MFJ MFJ-9420, Руководство по установке

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MFJ-9420 Installation Manual 20-Meter SSB Travel Radio
DC VOLTAGE CHART TROUBLESHOOTING GUIDE
For advanced troubleshooters, the following are typical DC voltages found in the MFJ-9420. Voltages were checked
with handheld probe type DVM to minimize effects of lead inductance and to limit the potential for RF feedback.
Vcc = 13.8 (Supply Voltage)
TP1 = 10.0 (LM-317 Output)
TP2 = 4.3 (AGC Bias Voltage)
INTEGRATED CIRCUITS: (TX checks made with mic. keyed, no audio)
-----------------RX----------------- ------TX-----
PIN U1 U2 U3 U4 U5 U6 U7
1 1.4 10.0 1.4 5.0 9.9 1.3 1.4
2 1.4 10.0 1.4 5.0 2.5 1.3 1.4
3 0 0 0 5.0 0 0 0
4 3.9 3.3 4.0 0 2.9 4.9 4.7
5 3.9 4.9 4.0 5.0 4.9 4.9 4.7
6 4.9 3.3 5.0 5.0 0 5.7 5.8
7 4.5 0 4.6 5.0 0 4.9 5.2
8 5.0 10.0 5.1 9.9 4.9 4.9 5.8
BIPOLAR AND JFET DEVICES:
D/E = Drain/Emitter
S/B = Source/Base
G/C = Gate/Collector
* = Test in TRANSMIT mode
** = Test with TUNE switch depressed
*** = DO NOT TEST gate of Q9 may cause generation of parasitic oscillations.
Q1 Q2 Q3 Q4 Q5* Q6 Q7* Q8** Q9 Q10
D/E 9.8 0 9.0 9.7 0 0 3.5 0 13.0 0.25
S/B 2.3 0.7 3.9 8.9 0.7 0.7 2.8 0 0 1.0
G/C 0 13.2 0 4.3 13.0 0 0 9.0 *** 13.7
Q11 (MRF477 PA Transistor): To avoid RF damage to DVM, check collector voltage in receive mode only full
supply voltage (13.8 V) should be present. Check base (bias) with PTT pressed, no audio this should indicate 0.6v.
Emitter is grounded.