resolution.
For example, if a 50 ps initial
transmitter pulse length is
selected, and the Suppressor
control is rotated to maximum, the
transmitter pulse length would be
850 ps. Returning the Suppressor
control to minimum will restore the
unit to a 50 ps transmitter pulse
length.
The X-15A will display the initial
transmitter pulse length at the bot-
tom of the paper when
you over-
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 us
initial pulse length would be dis-
played as P-SO.
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
the initial pulse length.
Example: Set the initial transmit
pulse length to 100
micro-seconds.
Press: 1 - 0 - 0 - PULSE
Result:
---—-bO-—-F-ILU -•-—--
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 images.
Discrimination is a program
installed in the X-15A's
micro-processor that enables it to
process the output
from the re-
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, therefore records with
high resolution and high noise im-
munity can be achieved.
(The Suppressor Control may
be used with the Discrimination to
cancel OUT
heavy interference or
noise whenever high resolution is
not required.)
There are four levels of Dis-
crimination that can be used. The
lowest value (1) is the weakest
SPECIFICATIONS — X-15A
Depth Ranges:
Feet, fathoms, meters.
Operating Frequency:
192 kHz (192,000 cycles per
second); accuracy is within 0.6
percent.
Pulse Length:
(duration of pulse): 200-l000ps
(30-2000gs 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 - 12¼"
Height - 9"
Depth
- 6%"
Instrument Only:
Width - 101/4"
Height - 8¼"
Depth
- 6%"
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
may 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.
(Toil-free 1-800-331-3889).
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.
SCHEMATIC DIAGRAM AND
PARTS LIST
Should you desire a Schematic
Diagram and Parts list for your
Lowrance TRUELINE RECORD-
ER, send $1.00 to PARTS LIST,
Lowrance Electronics, Inc., 12000
East
Skelly
Drive, Tulsa, Okla-
homa 74128. Be sure and give us
the Model Number and Serial
Number of your SONAR
INSTRUMENT
— Ia—-— —•---••-—- —.
2L1---——.-— ———- 29-—-
20
NOTE: This sonar uses LPG -605 Chart Paper. PDF compression, OCR, web-optimization with CVISION's PdfCompressor