Balun for 450 ohms balanced antenna to 50 ohms co-axial. 9:1 W2FMI Jerry Sevick

Description

CWS  9:1 Balun Current Type Jerry Sevick W2FMI Series
High Power Powder Coated  Core 9:1 ratio; 450 balance antenna to 50 ohms co-axial; 1.5 - 30 Mhz.; Weatherproof box.
Specifications:
Frequency Range:
1.5 - 30 MHz
Ratio:
9
:1
Termination Impedance (Ohms):
450
balanced
Termination Location:
Top
Termination
Type: High Voltage
Ceramic feed through
Enclosure Type:
Weatherproof box. Can widthstand rain, snow, sun, etc
Enclosure Material:
Anodized Aluminium
Metal
Core Type:
K-Type High Power Ferrite core
Power Handling (CW/SSB):
1 kW / 2 kW
Enclosure Height:
6.25
in. (6.8 inch with flange)
Enclosure Width:
3.80 in.
Enclosure Depth:
3.60
in.
Lowest Band of Operation:
200 meters
Highest Band of Operation:
10
meters
Antenna Mounting Type:
Antenna wires
Details:
Custom K type core is used to obtain the widest bandwidth.
Typically insertion loss is less than 0.2 dB.
Highest voltage breakdown ratings.
BALUN is "
Current" type
Anodized
Aluminum case with SO 239 connector and 2 ceramic feed through post as outputs.
Application:
1. Use W2FMI 9:1 balun to matching 50 ohms cable to a balanced load of 450 ohms
2. Use 2 of these baluns when a 450 ohms ladder line or twin leads is used to replace long runs of coaxial cable. The co-axial cable has more loss at frequencies above 14 mhz as compared to ladder lines. Install one balun on each ends.
3. Be careful when using the 9:1 balun as the terminations can cause the impedances even though the feedline maybe 450 ohms.
For example, a center fed half wave dipole, the impedance could be from 50 ohms to 4000 ohms. Also if the center fed dipole is a full wave long, the balun could be seeing impedance of less than 50 ohms to as high as 10K ohms depending on the length of the transmission line.