The Belcom LS-202E is a portable SSB&FM handy transceiver designed for amateur radio use, primarily in the 2-meter band. This operating manual provides comprehensive details on its specifications, operation, and maintenance.

Function Description

The LS-202E is a compact, handheld transceiver capable of operating in both Single Sideband (SSB) and Frequency Modulation (FM) modes. It covers the 144.000-145.995 MHz frequency range in 5 kHz steps, with the possibility of extending up to 147.995 MHz. The device features a dual-gate FET PLL synthesizer circuit, ensuring high sensitivity and dynamic range.

In FM mode, the transceiver utilizes a double conversion superheterodyne receiver, while in SSB mode, it employs a single conversion superheterodyne receiver. The transmitter section uses balanced modulation for SSB and reactance direct shift for FM. A built-in electret condenser microphone is integrated for voice input.

Key functional components include:

Antenna Switching Circuit: Manages the signal path between the antenna and the receiver/transmitter sections.
RF Amplifier: Boosts incoming RF signals and outgoing transmit signals.
Mixer Circuit: Combines signals for frequency conversion.
FM IF Amplifier: Processes intermediate frequency signals in FM mode.
SSB IF Amplifier: Processes intermediate frequency signals in SSB mode.
AF Amplifier: Amplifies audio frequency signals for the loudspeaker.
Squelch Circuit: Suppresses background noise when no signal is present.
AGC Circuit: Automatic Gain Control to maintain a consistent audio output level.
Meter Circuit: Displays signal strength (S-meter) and battery voltage (BATT meter).
VCO (Voltage Controlled Oscillator): Generates the carrier frequency.
Microphone Amplifier: Amplifies the microphone input.
PTT Circuit: Activates the transmitter when the Push-To-Talk button is pressed.
PLL OSC Circuit: Generates and shifts frequencies for the Phase-Locked Loop.
Phase Comparison, Master OSC, VCO Circuit: Manages frequency stability and locking.
Mixer, Programmable Divider: Processes VCO signals and programming data from thumbwheel switches.
Carrier Oscillator: Generates carrier frequencies for different modes.
Power Supply: Regulates voltage for various internal circuits.
Tone Circuit: Generates a 1750 Hz tone for repeater access.

Important Technical Specifications

General:

Frequency Range: 144.000-145.995 MHz in 5 kHz steps (up to 147.995 MHz possible).
Mode: F3 (FM), A3J (SSB). SSB VXO ± 5 kHz or more.
Frequency Stability: ± 20 ppm (-10°C to +60°C).
Operating Voltage Range: 7V - 12V DC (9V nominal).
Grounding: Negative.
RF Output Impedance: 50 ohm unbalanced.
Dimensions: 165(H) x 62(W) x 40(D) mm (excluding projections); 179(H) x 64(W) x 44(D) mm (including projections).
Weight: Approx. 500 g (including batteries and flexible rubber antenna).
Operating Temperature: -10°C to +60°C.

Current Drain (at 9V):

Receive (no input signal): 30mA.
Receive (maximum signal): 200mA.
Transmit (FM): 750mA.
Transmit (non-modulated SSB): 200mA.
Transmit (modulated SSB): 700mA.

Transmitter:

RF Power Output:
- Hi: 2.5W (at 9V) SSB (PEP), FM; 3.5W (at 10.8V); 1.5W (at 7.2V).
- Lo: 0.5W (at 9V).
Modulation: SSB = Balanced Modulation; FM = Reactance Direct Shift.
Bandwidth: Less than 3 kHz SSB.
Maximum Frequency Deviation: ± 5 kHz FM.
Spurious Radiation: Better than -60 dB.
Carrier Suppression: Better than 40 dB.
Microphone: 2 Kohm Built-in Electret Condenser microphone.

Receiver:

Circuitry: FM = Double Conversion Superheterodyne; SSB = Single Conversion Superheterodyne.
Intermediate Frequency: 1st IF = 10.695 MHz (FM, SSB); 2nd IF = 455 kHz (FM).
Sensitivity: FM = -12dBμ Better than 0.25 μV (S/N = 10 dB); SSB = -12dBμ Better than 0.25μV (SINAD = 12 dB).
Spurious Response: Better than 60 dB.
RIT Control: More than ± 1 kHz.
Selectivity: FM = ± 7.5 kHz/-6 dB, ± 15 kHz/-60 dB; SSB = ± 1.2 kHz/-6 dB, ± 3 kHz/-60 dB.
AF Output Power: More than 400 mW (10% distortion, 8 ohm loading).

Usage Features

Controls and Terminals:

Antenna Connector: BNC type for connecting the supplied rubber-flex antenna or optional AN-2 1/4 λ rod antenna.
S/BATT Meter: Displays receiver signal strength and battery voltage during transmit.
VXO Control (SSB only): Shifts transmit and receive frequency simultaneously by +/-5 kHz or more to fine-tune frequencies.
RIT Control (SSB only): Shifts receive frequency by about +/- 1 kHz without changing transmit frequency, useful for adjusting to drifting stations.
Power Switch/Volume: Turns the unit on/off and adjusts receiver volume.
Squelch Control: Adjusts the threshold for squelch operation to cut off background noise.
+5 kHz Switch: Adds a 5 kHz frequency shift to the thumbwheel settings.
Mode Switch: Selects between FM (F), USB (U), or LSB (L) modes.
Noise Blanker Switch (SSB only): Reduces pulse-type ignition noise.
Channel Selector: Three thumbwheel switches for setting frequency in MHz, 100 kHz, and 10 kHz steps.
LED Illumination: Green LED illuminates the S/BATT meter and thumbwheel switches; red LED indicates transmit mode and flashes when batteries are low.
External Speaker Connector (3.5 φ plug): For an 8 ohm external speaker or earphone.
External Microphone Connector (2.5 φ plug): For an external microphone (2 Kohm impedance), such as the SH-1 speaker/mic.
Lamp Switch: Illuminates the S/BATT meter and thumbwheel switches.
Hi/Lo Switch: Selects transmit output power (2.5W or 0.5W at 9V).
PTT Switch: Activates the transmitter.
Battery Case: Houses six AA size batteries.
Charger Terminal: For connecting optional Ni-Cd battery chargers (CA-910E, CS-912, CA-110E, CS-112).
+/- 600 kHz Repeater Offset Switch: Allows for repeater offset operation.
Tone Switch: Transmits a 1750 Hz tone burst for repeater access.

Operation:

Preparations: Load batteries with correct polarity, mount the antenna, set squelch fully anticlockwise, and select desired mode and frequency.
Reception: Turn on the unit, adjust volume and squelch. In SSB mode, use the VXO control to search for signals.
Transmission: Set repeater offset to simplex, press PTT, and speak into the microphone. The red LED will light.
Repeater Operation: Set repeater offset as required, turn on the Tone switch, press PTT, and transmit the 1750 Hz tone.

Maintenance Features

Battery Installation and Notes:

Requires six AA size high-power leakproof batteries.
Observe correct battery polarity during installation.
Replace all six batteries simultaneously when they fail.
Never mix old and new batteries, or different types of batteries.
Do not attempt to charge normal dry or alkaline batteries.
Manganese and alkaline batteries reduce capacity at low temperatures (<10°C); keep them warm for normal operation.
Recommended use of optional NP-6 or NP-9 Ni-Cd battery packs for longer life and better performance.

External Power Supply:

The LS-202E can be powered by external 7V to 12V DC.
Do not directly wire to a car battery (13.8V DC) without using a cigarette lighter plug.

Ni-Cd Battery Pack (NP-6, NP-9):

Optional Ni-Cd battery packs charge in 4 to 6 hours.
The transceiver can operate longer with Ni-Cd packs.
Use specific AC or DC chargers (CA-910E, CS-912 for NP-6; CA-110E, CS-112 for NP-9).
Do not attempt to continue charging fully charged Ni-Cd batteries.
Charge batteries at temperatures between 0°C and 45°C.

Troubleshooting:

No noise appears: Check power switch, squelch control, and battery status (exhausted or incorrectly loaded).
Not operating on required frequency: Check frequency selector switches and mode switch for incorrect settings.
Red LED flashes on and off: Indicates exhausted batteries.

For any queries regarding operation, users are advised to contact their Belcom dealer. The manual also includes detailed PCB layouts and block diagrams for advanced troubleshooting and repair, although specific repair instructions are not provided for end-users. Circuit and ratings may change without notice due to ongoing technological development.

Belcom LS-202E - Page 21

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