sunair RT-9000C, Operation And Maintenance Manual

Page: 256 / 393

Document No. 8128000560
Software Revision – N1B (07 Oct 04)
7-24
RT-9000 B
7.3.2.9.5 Transmitter Power Output Level Entry
Depress the Power Level (‘PWR LVL’) key at
18 successively until desired Power Level appears on the
Operational Display at 19 . The available choices depend on whether an external Linear Power Amplifier
is present in the system and its power output capability. The available choices are: ‘65W’ or ‘125W’ when
an external amplifier IS NOT present. When an external amplifier IS present, the additional choices will
be: ‘500W’ for the LPA-9500 Amplifier or ‘500W’ and ‘1000W’ for the LPA-9600 Amplifier. Depress the
Enter key (‘ENTR’) at
6 to permanently store a new Power Level selection into the currently selected
Pre-set Channel.
After the desired Power Level setting has been entered for the currently selected Pre-set Channel,
proceed to the next heading if other equipment is being used in conjunction with the RT-9000 B
Transceiver. If no other equipment is being used, skip the next heading and go directly to the end of this
section.
7.3.2.9.6 External Equipment Set up and initialization
If the RT-9000 B Transceiver is part of a system with external equipment having Pre-set Channel
capability, this equipment should now be set up and initialized as described in the appropriate equipment
manuals.
The most common type of external equipment will be an Antenna Coupler. The User should refer to
section 7.3.2.4 for guidance.
After completing entry of all settings in this section, the RT-9000 B Transceiver is now ready for control on
this Pre-set Channel. Additional Pre-set Channels may be set up by repeating the preceding steps 7.3.2.9.1
through 7.3.2.9.5 for each new Channel Number.
7.3.2.10 BFO OPERATION
A Beat Frequency Oscillator (BFO) originally was required to receive Continuous Wave (CW) and later,
various suppressed-carrier mode signals such as Single Sideband (SSB). Modern Receiving equipment, like
the RT-9000 B , instead uses a Product Detector circuit to perform the detection (or demodulation) for these
signal types.
Even though the BFO function is no longer used for its original purpose, it still performs a useful function in
today’s equipment. The BFO function is a receive-only feature that provides fine frequency adjustment or
compensation for incoming signals. This permits the RT-9000 B to faithfully receive off-frequency signals
without affecting the RT-9000 B ’s transmitting frequency. Up to a ± 1.99 kHz frequency deviation from the
indicated or nominal receive frequency can be handled.
A common use of the BFO is to use it in voice modes as a “Clarifier” to correct unpleasant speech output
caused by a frequency offset. Other possible uses might include improving the operation of external tone
operated devices or modems.
To use the BFO function, depress the ‘MORE’ key from the main menu successively until the Feature Menu
Display shown in Figure 7.3.2.9 appears.