IA          State University of Iowa
8ZK  Kane, PA               John Fleming
2ZB  Schenectady, NY        Wallace L. Brooks

5/1915 Radio Service Bulletin #5 (updates to the 7/1/1914 list)
                            ADDITIONS
9YF  Fargo, ND              Theo L. Wanner
1ZT  Hartford, CT           Clarence D. Tuska
2XE  Montauk, L. I., NY     Western Electric Co.
8ZN  New Castle, PA         R. L. Patch
2XR  New York, NY           Marconi Co.                                     DEL 9/1916
1XK  Orono, ME              University of Maine
9XR  Rock Island, IL        R. Karlowa & R. Hall (Tri-City Radio Lab.)
2XI  Schenectady, NY        General Electric Co.
8XW  Warren, OH             Goodyear Tire & Rubber Co.                      DEL 9/1916
9YE  Wichita, KS            Walter S. Ezell

6/1915 Radio Service Bulletin #6 (updates to the 7/1/1914 list)
                            ADDITIONS
7XU  Algona, WA             Universal High Power Telephone Co.
5ZQ  Grand Coteau, LA       Saint Charles College
8YC  Ithaca, NY             Cornell University (later 8XU)
9XP  Lawrence, KS           University of Kansas
8YI  Pittsburgh, PA         University of Pittsburgh
1ZP  Providence, RI         Ralph C. Watrous
1ZR  Rockland, ME           Edward L. Norton
7XK  Seattle, WA            Kilbourne & Clark Mfg. Co.
7XM  Seattle, WA            Wireless Instrument Co.                         DEL 9/1916
1ZW  Worcester, MA          Wm. H. Allison

7/1915 Radio Service Bulletin #7 (updates to the 7/1/1914 list)
                            ADDITIONS
2XL  Aldene, NJ             Marconi Co.
9YH  Chicago, IL            Frank S. Jones                                  DEL 5/1916
9ZA  Denver, CO             Co. A, Sig. Corps, Colorado Natl. Guard
9YW  Lake Geneva, WI        Northwestern Military and Naval Academy
9YX  Lake Geneva, WI        Northwestern Military and Naval Academy
9XM  Madison, WI            University of Wisconsin
2XG  New York, NY           Radio Telephone & Telegraph Co.
2YS  New York, NY           William Wilson / Joseph Baier [Stuyvesant H.S. Radio Club]
2ZP  Port Chester, NY       John W. Hubbard
6XD  San Francisco, CA      Dwyer Wireless Telephone & Telegraph Co.        DEL 3/1916
9ZB  Trinidad, CO           Co. A, Sig. Corps, Colorado Natl. Guard

8/1915 Radio Service Bulletin #8 (updates to the 7/1/1914 list)
                            ADDITIONS
8YP  Athens, OH             Ohio University
7XL  Bremerton, WA          T. M. Libby
9XA  Rapid City, SD         Claude C. Van Nuys (S.D. School of Mines)
                            CHANGES
1XA  Amesbury, MA -- DELETED (Wireless Specialty Apparatus Co.)
8YD  Detroit, MI -- DELETED (Wm. J. Meisenheimer)

9/1915 Radio Service Bulletin #9 (updates to the 7/1/1914 list)
                            ADDITIONS
8ZH  Cincinnati, OH         Clayton M. Howe (Hughes High School)
8YL  Lima, OH               J. E. Collins (Board of Education)
5ZM  Mobile, AL             Ben W. Martin

10/1915 Radio Service Bulletin #10 (updates to the 7/1/1915 list)
                            ADDITIONS
5YA  Auburn, AL             Alabama Polytechnic Institute
9XE  Davenport, IA          William H. Kirwan
9ZD  Denver, CO             Edward C. Stockman
9ZL  Louisville, IL         Cecil Bridges
5XM  New Orleans, LA        Marconi Co.
2YM  New York, NY           Y. M. C. A. Telegraph School
8XO  Ridgway, PA            W. P. Osterhout (Pittsburgh Wireless Equip. Co.)
9YB  Rockford, IL           Rockford School of Engineering                  DEL 1/1917
8ZT  Tiffin, OH             John J. Grossman                                DEL 11/1916
3YM  Washington, DC         McKinley Manual Training School
3YN  Washington, DC         James E. Smith (National Radio School)
                            CHANGES
1XH  Boston, MA -- DELETED (Holtzer-Cabot Electric Co.)

11/1915 Radio Service Bulletin #11 (updates to the 7/1/1915 list)
                            ADDITIONS
8ZC  Battle Creek, MI       Bert E. Clough
2YU  Schenectady, NY        Walter L. Upson (Union College)

12/1915 Radio Service Bulletin #12 (updates to the 7/1/1915 list)
                            ADDITIONS
9YL  Lexington, KY          Otto Holstein (Co. A, Sig. Corps, Ky Natl. Guard)
8ZD  Marion, OH             Keith Henney
5ZB  New Braunfels, TX      Arthur E. Mollenhauer
6XF  San Jose, CA           Charles D. Herrold
9YT  Wayne, NE              U. S. Conn, president, State Normal School
                            CHANGES
1XB  Boston, MA -- DELETED (Wireless Specialty Apparatus Co.)

1/1916 Radio Service Bulletin #13 (updates to the 7/1/1915 list)
                            ADDITIONS
1XO  Cambridge, MA          General Radio Co.
6XN  Fruitvale, CA          Natl. Wireless Telep & Teleg Co. (later Natl. Radio Co.)
8ZG  Ironton, OH            Henry W. Campbell
8ZI  Norwalk, OH            Roy C. Burr                                     DEL 5/1916
8ZO  Oberlin, OH            Ross Gunn                                       DEL 5/1916
6ZV  Salt Lake City, UT     Julian G. McCollom
6XO  San Francisco, CA      Natl. Wireless Telep & Teleg Co. (later Natl. Radio Co.)

2/1916 Radio Service Bulletin #14 (updates to the 7/1/1915 list)
                            ADDITIONS
9XQ  Columbia, MO           University of Missouri (Dept. of Physics)       DEL 2/1917
1ZF  Fall River, MA         Harold C. Bowen
9XT  Lincoln, NE            Thomas C. Rice                                  DEL 6/1916
5XO  Little Rock, AR        Ed Cornish
5ZF  San Antonio, TX        Sidney Friedrich
5ZR  San Antonio, TX        John C. Rodriguez
7XZ  Seattle, WA            University of Washington
1YK  Worcester, MA          Worcester Polytechnic Institute
                            CHANGES
9ZK  Illiopolis, IL -- DELETED (Harry J. E. Knotts [State-Center Record])
1ZO  New Bedford, MA -- DELETED (Lester I. Jenkins)

3/1916 Radio Service Bulletin #15 (updates to the 7/1/1915 list)
                            ADDITIONS
5ZC  Dallas, TX             Frank M. Corlett
9YU  Kansas City, MO        Field Co. A., Sig. Corps, Mo. Natl. Guard
7ZH  La Grande, OR          Orland M. Heacock                               DEL 3/1917
2ZE  Leonia, NJ             Paul F. Godley                                  DEL 1/1917
9ZM  Minneapolis, MN        Marc Frazer
2ZI  Montclair, NJ          Alfred P. Morgan (Adams-Morgan Co.)
1ZN  New Bedford, MA        Milton A. Baylies
7YI  Pullman, WA            State College of Washington
8XE  State College, PA      Pennsylvania State College
5YG  Waco, TX               E. T. Genheimer (Waco H. S. Radio Club)
                            CHANGES
1ZL  Northampton, MA -- Owner now Dean A. Lewis & G. C. Sabin (was Dean A. Lewis)
6XD  San Francisco, CA -- DELETED (Dwyer Wireless Telephone & Telegraph Co.)

4/1916 Radio Service Bulletin #16 (updates to the 7/1/1915 list)
                            ADDITIONS
9YS  Columbia, MO           University of Missouri (School of Engineering)
5YM  Fayetteville, AR       University of Arkansas
2ZV  Richmond Hill, NY      Alfred H. Grebe
9YD  University Place, NE   Nebraska Wesleyan University
1ZQ  Westbrook, ME          Wm. H. Rocheleau

5/1916 Radio Service Bulletin #17 (updates to the 7/1/1915 list)
                            ADDITIONS
7ZD  Bozeman, MT            R. Earl Dawes
9YK  Indianapolis, IN       James E. Weyant (Shortridge High School)
7YS  Lacey, WA              Saint Martin's College
5XF  Little Rock, AR        Arthur R. McCreary
3XO  Media, PA              Simon Delbert, Jr.
8YR  Oxford, OH             Miami University
3XP  Philadelphia, PA       Simon Delbert, Jr.
                            CHANGES
6XS  Alameda, CA -- DELETED (Hugh R. Sprado)
9XL  Burlington, IA -- Owner now Wm. Peters (Burlington H.S.)(was Leslie W. Lyon)
9YH  Chicago, IL -- DELETED (Frank S. Jones)
8ZI  Norwalk, OH -- DELETED (Roy C. Burr)
8ZO  Oberlin, OH -- DELETED (Ross Gunn)

6/1916 Radio Service Bulletin #18 (updates to the 7/1/1915 list)
                            ADDITIONS
1XU  Cambridge, MA          Cutting & Washington, Inc.
5ZH  Cleveland, TN          W. O. Horner
9ZF  Denver, CO             Co. A, Sig. Corps, Colorado Natl. Guard
8ZE  Elmira, NY             Harry E. Fitch
8XT  Ithaca, NY             Cornell University
8YW  Oil City, PA           Clarence M. Wickes (Electra Club)               DEL 11/1916
8YZ  Pittsburgh, PA         Charles C. Dunning (Peabody H.S.)
5ZS  Shreveport, LA         Willis E. Antony
1ZS  Springfield, MA        George U. Readio
                            CHANGES
9XT  Lincoln, NE -- DELETED (Thomas C. Rice)
9XY  Saint Louis, MO -- Call changed from 9YR (Saint Louis University)

7/1/1916 Radio Service Bulletin #19 (updates to the 7/1/1915 list)
                            ADDITIONS
6ZW  Bakersfield, CA        Lindley Winser
1ZH  Beverly Farms, MA      Wilbur H. Hardy
9ZI  Eldora, IA             Donald R. Lewis
7ZC  Lewiston, MT           Arthur C. Campbell
1XS  Marlboro, MA           Louis Waldo Stevens
8XG  Morgantown, WV         C. W. Waggoner (West Virginia University)
2ZK  New Rochelle, NY       George C. Cannon
2ZA  New York, NY           New York police department
9ZP  Pierre, SD             Dana McNeil
8XC  Pittsburgh, PA         Carnegie Institute of Technology
7XE  Seattle, WA            Marconi Co.
9YM  Stillwater, MN         Fred Wood, Co. K, 3rd Infantry, Minn. Natl. Guard
7ZN  Vancouver, WA          George H. Wallace
3ZW  Washington, DC         Walther A. Parks
                            CHANGES
4XG  Atlanta, GA -- DELETED (Georgia School of Technology)
1ZC  Hartford, CT -- DELETED (Harry E. Chapman)

8/1/1916 Radio Service Bulletin #20 (updates to the 7/1/1916 list)
                            ADDITIONS
7ZA  Hoquiam, WA            Donald E. McGee
9YH  Jacksonville, IL       Illinois Woman's College
9YO  Lamoni, IA             Graceland College
6XE  Monterey, CA (port)    National Radio Co.
9XU  Omaha, NE              Union Pacific R. R. Co.
8XK  Pittsburgh, PA         Frank Conrad
8ZR  Pottsville, PA         Cotesworth M. Jackson
9ZR  Rapid City, SD         S. R. Halley
6ZI  Salt Lake City, UT     Stephen H. Besley
6XI  San Francisco, CA      Clarence W. Smith

9/1/1916 Radio Service Bulletin #21 (updates to the 7/1/1916 list)
                            ADDITIONS
2YT  New York, NY           Marconi Co.
6XW  San Francisco, CA      Eldridge Buckingham
                            CHANGES
1ZZ  Farmington, CT -- DELETED (David Lyon Moore)
8XU  Ithaca, NY -- Call changed from 8YC (Cornell University)
5XC  Memphis, TN -- DELETED (Christian Brothers College)
2XH  New York, NY -- DELETED (Walter G. Hudson)
2XR  New York, NY -- DELETED (Marconi Co.)
2YS  New York, NY -- Owner Joseph Baier[Stuyvesant H.S. Radio Club](was William Wilson)
6XC  Oakland, CA -- DELETED (Lewis Mason Clement)
6XT  Oakland, CA -- DELETED (Howard H. Tremble)
7XM  Seattle, WA -- DELETED (Wireless Instrument Co.)
2XT  Steamship "Tyler" -- DELETED (D. G. McCaa)
8XW  Warren, OH -- DELETED (Goodyear Tire & Rubber Co.)

10/1/1916 Radio Service Bulletin #22 (updates to the 7/1/1916 list)
                   (No Special Land station changes listed)

11/1/1916 Radio Service Bulletin #23 (updates to the 7/1/1916 list)
                            ADDITIONS
2XK  Albany, NY             New York State College for Teachers
7XB  Bozeman, MT            Montana State College
8YW  Brookville, PA         Clarence M. Wickes
6XG  Clayton, CA            National Radio Co.
6ZF  Fresno, CA             Oliver M. Howard
6XU  Keddie, CA             National Radio Co.
6XK  Las Plumas, CA         National Radio Co.
8ZL  Toledo, OH             Willis K. Wing (Scott High School)
8XX  Williamsport, PA       Earl R. Thomas
                            CHANGES
8YW  Oil City, PA -- DELETED (Clarence M. Wickes [Electra Club])
3ZK  Richmond, VA -- DELETED (Frank S. Splatt [Signal Corps, Va. Nat. Guard])
6YS  San Diego, CA -- DELETED (Southern Electrical Co.)
8ZT  Tiffin, OH -- DELETED (John J. Grossman)


12/1/1916 Radio Service Bulletin #24 (updates to the 7/1/1916 list)
                            ADDITIONS
1ZI  Bar Harbor, ME         Arthur H. Lawford
9YV  Manhattan, KS          Kansas State Agricultural College
3ZO  Philadelphia, PA       Maynard C. Morris                               DEL 3/1917
6YP  San Bernardino, CA     Y. M. C. A.
9ZO  Superior, WI           F. W. Keeler

1/1/1917 Radio Service Bulletin #25 (updates to the 7/1/1916 list)
                            ADDITIONS
8ZJ  Buffalo, NY            Edward C. Wahl
8ZP  Buffalo, NY            W. D. Woodcock
1XW  Charlestown, RI        Ralph C. Watrous
9ZN  Chicago, IL            Ralph H. G. Mathews
5ZD  Fresno, CA             Robert C. Denny
2ZE  Montclair, NJ          Paul F. Godley
3YV  University, VA         University of Virginia
2XP  Winfield, L. I., NY    Louis G. Pacent
                            CHANGES
6XN  Fruitvale, CA -- Owner now Natl. Radio Co. (was Natl. Wireless Telep & Teleg Co.)
2ZE  Leonia, NJ -- DELETED (Paul F. Godley)
9YB  Rockford, IL -- DELETED (Rockford School of Engineering)
6XO  San Francisco, CA -- Owner Natl. Radio Co. (was Natl. Wireless Telep & Teleg Co.)
1XW  Watchaug Pond, RI -- DELETED (Ralph C. Watrous)

2/1/1917 Radio Service Bulletin #26 (updates to the 7/1/1916 list)
                            ADDITIONS
1XE  Medford, MA            American Radio & Research Corp.
9YP  Minneapolis, MN        American Telegraph College
7ZR  Rawson Ranch, ID       Homer E. Rawson (near Kuna, ID)
3XA  Roland Park, MD        Louis D. Coriell
2ZL  Valley Stream, NY      J. Owen Smith
9ZG  Woodstock, IL          Sydnie A. Greenleaf
                            CHANGES
9XQ  Columbia, MO -- DELETED (University of Missouri [Dept. of Physics])
4XA  Key West, FL -- DELETED (Geo. W. Almour)

3/1/1917 Radio Service Bulletin #27 (updates to the 7/1/1916 list)
                            ADDITIONS
6XV  Big Creek, CA          Walter Burnett and Oscar Kipf
9XG  Chicago, IL            Austin A. Howard
9YN  Culver, IN             Culver Military Academy
9YJ  Decatur, IL            James Millikin University
7ZH  Enterprise, OR         Orland M. Heacock
9YQ  Eureka, IL             Eureka College
9YZ  Greeley, CO            State Teachers' College
8YV  Grove City, PA         Grove City College
9ZK  Kansas City, MO        Albert I. Graham
6ZP  Phoenix, AZ            Harry K. Behn, Jr.
6ZS  Red Bluff, CA          Herbert G. Strain
1ZK  Springfield, MA        Glenn C. Sabin
8ZQ  Springfield, OH        Charles K. Brain
                            CHANGES
7ZH  La Grande, OR -- DELETED (Orland M. Heacock)
9XF  Minneapolis, MN -- Call changed from 9ZE (Philip E. Edelman)
1ZL  Northampton, MA -- DELETED (Dean A. Lewis [Dean Lewis & G. C. Sabin])
3ZO  Philadelphia, PA -- DELETED (Maynard C. Morris)
9XC  Saint Louis, MO -- DELETED (Christian Brothers College, originally 9YC)

4/7/1917 entry of United States into World War One
With the entry of the United States into World War One, by executive order all radio stations were either closed or taken over by the government. In addition, all the station licences listed above expired during the war.
 
WORLD  WAR  ONE  INTERREGNUM
End of war restrictions
After the end of the war, all stations had to reapply for new licences if they wanted to return to the air. (Many of the returning stations were issued the same callsigns they held before the war.)
6/15/1919 edition of Radio Stations of the United States
          (First station list after WWI -- no Special Land station licences issued yet)

8/1/1919 Radio Service Bulletin #28 (updates to the 6/15/1919 list)
                            ADDITIONS
5YA  College Station, TX    Agricultural and Mechanical College of Texas
4YA  Atlanta, GA            Georgia School of Technology
9YB  Agric. College, ND     North Dakota Agricultural College (later 9YG)
9YA  Lafayette, IN          Purdue University (later 9YB)
1YA  Kingston, RI           Rhode Island State College                      DEL 11/1920
5YB  Tuscaloosa, AL         University of Alabama
6YA  Los Angeles, CA        University of Southern California
8YA  Morgantown, WV         West Virginia University

9/1/1919 Radio Service Bulletin #29 (updates to the 6/15/1919 list)
                            (No Special Land station changes listed)

10/1/1919 Radio Service Bulletin #30 (updates to the 6/15/1919 list)
                            ADDITIONS
3XD  Baltimore, MD          Johns Hopkins University
2YA  Camp Dix, NJ           Knights of Columbus

11/1/1919 Radio Service Bulletin #31 (updates to the 6/15/1919 list)
                            ADDITIONS
2ZM  Clifton, NJ            Lester Spangenberg
7XB  Bozeman, MT            Montana State College
7XD  Bozeman, MT            R. Earle Dawes
2XF  Cliffwood, NJ          Western Electric Company
2XJ  Elberon, NJ            Western Electric Company (later Deal Beach, NJ)
1XD  Green Harbor, MA       Western Electric Company
7YS  Lacey, WA              Saint Martins College
2XB  New York, NY           Western Electric Co.
2XO  New York, NY           Walter G. Hudson
2YT  New York, NY           Marconi Institute
2XN  New York, NY           College of the City of New York
7XZ  Seattle, WA            University of Washington
7ZB  Vancouver, WA          John B. Hertz

12/1/1919 Radio Service Bulletin #32 (updates to the 6/15/1919 list)
                            ADDITIONS
6XE  Monterey, CA           National Radio Co.
1ZC  New Haven, CT          A. C. Gilbert Co.
6XG  San Francisco, CA      National Radio Co.                              DEL 6/1921
6XK  San Francisco, CA      National Radio Co.
6XO  San Francisco, CA      National Radio Co.                              DEL 8/1920

1/2/1920 Radio Service Bulletin #33 (updates to the 6/15/1919 list)
                            ADDITIONS
5XA  Auburn, AL             Alabama Polytechnic Institute
3ZA  Bala, PA               Charles A. Service, Jr.
3XE  Clinton, MD            W. W. Conners
5ZK  Franklinton, LA        Paul Ellis Greenlaw
5YB  Jackson, TN            Young Men's Christian Association
5ZL  Little Rock, AR        John M. Clayton
2XS  Montclair, NJ          Adams Morgan Co.
1XF  Providence, RI         Electrical Products Manufacturing Co.           DEL 12/1921
2XR  Roselle Park, NJ       Marconi Wireless Telegraph Co. of America
5ZA  Roswell, NM            Louis Falconi
6ZA  Salt Lake City, UT     Ira Johnston Kaar
6XJ  San Francisco, CA      Otis B. Moorhead
6XP  San Francisco, CA      Moorhead Laboratories, Inc.
2XQ  Schenectady, NY        Union College
5ZJ  Waco, TX               Henry M. Harris                                 DEL 6/1920

2/2/1920 Radio Service Bulletin #34 (updates to the 6/15/1919 list)
                            ADDITIONS
5YD  Agric. College, MS     Mississippi Agricultural & Mechanical College
5ZU  Austin, TX             Wesley Hope Tilley
9ZC  Baudette, MN           John A. Gjelhaug
9YS  Bloomington, IL        Illinois Wesleyan University
7YA  Boise, ID              Independent School District of Boise City
1XJ  Cambridge, MA          Harvard University
8ZV  Canton, OH             Henry L. Ley
8XB  Cincinnati, OH         Precision Equipment Co.
8XF  Cleveland, OH          Emil J. Simon                                   DEL 4/1920
8ZY  Defiance, OH           K. A. Duerk
8XD  Detroit, MI            Emil J. Simon                                   DEL 4/1920
7ZE  Elk, WY                Harold P. Sheard
2XV  Glenridge, NJ          Western Electric Co.
5ZO  Houston, TX            Clifford W. Vick
5ZT  Houston, TX            Ingham S. Roberts III
9ZJ  Indianapolis, IN       Francis F. Hamilton
9YY  Lincoln, NE            University of Nebraska
6XY  Los Altos, CA          National Radio Co.                              DEL 8/1920
6XQ  Los Angeles, CA        Southern California Edison Co.
9ZL  Manitowoc, WI          H. J. Burhop and W. C. Bridges (later just Burhop)
8YB  Manlius, NY            Saint John's School                             DEL 11/1921
9ZT  Minneapolis, MN        Minnesota Wireless Association
5YC  New Orleans, LA        Nola Radio School
5ZP  New Orleans, LA        Herbert E. De Ben
2YB  New York, NY           B. B. Brownlee
6XX  Oakland, CA            Saint Mary's College                            DEL 9/1921
9ZQ  Oelwein, IA            George Raymond Hammond                          DEL 6/1921
2XX  Ossining, NY           De Forest Radio Telephone & Telegraph Co.
6XV  Palo Alto, CA          Federal Telegraph Co.
2XY  Schenectady, NY        Wallace L. Brooks
2ZC  South Orange, NJ       Henry L. Leeb
5YE  University, MS         University of Mississippi
9YD  University Place, NE   Nebraska Wesleyan University
3XF  Washington, DC         Francis Meyer Baer

3/1/1920 Radio Service Bulletin #35 (updates to the 6/15/1919 list)
                            ADDITIONS
6XR  Auberry, CA            San Joaquin Light & Power Corporation           DEL 12/1920
6ZC  Cochise, AZ            Dr. J. B. Ellis
9YN  Lawrence, KS           University of Kansas                            DEL 7/1921
9YB  Lexington, KY          University of Kentucky (later 9YC)
6XC  Oakland, CA            National Radio Co.                              DEL 8/1920
6ZE  San Francisco, CA      D. B McGown
9ZU  Sioux City, IA         Sioux City Radio Laboratory
9ZV  Saint Louis, MO        James Albert Crowdus
                            CHANGES
9YG  Agric. College, ND -- Call changed from 9YB (North Dakota Agricultural College)
9YB  Lafayette, IN -- Call changed from 9YA (Purdue University)

4/1/1920 Radio Service Bulletin #36 (updates to the 6/15/1919 list)
                            ADDITIONS
3XG  Baltimore, MD          Edward O. Hurlburt
8ZM  Buffalo, NY            Cyrus H. Fraser                                 DEL 11/1921
5YF  College Station, TX    Agricultural & Mechanical College of Texas
8XI  Columbus, OH           Ohio State University                           DEL 11/1921
7YB  Eugene, OR             University of Oregon
1YB  Hanover, NH            Dartmouth College
5ZW  House, TX              Donald Harper Graham
5ZV  Houston, TX            Hallet E. Worthington
5ZX  Houston, TX            James L. Autry, Jr.                             DEL 12/1920
6XD  Los Angeles, CA        Western Radio Electric Co.
9XI  Minneapolis, MN        University of Minnesota
5ZY  Mulga, AL              Thos. D. Sewell
9YR  Muncie, IN             Muncie Technical High School
2XZ  New York, NY           Fordham University
3YC  Philadelphia, PA       North East High School
8XH  Pittsburgh, PA         Parker Elliot Wiggin                            DEL 10/1921
8ZK  Rochester, NY          Alexander Miller Lindsay, Jr.
6XZ  San Diego, CA          R. O. Shelton, M.D.
3YB  Savannah, GA           Knights of Columbus (later 4YB)
7YC  Seattle, WA            Young Men's Christian Association
7YD  Seattle, WA            Knights of Columbus
8ZI  Toledo, Ohio           Adelbert Jacob Gogel                            DEL 11/1921
9ZX  Valley City, ND        Russell H. Pray                                 DEL 5/1921
3YA  Washington, DC         Loomis Radio School
3ZB  Washington, DC         A. B. Brown (Bliss Electrical School)
2XH  Woodmere, NY           Cutting & Washington Radio Corporation
                            CHANGES
8XF  Cleveland, OH -- DELETED (Emil J. Simon)
8XD  Detroit, MI -- DELETED (Emil J. Simon)

5/1/1920 Radio Service Bulletin #37 (updates to the 6/15/1919 list)
NOTE: For some reason, this list included numerous stations already listed as additions
      in earlier editions of the Radio Service Bulletin.
                            ADDITIONS
8XA  Ann Arbor, MI          University of Michigan                          DEL 11/1921
8YA  Auburn, NY             Colby's Telegraph School
3XD  Baltimore, MD          Johns Hopkins University
8ZC  Battle Creek, MI       Bert E. Clough                                  DEL 11/1921
5ZZ  Blackwell, OK          Harold Schonwald
1YC  Boston, MA             Eastern Radio Institute
7XB  Bozeman, MT            Montana State College
7ZD  Bozeman, MT            R. Earl Dawes
1XJ  Cambridge, MA          Harvard University
2YA  Camp Dix, NJ           Knights of Columbus
9ZN  Chicago, IL            Ralph H. G. Mathews
2XF  Cliffwood, NJ          Western Electric Co.
2ZM  Clifton, NJ            Lester Spangenburg
5XB  College Station, TX    Agricultural & Mechanical College of Texas
9ZD  Denver, CO             Edward C. Stockman
8ZX  Dover, OH              Harry S. Weber
5ZN  Eagle Pass, TX         Ed Nettleton
2XJ  Elberon, NJ            Western Electric Co. (later Deal Beach, NJ)
7ZE  Elk, WY                Harold Prescott Sheerd
1XD  Green Harbor, MA       Western Electric Co.
9ZH  Independence, MO       Reorganized Church of Christ of Latter Day Saints
8XU  Ithaca, NY             Cornell University
1YA  Kingston, RI           Rhode Island State College
7YS  Lacey, WA              Saint Martin's College
5YH  Little Rock, AR        United States Signal Corps.
1XL  Lynn, MA               General Electric Co.
9XM  Madison, WI            University of Wisconsin
9YV  Manhattan, KS          Kansas State Agricultural College
9ZL  Manitowoc, WI          W. C. Bridges and H. J. Burhop
1ZC  New Haven, CT          A. C. Gilbert Co.
2ZK  New Rochelle, NY       George C. Cannon
2YT  New York, NY           Marconi Institute
2XB  New York, NY           Western Electric Co.
2XG  New York, NY           De Forest Radio Telephone & Telegraph Co.
2XO  New York, NY           Walter G. Hudson
3ZC  Norfolk, VA            City of Norfolk, Department of Public Safety    DEL 8/1921
2ZH  Nutley, NJ             Arthur A. Hebert
8XK  Pittsburgh, PA         Frank Conrad
8YZ  Pittsburgh, PA         Peabody High School (Charles C. Dunning)
2ZL  Rockville Center, NY   J. Owen Smith (later Valley Stream, NY)         DEL 2/1921
4XB  Savannah, GA           Board of Public Education
2XA  Schenectady, NY        E. M. Kinney
7XZ  Seattle, WA            University of Washington
5ZS  Shreveport, LA         William E. Antony
9ZS  Springfield, IL        Illinois Watch Co.
1ZK  Springfield, MA        Glenn C. Sabin                                  DEL 11/1920
5XD  State College, NM      New Mexico College
8XE  State College, PA      Pennsylvania State College                      DEL 11/1921
9XD  Valparaiso, IN         Dodge's Institute of Telegraphy
7ZB  Vancouver, WA          John D. Hertz
3XH  Washington, DC         Lester Stewart Barr
9YT  Wayne, NE              State Normal School
8ZW  Wheeling, WV           John C. Stroebel, Jr.
8ZS  Wilkes-Barre, PA       John H. Stenger, Jr.
                            CHANGES
9YC  Lexington, KY -- Call changed from 9YB (University of Kentucky)

6/1/1920 Radio Service Bulletin #38 (updates to the 6/15/1919 list)
                            CHANGES
5ZJ  Waco, TX -- DELETED (Henry M. Harris)

7/1/1920 Radio Service Bulletin #39 (updates to the 6/15/1919 list)
                            ADDITIONS
7ZG  Bear Creek, MT         Winfred E. Slauson
2XT  Brooklyn, NY           Lowenstein Radio Co.
7YF  Burley, ID             Burley High School
5XE  Burrwood, LA           Tropical Radio Telegraph Co.
1XM  Cambridge, MA          Massachusetts Institute of Technology
8ZJ  Cincinnati, OH         Hughes High School                              DEL 11/1921
8XD  Dearborn, MI           Henry Ford                                      DEL 9/1920
8ZN  Detroit, MI            George W. Carter
6XU  Fresno, CA             San Joaquin Light & Power Corporation           DEL 12/1920
5YI  Houston, TX            Rice Institute
9ZZ  Kansas City, MO        Walter M. Aronson and Albert R. Perkins         DEL 9/1921
9ZY  La Crosse, WI          Ben A. Ott
8XJ  Lewisburg, PA          Bucknell University                             DEL 11/1921
6ZG  Los Angeles, CA        Forbes W. Van Why
5ZJ  Mesilla Park, NM       R. W. Goddard
1XN  Middletown, CT         Walter G. Cady (later Wesleyan University)
3YD  Norfolk, VA            Norfolk Radio School                            DEL 7/1921
8XL  Northville, MI         Henry Ford                                      DEL 9/1920
9YP  Omaha, NE              High School of Commerce
3XI  Philadelphia, PA       Lester H. Damon
8ZO  Pittsburgh, PA         Frank Moore, Jr.                                DEL 11/1921
7YG  Portland, OR           Young Men's Christian Association
7ZI  Portland, OR           Charles L. Austin
6XT  San Francisco, CA      Baruch Research Laboratories
6XS  San Gabriel, CA        R. B. Ashbrook
7XK  Seattle, WA            Kilbourne & Clark Manufacturing Co.
7YE  Seattle, WA            City of Seattle School District (Broadway High Schoool)
3YE  Staunton, VA           Staunton Military Academy
9XJ  Urbana, IL             University of Illinois

8/2/1920 Radio Service Bulletin #40 (updates to the 6/30/1920 list)
                            ADDITIONS
9YE  Chicago, IL            Tilden Technical High School
9YH  Evanston, IL           Evanston High School
                            CHANGES
4YB  Savannah, GA -- Call changed from 3YB (Knights of Columbus)
6XY  Los Altos, CA -- DELETED (National Radio Co.)
6XC  Oakland, CA -- DELETED (National Radio Co.)
6XO  San Francisco, CA -- DELETED (National Radio Co.)

9/1/1920 Radio Service Bulletin #41 (updates to the 6/30/1920 list)
                            ADDITIONS
1XR  Belfast, ME            International Radio Telegraph Co.
lYS  Boston, MA             Massachusetts Radio and Training School
9YL  Chicago, IL            Armour Institute of Technology
8XC  Cleveland, OH          Glenn L. Martin Co.                             DEL 4/1921
9YQ  Culver, IN             Culver Military Academy
8YE  Detroit, MI            Case Technical High School                      DEL 11/1921
5YJ  New Orleans, LA        Knights of Columbus
3YF  Philadelphia, PA       Pennsylvania-Marconi Wireless School
1XQ  Rockland, ME           International Radio Telegraph Co.               DEL 9/1921
9YK  Saint Louis, MO        Saint Louis University
2XO  Yonkers, NY            Walter G. Hudson
                            CHANGES
8XD  Dearborn, MI -- DELETED (Henry Ford)
8XL  Northville, MI -- DELETED (Henry Ford)

10/1/1920 Radio Service Bulletin #42 (updates to the 6/30/1920 list)
                            ADDITIONS
5ZD  Alexandria, LA         Frank B. Beuhler
4XC  Atlanta, GA            B. W. Benning
3ZF  Bethesda, MD           John V. Purssell
8ZH  Cincinnati, OH         East High School                                DEL 11/1921
8XD  Dearborn, MI           Henry Ford
8XR  Detroit, MI            Detroit Edison Co.                              DEL 4/1921
8ZQ  Dunmore, PA            Roy C. Ehrhardt
3ZI  Hagerstown, MD         Roy C. Corderman
1XV  Hartford, CT           C. D. Tuska Co.                                 DEL 9/1921
5ZC  Houston, TX            B. J. Still (later 5ZE)
8ZF  Lansing, MI            Maurice H. Pancost
6XN  Los Angeles, CA        A. H. McClelland, J. B. Farrington, and A. A. Kluge
8ZE  Marietta, OH           Norman A. Thomas and Edward Manley              DEL 11/1921
8ZT  Marietta, OH           George M. Withington, Jr.
4XD  Mecklenburg, NC        F. M. Laxton
5YK  New Braunfels, TX      Edgar A. Sahm
8ZA  New Philadelphia, OH   Charles J. Murray
2XD  New York, NY           Ware Radio Co. (later Hoboken, NJ)
8XL  Northville, MI         Henry Ford
3XJ  Philadelphia, PA       Saint Joseph's College
3YG  Philadelphia, PA       Philadelphia School of Wireless Telegraphy
3ZG  Philadelphia, PA       Allyn E. Seuffert
3ZJ  Philadelphia, PA       Maj. J. H. Clinton
5ZB  Pilot Point, TX        Clyde S. Mosteller
8XN  Pittsburgh, PA         Carnegie Institute of Technology Radio Club     DEL 11/1921
8ZD  Pittsburgh, PA         Burton P. Williams (later Parker Elliot Wiggin)
2ZE  Port Chester, NY       Paul F. Godley
8XP  Port Huron, MI         Detroit Edison Co.                              DEL 4/1921
7XA  Portland, OR           Radio Corp. of America
1XX  Providence, RI         Brown University (Physics Department)
6ZJ  Redlands, CA           Arthur L. Munzig
6ZH  Richfield, UT          Wesley C. Thompson
2XE  Richmond Hill, NY      A. H. Grebe & Co.
2ZV  Richmond Hill, NY      A. H. Grebe & Co.
8ZG  Salem, Ohio            A. J. Manning
6ZB  San Diego, CA          Dr. Alfred E. Banks
6XC  San Francisco, CA      Lee de Forest, Inc. (later Pacific Radio Supplies Co.)
6XE  San Jose, CA (portable)Charles D. Herrold
7XC  Seattle, WA            Vincent I. Kraft
1XT  South Manchester, CT   John L. Reinartz
6ZK  Sunnyvale, CA          Arthur E. Bessey
8XQ  Superior, MI           Detroit Edison Co.                              DEL 4/1921
8ZB  Toledo, OH             Earl S. Ensign and Willlam P. Van Behren
7ZG  Vancouver, WA          Royal Mumford
5ZF  Waco, TX               Henry M. Harris
3XL  Washington, DC         ALfred Crossley
3ZE  Washington, DC         Harold A. Snow
2ZD  Woodside, NY           Ship Owners' Radio Service
6ZL  Yuma, AZ               Alexander N. Marquis
                            CHANGES
1XN  Middletown, CT -- Change owner to Wesleyan University (was Walter G. Cady)

11/1/1920 Radio Service Bulletin #43 (updates to the 6/30/1920 list)
                            ADDITIONS
8YF  Alderson, WV           Camp Greenbrier
4YA  Atlanta, GA            Georgia School of Technology
8ZP  Cleveland, OH          Edward I. Deighan
1XY  Hampton, NH            DeLancey Felch & Co.
1XH  New Haven, CT          Yale University
2XN* New York, NY           College of the City of New York
3XC* Philadelphia, PA       Frank B. Chambers
8XO  Ridgway, PA            Pittsburgh Wireless Equipment Co.               DEL 11/1921
3ZS* Saint Davids, PA       Charles H. Stewart
3YV  University, VA         University of Virginia
* Omitted from List of Commercial and Government Stations, edition June 30, 1920.
                            CHANGES
1YA  Kingston, RI -- DELETED (Rhode Island State College)
1ZK  Springfield, MA -- DELETED (Glenn C. Sabin)


12/1/1920 Radio Service Bulletin #44 (updates to the 6/30/1920 list)
                            ADDITIONS
3YH  Baltimore, MD          Young Men's Christian Association Radio School
8YJ  Detroit, MI            George W. Carter
9ZB  Dubuque, IA            Clifford W. Patch
8YG  East Lansing, MI       Michigan Agricultural College
8ZZ  Highland Park, MI      Clyde E. Darr
8XS  Lansing, MI            Wilcox Laboratories
8ZR  Mansfield, MI          Radio Club of Mansfield
8YH  Morgantown, WV         West Virginia University
8YR  Oxford, OH             Miami University
6ZM  Salt Lake City, UT     The Deseret News
2XI  Schenectady, NY        General Electric Co.
8ZL  Saint Marys, OH        Charles Candler
7ZK  Vancouver, WA          Vernon J. Bird
9YB  West Lafayette, IN     Purdue University
                            CHANGES
6XR  Auberry, CA -- DELETED (San Joaquin Light & Power Corporation)
2XJ  Deal Beach, NJ -- City changed from Elberon, NJ (Western Electric Co.)
6XU  Fresno, CA -- DELETED (San Joaquin Light & Power Corporation)
5ZX  Houston, TX -- DELETED (James L. Autry, Jr.)

1/3/1921 Radio Service Bulletin #45 (updates to the 6/30/1920 list)
                            ADDITIONS
9YI  Ames, IA               Iowa State College
7XB  Bozeman, MT            Montana State College
9YM  Columbia, MO           University of Missouri
5ZC  Dallas, TX             Frank M. Corlett
5ZG  Dallas, TX             Bennett Emerson                                 DEL 9/1921
8YK  Delaware, OH           Ohio Wesleyan University
4ZA  Greensboro, NC         James R. Wikle
5ZX  Houston, TX            Alfred P. Daniel
3ZM  Media, PA              Simon Deibert, Jr.
2XK  New York, NY           L. M. Cockaday & Co. (later Superadio Corporation)
2XP  New York, NY           Radio Corporation of America
2XU  New York, NY           Samuel E. Adair
3YI  Philadelphia, PA       Knights of Columbus School
7XD  Polytechnic, MT        Billings Polytechnic Institute
9YW  Rapid City, SD         South Dakota State School of Mines
3ZL  Richmond, VA           Clay D. Blair
6ZN  San Fernando, CA       B. H. Dennis and C. A. Taylor
5ZH  Sanford, FL            Clarence M. Wickes
6XO  San Francisco, CA      National Radio Co.                              DEL 5/1921
9XS  Saint Louis, MO        Manhattan Electrical Supply Co.
9ZB  Saint Louis, MO        Lester A. Benson
7ZL  Tacoma, WA             Anton R. Tingstad
2ZL  Valley Stream, NY      J. Owen Smith

2/1/1921 Radio Service Bulletin #46 (updates to the 6/30/1920 list)
                            ADDITIONS
4YJ  Atlanta, GA            Knights of Columbus School
9XX  Belleville, IL         Chas. B. Harrison
6ZR  Burlingame, CA         Hall Berringer (later Los Angeles, CA)
9XT  Collegeville, MN       Saint Johns University
9XW  Gatesburg, IL          Lombard College
1XE  Medford, MA            American Radio and Research Corp.
3ZO  Parkesburg, PA         Horace A. Beale, Jr.
3XM  Princeton, NJ          David Richardson
6ZO  Reno, NV               Hadley S. Beddle
9XZ  Urbana, IL             Paul G. Busey
                            CHANGES
2ZL  Rockville Center, NY -- DELETED  (J. Owen Smith -- now Valley Stream, NY)

3/1/1921 Radio Service Bulletin #47 (updates to the 6/30/1920 list)
                   (No Special Land station changes listed)

4/1/1921 Radio Service Bulletin #48 (updates to the 6/30/1920 list)
                            ADDITIONS
9ZAC Anthony, KS            Perry E. Thurman
8ZN  Ashland, OH            J. W. Kauffman
4ZB  Atlanta, GA            Georgia Railway & Power Co.
6XAD Avalon, CA             Lawrence Mott
5ZAC Baton Rouge, LA        Wilmer L. Barrow
8YN  Battle Creek, MI       Battle Creek High School
6XK  Berkeley, CA           Bernard F. McNamee
6XM  Berkeley, CA           University of California
3XN  Blacksburg, VA         Virginia Polytechnic Institute
8YQ  Buffalo, NY            Independent Wireless Telegraph Co.
8XY  Cincinnati, OH         Cino Radio Mfg. Co.                             DEL 11/1921
8YS  Cincinnati, OH         University of Cincinnati
9ZAA Clarinda, IA           Farmers Mutual Telephone Co.
5XG  Dallas, TX             Frank M. Corlett
9XE  Davenport, IA          William H. Kirwan
6ZZ  Douglas, AZ            Harry L. Gooding
5XJ  Dublin, TX             Guy W. Neel
5ZAD El Paso, TX            A. Le Roy Hill
9YAA Emporia, KS            College of Emporia
4ZN  Fort Pierce, FL        Otis Atlee Gulledge
6ZU  Fresno, CA             Lloyd E. Martin
4ZC  Gainesville, FL        University of Florida
8YM  Granville, OH          Richard H. Howe
5ZAB Houma, LA              Francis L. Pullen
5ZAA Houston, TX            Francis M. Austin
9ZAD Independence, MO       George S. Turner
2XAD Jersey City, NJ        Ship Owners Radio Service
5ZW  Juliff, TX             Donald Harper Graham
9XAB Kansas City, MO        McCreary Radio Supply Co.
9ZAB Kearney, NE            S. L. Keller
5XK  Knoxville, TN          Philip Stout
2XW  Lancaster (tugboat)    Pennsylvania R. R. Co.
9YAE Le Mars, IA            Western Union College
3YK  Lexington, VA          Virginia Military Institute
6XAC Los Altos, CA          Colin B. Kennedy Co.
9YAD Milwaukee, WI          School of Engineering of Milwaukee
7ZM  Moscow, ID             Jack Woodworth
5XH  New Orleans, LA        Tropical Radio Telegraph Co.
2XAF New York, NY           International Radio Telegraph Co.
2XAG New York, NY           Ware Radio Co.                                  DEL 10/1921
2XC  New York, NY           Ware Radio Co.
2YM  New York, NY           East Side Y. M. C. A.
9XAA Omaha, NE              Cramer and Swain
9XAD Ottumwa, IA            William W. Harper
9YAF Pembina, ND            Pembina High School
3ZQ  Philadelphia PA        Stanley C. Bryce
8YI  Pittsburgh, PA         University of Pittsburgh
7ZB  Portland, OR           John D. Hertz                                   DEL 6/1921
2XAA Port Richmond, NY      Radio Corporation of America
9XAC Rock Island, IL        Karlena Radio Corporation
3ZP  Richmond, VA           Ralph R. Chappell
6ZT  Salt Lake City, UT     Art Johnson
6XAA San Francisco, CA      Pacific Telephone & Telegraph Co.
6XAB San Francisco, CA      Colin B. Kennedy Co.
6XF  San Jose, CA           Chas. D. Herrold
6ZY  Santa Barbara, CA      Frederick C. Roebuck                            DEL 7/1921
2XAB Sisco No. 4 (tugboat)  Radio Corporation of America
5XI  South San Antonio, TX  George H. Burgess
9YAB Saint Louis, MO        Washington University
9YAC Superior, WI           State Normal School
6ZX  Walnut Grove, CA       J. V. Wise
3XQ  Washington, DC         Robert H. Worrall
3ZW  Washington, DC         Walther A. Parks
3ZT  Whitford, PA           George Thomas
9XAE Wichita, KS            Cosradio Co.
2XP  Winfield, NY           Louis G. Pacent
2XAC Woodside, NY           Ship Owners Radio Service
1XZ  Worcester, MA          Clark University
                            CHANGES
8XC  Cleveland, OH -- DELETED (Glenn L. Martin Co.)
5ZC  Dallas, TX -- Call changed from 5ZE (Frank M. Corlett)
8XR  Detroit, MI -- DELETED (Detroit Edison Co.)
5ZE  Houston, TX -- Call changed from 5ZC (B. J. Still)
9ZL  Manitowoc, WI -- Owner change to H. J. Burhop (was H. J. Burhop and W. C. Bridges)
8XP  Port Huron, MI -- DELETED (Detroit Edison Co.)
8XQ  Superior, MI -- DELETED (Detroit Edison Co.)

5/2/1921 Radio Service Bulletin #49 (updates to the 6/30/1920 list)
                            ADDITIONS
8YT  Alliance, OH           Mount Union College
5ZAG Austin, TX             George E. Endress
3ZU  Baltimore, MD          Southern Wireless Institute
5ZAH Biloxi, MS             Hubert S. Ogden
9YAG Bloomington, IN        Indiana University
7ZO  Casper, WY             Norman R. Hood
8YX  Cincinnati, OH         University of Cincinnati
8XV  Cleveland, OH          Frederick S. McCullough (later Pittsburgh, PA)
7YJ  Corvallis, OR          Oregon Agricultural College
8YU  Dayton, OH             Young Men's Christian Association
9XAG Denver, CO             Harry H. Buckwalter
3YO  Easton, PA             Lafayette College
9ZX  Ellendale, ND          H. J. Goddard and F. S. Leavenworth
3ZV  Norristown, PA         Samuel W. Place
6XAF Oakland, CA            Pacific Telephone & Telegraph Co. (later Piedmont, CA)
9XAF Peoria, IL             Bradley Institute
7YH  Portland, OR           Washington High School
5ZAE San Antonio, TX        Leavell D. Wall
6XAE San Francisco, CA      The Radio Telephone Shop
6ZAA San Jose, CA           E. Garratt Arnold
7XJ  Seattle WA             Charles W. Peterson
8ZAA Springfield, OH        J. Warren Wright
5YL  Thibodaux, LA          Thibodaux High School
3YP  Villanova, PA          Villanova College
5ZAF Waco, TX               William P. Clarke
3YL  Washington, DC         Knights of Columbus Service School
                            CHANGES
6XO  San Francisco, CA -- DELETED (National Radio Co.)
9ZX  Valley City, ND -- DELETED (Russell H. Pray)

6/1/1921 Radio Service Bulletin #50 (updates to the 6/30/1920 list)
                            ADDITIONS
4ZD  Asheville, NC          Piedmont Electric Co.
9XAJ Bedford, IA            Bedford Light, Heat & Power Co.
4XE  Buena Vista, GA        William B. Short
3YQ  Camden, NJ             Federal Institute of Radio Telegraphy
4XD  Charlotte NC           F. M. Laxton
9XG  Chicago, IL            Austin A. Howard
9XAH Evansville, IN         Ideal Apparatus Co.
9XAI Golden, CO             Colorado School of Mines
8XZ  Forest Hills, PA       Harry M. Ryder
9YAH Gunnison, CO           Colorado State Normal School
9YAI Lexington, KY          Transylvania University
6ZAC Lihue, HI              Clifford J. Dow
6YA  Los Angeles, CA        Young Men's Christian Association
1ZE  Marion, MA             Irving Vermilya
5XL  Memphis, TN            William B. Stieg
2XNA New York, NY           City College Radio Club
2XNB New York, NY           Townsend Harris Hall Radio Club
1XAA Noroton Heights, CT    Percival E. Fansler
9YAJ Northfield, MN         Saint Olaf College
3XS  Philadelphia, PA       George W. Carns
7XF  Portland, OR           Northwestern Radio Manufacturing Co.
7YK  Portland, OR           Benson Polytechnic School
7ZB  Portland, OR           William A. Leidigh, Jr.
3XU  Princeton, NJ          Walter V. Roberts
9ZAE Richmond, IN           Palladium Printing Co.
6XG  San Francisco, CA      Leo J. Meyberg Co.
6ZAB San Francisco, CA      S. Peterson and Hal Shaw
                            CHANGES
9ZQ  Oelwein, IA -- DELETED (George Raymond Hammond)
7ZB  Portland, OR -- DELETED (John D. Hertz)
6XG  San Francisco, CA -- DELETED (National Radio Co.)

7/1/1921 Radio Service Bulletin #51 (updates to the 6/30/1920 list)
                            ADDITIONS
1XAB Cambridge, MA          Clapp-Eastham Co.
3ZX  Lexington, VA          Harry M. Quisenberry
6ZAD Napa, CA               J. J. Mahler, Jr.
6ZAE Oakland, CA            Chris F. Eiferle
7ZP  Olympia, WA            Edwin W. Wilson
3XV  Philadelphia, PA       Thomas Appleby
8XM  Pittsburgh, PA         Phillips Thomas
5XP  San Antonio, TX        E. M. Baker
5ZAI San Antonio, TX        R. C. Walker (later 5ZAK)
5ZR  San Antonio, TX        John C. Rodriguez
7YL  Spokane, WA            North Central High School
6XAG Sunnyvale, CA          The Radio Shop
1YK  Worcester, MA          Worcester Polytechnic Institute
                            CHANGES
9YN  Lawrence, KS -- DELETED (University of Kansas)
2XK  New York, NY -- Owner now Superadio Corporation (was L. M. Cockaday & Co.)
3YD  Norfolk, VA -- DELETED (Norfolk Radio School)
6ZY  Santa Barbara, CA -- DELETED (Frederick C. Roebuck)

8/1/1921 Radio Service Bulletin #52 (updates to the 6/30/1920 list)
                            ADDITIONS
5YN  Abliene, TX           Simmons College
3YR  Baltimore, MD         Polytechnic Institute, city of Baltimore
6ZAF Berkeley, CA          A. H. Babcock
1XO  Cambridge, MA         General Radio Co.
9YAK Chicago, IL           City of Chicago
8XAA Cincinnati, OH        Crosley Manufacturing Co.
9ZAF Denver, CO            Wm. D. Reynolds
5ZAJ Kountze, TX           Arthur H. Holt
1XAC Middletown, CT        Wesleyan University
5XQ  New Orleans, LA       Pendleton E. Lehde
6XAJ Oakland, CA           Preston D. Allen
3XW  Parkesburg, PA        Horace A. Beale, Jr.
1XAD Pawtucket, RI         Standard Radio & Electric Co.
7ZT  Portland, OR          G. B. Criteser
7ZS  Pullman, WA           Hugh E. Allen
6ZAG San Francisco, CA     Clyde C. Young
6ZAH San Francisco, CA     Boy Scouts of America
6ZAI San Francisco, CA     Boy Scouts of America
4ZE  Spring Glen, FL       James C. Kellow
3XZ  Washington, DC        Radio Construction Co.
3ZY  Washington, DC        Lawrence M. Dunnan
                            CHANGES
3ZC  Norfolk, VA -- DELETED (City of Norfolk, Department of Public Safety)

9/1/1921 Radio Service Bulletin #53 (updates to the 6/30/1921 list)
                            ADDITIONS
3XAA Baltimore, MD          E. Craig Densten
3XT  Baltimore, MD          R. Selway Collmus (later Louis E. Richwien)
3XX  Baltimore, MD          Louis E. Richwien (later R. Selway Collmus)
8XAB Detroit, MI            City of Detroit, Police Department
7ZH  Enterprise, OR         Orland M. Heacock
5XS  Houston, TX            Tel Electric Co.
9XK  Kansas City, MO        Robert R. Moore
5XR  Montgomery, AL         S. G. F. Rathborne
3XY  Norfolk, VA            R. L. Hopkins and H. L. Buskey
                            CHANGES
6ZR  Burlingame, CA -- Change city to Los Angeles, CA (Hall Berringer)
5ZG  Dallas, TX -- DELETED (Bennett Emerson)
1XV  Hartford, CT -- DELETED (C. D. Tuska Co.)
9ZZ  Kansas City, MO -- DELETED (Walter M. Aronson and Albert R. Perkins)
6XX  Oakland, CA -- DELETED (Saint Mary's College)
1XQ  Rockland, ME -- DELETED (International Radio Telegraph Co.)
5ZAK San Antonio, TX -- Call changed from 5ZAI (R. C. Walker)
6XC  San Francisco, CA -- Owner to Pacific Radio Supplies Co.(was Lee de Forest, Inc.)

10/1/1921 Radio Service Bulletin #54 (updates to the 6/30/1921 list)
                            ADDITIONS
3ZN  Baltimore, MD          Harold A. Hogan
3XAB Charlottesville, VA    Virginia Radio Co.
3ZZ  Cradock, VA            Aloysius A. Kubiac
5ZAM Commerce, TX           Arthur C. West
4ZF  Decatur, GA            Thurston Hatcher
5YM  Fayetteville, AR       University of Arkansas
5XU  Austin, TX             University of Texas
6XAK Los Angeles, CA        Leo J. Meyberg Co.
6XAL Oakland, CA            Alfred H. Cohen
6XAM Oakland, CA            Stafford W. Warner
5XT  Oklahoma City, OK      Oklahoma Radio Shop
1XAE Springfield, MA        Westinghouse Electric & Manufacturing Co.
3YN  Washington, DC         National Radio Institute
9YAK Yankton, SD            Yankton College
                            CHANGES
2XAG New York, NY -- DELETED (Ware Radio Co.)
8XH  Pittsburgh, PA -- DELETED (Parker Elliot Wiggin)

11/1/1921 Radio Service Bulletin #55 (updates to the 6/30/1921 list)
                            ADDITIONS
1XAF Boston, MA             Edison Electric Illuminating Co. of Boston
1XAG Boston, MA (portable)  Edison Electric Illuminating Co. of Boston
9XAM Chicago, IL            City of Chicago, Dept. of Electricity
9XAN Chicago, IL            City of Chicago
8YO  Columbus, OH           Ohio State University
9YAL Denver, CO             Y. M. C. A., Radio Telegraph and Telephone School
6XU  Fresno, CA             San Joaquin Light & Power Co.
9YA  Iowa City, IA          State University of Iowa
6XAO Los Angeles, CA        Arno A. Kluge
9XAO Minneapolis, MN        Northern States Power Co.
7ZU  Polytechnic, MT        Glen E. West
8ZAB Scranton, PA           Shotten Radio Manufacturing Co.
6XH  Stanford Univ., CA     Herbert Hoover, Jr.
7ZJ  Vancouver, WA          Royal Mumford
                            CHANGES
3XT  Baltimore, MD -- Owner now Louis E. Richwien (was R. Selway Collmus)
3XX  Baltimore, MD -- Owner now R. Selway Collmus (was Louis E. Richwien)
8XV  Pittsburgh, PA -- City changed from Cleveland, OH (Frederick S. McCullough)
6XAF Piedmont, CA -- City changed from Oakland, CA (Pacific Telephone & Telegraph Co.)
8ZD  Pittsburgh, PA -- Owner now Parker Elliot Wiggin (was Burton P. Williams)
8XA  Ann Arbor, MI -- DELETED (University of Michigan)
8ZC  Battle Creek, MI -- DELETED (Bert E. Clough)
8ZM  Buffalo, NY -- DELETED (Cyrus H. Fraser)
8XY  Cincinnati, OH -- DELETED (Cino Radio Mfg. Co.)
8ZH  Cincinnati, OH -- DELETED (East High School)
8ZJ  Cincinnati, OH -- DELETED (Hughes High School)
8XI  Columbus, OH -- DELETED (Ohio State University)
8YE  Detroit, MI -- DELETED (Case Technical High School)
8XJ  Lewisburg, PA -- DELETED (Bucknell University)
8YB  Manlius, NY -- DELETED (Saint John's School)
8ZE  Marietta, OH -- DELETED (Norman A. Thomas and Edward Manley)
8XN  Pittsburgh, PA -- DELETED (Carnegie Institute of Technology Radio Club)
8ZO  Pittsburgh, PA -- DELETED (Frank Moore, Jr.)
8XO  Ridgway, PA -- DELETED (Pittsburgh Wireless Equipment Co.)
8XE  State College, PA -- DELETED (Pennsylvania State College)
8ZI  Toledo, Ohio -- DELETED (Adelbert Jacob Gogel)

12/1/1921 Radio Service Bulletin #56 (updates to the 6/30/1921 list)
                            ADDITIONS
4XF  Atlanta, GA            Charles L. Pierce
4XH  Atlanta, GA            H. E. Bussey
8ZAC Barnesville, OH        Clifford H. Galloway
3ZAA Buena Vista, VA        J. Frank Kay
8XAD Buffalo, NY            Federal Telephone & Telegraph Co.
8YV  Grove City, PA         Grove City College
6XAP Honolulu, HI           Radio Shop
5ZAN Laredo, TX             Charles G. Clark
8YAA Marietta, OH           Marietta College
8ZAD Mayville, NY           Experimental Radio Association
1YD  Northfield, VT         Norwich University
6XW  Oakland, CA            Richard C. Tavers
1XAH Orono, ME              University of Maine
3XAC Philadelphia, PA       Ship Owners Radio Service
6ZAJ Richfield, UT          M. S. Andelin
3ZAB Roanoke, VA            Charles L. Zimmerman
8XAC Toledo, OH             William B. Duck Co.
6ZAK Yuma, AZ               Charles E. Blalack
                            CHANGES
2XD  Hoboken, NJ -- City changed from New York, NY (Ware Radio Co.)
1XF  Providence, RI -- DELETED (Electrical Products Manufacturing Co.)