Source: Broadcasting Yearbook, 1940.
| Mod | Freq | Call | City | State | Licensee | Watts |
|---|---|---|---|---|---|---|
| AM | 25300 | W5XD | Dallas | TX | A. H. Belo Corp. (WFAA) | 100 |
| AM | 25300 | W2XJI | New York | NY | Bamberger Broadcasting Service (WOR) | 100 |
| AM | 25300 | W9XOK | St. Louis | MO | Star Times Publishing Co. (KXOK) | 100 |
| AM | 25400 | W9XLA | Denver | CO | KLZ Broadcasting Co. (KLZ) | 100 |
| AM | 25500 | W2XQO | New York | NY | Knickerbocker Broadcasting Co. (WMCA) | 100 |
| AM | 25900 | W9XPD | St. Louis | MO | Pulitzer Publishing Co. (KSD) | 100 |
| AM | 25950 | W8XNU | Cincinnati | OH | The Crosley Corp. (WLW) | 1000 |
| AM | 25950 | W6XKG | Los Angeles | CA | Ben S. McGlashan (KGFJ) | 1000 |
| AM | 26000 | W4XBW | Chattanooga | TN | WDOD Broadcasting Corp. | 100 |
| AM | 26000 | W9XA | Kansas City | MO | Commercial Radio Equipment Co. | 1000 |
| AM | 26050 | W9XH | South Bend | IN | South Bend Tribune (WSBT) | 100 |
| AM | 26100 | W9XBA | Kansas City | MO | WHB Broadcasting Co. | 100 |
| AM | 26100 | W2XVP | New York | NY | Municipal Broadcasting System (WNYC) | CP-1000 |
| AM | 26100 | W9XJL | Superior | WI | Head of the Lakes Broadcasting Co. (WEBC) | 250 |
| AM | 26125 | W5XAU | Oklahoma City | OK | WKY Radiophone Co. | 100 |
| AM | 26150 | W4XCA | Memphis | TN | Memphis Commercial Appeal Co. (WMC) | 250 |
| AM | 26150 | W4XA | Nashville | TN | National Life & Accident Ins. Co. (WSM) | 1000 |
| AM | 42060 | W8XWJ | Detroit | MI | Evening News Association (WWJ) | 500 |
| AM | 42140 | W3XIR | Philadelphia | PA | WCAU Broadcasting Co. | 100 |
| AM | 42180 | W2XWF | New York | NY | Wm. G. H. Finch | 1000 |
| AM | 42220 | W1XKA | Boston | MA | Westinghouse E. & M. Co. (WBZ) | 50 |
| AM | 42260 | W9XAZ | Milwaukee | WI | The Journal Co. (WTMJ) | CP-500 |
| AM | 42300 | W6XDA | Los Angeles | CA | Columbia Broadcasting System (KNX) | 100 |
| AM | 42300 | W6XRE | Los Angeles | CA | Ben S. McGlashan (KGFJ) | 500 |
| AM | 42300 | W9XHW | Minneapolis | MN | Columbia Broadcasting System (WCCO) | 50 |
| AM | 42300 | W1XEQ | New Bedford | MA | E. Anthony & Sons (WNBH) | 100 |
| AM | 42300 | W2XDV | New York | NY | Columbia Broadcasting System (WABC) | 50 |
| AM | 42340 | W1XER | Boston* | MA | Yankee Network | 500 |
| AM | 42340 | W8XNT | Cleveland | OH | United Broadcasting Co. (WHK) | 50 |
| AM | 42380 | W1XKB | Springfield | MA | Westinghouse E. & M. Co. (WBZA) | 1000 |
| AM | 42460 | W1XEH | Hartford | CT | Travelers Broadcasting Service Corp. (WTIC) | 150 |
| AM | 42460 | W9XER | Kansas City | MO | Midland Broadcasting Co. (KMBC) | 500 |
| FM | 42600 | W3XMC | Bethesda | MD | McNary & Chambers | CP-100 |
| FM | 42600 | W1XK | Boston | MA | Westinghouse E. & M. Co. (WBZ) | CP-1000 |
| FM | 42600 | W9XAO | Milwaukee | WI | The Journal Co. (WTMJ) | CP-1000 |
| FM | 42600 | W2XWG | New York | NY | National Broadcasting Co. (WEAF) | CP-1000 |
| FM | 42600 | W8XAD | Rochester | NY | WHEC Inc. | CP-1000 |
| FM | 42600 | W1XSN | Springfield | MA | Westinghouse E. & M. Co. (WBZA) | 1000 |
| FM | 42800 | W9XEN | Chicago | IL | Zenith Radio Corp. | CP-1000 |
| FM | 42800 | W2XMN | N. of Alpine | NJ | Edwin H. Armstrong | 40000 |
| FM | 43000 | W1XOJ | Boston | MA | Yankee Network | CP-50000 |
| FM | 43000 | W8XVH | Columbus | OH | WBNS Inc. | CP-250 |
| FM | 43000 | W8XYH | Superior | WI | Head of the Lakes Broadcasting Co. (WEBC) | CP-1000 |
| FM | 43200 | W2XOY | Albany | NY | General Electric Co. (WGY) | 150 |
| FM | 43200 | W1XSO | Hartford | CT | Travelers Broadcasting Service Corp. (WTIC) | CP-1000 |
| FM | 43200 | W2XQR | New York | NY | John V. L. Hogan (WQXR) | 1000 |
| FM | 43200 | W8XVB | Rochester | NY | Stromberg-Carlson Co. (WHAM) | 1000 |
| FM | 43200 | W2XDA | Schenectady | NY | General Electric Co. (WGY) | 50 |
| FM | 43200 | W3XO | Washington | DC | Jansky & Bailey | 1000 |
| FM | 43400 | W1XPW | Hartford | CT | WDRC Inc. | 1000 |
| FM | 43400 | W2XOR | New York | NY | Bamberger Broadcasting Service (WOR) | CP-1000 |
| FM | 43400 | W1XTQ | Worcester | MA | Telegram Publishing Co. | CP-1000 |
| AM | 116950 | W6XRE | Los Angeles | CA | Ben S. McGlashan (KGFJ) | ... |
| FM | 117190 | W2XAG | Yonkers | NY | Carman R. Runyon Jr. | 5000 |
| FM | 117430 | W2XMN | N.of Alpine | NJ | Edwin H. Armstrong | ... |
| AM | 350000 | W6XRE | Los Angeles | CA | Ben S. McGlashan (KGFJ) | ... |
* Transmitter location: Sargents Purchase, NH.