Service Manual 7.UHF3 (350-400 MHz) Information
229
Descriptions of Normal Situations:
1) Voltage of the power supply: about 13.6 V.
2) For low power, APC_CTRL_Vgg: 1.0-1.2 V; for medium power, APC_CTRL_Vgg: 1.4-1.8
V; for high power, APC_CTRL_Vgg: 1.8-2.2 V.
3) For low power, TV_APC: 1.2-1.4 V; for medium power, TV_APC: 1.6-2.0 V; for high
power, TV_APC: 2.0-2.4 V.
4) PS_APC: about 3.3 V.
5) T5V: about 5 V.
6) PS_TX: about 3.3 V. 5VRT: about 5 V.
7) Start-up voltage of D8004: about 0.7 V. The low-pass coil must be soldered appropriately
and remain in good condition.
8) PA bias of Q8004 is normal. Input voltage: about 2.8 V, output voltage: 13.6 V, gain:
about 12 dB. The components must be soldered appropriately and remain in good
condition.
9) PA bias of Q8005 is normal. Input voltage: 1.0-1.5 V, output voltage: 9.3 V, gain: about 15
dB. Gain amplifier bias of Q8006 is normal. Input voltage: 1.5-2.3 V, output voltage: 9.3 V,
gain: about 15 dB. The components must be soldered appropriately and remain in good
condition.
10) Gain amplifier bias of U8004 is normal. Output voltage: 1.3 V, gain: about 10 dB. The
components must be soldered appropriately and remain in good condition.
Note: The above check operations should be performed with the supply voltage of 13.6V.
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