Polaroid IC-V8000 service manual Transmitter Circuits

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The AF signals are applied to the AF power amplifier circuit (IC9, pin 1) to obtain the specified audio level. The amplified AF signals, output from pin 4, are applied to the internal speaker (CHASSIS UNIT; SP1) via the speaker jack (J6) when no plug is connected to the external speaker jack (J1).

4-1-6 SQUELCH CIRCUIT (MAIN AND LOGIC UNITS)

A squelch circuit cuts out AF signals when no RF signals are received. By detecting noise components in the AF signals, the squelch switches the analog swtich.

A portion of the AF signals from the FM IF IC (IC4, pin 9) are applied to the D/A converter (IC5, pin 13) as the DETO sig- nal. The signals from the D/A converter (IC5, pin 14) are applied to the FM IF IC active filter section (IC4, pin 8) where noise components are amplified and detected with an inter- nal noise detector via the SQLIN line.

The trigger circuit converts the detected signals to a HIGH or LOW signal and applies this (from pin 13) to the CPU (LOGIC UNIT; IC7, pin 19) as the NOIS signal.The CPU controls the analog swtich IC (LOGIC UNIT; IC6) via the expander IC (LOGIC UNIT; IC8). When the CPU receives a HIGH level NOIS signal, the CPU controls the RMUT line to cut the AF signals at the analog swtich IC (LOGIC UNIT; IC6). At the same time, the AFON line controls the AF mute circuit (Q29) to cut out the VOLOUT signal for the AF power amplifier (IC9).

4-2 TRANSMITTER CIRCUITS

4-2-1 MICROPHONE AMPLIFIER CIRCUIT (LOGIC AND MAIN UNITS)

The microphone amplifier circuit amplifies audio signals with +6 dB/octave pre-emphasis from the microphone to a level needed for the modulation circuit.

The AF signals from the microphone pass through the MIC switch (IC2, D4) and high-pass filter (IC3a, pin 2), and are then applied to the microphone amplifier circuit (IC3d, pin

12)via the R39 and C47 for +6 dB/octave pre-emphasis. The amplified AF signals are applied to the analog swtich (IC6, pin 4), and are then applied to the D/A converter (MAIN UNIT; IC5, pin 1) via the MODIN signal. The AF signals are applied to the modulator circuit via the MOD signal.

4-2-2 MODULATION CIRCUIT (MAIN UNIT)

The modulation circuit modulates the VCO oscillating signal (RF signal) using the microphone audio signals.

The audio signals (SHIFT) change the reactance of D2 to modulate an oscillated signal at the VCO (Q6, D4). The oscillated signal is amplified at the LO (Q9) and buffer (Q11) amplifiers, then applied to the TX/RX switch circuit (D6, D7).

4-2-3 DRIVE/POWER AMPLIFIER CIRCUITS (MAIN UNIT)

The signal from the VCO circuit passes through the TX/RX swtiching circuit (D6) and is amplified at the pre-drive (Q17), drive (Q18, Q20) and power (Q23) amplifiers to obtain 75 W of RF power (at 13.8 V DC/typical). The amplified signal passes through the low-pass filter (L37, L39, C151, C156, C159, C167, C176, C227–C229), and then applied to the antenna swtiching circuit (D12). The signal is applied to the antenna connector (CHASSIS UNIT; J1) after being passed through the low-pass filter (L44, L47, L48, L51, C190, C197, C203, C208, C210, C217, C218).

The bias current of the drive (Q18, Q20) and power (Q23) amplifiers is controlled by the APC circuit to stabilize the out- put power.

4-2-4 APC CIRCUIT (MAIN UNIT)

The APC (Automatic Power Control) circuit (IC6a, Q26) pro- tects drive and power amplifiers from excessive currents and selects HIGH or LOW output power.

The output voltage from the power detector circuit (D14, D17) is applied to the differential amplifier (IC6a, pin 2), and the “T3” signal from the D/A converter (IC5, pin 23) is applied to the other input for reference.

When the driving current increases, the input voltage of the differential amplifier (IC6a, pin 2) will be increased. In such cases, the differential amplifier output voltage (pin 1) is decreased to reduce the drive current.

Q26 is controlled by the TXC signal from the expander IC (IC2, pin 14) to select HIGH or LOW output power.

• APC CIRCUIT

HV

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SWHV

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RF signal from

Q18

 

Q20

 

Q23

 

ANT

Driver

 

Driver

 

Power

 

PLL IC (IC1)

 

 

 

SW

amp.

 

amp.

 

amp.

 

 

 

 

 

 

+5V

 

 

TXC

2

 

 

1

Q26

IC6a

 

 

T1

3

 

+

 

 

 

APC control circuit

L44, C190, C191, C196, C197

LPF to antenna

D14 D12

Power detector circuit (D12, D14)

4 - 2

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Contents VHF FM Transceiver Repair Notes IntroductionOrdering Parts Table of Contents Specifications ‘ General‘ Transmitter ‘ ReceiverLogic Board Inside ViewsMain Unit Disassembly and Option Instructions Optional Unit InstallationRemoving the Cover Removing the Main Unit Removing the Front PanelCircuit Description Receiver CircuitsTransmitter Circuits Power Supply Circuits PLL CircuitsPort Allocations CPU Logic Unit IC72 D/A Convertor IC Main Unit IC5 3 I/O Expander IC Main Unit IC2Parts List Order DescriptionElectrolytic ECEV1CA100SR Diode HVU131TRF Tantalum ECST1VY334R Tantalum ECST1CX106R Chassis Parts Mechanical Parts and DisassemblyAccessories Main unit HM-133V Diodes SEMI-CONDUCTOR InformationTransistor and FET’S Section Board Layouts TOP View Bottom ViewLogic Board TOP ViewB5801B Main Unit D20C219 C109 Block Diagram Swhv AntennaVoltage Diagram GND NJM12902VBU4066BCFV Ctcss Micout DTA113ZU DTC143ZU 22 k 2SC4116 BL Page 32, Kamiminami, Hirano-ku, Osaka, 547-0003, Japan

IC-V8000 specifications

The Polaroid IC-V8000 is a versatile and innovative action camera designed for adventure enthusiasts and content creators alike. With its sleek design and powerful features, it has quickly gained popularity among users who demand high-quality video and photo capabilities in a compact form factor.

One of the standout features of the IC-V8000 is its 4K video recording capability. It allows users to capture stunning videos at resolutions up to 3840 x 2160, providing remarkable clarity and detail. This feature ensures that every moment of an adventure is immortalized with exceptional quality. Additionally, the camera supports various frame rates, enabling users to choose the perfect balance between resolution and motion smoothness for their specific needs.

The Polaroid IC-V8000 is equipped with an impressive 170-degree wide-angle lens, which allows users to capture expansive landscapes and dynamic action shots without the need for cumbersome equipment. This wide field of view is perfect for outdoor activities such as biking, skiing, and surfing, where users want to showcase both their surroundings and the action taking place within the frame.

Another notable characteristic of the IC-V8000 is its built-in Wi-Fi connectivity. This feature allows users to connect the camera to their smartphones or tablets, enabling easy sharing of photos and videos on social media platforms. The accompanying mobile app provides remote control functionality, making it convenient to operate the camera from a distance and ensuring users can get the perfect shot without needing external help.

The camera is also designed with durability in mind. With an IP68 rating, it is waterproof up to 30 meters (approximately 98 feet) when housed in the included waterproof case. This robustness ensures that users can confidently take the IC-V8000 on diving trips, water sports, and other extreme conditions without worrying about damaging the device.

Battery life is crucial for any action camera, and the Polaroid IC-V8000 does not disappoint. It features a long-lasting rechargeable battery that provides ample recording time for extended adventures. With various shooting modes, including time-lapse and slow motion, users have the flexibility to get creative with their footage.

In summary, the Polaroid IC-V8000 is a feature-rich action camera that caters to a wide range of users. Its 4K video recording, wide-angle lens, Wi-Fi connectivity, waterproof design, and excellent battery life make it a reliable companion for anyone looking to capture their most exhilarating moments and memories. Whether you're an adrenaline junkie or a casual explorer, the IC-V8000 is an impressive tool that enhances the adventure experience.