Circuit Description; Frequency Configuration; Receiver; Front-End Rf Amplifier - HYT TC-500 Service Manual

Circuit Description

Frequency Configuration

The receiver utilizes double conversion superheterodyne. The first IF is 21.4MHz and the second is
455KHz. The first local oscillator signal is supplied from PLL circuit. Frequency needed in the transmitter
is supplied from PLL circuit. Figure 1 shows the frequency configuration.
Frequency Range: 136-150MHz

Receiver

The receiver utilizes double conversion superheterodyne.
1. Front -end RF Amplifier
The input signal from antenna is amplified in RF amplifier (Q27) after passing through the
receive/transmit switch circuit and a 3 -stage LC band pass filter. The amplified signals are
filtered by a band pass filter (a 3-stage LC BPF) to eliminate unwanted signals before they
go to the first frequency mixer.
2. The First Mixer
The signal from RF amplifier is mixed with the first local oscillator signal from PLL frequency
150-174MHz
370-390MHz 400-420MHz
Figure 1 frequency configuration
Figure 2 receiver section configuration
350-370MHz
450-470MHz
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TC-500 Service Manual