Kantronics 8040-B - User Manual

The Kantronics 8040-B Receiver is a specialized communication device designed for amateur radio enthusiasts, specifically covering the 80 and 40-meter bands. This instruction manual provides comprehensive details on its operation, specifications, and maintenance.

Function Description:

The 8040-B Receiver is primarily used for receiving radio signals within its specified frequency ranges. It features controls for audio gain (volume), RF gain (radio frequency amplification), and band selection. The vernier dial allows for precise frequency tuning. The device is designed to be used with external antennas and speakers or headphones.

Important Technical Specifications:

• Frequency Coverage:
  • 80 meters: 3.65 to 3.75 MHz
  • 40 meters: 7.05 to 7.15 MHz
• Power Requirements: Two 9-volt transistor batteries.
• Size: Approximately 3" (H) x 5" (W) x 7" (D).
• Audio Output: Eight-ohm speaker or optional eight-ohm monaural headphones. Uses a standard phono plug (¼" phone plug).
• Sensitivity: One microvolt provides a readable signal.
• Selectivity: 1000 Hz @ 6 DB.

Usage Features:

• Audio Gain: This control, when rotated clockwise, increases the audio amplification of the receiver, acting as a volume control.
• RF Gain: Rotating this control clockwise increases the radio frequency amplification. It is crucial for minimizing interference from surrounding stations. When a station is selected, the RF Gain should be adjusted to minimize interference, and then the Audio Gain can be set for the desired listening level.
• Power Switch: The receiver is turned on when the switch is in the right-hand position.
• Vernier Dial: This dial selects the frequency on both bands. The top calibration (in MHz) is for 80 meters, and the lower calibration (in MHz) is for 40 meters. Clockwise rotation decreases the frequency. The vernier dial turns almost seven times for each rotation of the tuning capacitor, allowing for slow and precise tuning, making it easier to locate stations.
• Band Switch: This switch selects between the 80-meter band (to the left) and the 40-meter band (to the right).
• Antenna Jack: This terminal is used for connecting antenna lead-ins. For a dipole antenna, one lead-in should be soldered to the RCA connector sleeve and the other to the connector center. The RCA-type plug is included. For a long-wire antenna, the wire should be soldered to the center terminal of the RCA plug, and an additional wire to the plug sleeve for grounding the 8040-B.
• Phono Jack: This terminal connects an eight-ohm speaker or optional monaural headphones. A standard ¼" phone plug is used for connection. Kantronics offers an optional monaural headphone set with a phone plug attached.
• Grounding: For optimal performance, especially with long-wire antennas, a good external ground connection is recommended. A wire should be soldered to the sleeve of the RCA plug (included) and connected to a reliable ground source such as a water pipe, copper ground rod, or an existing station ground system.
• Antenna Considerations: The 8040-B can operate by simply connecting a long-wire antenna to the antenna jack. A length of 65 feet or greater is recommended for long-wire antennas. Significantly improved results can be achieved with a dipole antenna. An example diagram shows a dipole antenna with 32.5' wire on each side, a coax cable, insulators, and tie-downs, with an ideal height of 45' and a tie-down height of 15'.

Maintenance Features:

• Battery Installation: The 8040-B operates on two 9-volt transistor batteries. To install them, remove the screws at the back of the unit that secure the top panel. Slide the panel out, locate the battery clips, and install the batteries, ensuring good connections. Batteries should be replaced when necessary and removed during periods of storage to prevent damage.
• Tuning Procedures (Preselector Coils): The preselector coils can be peaked using the plastic adjustment tool included with the unit. These preselectors help match the 8040-B with varying antenna impedances. To achieve maximum signal strength for a particular antenna, simply rotate the proper choke. Once set, the preselectors should remain peaked as long as the same antenna is used.
• High Frequency Oscillator (HFO): A critical warning states that users should not attempt to tune the HFO (High Frequency Oscillator) without proper equipment. The HFO is factory calibrated.
• Service Information and Repairs: For service or repairs, users are instructed to write to KANTRONICS, INCORPORATED, ATTN: Service Department AR, 1202 East 23rd Street, Lawrence, Kansas 66044. It is also advised to phone before returning the unit for repairs at (913) 842-7745.
• Further Information on Amateur Radio: For those seeking more information on amateur radio, the manual suggests writing to The American Radio Relay League, 225 Main Street, Newington, Connecticut 06111.