Raytheon Pathfinder 1200 Instruction Manual page 52

Trouble
8. No range rings
on the screen.
9. Range rings on
the screen but
no noise and no
echoes:
10. Noise and range
rings on the screen
but no echoes.
11. Poor sensitivity.
Dim echoes.
Remedy
Check:
o Fault of range rings generator cct on PC401.
o Fault of control cct on PC402.
Faulty circuit between IF amplifier of receiver unit and
input circuit of display unit video amplifier.
Check:
o Fault of GAIN, STC control settings.
o Fault of receiver unit.
o Fault of contact on terminal boards and connector.
o Fault of GAIN, STC cct on PC401.
If no transmission is present, check the modulator and
magnetron.
Check: If transmission appears to be present as indicated by
the correct MAG. I reading on Tester.
TBlOl MO
=
12 VDC
o Failure of Gunn Oscillator tuning.
If transmission appears to be present, carry out the
Gunn Oscillator tuning procedures and check the diodes.
o Fault of Gunn Oscillator.
o Fault of CD30l, 302.
If no transmission is present,
o Whether the lead wire to magnetron is contacted to chassis.
o Fault of magnetron.
Check:
o Reduction of transmitting output power.
o Fault of magnetron.
~ Check of MAG. I reading on TB 101-MO.
o Fault of diodes (CD30l, 302)
o Fault of CRT.
o Water in the radiator and waveguide.
(Dirt, caked salt, ice and snow on the radome?)
o Failure of Gunn Oscillator tuning.
o Failure of FOCUS adjustment.
o Failure of INTENSITY ADJ.
o Fault of video amplifier cct on PC401.
o Fault of receiver unit.
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