The Drake WH-7 Wattmeter manual provides detailed instructions for installation, operation, and troubleshooting, including how to set up the device between the transmitter and antenna, and how to measure VSWR and power accurately. It also includes maintenance tips and alignment procedures to ensure the wattmeter functions correctly, with guidance on diode replacement and calibration of power ranges.
Manual Overview
The Drake WH-7 Wattmeter is a through-line device designed for accurate measurement of forward and reverse power in RF applications. It operates within a frequency range of 1.8-30 MHz and supports a line impedance of 50 Ohms. The wattmeter offers three power measurement ranges: 20, 200, and 2000 watts, with specific accuracy levels for each range. Installation involves placing the wattmeter between the transmitter and antenna, using standard PL-259 coax connectors. The removable coupler allows flexible installation positions.
For troubleshooting, the manual emphasizes the importance of maintaining factory settings unless precision equipment is available. Diode replacement should be done with identical types to ensure accuracy. Calibration involves using a 50 Ohm dummy load and an RF voltmeter to adjust the calibration potentiometers for each power range. The null adjustment is performed by minimizing reflected power using a piston trimmer. The manual advises against unauthorized adjustments and recommends contacting R.L. Drake’s service department for unresolved issues.
Quick Issues Covered
- Diagnose diode rectifier malfunctions and replacement procedures.
- Calibrate forward power with specific voltage and pot adjustments.
- Trace circuits using detailed WH7 schematic for troubleshooting.
Overview
The WH7 Wattmeter by Drake is a through-line wattmeter designed to accurately measure forward and reverse power. It covers a frequency range of 1.8-30 MHz and is capable of handling up to 2000 watts RF continuous duty. The wattmeter features a removable RF coupler for convenient installation at the transmitter’s output. It includes a range selector switch on the front panel and provides three power measurement ranges: 20, 200, and 2000 watts. The manual covers installation, operation, and maintenance procedures, including instructions for unpacking, setting up, and aligning the device.
Specifications
- FREQUENCY COVERAGE: 1.8-30 MHz
- LINE IMPEDANCE: 50 Ohms resistance
- ACCURACY: Wattmeter accuracy is -+ (5% of reading + 0.2 watts) on 20 watts scale, = (5% of reading + 2 watts) on 200 watts scale, and = (5% of reading + 20 watts) on 2000 watts scale, throughout the range of 1.8-30 MHz
- VSWR INSERTION: Insertion of wattmeter in line changes VSWR no more than 1.05:1
- POWER CAPABILITY: 2000 Watts RF continuous duty
- FRONT PANEL: Range Selector Switch
- REMOVABLE COUPLER: Two input and output connectors (SO 239). Three range calibration potentiometers. One .5 to 5 pf piston trimmer null adjustment
- MAIN CABINET: 3.5" high x 6.5" wide, 7" cabinet depth (13.5 cm h, 17.5 cm w, 19 cm d)
- REMOVABLE COUPLER: 2.25" high, 3.75" wide, 2.5" deep
- WEIGHT: 2.4 lbs. (1.25 kg)
Controls & Indicators
Range Selector Switch.
Installation / Setup
The WH-7 Wattmeter should be installed between the output of the transmitter (or amplifier) and the antenna. It uses ordinary PL-259 coax connectors to couple with the SO 239 receptacles on the sensing element. The sensing element is removable for convenience and can be installed behind the operating table to avoid bringing bulky coax cables up. Approximately 3 feet of cable connects the sensing element to the meter, allowing for flexible installation positions.
Operation
The WH-7 Wattmeter allows for VSWR and power measurements. For VSWR measurements, set the selector switch to ‘SET’, adjust the ‘VSWR SET’ control to align the meter pointer with ‘SET’ at full scale, then switch to ‘VSWR’ to read the value directly. For power measurements, use the selector switch to choose between 20, 200, and 2000 watts full scale, ensuring the meter does not exceed full scale. The wattmeter measures forward and reflected power, and radiated power can be calculated using the supplied SWR calculator.
Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
Refer to the PDF for details.
Download 2 Service manual (PDF – 647.5 KB)
Drake WH-7 Model 2 Service Manual PDF: Guide for troubleshooting, calibrating, and assembling. File size: 647.5 KB.
- Brand: Drake-wh-7-instruction-service-manual
- Model: 2
- Type: Service manual
- File size: 647.5 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 2 service manual (PDF)
Drake WH-7 Instruction Service Manual Overview
The Drake WH-7 is a precision electronic device designed for professional audio and communication applications. This model -7- offers reliable performance and durability, making it ideal for technicians and enthusiasts who require accurate signal processing and control. The service manual provides comprehensive instructions for installation, operation, and maintenance to ensure optimal functionality.
Main Features and Specifications
- High-fidelity signal processing capabilities
- Robust construction for long-term durability
- Compact and ergonomic design for easy handling
- Wide frequency range support for versatile applications
- Clear and accessible control interface
- Comprehensive diagnostic and troubleshooting guides
Basic Usage and Operation Tips
To operate the Drake WH-7 effectively, ensure all connections are secure before powering on the device. Adjust the controls gradually to avoid signal distortion. Regularly monitor output levels to maintain optimal performance. Use the manual’s step-by-step setup instructions to configure the device according to your specific application needs.
Troubleshooting and Maintenance
Common issues such as signal loss or distortion can often be resolved by checking cable connections and verifying power supply integrity. Refer to the troubleshooting section for detailed diagnostic procedures. Routine maintenance includes cleaning connectors, inspecting for wear or damage, and recalibrating the device as outlined in the manual to prevent malfunctions.
Safety Reminder
Always disconnect the Drake WH-7 from power sources before performing any maintenance or repairs. Follow all safety guidelines provided in the manual to avoid electrical hazards and ensure safe operation. Use only manufacturer-recommended replacement parts to maintain device integrity and safety compliance.