Mirage B-24-G - User Manual

Need help?

Do you have a question about the Mirage B-24-G and is the answer not in the manual?

Overview

Function Description
Important Technical Specifications
Usage Features
Maintenance Features
Warranty

The Mirage B-24-G is a VHF band high-power linear amplifier designed for the 144 MHz band, offering a maximum output power of 50W. It is designed to enhance VHF DX QSO experiences by combining high output power with a built-in low-noise GaAsFET receive pre-amp.

Function Description:

The B-24-G serves as a booster amplifier for handy-transceivers, increasing their output power to 50W. It also incorporates a pre-amplifier to boost received signals, improving overall communication range and clarity. The device features a Carrier Operated T/R (Transmit/Receive) switch, which automatically switches between transmit and receive modes.

Important Technical Specifications:

Frequency: 144 MHz
Mode: F3 (FM)
Input Power: 1-5W
D.C. Output Power: 50W
DC Power Supply: DC 13.8V
Output Consumption: 8A (MAX.)
Input/Output Impedance: 50 Ohm
Input/Output Connector: BNC/M TYPE
RX Gain: 18 dB
Accessory Circuit: COX (Carrier Operated T/R switch, RX pre-amp)
Dimensions: 3.4(W) x 6.0(H) x 3.4(D) inches
Weight: Approximately 1.5 lbs.

Usage Features:

The B-24-G is designed for ease of use and integration with various handy-transceivers.

High Output Power: Achieves 50W output with 1-5W input power, significantly extending communication range.
Receive Pre-Amp: An 18 dB GaAsFET pre-amp boosts weak incoming signals, improving reception.
Indicators:
- PWR Indicator LED: Illuminates when the amplifier is transmitting or "on air."
- PRE-AMP Indicator LED: Indicates when the amplifier is in RX mode and the pre-amp is active, boosting the received signal.
- TX Indicator LED: Shows that the amplifier is ON and in Stand-By mode, ready to transmit.
Switches:
- PRE-AMP/OFF Switch: Toggles the pre-amp unit ON (upper position) to boost received signals or OFF.
- TX/OFF Switch: In the ON (upper) position, the amplifier is ready to transmit (Max. 50W). In the OFF (lower) position, the amplifier is in receive mode only.
DC Input (13.8V): Connects to a stable DC power supply or battery. The red wire (with fuse holder) is positive, and the black wire is negative.
Antenna Connection: The antenna can be connected directly to the amplifier.
TX (RF Input): A BNC connector for direct connection to the handy-transceiver.
Docking Adaptor: Various adaptors are available to suit different models of handy-transceivers, ensuring compatibility.
Mounting Bracket: Includes a mobile mounting bracket for easy attachment in a car.
Adapter Power Switch: Allows selection of adaptor power (10.8V for new HT models or 13.8V for older models) or can be turned OFF when not in use.

Maintenance Features:

To ensure optimal performance and longevity, several precautions are outlined:

Heat Dissipation: The B-24-G features an aluminum heat sink integrated with the case for excellent heat dissipation. During transmission, the heat sink can reach high temperatures (approx. 50°C-80°C). It should be placed in a well-ventilated area, away from direct sunlight or heaters, and no objects should be placed on top of it.
Antenna Matching: It is crucial to ensure good antenna matching (low SWR) to prevent damage and ensure efficient power transmission. The antenna must be properly connected without shorts or open circuits.
Input Power Limit: Keep the input power at 5W or less to avoid damaging the amplifier.
DC Voltage: The DC voltage must be kept below 13.8V (within 12-14V). Connecting to a 24V DC battery (e.g., for truck use) or an AC power source can damage the amplifier.
Coaxial Cable: Always use a 50Ω coaxial cable for connections. Using cables with different impedances (e.g., 75Ω) can cause reflected waves, leading to mis-matching, reduced power output, and potential damage to the RF power transistor.
Power Supply: When using a stabilized DC power supply, ensure it has sufficient current capacity (7A or more) and good protective devices against RF signal intrusions. If the power supply malfunctions, discontinue operation immediately.
Reverse Polarity Protection: The amplifier includes a protection circuit against reverse polarity connections, but it is essential to check polarity carefully before connecting, especially with batteries, to prevent cord damage.
Whip Antenna Connection: Never connect a handy-transceiver's whip antenna directly to the amplifier's antenna connector using an M-BNC converter. This can cause damage to the antenna due to insufficient power capacity and may harm the transceiver or amplifier from strong RF signal intrusions.
Internal Adjustments: All internal adjustments are factory set for optimal performance. Changing these adjustments may void the warranty.
Repair: For repairs during the warranty period, units should be returned to the factory.
Repeater Operation: The unit is not designed for repeater operation, and such use is at the user's own risk.
Cover Removal: Do not operate the unit with the cover removed, as the cover confines RF radiation and the harmonic filters may not suppress direct radiation if exposed.

Warranty:

Mirage Communications offers a one-year limited warranty, covering defects in materials or workmanship from the date of original purchase. Warranty service requires proof of purchase and shipping the product, fully insured and prepaid, to Mirage.