Heathkit-aw-1-audio-watt-meter SCHEMATICS2 – Manual (PDF)

The Heathkit Audio Wattmeter Model AW-1 manual provides detailed instructions for setting up and operating the device, including specifications for frequency response, wattage range, and load resistors. It also includes troubleshooting guidance, such as the use of a crystal diode bridge for frequency response and information on the power supply requirements.

• Brand: Heathkit
• Model: SCHEMATICS2
• Type: manual
• File size: 673.4 KB

Manual Overview

The Heathkit SCHEMATICS2 manual for the AW-1 Audio Wattmeter provides essential guidance for troubleshooting, diagnostics, calibration, and board-level adjustments. The troubleshooting flow involves checking the power supply, which includes a power transformer and selenium rectifier, ensuring it meets the 105-125 volt AC requirement. Error diagnostics are facilitated by the use of a crystal diode bridge, which supports a wide frequency response, and a 12AU7 tube functioning as both voltage and current amplifier. Calibration involves adjusting the wattage and dB ranges, which are switch-selected, covering a total range from -15 dB to +48 dB. The load resistors can be set to 4, 8, 16, and 600 ohms, allowing for precise adjustments based on the audio input power ratings. The manual emphasizes the importance of maintaining the duty cycle for continuous and intermittent power ratings to prevent overheating, aided by the ventilated cabinet design. Board-level guidance includes ensuring proper connections and component integrity, particularly around the precision multipliers and the 200 microampere meter movement.

Quick Issues Covered

• Diagnose power-up failures: check power transformer and selenium rectifier.
• Calibrate wattage range: verify precision type multipliers and load resistors.
• Trace circuit issues: use schematic for 12AU7 amplifier and diode bridge.

Overview

HEAT HKIT AUDIO WATTMETER MODEL AW-1 is an audio wattmeter with a frequency response of +1 db from 10 cycles to 250 kHz. It has a wattage range from 0-5 milliwatts to 50 watts full scale, and a dB range from -15 dB to +48 dB. The device includes load resistors that are switch selectable and can handle up to 25 watts maximum continuous duty and 50 watts maximum intermittent duty. It features a 4 1/2″ streamlined case with a 200 microampere movement, a crystal diode bridge for wide range frequency response, and a 12AU7 voltage and current amplifier for the meter. The power supply includes a power transformer and selenium rectifier, requiring 105-125 volt AC, 50/60 cycle, 6 watts. The dimensions are 7 3/8″ high x 4 11/16″ wide x 4 1/8″ deep, with a net weight of 3 lbs.

Specifications

• Frequency Response: +1 db, 10 cycles to 250 ke
• Wattage Range: 0-5 milliwatts, 50 milliwatts, 500 milliwatts, 5 watts, 50 watts full scale
• DB Ranges: Total range, -15 db to +48 db, scale -5 to +18 db (i mw – 6002). Five switch selected ranges from -10 db to +30 db
• Load Resistors: 4Ω, 8Ω, 16Ω and 600Ω-non-inductive, switch selected
• Audio Input Power Ratings: Up to 25 watts maximum continuous duty, 50 watts maximum intermittent. Duty cycle 50 watts is 3 minutes
• Meter: 4 1/2" streamlined case with 200 microampere movement
• Power Supply: Power transformer and selenium rectifier
• Power Requirements: 105-125 volt AC, 50/60 cycle, 6 watts
• Dimensions: 7 3/8" high x 4 11/16" wide x 4 1/8" deep

Controls & Indicators

Refer to the PDF for details.

Installation / Setup

Refer to the PDF for details.

Operation

Refer to the PDF for details.

Troubleshooting & Error Codes

Refer to the PDF for details.

Safety & Warnings

Refer to the PDF for details.

Download SCHEMATICS2 Manual (PDF – 673.4 KB)

Heathkit AW-1 Audio Watt Meter SCHEMATICS2 manual helps technicians troubleshoot and calibrate with detailed schematics. File size: 673.4 KB.

• Brand: Heathkit-aw-1-audio-watt-meter
• Model: SCHEMATICS2
• Type: Manual
• File size: 673.4 KB

Overview

Brief overview of the product.

Specifications

• Key spec 1
• Key spec 2

Controls & Indicators

Control panel/button layout.

Installation / Setup

1. Step 1…
2. Step 2…

Operation

Basic usage, modes, cycles.

Troubleshooting & Error Codes

Safety & Warnings

• Important warning…

Downloads

Download SCHEMATICS2 manual (PDF)

Heathkit AW-1 Audio Watt Meter Overview

The Heathkit AW-1 Audio Watt Meter is a precision instrument designed to measure audio power output in audio amplifiers and related equipment. It provides accurate wattage readings to help audio enthusiasts and technicians optimize amplifier performance and ensure proper power levels. Ideal for both hobbyists and professionals, the AW-1 offers reliable measurements across a wide frequency range, making it an essential tool for audio testing and troubleshooting.

Main Features and Specifications

• Measurement Range: 0.1 to 100 watts
• Frequency Response: 20 Hz to 20 kHz
• Input Impedance: 8 ohms nominal
• Analog meter display for real-time wattage readings
• Compact and durable Heathkit design
• Includes comprehensive schematics for easy repair and modification

Basic Usage and Operation Tips

To use the Heathkit AW-1, connect the meter in series with the speaker output of the amplifier under test. Ensure the amplifier is powered off before making connections to avoid damage. Power on the amplifier and gradually increase volume while observing the meter needle to monitor wattage output. For accurate readings, use speakers or dummy loads that match the meter’s input impedance. Avoid sudden volume spikes to prevent meter needle damage.

Troubleshooting and Maintenance

If the meter needle fails to move or shows erratic readings, first check all cable connections for secure contact. Inspect the internal fuse and replace if blown. Refer to the included schematics for detailed circuit diagnostics. Regularly clean the meter face and connectors to maintain accuracy. Avoid exposure to moisture or extreme temperatures to prolong device lifespan.

Safety Reminder

Always ensure the amplifier is powered off before connecting or disconnecting the watt meter to prevent electric shock or equipment damage. Use caution when working with high-power audio equipment and follow all manufacturer safety guidelines. Never operate the meter beyond its specified input ratings to avoid personal injury or device failure.