
39
Installing the De-icer System (if applicable)
7
Installing the De-icer System (if applicable)
Precautions
WARNING
Don't expose personnel to the medical hazards of intense radio fre-
quency (RF) radiation. Whenever working on the tower in the area of
the antenna, turn off all transmitters and lock them out so that they can-
not be turned on accidentally.
CAUTION
All parts of the de-icer system within approximately 20 feet (6 meters) of
any radiator must be shielded from RF energy, and the entire outdoor
portion of the system must be made waterproof.
CAUTION
An improperly installed de-icer can overheat and damage your antenna.
De-icer system
description
The de-icer system consists of the heating elements in the bays, their branch
cables, a bay junction box for each antenna bay, interbay cables, and a "pig-
tail" of wires about 10 feet (3 meters) long which you will connect to the
tower junction box you are to provide. The following will help in installation:
• System electrical schematic:
• Electrical specifications:
Your system may also include specially-ordered items, such as a ground-
mounted main control box, a power cable extending up the tower, or a tower-
mounted dual-setting thermostat.
Dual-setting thermostat
CAUTION
Remember that conditions may be favorable for icing on the tower, even
if they are not on the ground.
Shively Labs deicers are designed to prevent ice from forming on antenna ele-
ments and are not designed to melt ice that has already formed. For this rea-
son, Shively Labs recommends that the system be installed with a tower-
mounted dual-setting thermostat assembly (Shively Labs Model 55522-G502)
and de-icer control box (Shively Labs Model 94068) that ensure the deicers
are operated in the temperature range ice is most likely to form.
Electric power
The de-icer system requires 240 VAC, 50 - 60 Hz., single-phase.
shows
approximate heater leg resistances and current draw, respectively.
Table 3. De-icer specifications
Heater leg
resistance,
Heater leg (T1 or T2)
current draw, amps
1-Bay
288
0.42
2-Bay
144
0.84
3-Bay
96
1.3
4-Bay
72
1.7
5-Bay
57
2.1
6-Bay
48
2.5
WARNING
Installation should be per-
formed only by personnel
experienced in RF sys-
tems, qualified in electri-
cal work, and familiar
with this equipment.
Содержание 6822
Страница 4: ......
Страница 11: ...3 Preparation Figure 1 Mounting options ...
Страница 12: ...Preparation 4 Figure 2 Tower layout single antenna bay ...
Страница 19: ...11 Preparation Figure 9 Top mounted installation ...
Страница 20: ...Preparation 12 Figure 10 Proper and improper securing of bay cables ...
Страница 26: ......
Страница 30: ......
Страница 33: ...25 Connecting the Antenna 2 to 6 bay Figure 19 Slugged line section installation if applicable ...
Страница 35: ...27 Connecting the Antenna 2 to 6 bay Figure 20 Fine matching transformer installation ...
Страница 40: ...Connecting the Antenna 8 bay 32 Figure 23 Power divider mounting for 8 bay antenna ...
Страница 41: ...33 Connecting the Antenna 8 bay Figure 24 Slugged line section installation if applicable ...
Страница 43: ...35 Connecting the Antenna 8 bay Figure 25 Fine matching transformer installation ...
Страница 46: ...Connecting the Antenna 8 bay 38 Figure 27 Tower transmission line connection ...
Страница 55: ...47 Retuning Figure 37 Optimal VSWR at 108 MHz narrow feedstrap ...
Страница 56: ...Retuning 48 Figure 38 Optimal VSWR at 108 MHz wide feedstrap ...
Страница 57: ...49 Retuning Figure 39 Optimal VSWR at 88 MHz wide feedstrap ...
Страница 58: ......
Страница 62: ...Startup 54 Figure 41 Apply the signal ...
Страница 64: ......
Страница 66: ...Parts 58 Figure 42 Components 6822 bay without de icers ...
Страница 70: ...Parts 62 Figure 45 Components mounts for 3 1 2 to 6 mounting pipe ...
Страница 72: ...Parts 64 Figure 46 Feed system components for 2 to 6 bay antennas ...
Страница 75: ...67 Parts Figure 47 Feed system components 8 bay antenna ...
Страница 77: ...69 Parts Figure 48 Slugged line section if applicable components ...
Страница 78: ...Parts 70 Figure 49 Fine matching transformer optional components ...