Operational Description

FCC ID: QSRPT-400

Operational Description

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FCCID_1167578

PT-400 Circuit Description

AUDIO CIRCUIT
The audio signal is injected via the microphone sensor into the audio circuit composed of the IC 2
and IC 3. The level of the output signal is controlled by the resistors VR 1 and switch K2.

Tone Code Signal CIRCUIT
The Tone Squelch Signal is injected via the transistors Q4, Q5, crystal Y1 which produced
32.768KHz Signal. The Level of the output signal is controlled by the VR2.

MODULATOR CIRCUIT
The modulator circuit is a direct FM type built around the local oscillator controlled by D1 , crystal
Y2. Transistor Q6,Q7,Q8,Q9..The modulated output from the oscillator is sent to the RF amp.

RF PRE-AMPLIFIER &FINAL AMPLIFIER
One transistor amplifier stages, using Q10 transistor, culminating with a normal transmitter output
of . The output filter comprised of LBT1 to suppress the output harmonics and matches the output
to the integrate antenna.

POWER CIRCUIT
The power is controlled by IC 78L05

Document Created: 2009-09-08 16:11:04
Document Modified: 2009-09-08 16:11:04

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