CHA P-LOOP 2.0
Page 10
Loop Operation
The CHA P-LOOP 2.0 is easy to use. Perform the following steps whenever you change frequency more than half
the bandwidth listed in Table (1) on the band for which you are operating. For example, on 20 meters, you should
retune if you change frequency greater than 20 KHz.
1.
The CHA P-LOOP 2.0 is bidirectional favoring the sides, see plate (5). If possible, point one side toward the
target signal and rotate the antenna for maximum signal strength.
Plate 5. Magnetic Loop Antenna
Directivity.
2.
Adjust the Tuning Knob (h) for maximum
receive signal strength. Turn the Tuning
Knob right or clockwise to increase (+) the
resonant
frequency
and
left
or
counterclockwise to decrease (-) the
resonant frequency, see Plate (6). You will
know when you are close to resonant
frequency because you will start hearing
signals and a marked increase in receiver
background noise. The Tuning Knob uses a
6:1 reduction drive which allows for fine
adjustment and will rotate approximately
2¾ revolutions from lowest to highest
frequency. Do not attempt to force the
Tuning Knob past the stops.
3.
Ensure your transmitter is set to output no
more than 5 Watts during tuning.
4.
Transmit a carrier and slowly turn the
Tuning Knob slightly counterclockwise and
then clockwise, around the position of
highest receive signal found in step 2, to
obtain the lowest SWR. An SWR of less
than 2:1 is satisfactory. The bandwidth of
the loop on 40 meters is only 15 KHz, so
once you are close to resonance make only
the slightest Tuning Knob adjustments.
Due to the superior design of the CHA P-
LOOP 2.0, there is minimal body induction
while tuning the loop. The SWR should
remain stable while tuning with your hand
and operating while holding the antenna.
Plate 6. Tuning Knob Operation.
5.
Increase transmitter power to no more than
the specified limit for your mode and duty
cycle (see specifications).
Note:
If unsure,
y
ou are always safe using 10W without the
Power Compensator, and 20W when using
the Power Compensator.
