Startup and Operation
28
Figure 14. Pressurized gas
schematic
Purge your system as follows:
a. If you have any liquid water in your transformer or your transmission line,
use a vacuum pump to dry the transmission line and transformer. Apply as
much vacuum as you can to the system and hold the vacuum for 8 hours.
This should remove any liquid water. [A vacuum pump can be rented or
borrowed from a refrigeration contractor.]
b. Determine how wet the system is and thus how much purging will be
required. If a system of rigid line carefully protected from weather and
assembled in dry weather is average, a system exposed to moisture during
storage or installation will be relatively wet. New semi-flex transmission line,
delivered pressurized with dry gas, will be relatively dry; used semi-flex will
be extremely wet.
CAUTION
If all moisture is not
removed from the inte-
rior of the system, it will
condense when the
weather cools. The result-
ing water will cause arc-
ing and permanent
destruction of the coaxial
system, including the
transmitter output net-
work.
