The Hammarlund HQ-110A/VHF and HQ-170A/VHF receivers are designed to tune amateur frequencies from 160 meters through 2 meters, providing reception for CW, AM, and SSB signals. The manual covers the setup and operation of these receivers, including the use of a low noise 6CW4 pre-amplifier for improved sensitivity on the 6-meter band, and provides troubleshooting guidance such as alignment procedures and antenna connections.
Manual Overview
The Hammarlund HQ-110A/VHF and HQ-170A/VHF service manual provides detailed guidance on troubleshooting, calibration, and adjustments for technicians. The manual emphasizes the importance of using a suitable antenna and provides specific instructions for connecting antennas for 6 and 2-meter operations. It highlights the improved sensitivity on the 6-meter band due to a low noise 6CW4 pre-amplifier stage. For troubleshooting, the manual outlines a flow for identifying issues with the converter and pre-amplifier circuits, including checking relay operations and ensuring proper antenna connections. Calibration involves adjusting coils and capacitors to peak signal reception, using a signal generator to feed signals to the antenna terminals, and tuning specific components like L205, L206, and L211 for optimal performance. The manual advises against paralleling antenna terminations and recommends using a switch box for combination antennas. It also includes a schematic diagram for board-level guidance, detailing component locations and connections, ensuring technicians can accurately diagnose and repair issues.
Quick Issues Covered
- Diagnose power-up failures with 6CW4 pre-amplifier stage.
- Adjust L211 coil for optimal signal reception.
- Trace circuits using detailed schematic for HQ-110A/VHF model.
Overview
The Hammarlund HQ-110A/VHF and HQ-170A/VHF are receivers designed to tune all amateur frequencies from 160 meters through 2 meters, providing reception for CW, AM, and SSB signals. The manual covers the operation of these receivers, including the tuning and reception of 6 meter and 2 meter signals, the use of a low noise pre-amplifier for improved sensitivity, and the configuration of antennas for optimal performance. It also includes a detailed theory of operation, field alignment procedures, and modifications for antenna and crystal calibrator circuits.
Specifications
- HQ-110A/VHF and HQ-170A/VHF Receivers
- – Tunes all amateur frequencies from 160 meters through 2 meters
- – Reception of CW, AM, and SSB signals
- – Improved sensitivity on the 6 meter band with low noise 6CW4 pre-amplifier stage
- – Uses 4 type 6CW4 Nuvistor tubes in a combination 2 meter converter, 6 meter pre-amplifier circuit
- – Crystal controlled oscillator using a 31.333 Mc crystal +.002% with output on 94 Mc
- – Broadband filter approximately 5 Mc wide
- – Series trap tuned to 188 Mc to prevent spurious responses
- – Tunable neutralizing coil for alignment
- – No provision to feed the 6 meter jack from the long wire antenna as in the HQ-110A and HQ-170A
Controls & Indicators
Refer to the PDF for details.
Installation / Setup
Refer to the PDF for details.
Operation
To receive 6 meter signals (50 to 54 Mcs), place the bandswitch in the 50 to 54 Mc position and push in the volume control knob. Connect a suitable antenna to the proper antenna terminal. The HQ-110A/VHF and HQ-170A/VHF have improved sensitivity on the 6 meter band due to a low noise 6CW4 pre-amplifier stage. For 2 meter signals (144 to 148 Mc), pull out the volume control knob to activate frequency converter stages that convert these signals to 50 to 54 Mc. When not receiving 2 meter signals, push in the volume control knob to reduce power consumption. Separate antennas are recommended for 6 and 2 meter operations, and a switching unit should be used if a combination 6/2 meter antenna is desired. On 6 and 2 meters, the sideband switch is reversed, resulting in the upper sideband being received in the lower sideband position and vice versa.
Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
Refer to the PDF for details.
Download MANUAL Service manual (PDF – 479.6 KB)
Service manual for Hammarlund HQ-110A/170A: troubleshoot, calibrate, and repair conversion preamp. File size: 479.6 KB.
- Brand: Hammarlund-hq-110a-170a-conv-preamp-service
- Model: MANUAL
- Type: Service manual
- File size: 479.6 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 MANUAL service manual (PDF)
Hammarlund HQ-110A/170A Conv Preamp Service Manual Overview
The Hammarlund HQ-110A/170A Converter Preamp is a precision radio frequency preamplifier designed to enhance weak signals for improved reception in communications and radio equipment. This device is widely used in vintage and professional radio setups to boost signal clarity and sensitivity before further processing. The service manual provides detailed guidance on servicing, repairing, and maintaining the preamp to ensure optimal performance and longevity.
Main Features and Specifications
- Frequency range coverage suitable for HF and VHF bands
- Low noise figure for minimal signal distortion
- High gain amplification to improve weak signal reception
- Robust, vintage design with reliable components
- Adjustable gain controls for fine-tuning performance
- Compatible with a variety of radio receivers and converters
Basic Usage and Operation Tips
To operate the HQ-110A/170A preamp effectively, connect the input to your antenna or signal source and the output to your radio receiver or converter. Adjust the gain control to achieve the desired signal strength without introducing excessive noise or distortion. Regularly monitor the device for any unusual noises or signal drops, which may indicate the need for servicing. Ensure all connections are secure and free from corrosion for consistent performance.
Troubleshooting and Maintenance Notes
If the preamp exhibits reduced gain or intermittent operation, first check all cable connections and power supply voltages. Inspect tubes and components for signs of wear or damage, replacing any faulty parts as indicated in the service manual. Regular cleaning of contacts and chassis will prevent oxidation buildup. Use the schematic diagrams and test procedures in the manual to diagnose and repair faults accurately.
Safety Reminder
Always disconnect the preamp from power sources before performing any maintenance or repairs. Handle tubes and electronic components with care to avoid electric shock or damage. Follow all safety instructions outlined in the service manual to ensure safe operation and servicing of the equipment.
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