resolution.
For example, if a 50 Its initial
transmitter pulse length is
selected, and the Suppressor
control is rotated to maximum, the
transmitter pulse length would be
850 is. Returning the Suppressor
control to minimum will restore the
unit to a 50 ' transmitter pulse
length.
The X-15B
will display the initial
transmitter pulse length at the bot-
tom of the paper when
you ovei-
ride the micro-computer. To
distinguish the initial
transmitter
pulse from the other information
printed on the paper, the graph
will print P-100 (if
the pulse
is set
to 100 micro-seconds.) A 50 Its
initial pulse length would be dis-
played as P-SD.
To set the initial transmitter
pulse length, simply press on the
keyboard the initial
pulse length
desired and then press the
PULSE key. For example, to set
the initial transmit pulse length to
150 micro-seconds, press 1 - 5 - 0
- PULSE. This will override the
micro-computer's selection and
set the initial transmitter pulse
length to 150 micro-seconds.

P-iso will be printed at the bottom

of the paper to signify
that the en-
try has been confirmed. (Note:
When an initial transmit
pulse
length is set, this length will be
fixed for all depth settings until
changed.)
To return control back to the
micro-computer, press 0 - PULSE
and the micro-computer will Select
thelnitial pulse lenth.
Example: Set the initial transmit
pulse length to 100
mipro-secqnds..
Press; 1 -0- 0 - PULSE
Result:
2—
2'i ——— •——..-..
—-———2b
Nfl
Figure 39
Discrimination
Noise
pulses are the
largest
complaint most often received
about sonar units. Lowrance has
had the patented Suppression
system for many years
which is
quite
effective at eliminating noise
from the display. (See
Transmit
Pulse Width.) The
only drawback
to the
Suppression system is that
it increases the transmitter's pulse
length which decreases resolution
and causes targets
that are close
together
to merge into one "blob"
instead of two distinct
image
Discrimination is a program
installed in the X-lSBs
micro-processor that enables it to
process the output
from

the e-

ceiver, determine which
signals
are noise and eliminate them,
then print only the legitimate
echoes.
Using this concept, the transmit-
ted pulse
does not have to be
increased, thsrefpre records with
high
resolution and high noise
irri-
munity
can be achieved.
(The Suppressor Control may
be used
wth the Discrimination to
cancel OUT heavy interference er
noiSe whenever high resolution is
not requfred.)
There are four leyets of Dis-
crimination that can be used. The
lowest value (1) is the weakest
20
SPECIFICATIONS X-15 B
Depth Ranges:
Feet, fathoms, meters.
Operating Frequency:
192 kHz (192,000 cycles per
second); accuracy is within 0.6
percent.
Pulse Length:
(duration of pplse): 200-i
000p.s
(30-2000jis programable)
Operating Voltage:
Minimum: 10 volts•DC
Maximum: 15 volts DC
Operating Current:
0.7 to 1.8 amps depending on
printing density and output
power.
Output
Power:
1600 watts typical peak-to-peak.
(200 watts RMS)
Weight:
8.5 lb. (3.9 Kg)
Dimension:
With Gimbal Mount:
Width - 121/4"
Height - 8%"
Depth - 51/4"
Instrument Only:
Width - 91/2"
Height - 71/2"
Depth - 5¼"
NOTICE
Periodically wash the Trans-
ducer Face with soap and water
to remove any oil film that may
collect. Oil and dirt on the face
will reduce sensitivity or
mey even
prevent sounding.
GOT A PROBLEM? LET US
HELP!
If
you have a problem with your
sonar unit, please give us a
chance to help
before sending it in
for repair.
Assistance can often be ex-
tended by telephone or letter.
Write or call one of our Authorized
Service Centers or the Lowrance
Electronics, Inc., Customer Ser-
vice Department in Tulsa, OK.
Call
(918)
234-1452.
Please detail
the problem you
are experiencing. Our Service De-
partment may be able to save you
the inconvenience of returning
yoUr unit.
If it is determined that your unit
must be returned, full shipping in-
structions will be provided.
PDF compression, OCR, web-optimization with CVISION's PdfCompressor