CHA TD
Page 19
5.
If still not operational, replace Coaxial Cable assembly.
Most problems with antenna systems are caused by
the coaxial cables and connectors.
6.
If still not operational, connect a Standing Wave Ratio (SWR) Power Meter and check SWR.
7.
If SWR is greater than 3:1, connect a Multi-Meter to Termination Resistors (g). Termination Resistor should
measure 300 Ohms. Replace if they measures less than 285 Ohms or greater than 315 Ohms.
8.
If still not operational, connect a Multi-Meter to the Antenna Wires to check continuity. Replace assemblies
that do not pass a continuity check.
9.
If still not operational, replace Matching Transformer (a).
Specifications
Frequency: 1.8 MHz through 30.0 MHz continuous (including all Amateur Radio Service bands 160m to
10m), 30 .0 MHz through 54.0 MHz continuous (including the 6m Amateur Radio Service band) also
available when the CHA TD is installed in the Half Rhombic configuration
Power: 100 W continuous duty cycle (CW, AM, FM, RTTY), 300 W intermittent duty cycle (SSB and SSB-
based digital modes)
RF Connection: UHF Plug (PL-259)
SWR: Subject to frequency and configuration, but typically less than 2.5:1 (2.75:1 below 2 MHz)
Length: 120 ft (maximum), 112 ft (typical), 35 ft (minimum)
Footprint: 1,800 sq ft (maximum)
Weight: Less than 10 lbs
Personnel Requirements and Setup Time: one trained operator, less than 15 minutes
Far Field plots for the various CHA TD are shown in figures (9) through (13)
Figure 9. Sloping “V” Far Field Plot, 7 MHz (left), 14 MJHz (right).
