The AN/TPN-18A radar set has two ventilation points.
★
A vent cover is located on the
underside of the RT. Remove the
cover before turning the radar set on.
★
A filter hood door is located on
the front of the RT. Open this door
before turning the radar set on.
When the radar set is turned off,
replace the covers, close the filter
door and cap the vents when internal
components have cooled down
enough to prevent moisture buildup.
You know the unit is
cooled down
when no heat radiates from the unit
and it is cool to the touch.
PS 586
Cold Facts
Clarifying ATC
The AN/TPN-18 radar set has three ventilation points.
★
There are two capped vents.
One is on the receiver-trans-
mitter (RT) side panel and one
is on the rear panel. Uncap
both vents before turning the
radar set on.
★
A vent cover is located on
the underside of the RT.
Remove the cover
before turning the
radar set on.
But it does
not
tell
you how to vent the
radar sets or check the
azimuth drive oil level.
Here’s the scoop…
The
ATC
(air traffic
control)
Equipment Cold
Facts
article on Page 37
of PS 579 tells you how
to avoid short circuits
and blown seals.
The azimuth drive illustration in TM 11-5840-281-12, and -12-1, tells you to
check the oil level at the azimuth oil fill plug opening. But that spells trouble
because the oil fill plug doubles as a vent for the azimuth drive. If you fill this reser-
voir with oil, you’ll plug the vent and the overfill condition will lead to a blown
azimuth drive seal.
Check Azimuth Drive Oil
AN/TPN-18 & AN/TPN-18A Radar Sets . . .
The
oil level
should
always
be flush
with the
bottom of
the plug open-
ing. Otherwise, you need to add oil.
Check the oil level at the oil level check
plug and overfill problems will be a
thing of the past. So will blown seals.
The oil level check plug is located on
the opposite side of the drawing pic-
tured in your TM—and in PS—next to
the J1003. You must remove the plug to
check the oil level.
SEP 01
39
Venting Your Radar Set
AN/TPN-18
AN/TPN-18A
Oil fill
plug
Oil drain
plug
586. 38-39 (C)
8/6/01
2:40 PM
Page 1