The service manual for the Hallicrafters Model S-38 provides detailed instructions for setting up and operating the 6-tube AC/DC superheterodyne radio receiver, including information on band selection, tuning, and control settings for preliminary test operations. Additionally, it includes troubleshooting guidance such as dial cord restringing procedures, alignment instructions, and voltage measurements at tube terminals to assist with maintenance and repair.
Manual Overview
The service manual for the Hallicrafters Model S-38 radio receiver provides detailed instructions for troubleshooting, diagnostics, and adjustments. The Model S-38 is a 6-tube AC/DC superheterodyne receiver with four AM/CW bands. The manual outlines the power supply requirements, tube types, and their functions, which include mixing, amplification, detection, and power rectification. Troubleshooting guidance includes checking tube voltages and ensuring correct control settings, such as volume, band selector, and tuning, for preliminary tests. The manual provides specific alignment instructions for each band, emphasizing the use of standard signal generators and adjustments of trimmers and padders for optimal performance. Dial cord restringing procedures are detailed for both main tuning and bandspread tuning, requiring precise measurements and tension adjustments. The manual also includes a schematic diagram for board-level repairs and a list of resistor and capacitor values for component-level troubleshooting.
Quick Issues Covered
- Diagnose power-up failures with voltage checks at tube terminals.
- Calibrate IF frequency to 455 kc for optimal performance.
- Use schematics for circuit tracing and component identification.
Overview
Model S-38 is a 6-tube AC/DC superheterodyne table model radio receiver. It incorporates 4 bands of AM/CW reception, covering frequencies from 540 kc to 32.0 mc. The receiver includes features such as AVC, noise limiting, BFO pitch, headset reception, standby operation, and bandspreading. The rear panel has connections for a line cord, antenna, ground, and headset. It operates on 105 to 125 volts AC/DC with a power drain of 30 watts. The manual provides detailed service information, including tube types and functions, control settings, and instructions for restringing dial cords.
Specifications
- Model S-38 is a 6 tube AC DC superheterodyne radio receiver.
- 4 bands of AM/CW reception.
- Band #1: 540 kc to 1650 kc.
- Band #2: 1650 kc to 5.0 mc.
- Band #3: 5.0 mc to 14.5 mc.
- Band #4: 13.5 mc to 32.0 mc.
- Provision for AVC, noise limiting, BFO pitch, headset reception, standby operation, and bandspreading.
- Rear panel connections: line cord with plug, antenna and ground connector strip, headset connector plug strip.
- Power supply data: 105 to 125 volts AC, DC line voltage.
- Power drain: 30 watts.
- Tube types and function: 12SA7—mixer-oscillator; 12SK7—IF amplifier; 12SQ7GT—detector, AVC, audio amplifier; 35L6GT—audio power amplifier; 12SQ7GT—BFO and ANL; 35Z5GT—power rectifier for AC operation.
- IF frequency: 455 kc.
- IF selectivity: 7 kc wide at 6 db down, 65 kc wide at 60 db down.
- Image ratio: 2.7:1 at 30 mc, 6:1 at 14 mc, 10:1 at 5 mc, 35:1 at 1500 kc.
- Sensitivity: 12 microvolt at 600 kc, 12 microvolt at 5 mc, 11 microvolt at 14 mc, 23 microvolt at 30 mc.
- Audio output: 675 milliwatt with less than 10% distortion at 400 cycles (for 50 milliwatt output).
Controls & Indicators
Refer to the PDF for details.
Installation / Setup
Refer to the PDF for details.
Operation
Model S-38 is a 6-tube AC/DC superheterodyne table model radio receiver with 4 bands of AM/CW reception. It includes features such as AVC, noise limiting, BFO pitch, headset reception, standby operation, and bandspreading. The rear panel has connections for a line cord, antenna and ground connector strip, and a headset connector plug strip. The power supply requires 105 to 125 volts AC/DC and has a power drain of 30 watts. The control settings for preliminary test operation include standby set to “RECEIVE,” volume adjusted as necessary, band selector set to “1,” speaker/phones switch set to “SPEAKER,” CW/AM BFO switch set to “AM,” noise limiter set to “OFF,” main tuning set to local station frequency, and band spread set to “0.”
Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
Refer to the PDF for details.
Download NO.2-2 Service manual (PDF – 582.5 KB)
Service manual for Hallicrafters S-38 NO.2-2; assists technicians in troubleshooting and calibrating radio components. PDF size: 582.5 KB.
- Brand: Hallicrafters-s-38-service-bulletin
- Model: NO.2-2
- Type: Service manual
- File size: 582.5 KB
Overview
Brief overview of the product.
Specifications
- Key spec 1
- Key spec 2
Controls & Indicators
Control panel/button layout.
Installation / Setup
- Step 1…
- Step 2…
Operation
Basic usage, modes, cycles.
Troubleshooting & Error Codes
| Issue / Code | Fix |
|---|---|
| Example | How to fix… |
Safety & Warnings
- Important warning…
Downloads
Download NO.2-2 service manual (PDF)
Hallicrafters S-38 Service Bulletin NO.2-2 – Overview
The Hallicrafters S-38 is a classic shortwave communications receiver renowned for its reliability and performance in receiving AM broadcasts and amateur radio signals. Designed primarily for radio enthusiasts and technicians, the S-38 offers clear audio reception across a broad frequency range, making it ideal for both casual listening and technical experimentation.
Main Features and Specifications
- Frequency Coverage: 540 kHz to 30 MHz across multiple bands
- Superheterodyne receiver design for improved selectivity and sensitivity
- Single conversion with a fixed intermediate frequency (IF) of 455 kHz
- Built-in BFO (Beat Frequency Oscillator) for CW and SSB reception
- Audio output for external speaker or headphones
- Analog tuning dial with calibrated band spread
- Compact and durable chassis suitable for portable or stationary use
Basic Usage and Operation Tips
To operate the Hallicrafters S-38, first ensure the receiver is connected to a suitable antenna and power source. Use the band selector to choose the desired frequency range, then adjust the tuning dial slowly to locate the signal. The RF gain control helps optimize signal strength, while the BFO switch enables reception of Morse code (CW) and single sideband (SSB) transmissions. For best audio clarity, adjust the volume and tone controls accordingly.
Troubleshooting and Maintenance Notes
Common issues include weak reception or audio distortion, often caused by misaligned components or aging tubes. Regularly inspect and clean tube sockets, switches, and contacts to maintain optimal performance. If the receiver fails to power on, check the fuse and power cord for faults. Alignment procedures detailed in the service bulletin should be followed carefully to restore proper tuning and sensitivity.
Safety Reminder
Always disconnect the receiver from the power source before performing any maintenance or repairs. Use caution when handling vacuum tubes, as they can become hot during operation. Avoid exposing the unit to moisture or extreme temperatures to prevent electrical hazards and damage.