Replacement Audio Transformers

Strictly high-quality audio-frequency transformers, comparing favorably with many of the high priced brands. The characteristics of these transformers are such that they provide practically uniform amplification from 200 to 5000 cycles, with a gradual fall-off below 200 cycles. Ideal for replacement use because of compact, small size. 260U Transformer Equipped with upright type mounting bracket. Size 2J4 high, 2 wide, and V j thick. Shipping weight 1 pound NET 1.32 260S Transformer Same as...

Info

By making the resistive coating directly on the inside of the glass, the heat generated in the resistor passes directly through the glass to the outside air anil is carried away. The metallic resistive coating is fused to the inside of the glass and can run at great heat without change in value. It is not affected by humidity, and is non-absorbent. It is not to be confused with coatings of similar appearance but which are made of colloidal graphite or similar material. There is no spiral wire...

Sm

One of the finest receivers ever offered by S-M or any other parts manufacturers, the new 712, developed from the Sargent-Rayment 710 that established so many records last year, presents features never before available. A tuner only without audio amplification fully a. c. operated, it employs three of the new 224 a. c. shield-grid tubes in three stages of r. f. amplification, and with band selector tuning a power dectector. Any audio amplifier may be used, although it is recommended that the...

Radio Frequency Chokes

Type 90 An especially compact unit, so built as to fit into any standard grid-leak mounting. It is of the proper value for use in all by-passing work on the screen-grid or plate circuits of screen-grid tubes and between the detector and the first audio tube, in accordance with the best audio-amplifier 'practice. The multi-section winding makes this choke suitable for short wave as well as broadcast work. List, without mounting. 0.74 The Chi Rad R.F. choke is wound on bakelite tube and will...

Constant Input Resistance

A special typ of resistor for controlling the volume of one speaker without affecting the volume of others connected to the same amplifier. The resistance element is divided into two special tapers, one that will maintain a constant resistance in the line, a resistance equal to the impedance of the speaker used the other tapered to give a smooth and gradual control of volume. The first resistance is in series with the line and the second shunted across the speaker. Both are regulated by one...

The New National Screen Grid MB

Browning and James Millen Tlie new NATIONAL Screen-Grid MB-29 is the latest and most spectacular radio achievement of Glenn H. Browning and James Millen. NATIONAL Co., Inc., is soie licensee under patents issued and pending covering essential details of this remarkable receiver. An ultra-sensitive, sharply-selective, distance-getting screen grid tuner, built with a completely shielded and beautifully frosted aluminum chassis and employing 4 screen-grid AC tubes...

Audio Frequency Chokes

Designed for isolating the different stages of an audio frequency amplifier by insertion in B battery leads in conjunction with a by-pass condenser. When so used it conserves B batteries, eliminates howling or motor-boating, and suppresses distortion in audio amplifiers due to B eliminators or B batteries. Due to its helical winding (giving the exceedingly small self-capacitance of 5 micro-micro-farads), it will also act as a choke to radio frequencies. List 1.91 Type E Output choke to match...

Et Et Et Et

List Price 4.25 NET 2.50 List Price 4.50 NET 2.64 List Price 4.75 NET 2.80 List Price 5.00 NET 2.94 List Price 4.25 NET 2.50 List Price 4.50 NET 2.64 List Price 4.75 NET 2.80 List Price 5.00 NET 2.94 These Short Wave Type EC Condensers are of a Straight line frequency type, 270 rotation, built into our Girder frame. The spacing between plates has been doubled in the smaller sizes and a non-inductive pigtail added to insure positive and silent operation without detuning.

General Description

This Amplifier is a complete three-stage unit with self-contained power supply. One straight audio stage followed by two separate push-pull stages are responsible for the tremendous power developed. Such features as Clough system amplification, over-size power transformer, variable A. C. hum-adjuster, full-wave rectification with adequate filtering, and high un-distorted output of 15 to 16 watts, assures complete and lasting satisfaction to the user. All parts are solidly attached to a heavy...

Rel S W Coils

Every amateur receiver must spread each band over the entire tuning condenser scale. Modernize your present set by installing the REL amateur coil and condenser tuning combination. Maximum efficiency can only be obtained by using correct LC ratio. Each coil in the REL Cat. Number 182 coil kit is correctly designed to adapt itself to any type of short wave circuit which requires inductances having one, two or three independent windings. Slotted grooves hold coil to original calibration as each...

Sm Dc For Battery Operation

With the same circuit that Jives such excellent results in the A. C. 735, but adapted for D. C., the S-M 735DC employs ana 222 screen-grid tnbe and four 112 type, thereby securing power for excellent valume without great enrrent draia. Only the four short-wave coils, covering 17 to 200 meters, came with the 735DC receiver. S f flO Price, fully RCA-licsnsed. factary wired aad tested. Nat___________ 1 S-M 721 Chassis and Power Unit Case 2.55 1 S-M 812 Escutcheon .75 1 S-M 810R Drum Dial 2.25 1...

Practice Sets

Just the instrument for those who want to learn the code. The code is printed on a little brass plate fastened to base. Equipped with Type R-SO High Frequency Buzzer. List 3.40 NET 2.75 Signal Sr. Learner Set Golden finish brass bar frame sounding plate and key base. Aluminum sounding bar, nickel plated key lever, rubber covered coils and mahogany finish base. M-110 and M-lll same as M-108 and M-109 except sounder plate is steel and key base is black enamel....

Console Cabinets Of Distinction

Model 10051 2 Beautiful Tudor Period Cabinet. The finish is Satin Walnut with the natural colors of the different woods brought out. Mouldings are hand cut Russian Briar, carvings are of Walnut and Oak, and Veneers are of Butt Walnut, Japanese Tama, and Oriental Walnut. Speaker compartment specially constructed of five ply f stock. Radio compartment 25 wide, 13 deep and lO' i high. Speaker compartment 12J4 high. Overall dimensions are 53 high, 17 deep, and 30 wide NET 95.00

Transmitting Tube Filament Controls

Power rheostat rated 75 watts for continuous operation. Resistance range 4 to 150 ohms. A giant variable resistor of 250-watt rating. In 3 resistance ranges J4-10 ohms, 25-500 ohms, and 200-100,000 ohms. Dissipates heat rapidly and safely. Mica insulation and asbestos packing, special resistive material, and heavy brass case. Large bakelite knob. Long shaft which may be cut to any length. Special mounting bracket to hold hot casing away from panel. Ideal as filament and plate control for...

And Inspectors

For the first time an entire course of training in one book the most complete and up-to-date work on radio. Developed simply and clearly from the elementary stage right through all phases of principles, practice, and apparatus so that a beginner with no knowledge of electricity may get all he needs either for amateur operation or to qualify for a government license as operator or inspector. The author, G. E. Sterling, is Radio Inspector and Examining Officer, Radio Division, U. S. Dept. of...

Constant Resistance Volume Control

Carter Hi-Ohm Volume Control It is the ideal volume and tone control, plate-voltage control, regeneration control or stabilization control. It has many other uses in the receiver or loudspeaker circuits. A non-inductive, wire protected, high resistance volume control that is unique in principle and original in design. The carbonized resistance element is made of a special resistance material and is graduated so as to produce a curved line effect giving an increase in volume which is uniform in...

Mc Mc Mcu Mc Mc

A small neutralizing or balancing condenser, having an exceptionally wide capacity range. Very useful as a compensator for equalizing the units of a multiple-tuning condenser. Ruggedjy built with bakelite base mount, mica dielectric and a heavy phosphor-bronze spring plate. Very even, gradual capacity changes obtained by movement of the center screw. EC-35 2 to 35 mmfd. List 0.50 0.29 EC-80 The proper capacity grid condenser is a highly important factor towards successful short wave reception....

Light Socket Aerials

A device which makes an aerial of any wall socket or other outlet. All Bakelite, plugs in on any electric light line. Consumes no current absolutely safe. Every one tested. Listed by Hoard of Fire Underwriters. List 0.75 _______________________________NET 0.44 A 7-ft. combination radio antenna and extension cord. One cord provides a self-contained antenna and also connects the lighting current to the set. Equipped with the Belden Soft Rubber Plug and Bakelite Outlet. Plug, cord, and overall...

R

R-100 Universal replacement transformer to replace obsolete or burned out transformers. Unique, construction enables transformer to be mounted on side or end, and being slotted no new holes have to be drilled for installation, Remarkably faithful over the useful frequency band. List 2.25 NET 1.47 R-260 A transformer of remarkably goqd reproduction. The core is made of a special metal having a permeability 50 greater than the best silicon steel. Thus the transformer can be made small, which in...

For Operation On M Bands

The first high-power amplifier to use the JX-860 screen grid tubes. 1929 in every detail. 150 watts of pure D. C. signals with a stability which has caused favorable remarks everywhere. Flexibility that fills every ham need. You can use either two UX-852 tubes when using this new Aero Kit No. 52 as a single unit for a transmitter or two UX-860 screen grid tubes, employed when using with Aero Kit No. 55 or as a 150-watt amplifier in any master oscillator combination. For those desiring a master...

Volt Types

List 3.00 1.76 22 Shield Grid. List 7.50 NET 4.41 The name DeForest in connection with radio denotes an experience dating back to the earliest days of radio, and we have found that DeForest Audions have merits which are the result of this long experience. The vacuum to which DeForest Audions are evacuated is several times more rare than competing tubes, and our experience has shown them to be remarkably long lived. The price of the Type 401-A is considerably more than other...

The National Screengrid tube Thrill

The NATIONAL 4 Tube Shortwave Tuner or THRILL BOX, Type SW-4, has been designed in response to a continuous demand for a short-wave set capable of receiving the full short-wave range of from 15 to 175 meters, and which at the same time would give good loudspeaker operation on the broadcast band as well 175 to 570 meters. Previous difficulties in the satisfactory design of a set of this kind have been overcome by the use of an ingeniously designed two-sec-lion tuning condenser. At the touch of a...

Audio Transformers

A100 Audio transformer incorporating the latest advances in audio transformer design. This superior unit employs a special nickel-steel high permeability core and a split secondary winding of new design. The result is a transformer of small size with unusually fine characteristics. Turn ratio is P50 and P10 Push-pull Transformers Similar in construction to the A100 listed above. The frequency-characteristic curve of these transformers is essentially a straight line from 30 to 500 cycles. P50...

Phone Plugs

Fit any standard Jack. RPSC i fr ig- gt Perfect contact and bakelite insulation prevent leakage. ESpKSo Shorting impossible. List 0.50 NET 0.33 Same as the No. 75, excepting equipped with 500,000 ohm resistance so that head sets may be used as a speaker line. Same size as No. 75 phone plug. List 1.50 0.98 A volume control like a phone plug which can be substituted for the standard type of plug. No. 1 Standard Modu Plug. No. 2 Cord Type Standard Modu Plug. No. 3...

At

Plate Volts 500 Grid Volts 0 Screen Volts 125 Filament Volts-RMS 7.5 Plate Current ma. 21 Plate Resistance ohms 200000 Mutual Conductance ma.v. 0.75 Amplification Factor 150 22.00 A Mercury Vapor Rectifier which will replace the standard rectifier tubes. The Rectobulb has an overall height of 1V2 inches from the bottom of the base to the top of the terminal on Anode. The diameter of the bulb is 3 inches maximum at the center. The base is a regular UX Base and the cap is Bakelite and of regular...

Variable Resistances For Receivers And Power Supplies

Yaxley A ir-Cooled Rheostats and Potentiometers The Air-Cooled Rheostat is made with the precision of a fine watch. It has a smooth quiet action with an extremely close adjustment. In broadcasting stations where delicate adjustments must be made and in laboratory equipment and laboratories the Air-Cooled Rheostat is a favorite as it has been for several years in receiving equipment of the highest class. Now, it fits in to fill the exacting requirements of a Volume Control in phonograph...

Pilot A C Superwasp

Short Wave Set That Works Developed by David Grimes, John Geloso, Robert S. Kruse The New Pilot Super-Wasp operating from A. C. light socket now brings to everyone the thrills of trans-oceanic short-wave radio reception New, different programs greet you from Canada, Australia, South America, Europe 1 Covers all bands from 14 to 500 meters. Utilizes Screen-Grid and specially developed Pilotron 227. Complete Kit . Catalog No. K-115 Power Pack for Pilot A. C. Super-Wasp less...

Rola Cabinet Models

Brack Bakelite Storm King Non-Air Gap Lightning fl The Storm King Lightning Arrester fSL is non-grounding and is operated on the i feiajjM protection. List 1.00 NET 0.59 List 1.50 NET 0.88 fRwWSfff I WsflcK Type 210 Vacuum Arrester. B jfBBj St mW .a List 1.50 NET 0.88 . WMfefa 'niivuH-ml Type 223 Vacuum Arrester. UQ rcstenr - List 2-50 NET 1.47 y gt I Brach Lightning Arresters are listed 1 f USS by the National Board of Fire Under- fMS J Avrr- writers under the Re-examination Serv- - and are...

Filter Chokes

Thordarson Filter and Plate Reactors R-196 Code Polar. 30 Henry, 80 M. A., 1000 V. insulation, shielded. Weight, 2 lbs. List 5.00 NET 3.27 T-2353 Code Transit. 6 Henry, 150 M A., 3000 V. insulation, open frame. Weight. 3 lbs. List S7.50 NET 4.90 T-2071 Code Transition.'' 30 Henry, 150 M. A., 3000 V. insulation, open frame. 5 lbs. List 16.00 NET 10.46 T-2027 Code Transitive, 30 Henrv. 300 M.A., 3000V insulation, open frame. 14 lbs. List 22.00 NET 14.38 T-2073 Code Transitory. 30 Henry. 500 M.A...

Clough System Audios

223 Hi-Mu Audio Transformer for use between UX222 first stage, screen grid tube, space charge connection, and any standard power tube. Provides absolutely flat curve from 32 to 5000 cycles with average voltage gain of 42 per stage NET 5.29 225 First Stage Audio Transformer Provides a flat curve up to 5000 cycles with greater amplification at 32 cycles than at 1000. Unquestionably the finest A.F. transformer ever 5.29 226 Second Stage Audio Transformer for use with 225, above, between first and...

Power Transformers

Power Supply 281

Unless otherwise specified, transformers are for 110 volt, 60 cycle AC. ________ T-2387 Code Transfuse. Secondary 1500-1000-0-1000-1500 volts. Capacity .300 V. A. Weight, 20 lbs. T-2388 Code Transgress. Secondary 2000-1500-0-1500-2000 volts. Capacity 500 V. A. Weight, 27 lbs. T-2389 Code Transient. Secondary 2000-1500-0-1500-2000 volts. Capacity 1000 V. A. Weight, 40 lbs. List 40.00 26.14 T-2180 Code Filial. Secondary 5 volts, center- tapped. 15 V. A. Weight, 3XA lbs. List 5.00_ NET 3.26 T-2230...

Belden Aerial Kits

Choke Input 280 Power Supply

SEE PAGES 49 AND 50 FOR AERIAL WIRE, ETC. The aerial wire in every Belden Aerial Kit is full sire 7x22, either Beld-enamel or Bare Copper. No. 8800 Beldenamel Aerial Kit. Contents 100 ft. 7x22 Beldenamel, 25 ft. Belden Flexible Colorubber Ground Wire, 50 ft. 7x22 R. C. Lead-in Wire, 1 Belden Resister Type Lightning Arrester No. 8812, 1 1-15-inch Belden Lead-in Strip, 1 Belden Ground Clamp, 2 3-inch Belden Glass Insulators, 3 Nail-on Knobs, 2 Galvanized Screw Eyes, 2 Wood Screws, 6 Two-point...

Tubes For Transmitting

F. power amplifier or oscillator in transmitter circuits operating at the higher frequencies. Radiotron UX-865 will prove it effectiveness as a radio frequency power amplifier. Its screen-grid eliminates the necessity for neutralization to prevent feedback and oscijla-tion. Then too, in these days of staying put on a definite transmitting frequency, Radiotron UX-865 lends itself admirably for use by the amateur as a crystal-controlled oscillator. Max. Plate Dissipation...

Ux

If amplifier is for magnetic or other high impedance speaker, transformer T-2880 should be substituted. Price is the same as T-2903. Heavy Duty 250 Push-Pull Amplifier and B Eliminator- Designed for public address use, speech amplifier use, or as a phonograph or radio set amplifier to operate several speakers and to deliver sufficient output to fill a large auditorium or theater or to be audible over a considerable area out of doors. It is a complete audio system designed for either...

Transmitting Condensers

Type 686 Dubilier transmitting condensers are supplied for 1000 volts D. C. Through series parallel connections practically any working voltage and capacity can be obtained. A Tobe guarantee is enclosed with every Transmitting Condenser which reads This unit is guaranteed for one year if operated at voltage not in excess of that marked on the case. Capacity List Net List Net Mfd. 1000 Volt 1000 Volt 2000 Volt 2000 Volt 1.0 7.50 4.41 10.00 5.88

Portable Type Voltmeters

For testing B Eliminators 0-300 volts. 3. No. 347 D. C. only. For testing B Eliminators 0-500 volts. 3. List 5.00_NET 2.94 No. 46 D. C. only. 0-300 volts. 2 4 No. 246 D. C. only. 0-60-300 volts. 2J4. No 348 For testing A. C. or D. C. Current Supply Line 0-150 volts. No. 247 0-600 volts. A. C.-D. C. List 5.00 NET 2.94 PANEL TYPE METERS d c. Ammeters 0-10. 0-3, 1-0-1, 3-0-3, 6-0-6, 10-0-10, and 20-0-20 amperes. List 1.00 0.59 d. c. Milliammeters 0-25, 0-50, 0-100, 0-300, and...

Jewell D C Voltmeters With Selfcontained Switch

Double range voltmeters, designed primarily for use in testing a and B battery voltages. Both instruments are equipped with a switch with a sweeping action across the contacts which are moulded in a bakelite base. The switch lias a spring arrangement to throw it off the high range, except when manually held in position, thus preventing accidental draining of the I battery. Pattern 140 has 2 inch diameter case with a 2 jj-inch flange. Range 0-7.5-150. List 9.50 6.06 Pattern 55 has 2 t inch...

Tubes Required

1 UX227, 2 UX226, 2UX250, 2 UX28I, 1 UX874. Extra Heavy Duty 45 Volt This extra heavy duty Super B gives 30 to 50 longer service than other heavy duty batteries. Made of especially constructed larger cells. Size 7 x8'A x4 4. List 4.25 NET 3.20 Vertical 45 Volt This new Super B gives 35 to 40 greater capacity than the ordinary type such as No. 2308 Burgess. Size 71ix7iJx3'4''. List 2.95 List Net Price Net Price Price each, Less each in

Readrite No A Cd C Tester

Same case and meters as No. 215 tester, but provided with extra cords amf tip jack connections, permitting the use of each meter individually. Also checks line voltage. A very complete outfit. No. 216 Tester, not including extra voltmeter. List 7.94 Readrite Model IS Set Analyzer and Service Kit An ideal servicing outfit for either A. C. or C. Sets. Embodies new and valuable fea- i'TTtIiUth iLhI tures. Equipped with regular adapters, and also ffi wBf'' i lk. a new a lt aI ,er f r testing screen...

List Of Parts

1 S-M 333 Dual Filter Choke 3.60 l-S-M 511 Tube Socket 1 S-M 669 ABC Case, Chassis and Panel 1.80 2 S-M 672 Resistors 1.35 2.70 1_S-M 818 Coil Hookup Wire 25 ft. ------ 30 13 Insulated Binding Posts 0.06 78 1 Connecting Cord and Plug 1 Set of Hardware Complete as described above, fully wired and tested. Substantially packed in wooden box less 1 280 tube . Shipping weight 14 pounds. Each NET 27.73 No. 8815 Belden Ground Clamp Sturdy copper with Belden Clip. Ekko Ground Clamp Attached instantly....

Vhcc Vhc Vhccr Vhcr

Monocolor, counter clockwise Monocolor. clockwise Rainbow, counter Rainbow, clockwise Type F National Velvet Vernier Drum Dial Constructed with a mechanism that has that same velvet smoothness that has featured all of our former types. Automatic spring takeup assures a positive drive at all times. Easily attached to the shaft of any standard clockwise condenser. A template for drilling the panel is furnished with each dial. A small concealed 6-volt lamp may be easily attached to light up the...