The Power Connector; Terminal Function - SEA 222 Operator's Manual

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4.3
4.3.1
4.3.2
4.3.3
Any radio conununications system operating in the MF-HF spectrum MUST
have an adequate ground connection, otherwise the overall efficiency of
the radio installation is degraded. In extreme cases, it may be
impossible to properly load the radiotelephone int!> the antenna.
The 50 Ohm output impedance of the SEA 222 makes it necessary to
employ an antenna system of the resonant or externally matched type.
The use of the SEA 1612 antenna coupler in conjunction with a whip
antenna allows an effiecient installation which will cover both the MF
and HF bands. The SEA 1612 was designed specifically for Marine
applications and will easily in.terface with the transceiver.
On wooden or fiberglass boats, the use of copper ground plate or
the keel on a sailboat perform adequately. The ground system ~UST be
joined to the antenna coupler with a heavy copper strap.
REAR PANEL CONNECTIONS AND FUSES
THE POWER CONNECTOR
A heavy duty power plug is employed on the SEA 222 to assure minimum
voltage drop in the primary power circuit. See Figure 4.3.1 for proper
assembly of the power plug •
THE RF CONNECTOR
One type of VHF female connector is provided on the SEA 222 rear
panel. The output impedance of this transceiver if 50 Ohms. The most
conunon types of coaxial cables used are RG-58C/U ·and RG-213/U. The
correct mating plug is the PL-259 or Amphenol 83-lSP.
THE REMOTE PLUG
A nine contact screw terminal type plug is provided on the SEA 222
rear panel, Figure 4.3.3, to allow the installation of an extension
(simple remote), an external loudspeaker or a handset. Also provided
i·s the switched, fused primary power (13.6 Volts) to operate an antenna
coupler, along with an "all tuned" flag line.
TERMINAL FUNCTION
AF - Output of the audio power amplifier,- AC coupled. Speaker impe-
dance to be used is 3.2 Ohms or more.
SPKR - Internal speaker input. A jumper to AF is needed to operate
the internal loudspeaker.
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