Mounting The Transceiver; A Typical Installation - SEA 222 Operator's Manual

3.5 CAUTION! FREQUENCY TOLERANCE
3.6
3.6.1
Under FCC Rules, the frequency tolerance for the Marine Service is
±
20 Hz. In order to achieve this accuracy a frequency counter
with a long term accuracy of 1-3 Hertz should be used.
All work affecting the transmitter performance must be done by, or
under the supervision of a person holding at least a General Radio-
telephone FCC license.
SETTING THE TRANSMITTER FREQUENCIES
THE MASTER CLOCK OSCILLATOR
Either of two methods may be used to adjust the Master Clock:
1.
Connect a high stabi
1
ity frequency counter to Pin 8 or Pin 11
of U17 on the Main Board (ASY 0222-01). Signal amplitude is approx-
imately 5 Volts P-P. Adjust trilTlller capacitor Cl51 for a frequency
reading of exactly 6400.00 KHz.
2. Select the highest desired transmitter frequency (such as 22101.5
KHz). With the transmitter output connected to an appropriate dulTllly
load and a few watts of re-inserted carrier being generated, connect an
appropriate counter to the RF dummy load and adjust trinmer capacitor
Cl51 for the correct carrier frequency. NOTE: This technique, when
used with a good frequency counter is generally superior to method
#
1.
4. INSTALLATION
4.1 MOUNTING THE TRANSCEIVER
All SEA models are compact enough to allow great flexibility in loca-
tion, even on smaller vessels. Several options for mounting are
available. The mounting bracket fits underneath or on top of the
transceiver for bulkhead, overhead or shelf locations. Figure 4.1
shows the outline. dimensions of the SEA. 222 and mounting holes. When
choosing a location for the radio set, take care to avoid areas
directly over a heater or lacking adequate ventilation.
4.2 A TYPICAL INSTALLATION
Figure 4.2 shows a typical installation consisting of three parts:
(1) The radio equipment; (2) Interconnecting cable; (3) The
antenna system.