AUDIMAX 362 HD, Owner'S Manual

Page: 7 / 19

allows to connect a backup transmitter. Or a second
transmitter to nocturnal emission.
The connectors are a BNC. For MPX output use 75
ohms coaxial cable (standard in CCTV). The
maximum recommended length is 25 meters.
When use the MPX input of the transmitter, make
sure that the internal pre-emphasis stage is
disabled (flat response between 20 – 100 KHz).
Is important to have an adequate ground
installation. In case of doubt, refers to your Solidyne
dealer.
1.4.1 Humming
If some residual humming appears when the
system is started up; turn off the unit. If humming
disappears, check the 462 input connections. If the
humming still here; unplug the MPX cable. If
humming ends, this indicates that a problem occurs
with the ground connections.
Nevertheless, this problem rarely can occur since
the Audimax MPX output is differential type, where
the BNC connector has floating GND to cancel
possible humming.
1.4.2 Modulation level
The modulation depth is adjusted by changing the
MPX output level. It is recommended to use a
program material with voice and loud music
(contemporary pop for instance).
•
The level of audio on the console must
peak at
0 VU , in order to the AGC stage
works in its point of equilibrium.
•
Move all knobs to the center position.
•
If the transmitter has modulation level,
move to the minimun..
•
Change the output level of 362's MPX until
reach 75KHz of deviation (100%),
measurred at an FM Modulation Meter (like
Solidyne VA16) o using the instrument of
the tranmiter.
Some countries allows non-recurrent peaks at 110%
(I.e. FCC on USA).
n daily use processor probably modulation indicators
show needle-highest peaks at 100%. This may be
due to overshoot or ballistic responsive average
values of sine wave and the indication is wrong with
very processed audio material.
After adjusting the modulation level, you can proceed
to customize the sound of the radio; adjusting 362HD
Audimax controls. Obviously this does not affect
modulation adjustment, because the processor
delivers a constant level signal peak. To set the
personality of sound in air, proceed as described in
"2.2 - Audio settings".
1.5 ADITIONAL TECHNICAL
INFORMATION
Balanced and unbalanced I/O
In the following paragraphs you will find information
about how to connect unbalanced outs to balanced
inputs, and viceversa. This information will be of
extreme utility, not only for Audimax 362HD, but
also for other equipment of your radio. Different
cases are decrypted.
1.5.1 Balancead lines
Balanced lines use three cables to transmit the
signal: positive, negative and ground. The negative
takes the same audio signal of that the positive but
inverted 180°. GND corresponds to the shield of the
cable, which rejects the electrostatic noise
(switches, big motors, etc.). The fact that the audio
signal is sent by two cables, inverted in one of
them, practically annuls the noise induced on the
cable, specially the electromagnetic one, caused by
fluorescent tubes, AC lines, etc.
A balanced input amplifies only the difference
between both positive and negative signal. Since
the induced noise causes the same deviation in
both cables, when reducing both signals the noise
is eliminated (the (-) wire invert its phase, then, the
induced noise is reduced to itself). In addition,
equipments that uses balanced I/O are of
professional category and uses line levels of +4dBu
(1,23 Volts). Connectors are XLR or stereo plugs
(one by channel).
1.5.2 Unbalanced lines
They are used in “home” and non-professional
equipment. The audio is sent by a pair of cables;
being the one alive and other the shield of the
cable. These cables are much more
sensible to
the noise , mainly of electromagnetic type. They
handle line levels of the order of -10dBv (0.36
Volts).
The connectors typically used on this kind of units
are RCA o male plugs (TRS).
SOLIDYNE Audimax 362HD Page 7