MFJ-1026 Instruction Manual
Deluxe Noise Canceling Signal Enhancer
1
MFJ-1026
MFJ Deluxe Noise Canceling Signal Enhancer
Instruction Manual
Introduction
To get the best performance from your MFJ-1026, read this manual. It is especially important to heed all
warnings to prevent equipment damage.
The MFJ-1026 is designed to reduce noise or interference, or improve desired signals, before the noise
affects sensitive receiver circuits. Unlike conventional noise blankers, the MFJ-1026 can be effective on
all types of noise, including interference (QRM) from unwanted signals. The MFJ-1026 allows the user
to adjust both phase and amplitude while combining two antenna inputs. The antenna inputs can be
from two external antennas, or an external antenna and the MFJ-1026 internal whip antenna. The signal
output for the receiver is the vector addition or subtraction of signals from two separate antennas. This
allows unwanted noise to be removed or desired signals to be enhanced. The MFJ-1026 is optimized
over the range of 1.8 to 30 MHz.
The phasing method of signal enhancement or null removal has several advantages over conventional
noise blankers. The advantages are:
1. Interference can be much stronger than the signal and be completely removed without affecting the
desired signal.
2. The MFJ-1026 can be effective with all types of interference and on all modes.
3. Signals can be added instead of subtracted with the simple push of a button.
The circuitry in the MFJ-1026 has exceptional phase amplitude flatness, making adjustments easy and
very repeatable. Typical phasing systems provide either limited phase adjustment range, or changes the
signal's level as phase is adjusted. In the MFJ-1026, gain changes less than 3 dB (and typically less than
1 dB) as the phase control is rotated throughout its range.
Effective and proper operation occurs only when the
same
noise (for nulling noise) or desired signal (for
signal enhancement) is present on both the AUXILIARY (or internal whip antenna) and MAIN antennas.
If the interfering source is
not
audible on the internal whip antenna, the MFJ-1026 has provisions for
using an external noise antenna (labeled "AUXILIARY ANTENNA" on the rear panel).
In most cases, it
will be necessary to use the external
AUXILIARY ANTENNA
input.
The MFJ-1026 contains interface circuitry necessary for operation with most modern HF transceivers.
Although the MFJ-1026 contains internal T/R (transmit-receive) RF sensing, w
e STRONGLY
recommend using the external T/R Control line on the rear panel for keying the MFJ-1026.
