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Company Name | Date | Location | Comments |
ACME Apparatus Co. | QST ad Nov/1920 | Cambridge, MA |
Non-resonant transformers for high spark frequencies: List No.12016 full power 250W List No.12017 full power 500W List No.12018 full power 1000W |
ACME Wireless Construction Co. | 1909 | Cambridge, MA |
Probably same as ACME Apparatus Co. with older name. Type A and Type B Helices & loading coils Induction coils 1/2", 1", 1-1/2", 2" Spark gaps Type A, B & C transmitting condensers |
Amalgamated Wireless Australasia | 1913 | Australia |
Formed from merger of Telefunken and Marconi interests in Australia. Transmitting Helix Plain Discharger (straight gap) |
American Radio Sales & Service Co. | QST ad July/1921 | Mansfield, OH |
DX-52 Oscillation Transformer DX-51 Spark Gap |
AMRAD American Radio and Research Corporation | QST ad November/1919 | Medford Hillside, MA |
Lightning Switch 100A, 500V Induction Coils: Type C, 6 Volt Type C1, 32 Volt Quenched Gap Type G-1 1 KW gap Type G-2 1/2 KW gap Type G-3 1/4 KW gap |
Armorl (Armstrong-Orling) | ? | England |
"Induction coils in all sizes" up to 20" |
Benwood Specialty Co. | QST ad Dec/1919 | St. Louis, MO |
"Benwood" Rotary Spark Gap No.1 Benwood Gap complete No.8 8 stud rotor No.10 10 stud rotor No.14 14 stud rotor |
A.W. Bowman | 1911-1922+ | Lexington & Cambridge, MA | Spark gap on 2-1/8" x 3-5/9" Bakelite base with name molded into it. |
J.H. Bunnell & Co. | ca 1915 | New York |
Rotary and straight gaps sold under model names Beeko, Mascot, Dandy, and Jove Spark Coil under brand name Mascot |
F.B. Chambers & Co. | QST ad Dec/1915 | Phila., PA |
Rotary spark gaps, mahogany or marble bases spark coil |
Chelsea Radio Co. | QST ad Aug/1920 | Chelsea, MA |
Spark Load Coil (tapped loading inductance 0-3500 meters) |
Chicago Radio Laboratory | QST ad Nov/1919 | Chicago, IL |
Hyrad synchronous rotary gap |
Cino Radio Mfg. Co. | QST ad Feb/1922 | Cincinnati, Ohio |
"Cino Sink" rotary gap and motor |
Clapp-Eastham | began making radio equipment ca 1910 | Cambridge MA |
Type Y 658 Antenna Switch (Oct/1920 QST ad) Semi-Quenched Cambridge Rotating Discharger (rotary gap) from 8/1916 ad Rotary Spark Gap No. 741 (QST ad Oct/1920) Type F656 spark gap Oscillation transformers: No. Y-200 1/2 KW and up No. TXL-101-A International, up to 1 KW No. Y-100 up to 1/2 KW Type 651 oscillation transformer Type 653 "radiocoupler" oscillation transformer Type Z642 protective device (2 condensers across line) Type ZRL high tension transformer for use with rotary gaps Type L spark transformer (1/4, 1/2, & 1 KW spark coil) 1/4, 1/2, 1, 2, & 3 KW Type E transformers (spark coil) High potential condensers F654, F655, F655A, F655B, F655C Type 611 electrolytic interrupter |
Continental Electric Co. | QST ad January/1920 | New York, NY |
No. 1031 straight spark gap Rotary spark gap |
Doubleday-Hill Electric Co. | QST ad April/1917 | Pittsburgh, PA |
Rotary gap |
Dubilier Condenser Company | 1915 | New York |
Founded by William Dubilier, and merged in 1933 with Cornell Electric. CD 53 and CD 53A Spark Type Protective Device; capacity 150 amps, 500 volts for 1,2,5, and 10 KW spark sets. Mica transmitting condensers (CD 54, etc.) |
Wm. B. Duck Co. | QST ad May/1917 | Toledo, OH | Some of these components probably only marketed by Duck and
made by others. Type "C" Sayville Gap (rotary gap, initially a Halcun product) Type "D" Rotary spark gaps, in 1/2 KW and 1 KW rating No.60X15A Zinc Spark Gap No.60X15 Zinc Spark Gap No.44X0 Spark Gap No.A4018 Spark Gap with Porcelain Base No.A4019 Standard Spark Gap with Porcelain Base (this made by J.H. Bunnell & Co.) No.A395 Commercial Type Oscillation transformer No.A7628 Oscillation transformer No.A555 Junior Oscillation Transformer No.39X0 1/4 inch spark coil No.44X6 1 inch spark coil No.40X0 1/2 inch spark coil No.41X0 1.5" spark coil No.42X0 2" spark coil No.43X0 3" spark coil No.44X0 4" spark coil No.45X0 6" spark coil Also offered "Bull Dog" type spark coils 1/4, 1/2, 1, 1-1/2, and 2" types No.A560 Pancake Helix High Voltage transformer in 1914 catalog, called a "Flexible step-up wireless transformer", adjustable by wingnut on top. No.A1921 Solenoid Operated Antenna Switch Flexible Step-Up Transformer No.63X0 (Type T-0), No.63X1 (Type T-1), No.63X2 (Type T-2), No.63X3 (Type T-3) Rotary Spark Gap No.A442 Magnetic Key No.A1925 High Potential Condensers complete in rack (No.6051 to 6053, and No.A6100) Model IX Glass Plate Condenser (No.A1923 and A1924) 1 KW Antenna Switch No.70X05 2 KW Antenna Switch No.70X06 Electrolytic Interruptor No.71X13 (parts individually can be ordered) |
Ducretet | 1899-1919 | Paris, France |
Rotary Spark gap with rotating ball copper electrode |
Economic Electric Co. | 1909 or earlier? to about 1920 | London, England |
Spark coils in at least 15 different spark lengths |
Electric Machine Co. | QST ad Nov/1920 | Indianapolis, IN |
"Bell" Rotary Spark Gap |
Electro Importing Company EICo | 1904-1915+ | New York |
Components listed in the EICo Catalog 14, 1914: Electro Zinc Spark Gap Electro Commercial Spark Gap Electro Sending Helix Electro Commercial Oscillation Transformer Electro Adjustable Sending Condenser Electro Leyden Jars Electro Adjustable High Tension Condensers Electro 1/2 KW Transformer-Coil Gernsback Electrolytic Interrupter Electro Antenna Switch Electro Wireless Lightning Switch 0.25 inch Bulldog spark coil dated 1912 0.5, 1.0 and 1.5 inch (Bulldog) spark coils (1914) The "Electro" Rotary Spark Gap (1915) The "Electro" Quenched Spark Gap (1915), 8 sections, capacity 1 KW |
Electro-Set Co. | 1914 | Cleveland, OH |
1/6 KW Closed Core High Tension Transformer 1/2, 3/4, and 1 KW Flexible Wireless Transformers Electrolytic Interrupter Electro-Set Box Type Spark Coils 1/8, 1/4, 1/2, 1, 2, 3 inch spark No.801 Spark Gap Senior Spark Gap Electro-Set Special Air Cooled Spark Gap Type "P" Rotary Spark Gap Type "A" Rotary Spark Gap Transmitting condensers Leyden jars No.606 Oscillation Helix for Small Stations No.607 Loose coupled Oscillation Helix No.610 Antenna Switch (for up to 1/2 kw) No.611 Antenna Switch (for up to 1 kw) No.612 Antenna Switch (for higher power) No.615M Lightning Switch (60A rating) No.616M Lightning Switch (100A rating) No.617M Lightning Switch (100A, 600V rating) Electro-Set Line Protector |
Elliott Electric Co. | QST ad May/1917 | Shreveport, LA |
Rotary gap |
J. Herbert Ferris | QST ad Jan/1917 | Royal Oak, MI |
Rotary Gap |
Fisher | 1919 | ? |
1 KW air cooled (cooling flanges) straight spark gap |
Fosco Corp. | QST ad Jan/1917 | Chicago, IL |
"A-Motor" motor and aluminum rotary gap rotor |
Franklin Sales Co. | QST ad Oct/1920 | Chicago, IL | Franklin Rotary Spark Gap (Hamilton Beach Motor) 1/2 to 1 KW |
A.H. Grebe & Co. | QST ad June/1920 | Richmond Hill, NY |
Type TGAC Synchronous Rotary Gap with 220V motor Type TGAD Synchronous Rotary Gap with 110V motor Both were also advertised by MESCO |
Edward E. Hayward, Jr. | QST ad May/1920 | Boston, MA |
Little Wonder Gap, Rotary Gap. |
The High Tension Co. | 1916 | Westminster, England |
Standard 12" spark coil 200 watt spark coil |
Hunt & McCree | 1917 | NY |
Spark coils 1/4" to 10" |
J-Ray M'F'G Co. | QST ad Mar/1921 | St. Louis, MO |
Rotary Spark Gap |
Karlowa Radio Corp. | QST ad Mar/1921 | Rock Island, IL |
K20A (with Motor) and K20B (Pulley drive only) rotary gap |
Kilbourne & Clark | 1901-1920+ | Seattle, WA | Antenna switches for commercial and amateur use-- contacts arranged in the shape of a triangle on electrose insulators. |
Fr. Klingelfuss & Co. | 1903 | Basel, Switzerland |
Spark coils for 10-150 cm spark length |
Klitzen Wireless Apparatus Co. | QST ad 1916 | Racine, WI |
Klitzen Rotary Gap |
Max Kohl A.G. | 1909-1927+ | Chemnitz, Germany |
Large induction coil |
Lowenstein Radio Co. | 1918, but drawings of Lowenstein keys as early as 1916 exist | Brooklyn NY |
Type No. SE-994 1/2 KW Antenna Switch Type No. SE 1499 1/2 KW Lightning Switch |
Manhattan Electric Supply Co. MESCO | ca. 1910 | New York |
Zinc straight spark gap List No.467 (by 1915) "High Efficiency Spark Gap" List No.465 up to 1/4 KW capacity, hard rubber base and zinc terminals Rotary spark gap (QST ad Dec/1915) Spark coils in polished oak case with vibrator: 1/4", 1/2", 3/4", 1", 1-1/2", 2", 3", 4" operating on 5 dry cells, List Nos. 459-464, 495-6 Adjustable Primary condenser List No.439 Sending Helix No.484 Leyden Jars and Fixed Condensers Antenna Switch List No.416 Antenna Switch List No.422 Improved Antenna Switch No.253 (looks like Clapp-Eastham Type Y 653) Lightning Switch List No.384 |
Marconi | 1899-1919 (Aldene, NJ plant mfg starts 1912) | England, Canada, New York and New Jersey |
Type S H Antenna Switch Type I antenna switch Marconi Model 230 10" Spark Coil Type B3 Transformer (1914) From Marconi Catalog of Used Apparatus: Motor Starter No.201 Motor Generator and disc discharger No.200, and No.214 Starting Switch No.202 2 KW 240-cycle transformer No.206 High Potential transformer No.216 High potential condenser No.207 and 218 Oscillation transformer No.208 Aerial Tuning Inductance No.209 Non-synchronous spark discharger No.220 Oscillation transformer No.221 Aerial changeover switch No.213 |
W.D. Mathews | QST ad May/1920 | Marlette, MI |
Improved Spark Gap |
Mi-Kerm Radio Co. | QST ad Sept/1921 | Burlington, IA | Mi-Kerm Rotary Quenched Spark Gap |
Murdock, Wm.J. | founded 1896 | Chelsea, MA |
Beautiful oscillation transformer on wooden base. (No. 424) Moulded Transmitting Condenser No.440 Straight Spark Gap (1919) on hard rubber base From April, 1910 catalog (transformers, condensers, spark gaps, and helices all in 1/4, 1/2, 1 & 2 KW sizes: Transformers No.400, 110VAC 60 cycle with hard rubber pillars Sending Condensers No.481, glass plate type, jar type on request Straight Spark gaps No.441 on polished marble base Helices No.421, copper ribbon Antenna Switch No.462 on polished marble base Sending Helix No. 420 wound with round copper wire From 1913 catalog: Transmitting Helix No.422 otherwise same as 1910 From 1920 catalog: No.463 Antenna Switch No.483 transmitting condenser No.488 transmitting condenser No.443 rotary spark gap No.265, 266, 267 induction coils |
Radiguet & Massiot | 1906 | Paris, France |
large & small size spark coils |
Radio Apparatus Company of America | QST ad Sept/1916 | Phila., PA |
Hy-Tone Rotary spark gap |
Radio Equipment Co. | QST ad Feb/1921 | Boston, MA | Rotary Spark Gap |
Radiolectric Shop | ad QST Oct/1920 | Cleveland, OH |
"73" single blade antenna switch, Type A with Marble base and Type B with wooden base |
Radio Supply & Mfg. Co. | QST ad May/1921 | St. Paul, MI |
4 or 8 tooth disc rotary gap |
Ray-Di-Co | QST ad Feb/1921 | Chicago, IL |
Synchronous Rotary Gap |
H.A. Reverend Mfg. Co. | QST ad Feb/1917 | Kansas City, MO | Rotary Spark Gap |
Saginaw Radio & Electric Co. | QST ad July/1921 | Saginaw, MI |
Sag-Re-Co products, "improved" spark gap with interchangeable teeth |
Shotton Radio Manufacturing Co. | QST ad Dec/1920 | Scranton, PA |
"Shramco" Oscillation Transformer |
Signal Electric Mfg. Co. | QST ad Dec/1920 | Menominee, MI |
"Signal Switch" Aerial changeover switch (QST ad 11/21) "Signal" Rotary Spark Gap Motor |
E.J. Simon | 1915 | New York |
CE 613 antenna switch and board |
L. Brainerd Stratton | QST ad Feb/1917 | Oneida, NY |
The Monotone Quenched Gap |
T & H Radio Co. | QST ad June/1921 | Anthony, KS |
Type TH-1 Oscillation Transformer, smaller ribbon on primary Type TH-2 Oscillation Transformer, larger ribbon on primary |
Telefunken | QST ad April/1920 | Germany |
Pancake Type Oscillation Transformer, marketed by Radio Equipment Co. of Phila.,PA |
Thordarson Electric Mfg. Co | QST ad March/1921 | Chicago, IL |
Type R transformers 1 KVA, 0.75 KVA, 0.5 KVA Type RS transformers 1 KVA, 0.5 KVA, 0.25 KVA Oscillation transformer Type T-OT Oscillation Transformer (QST ad Oct/1919) 8, 12, & 16 tooth rotary discs |
Trumbull | 1915 | ? |
100 Amp Ground Switch |
Twin City Radio Lab. | QST ad July/1921 | St. Paul, MI |
The Arrow Disc "Spark-Thru" Type Rotary disc |
United States Electrical Supply Co. | 1900 | New York |
Induction coil/gap for wireless telegraphy |
WEACO Wireless Experimental Apparatus Co. | QST ad Jan/1917 | Phila., PA |
Rotary Gap |
Western Radio Electric Co. | QST ad Aug/1920 | Los Angeles, CA |
WESRAD Oscillation Transformer designed for 200 meters, up to 1 KW |
Wilcox Laboratories | QST ad May/1920 | Lansing, MI |
"Wilcox" Rotary Gap |
Winn Radio & Electric Mfg. Co. | QST ad June/1920 | Chicago, IL |
"Winn" Transmitter Coil-- induction coil with interrupter, No. 210 |
Wireless Manufacturing Co. | QST ad June/1920 | Canton, OH |
Rotary Spark Gap |
Wireless Specialty Apparatus Company | 1907-1919 | Boston, MA |
Components from 1919 Catalog: Antenna Switch, Type Q-S-5001 Lightning Switch, Type Q-S-5002 Antenna Switch Type Q-S-501 Faradon condensers Lightning Switch, Type Q-S-5007 Rotary Spark Gap, Type Q-S-5006 |
Young & McCombs | QST ad Oct/1920 | ? |
Young & McCombs Rotary Spark Gap |