International Radio Corp. Model 90 4-Tube Set and Power Supply
Radio Service Data Sheet
March 1936 Radio-Craft

March 1936 Radio-Craft [Table of Contents] People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Radio-Craft was published from 1929 through 1953. All copyrights are hereby acknowledged. See all articles from Radio-Craft.

This is another Radio Service Data Sheet that appeared in the March 1936 edition of Radio-Craft magazine. I post this schematic and functional description of the International Radio Corp. Model 90 4-Tube Set and Power Supply radio manufacturers' publications for the benefit of hobbyists and archivists who might be searching for such information either in a effort to restore a radio to working condition, or to collect archival information.

International Radio Corp. Model 90 4-Tube Set and Power Supply Radio Service Data Sheet

(110 V. A.C.; and 6 V. or 32 V. D.C. service; 6-tube operation; A.V.C.; small size)

The following table gives voltages as measured between points indicated and ground:

*Depends on applied signal. The above table holds true only when the line voltage is 115 V.

A standard type of output meter should be used and is connected between the amplifier section plate prong of V4 and ground. The signal from the service oscillator must be kept at a low level in order to get below the A.V.C. action.

To align the I.F., first turn the tuning condenser to about 600 kc. - do not ground the oscillator section of the gang condenser. Set service oscillator to correct frequency and attach to antenna of set. Adjust primary and secondary of both I.F. transformers for maximum gain. Insulated screwdriver and socket wrench are necessary for this operation.

Next, set oscillator at 1,500 kc. Turn gang condenser of set so that the plates are slightly meshed (about 1/8-in.). Adjust trimmers on both sections for maximum signal.

If the coils have been changed it may be necessary to bend plates at 1,000 kc. and 550 kc, Do not bend oscillator plates (rear section) unless absolutely necessary.

The power supply of the set is designed for use on 110 V. A.C. but separate power units are made which supply 110 V. A.C. when connected to 6 V. or 32 V. D.C.

Keep the green wire on the antenna section of the gang condenser as far as possible from the oscillator. Keep antenna coil as far as possible from sockets. Keep A.C. power cord clear at the end of chassis. If the set becomes microphonic, push a piece of rubber between speaker and chassis base.

If the D.C. power supply does not deliver the proper voltage (between 110 and 120 V., under the load of the set) the trouble is usually a defective vibrator or the set is drawing abnormal current.

To adjust the speaker remove cover plate from unit. There are 2 screws at each end of the unit within the magnets. When adjusting either pair of screws, one is to he loosened slightly and the other tightened. You will notice that this moves the armature slightly to one side. The air gap at both sides should be the same.

 

 

Posted July 13, 2015

Radio Service Data Sheets These schematics, tuning instructions, and other data are reproduced from my collection of vintage radio and electronics magazines. As back in the era, similar schematic and service info was available for purchase from sources such as SAMS Photofacts, but these printings were a no-cost bonus for readers.

Crosley Model AC-7 and AC-7C Westinghouse "Columnaire" Models WR-8 and WR-8-R (Remote Control) Characteristics of Metal Tubes - and Other "Octal" (8-Prong) Base Types Kolster K20, K22, K25, K27 and K37 Six-Tube Receivers Stromberg-Carlson Nos. 62 and 63, 8-Tube High-Fidelity Chassis RCA Model 103, 4-Tube A.C. Compact Dual-Wave FADA "Special" Model 265-A and FADA "7" Model 475-A General Electric Model C-62 6-Tube Battery Emerson 5A Automotive Zenith 666 Automotive Motorola 100 Automotive Crosley Roamio 4-A-1 Automotive American-Bosch 524A Automotive Crosley Model 1316 (in Model 167 Console) RCA Victor "High-Fidelity Electrola," Model R-99 AMRAD Model 81 ("Bel Canto" Series) Receiver Fada 103 Fadalette, Stewart-Warner Series 108, DeWald 54 Dynette Sets RCA Victor R-27 and Philco 53 Ultra-Midget A.C.-D.C. Radio Receivers Majestic Models Fairfax and Sheffield 8-Tube Stromberg-Carlson No. 29, 9-Tube Superhet International Kadette Model 400 4-Tube Battery-Operated Superhet RCA Victor Model 5M 5-Tube Auto Superhet Majestic Model 11 Short-Wave Converter Silver-Marshall Model 727-DC Battery-Operated Superheterodyne RCA Victor Model VHR-307 Home Recording - Phono-Radio Combination Delco 32-Volt Radio Receiver Chassis Models RA-3, RB-3 and RC-3 Majestic Chassis Models 380 A.C. T.R.F., and 400 A.C.-D.C. Superheterodyne General Motors S1A, S1B Admiral Model 7C63, Chassis 7C1 Westinghouse Model H-133 Arvin Models 150TC, 151TC Kadette Model 90 Duplex RCA-Victor "Magic Brain" Model 281 Grunow 11A Chassis 11-Tube All-Wave Superheterodyne Sears, Roebuck & Co., Silvertone "Rocket" Models 6110 and 6111 General Electric Model GD-52 Zenith Models 6D302, 6D311, 6D326, 6D336, 6D360 Allied Radio, Knight Model E10913 Arvin Model 140P Emerson Models 501, 502, 504 Crosley Model 56TD-W Hoffman Model A500 Stewart-Warner Model 9003-B Zenith Models 6D014, 6D029 Coronet Model C-2 Sparton Models 7-46, 7-46PA, 8-46, 8-46PA Stewart-Warner Models 9001-C, D, E, F Zenith Models 5D011-5D027 Bendix Models 636A, C, D ECA Model 108 International Model 66 and 666, 6-Tube Superhet Ford-Philco Radio, Model FT9, 6-Tube Auto-Radio Receiver Howard Explorer Model W Deluxe 19 Tube All-Wave Superhet RCA Victor Portable Table Electrola Model R-95 Atwater Kent Model 305Z 5-Tube 32 V. D.C. Superhet Kadette Jewel Model 40 Chassis 3-Tube Ultra-Midget Receivers General Electric Model N-60 6-Tube Auto Superheterodyne Sparton Model 40 6-Tube T.R.F. Automotive Receiver Clarion "Replacement" Chassis, Model AC-160 A.V.C. Superheterodyne Emerson Models 20A and 25A General Electric K-40A Pilot Model B-2 RCA-Victor Radiola Model M-30 Automotive Radio Motovox Models 10A All-Electric and 10E Battery-Operated "Moto-Tetradynes" Kennedy Superheterodyne Short-Wave Converter RCA Victor Model R-78 B1-Acoustic 12-Tube Philco Model 15 Series, 11-Tube Superheterodyne Chassis Zenith Challenger Model 740

Atwater Kent Models 30, 33, 35, 48 and 49 Crosley Model 120 Senior Superheterodyne (Pliodynatron) Chassis Columbia Screen-Grid 8 Receiver General Electric Models A82 and A87, 8-Metal-Tube All-Wave A.C. Superhet. Colonial 31 and 32 D.C. Zenith 5-Tube Triple-Wave Chassis nos. 5508 and 5509 Remler Model 46 ("Scottie") General Electric FA-60 and FA-61 Stewart-Warner Series 900 Howard Model B-5 (715), Series 1 and 2 (Sheaffer Radio-Clock-Pen Desk Set) Ford-Philco Car-Radio Models F-1440 and F-1442 Brunswick Model 31 Combination Radio and Panatrope Emerson Models 38, 42 and 49, 6-Tube Dual-Wave (Chassis U6) General Motors Chevrolet No. 601574 Automotive RCA Victor M-104 (and M-108) Automotive Arvin-Ford 17-A Automotive Westinghouse Model WR 207 & WR 208 5-Tube Dual-Band Superheterodyne Radiolas "Super VIII" (AR-810, "Semi-Portable" (AR-812), 24 and 26 Howard Model 45 A. V. C. Majestic Model 25 Galvin Motorola Model 61 Arvin Model 6 Admiral Models 7T06, 7T12 Garod Model 5A1 Hoffman Model A301 Knight Model E10716 Battery Portable Arvin Models 555, 555A, 552N, 552AN Grantline Models 605, 606 Truetone Model D2616 Belmont Model 5D128 Arvin Models 444, 444A International Kadette Model 1019 Stewart-Warner Models 97-561 to 97-569 General Electric Model 280 Zenith Models 5R080, 5R086 Truetone Models D1747, D1748 Crosley Roamio Automotive T.R.F. Models 90, 91, 92 Crosley Roamio Automotive Superheterodyne Models 95, 96 Wells-Gardner Series 062 Emerson Model AZ-196 Belmont Model 5P19 Crosley Model 56FC Emerson Models 507, 509, 518, 522, 535 Garod Model 6AU-1 General Electric Models 219, 202, 221 Crosley "Chairside" Model 567 Belmont Model 408 Battery "Farm" Wards Model 74BR-1055A Farnsworth Models EK-081, EK-082, EK-083, EK-681 Philco Model 200-X Radio Admiral "Aeroscope" Models 161-5L, 162-5L and 163-5L Philco Model 59, 4-Tube A.C. Midget Superheterodyne Zenith Farm Model 6V 27, 6-Tube Superhet Ward 10-Tube All-Wave High-Fidelity Superhet, Series ODM Philco-Packard Deluxe Canadian Westinghouse Model 175 Crosley Model 1155 Philco Models 39 and 39A Arvin Model 35 8-Tube Car-Radio Hetro Air-Ace Series M Westinghouse Models H-161, H-168, H-168A Garod Model 5A4 Arvin Models 152T, 153T Belmont Model 5240 Mantola Models 92505, 92506 General Electric Models 102, 102W, 107, 107W, 114, 114W, 115, 115W Crosley Model 555 (A.F.M.) Crosley Model 515 (Fiver) Crosley Model 425 (Travo) Firestone-Stewart-Warner Model R1332 Fairbanks-Morse Model 81 "Farm" Set Clarion Model 423, 470, 471, 472, 480 International Radio Corp. Model 90 Belmont Model 578 Series A