The HDR-300A is a heavy-duty antenna rotator system designed for precise positioning of large antenna systems. It consists of a gear motor assembly and a control console, offering robust performance and user-friendly operation.
Function Description:
The HDR-300A's primary function is to rotate large antenna systems to desired azimuth positions. The gear motor assembly, featuring heavy steel-spur gears and a fiber drive gear, ensures maximum strength, reliability, and quiet, vibration-free operation. An aluminum housing contributes to reduced weight and corrosion resistance. Azimuth indication is provided by a 3-turn, 1000-ohm wire-wound potentiometer geared to the rotator output shaft, which generates an analog DC voltage signal. This signal is then converted into a digital format and displayed on the control console's front panel using seven-segment LEDs.
The control console manages the rotator's operation, supplying 24 VAC to the motor and 5 VDC to the azimuth potentiometer. It features a brake control switch and a rotation control switch. The brake must be in the "FREE" position for the antenna to turn, allowing the antenna to coast to a stop before the brake is locked, which prevents clutch slipping under high torque conditions. A reminder light on the brake switch indicates when the antenna is free to rotate. The digital display system is capable of showing readings from -99° to +999°, although limit switches restrict rotation from -20° to +380°. The system can be configured for either North-centered or South-centered operation via a slide switch and trim pots on the main PC Board.
Important Technical Specifications:
Mechanical:
- Full Load Torque: 2,300 in.-lbs. (2656 kg-cm)
- Stall Torque: 5,000 in.-lbs. (5774 kg-cm)
- Braking Torque (minimum): 5,000 in.-lbs. (5774 kg-cm)
- Coasting Torque: 600 in.-lbs. (693 kg-cm)
- Maximum Vertical Load: 500 lbs. (226.8 kg)
- Maximum Antenna Area (when mounted inside tower): 25 sq. ft. (2.325 sq. m)
- Maximum Effective Moment: 5,000 ft-lbs. (691 kg-m) (defined as the product of antenna weight and turning radius; effective moments of stacked antennas can be added)
- Maximum Travel: 400°
- Rotation Time: Approximately 60 seconds for 360°
- Mast Size: 1 1/4" to 3" O.D. (3.2 to 7.6 cm)
- Temperature Range: -30°F to +120°F (-35°C to 49°C)
- Weight:
- Rotator: 27 lbs. (12.2 kg)
- Control Console: 21 lbs. (9.52 kg)
- Recommended Inside Tower Width: 9.5" (24.1 cm) minimum
Electrical:
- Power Requirement: 108-130 VAC 50/60 cycle 2.5A or 215-245 VAC 50/60 cycle 1.5A
- Motor: 24 VAC, 6A maximum, 1/10 HP, PSC, single phase
- Solenoid: 24 VAC, 0.5A maximum
- Digital Readout Accuracy: ± 1°
Control Cable Requirements:
- 0-100 Feet: Minimum: two #18 and six #22 AWG (Bertek 6308-18 or Belden 8448). Recommended: two #16 and six #18 AWG (Belden 9405).
- 100-200 Feet: Minimum: two #16 and six #18 Belden 9405. Recommended: seven #14 Belden 8628.
- 200-300 Feet: Minimum: seven #14 Belden 8628. Recommended: twelve #14 Belden 8629.
- The three large wires are used on pins 1, 2, and 3. The four smaller wires are used on pins 4, 8, 9, and 10. Maximum resistance in the three large wires should not exceed 0.5 ohms each.
Usage Features:
- Pre-Installation Check: A preliminary operational check is required before installation to ensure all components are present and undamaged, and to verify basic functionality.
- Voltage Conversion: The unit comes prewired for 115 VAC but can be easily modified for 230 VAC operation by rearranging internal wiring and installing the appropriate fuse.
- Calibration: The HDR-300A is factory-calibrated for the potentiometer and digital display. If recalibration is needed, a gain adjustment to the digital voltmeter can be performed on the bench or in the tower. North-centered and South-centered operation modes are selectable and require specific calibration steps.
- Tower and Antenna Compatibility: Designed for towers capable of withstanding 25 square feet of wind loading. For smaller towers (less than 15 sq. ft.), other rotators like the T2X "Tailtwister" or Ham IV are recommended. Maximum antenna area of 25 sq. ft. is valid only if no antenna boom is longer than 30 feet and all elements are less than 50 feet long.
- Brake Release Feature: This feature allows the antenna to coast to a stop before the brake is locked, minimizing torsional forces on the tower and rotator, thereby prolonging system life. The brake switch must be in the "FREE" position for rotation.
- Digital Readout System: Provides accurate azimuth bearing information, indicating North (000°), East (090°), South (180°), West (270°), and North again (360°). Overtravel in clockwise direction is indicated by 360-385 degrees, and counterclockwise by negative numbers (-01 to -125 degrees). During rotation, the display increments in steps of approximately 4 degrees, then 1 degree when coasting, preventing rapid flickering. Includes filters for 50/60 Hz and RF modulation.
Maintenance Features:
- Gear Motor Lubrication: Gears are lubricated with a special low-temperature grease (stable from -60°F to +280°F). After 3-5 years, the gears should be checked for adequate lubricant.
- Corrosion Prevention: The output shaft is stainless steel. The platform hole should be coated with heavy grease during installation to prevent corrosion.
- Water Entry Prevention: The HDR-300A incorporates features to prevent water entry, including a V-shaped O-ring on the output shaft and a plastic housing to keep the motor, capacitor, limit switches, and potentiometer dry. A drain hole is provided for condensation. Periodic checks of the O-ring and plastic housing are recommended to ensure moisture resistance.
- Troubleshooting Guide: The manual includes detailed troubleshooting charts for common issues, listing symptoms and possible causes, such as fuse problems, wiring errors, potentiometer installation issues, and motor binding.
- Factory Service Information: Instructions are provided for obtaining factory service, including shipping procedures, warranty claims, and ordering replacement parts. Most replacement parts do not require adjustment or calibration, with the 3-turn potentiometer and main P.C. board being exceptions.
Need help?
General
To Next Page