31
Startup and Operation
f. VSWR at this point should be below 1.10 : 1. If it is not, call Shively Labs to
help identify the problem.
g. When you have set the transformer, use a sharp point to scribe the shaft
where it leaves the flange collar.
h. Record the control settings of the two control rods and file this information
with this manual for future reference.
i. Tighten both hose clamps. If the clamps are left loose, vibration may change
the adjustments.
System sweep
(recommended)
Shively Labs strongly recommends that you perform a system sweep of your
transmission line and antenna while you have the installation crew on site.
Should any problems arise later with your antenna, it will be extremely helpful
to know what the system’s characteristics were when it was new. We recom-
mend you perform a system sweep after installation.
CAUTION
A high voltage standing wave ratio (VSWR) may indicate damaged trans-
mission line or incorrectly assembled components. This condition will
cause serious damage to your equipment when full power is applied.
Many riggers can sweep your system after installation or recommend a con-
tractor to perform it. Alternatively, Shively Labs makes available instructions
for system sweep on our Web site, www.shively.com.
Checkout
Before beginning checkout of the antenna system, be sure the following items
have been done:
• The antenna system has been installed in accordance with this
manual and the installation drawing.
• The de-icer system, if purchased, has been checked out in accor-
dance with
Chapter 3
.
• All radiators are operating; impedance has been trimmed, and
VSWR is low.
• The transformer settings and initial characterization data have been
recorded.
• The system is gas-tight and purged.
Check the system out as follows:
a. Bring up RF power slowly and observe transmitter readings, stability, and
general operation.
b. Run at about half power for at least an hour, reading forward and reflected
power, stability, etc.
c. If the system is stable and seems to be operating properly, bring it up to full
power. Take initial readings, and repeat the readings periodically.
d. Performance readings should not change, and there should be no evidence
of heating in the antenna system.
If any problem is found, fix it now. Call Shively Labs if you need help or
advice.
