MFJ MFJ-4724 User Manual

MFJ-4724 Desktop/Remote Antenna/Transceiver Switch Instruction Manual

Desktop/Remote Four-Position

Antenna/Transceiver Switch

INTRODUCTION

The MFJ-4724 is a versatile multiple antenna/transceiver switch designed to
switch up to four 50-ohm antenna systems or four transceivers in any
combination. It handles high power, up to 1500 Watts and sealed relays offer
excellent life and connection reliability. The unit is operational from 1-60 MHz
and useable to 150 MHz. See Table 1 and 2 for the best Antenna/Transceiver
combination for your particular frequency.

The MFJ-4724 Desktop/Remote Antenna/Transceiver Switch uses two simple
rotary switches to select one-of-four antennas or four transceivers in any
combination. Use the MFJ-4724 Desktop/Remote Antenna/Transceiver Switch
on your desk or place it out-of-way under your desk or in another room and use a
remote control. In the OFF/Remote position, all inputs are grounded or control is
transferred to the MFJ-4724RC Remote Control. All unused inputs are grounded.
You can connect a sense line to your transceiver so when it’s off all inputs are
automatically grounded.

The MFJ-4724 will work well in nearly any system requiring switching of coaxial
lines, especially those requiring good quality 50-ohm RF switches, so you can
select one-of-four radios to one feedline or one-of-four antennas to a radio.

MFJ-4724 Desktop/Remote Antenna Switch Features

• High Power Capability: Handles 1500 Watts/50-75 Ohm load.

• Wide Frequency Range: 1-60 MHz. Useable to 150 MHz.

• Easy-to-Use: Two simple rotary switches allow you to select one-of-four

antennas and one-of-four transceivers.

• Versatile: Use on your desk or place it out-of-way under your desk or in
another room and use a Remote Control.

• Lightening Protection: Ultra-fast gas discharge tube lightning surge
protector protects transceiver and safely shunts static electricity and
lightning induced surges safely to ground. All unused inputs are grounded.
Does not protect against a direct lightening hit.

• Radio Sense: You can connect a sense line to the 12VDC accessory jack
on your transceiver so when it’s off all inputs are automatically grounded.

• Standard Connectors: Uses SO-239 connectors.

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MFJ-4724 Desktop/Remote Antenna/Transceiver Switch Instruction Manual

ELECTRICAL CHARACTERISTICS

SWR for each Antenna Connection

Frequency

(MHz)

1.8 1.0 1.0 1.0 1.0

3.5 1.0 1.0 1.0 1.0

7.1 1.0 1.0 1.0 1.0

14.1 1.1 1.0 1.0 1.1

21.0 1.1 1.1 1.1 1.1

29.7 1.1 1.1 1.1 1.1

54.0 1.8 1.5 1.5 1.8

150.0 1.7 1.5 1.5 1.7

Table 1: SWR for each Antenna Connection on Selected Frequencies

1 2 3 4

Frequency

(MHz)

SWR for each Transceiver Connection

A B C D

1.8 1.0 1.0 1.0 1.0

3.5 1.0 1.0 1.0 1.0

7.1 1.0 1.0 1.0 1.0

14.1 1.1 1.0 1.0 1.1

21.0 1.1 1.1 1.1 1.1

29.7 1.1 1.1 1.1 1.1

54.0 1.8 1.5 1.5 1.8

150.0 1.7 1.5 1.5 1.7

Table 2: SWR for each Transceiver Connection on Selected Frequencies

Tables 1 & 2 show the SWR for each Antenna and Transceiver Connection. To
determine the best Antenna and Transceiver combination for your particular
frequency, simply choose the connections with the best SWR on the desired
frequency and match them.
For Example: At 150MHz, the best Antenna connection is 2 or 3 and the best
Transceiver connection is B or C. Therefore, I will connect my Antenna to
connection 2 or 3 and my Transceiver to connection B or C.

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