MFJ MFJ-1046 User Manual

MFJ-1046 Instruction Manual

Passive Preselector

MFJ-1046 PASSIVE PRESELECTOR

Introduction

The MFJ-1046 Passive Preselector is designed to reduce receive overload from strong out of band signals. It contains selective circuits that cover 1.6 to 33 MHz in six steps, providing the greatest selectivity on the lowest frequencies where overload is most common.

The MFJ-1046 has two rear panel SO-239 connectors for RF connections and a bypass switch to take the unit in and out of the circuit.

Installation

Connect the MFJ-1046 Passive Preselector between your antenna and receiver as shown in Figure 1. The Radio connector goes directly to the receiver with a short well shielded lead; the Antenna connector goes to the antenna.

Figure 1

WARNING: NEVER connect an amplifier or transmitter to the MFJ-1046 Passive Preselector. Failure to follow this warning may cause MFJ-1046 Passive Preselector or other equipment to be damaged.

1

MFJ-1046 Instruction Manual

Passive Preselector

Operation

With the MFJ-1046 Passive Preselector properly connected, simply turn the Band switch to the desired band and adjust the Tune control for maximum signal level. With the Bypass switch depressed, the MFJ-1046 Passive Preselector becomes active.

Adjust the Tune control for maximum signal level. The maximum loss on the desired amateur band is less than 5dB if the correct frequency range is selected.

Note: Always use the highest frequency band range that covers the desired band for minimum loss.

Typical frequency response is shown in Figure 2.

A: Transmission Loss

Figure 2

2