Smiths Kelvin Hughes Nucleus 3 5000 Series, System Handbook

Page: 369 / 510

In di ca tors, Test Points, Links and Switches
(Fig ures 6d, 7d & 8d)
38 In di ca tors pro vided on PCBs are as follows:
(1) 25 kW FET Modulator PCB (CTX-A345)
(2) Tx Microcontroller PC Figure 6d - 25kW Modulator
Power PCB (CTX-A345): Indicators and Test
Point Locations (CTX-A346)
39 Test points are located on the following PCBs;
(1) 25 kW FET Modulator PCB (CTX-A345)
May 01 7d.10 Original
KH 2020
Chap 7d
Grid
D22 9G 300V SAFE Lit when +27V disconnected
from 300V power supply
circuits (SW1 set to OFF)
D23 9F 300V UNSAFE Lit when +27V applied to 300V
power supply circuits
(SW1 set to ON)
D24 4G 300V ACTIVE Lit when 300V supply present
Note: only lit when Tx Run
command present.
D33 6E HEATER Lit when Heater Turndown
circuit active
TURNDOWN
D34 7D S BAND Lit for S-band magnetron
Grid
D18 8F TUNE Lit when Tune ind signal
present
D41 4E PROCESSOR
RUNNING
Flashes when processor
running
D42 4E EXT TRIG Lit when external trigger
pulses present
D43 4E HEATER OK Lit when heater OK, flashes
slowly when timer running,
flashes fast when heater has
timed out
D44 4E Not used