27
Lightning Protection
While amateur radio installations rarely suffer damage from lightning, the best protection is to
disconnect electrical devices during storms. The key to lightning survival is to properly ground
feedlines and equipment and to maintain the integrity of shield connections. A proper installation
improves lightning protection and enhances weak signal receiving performance.
Consult lightning protection and station grounding information in the ARRL handbooks, or by
referring to the NEC (National Electric Code). The DX Engineering website also has technical and
product information listed under “
Lightning Protection and Grounding
”. Use lightning surge
protectors available from DX Engineering for the coax feedline and control lines.
Turn On and Test
After installation is complete, a quick receiving test can be made by using a signal source such as a
mobile station which can drive to points directly away from the four selected directions. A
minimum distance of 2-wavelengths up to one mile maximum will yield the best test results.
You can also find signals on the air for receive testing.
When switching directions, the Four Square array should produce maximum signal only in the
direction of the signal source. There should be a very noticeable decrease in signal level when
switching to the opposite direction. Once the directional switching has been proven, you should
check SWR. SWR should be under 1.3:1.
If SWR is good, you can run on-the-air tests with stations either on groundwave (within a few
miles) or at reasonably long distances (500 miles or more). You should typically see about 5 dB
forward gain over omni, and at least 15 dB F/B ratio.
Power ON Relay Exercise
The Transmit Four Square Control Console has a factory default program installed to exercise the
relays throughout the system when power is turned on. When the unit is properly connected and
power is turned on, the first and last LED will blink for approximately 6 seconds. While the LEDs
are blinking, all of the relays in the system are being turned on and off to ensure the relays are kept
in peak operating performance. During this routine, if any position push-button switch is pressed,
the routine will stop and the system will return to the last position that was selected prior to the
system being turned off.
The operator can manually turn this routine on or off by pressing a sequence of front panel buttons.
To turn the factory default
OFF
:
1. Turn power ON. Wait until the first and last LEDs stop blinking.
2. Press any two of the push-button switches simultaneously and hold them in (LEDs will start
to blink) until the blinking stops. The factory default is now turned off. If you turn power
OFF, wait about 8 seconds (allows internal capacitors to discharge), then turn power ON, the
system will not run the relay exercise routine.