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| ALL-NEW
LEADING EDGE RECEIVER DESIGN |
Catching DX
on all the amateur bands between 1.8 and 450 MHz requires
a receiver with several basic characteristics: (A)
excellent sensitivity, to pull out weak signals: (B)
minimal noise contributed by the receiver: and (C)
the ability of the receiver to survive in the presence
of extremely strong signals. The FT-847 was specifically
design to excel in all these areas.
On all bands, the fundamental architecture of the receiver is the same.
After input bandpass filtering, a defeatable RF preamplifier provides front-end
gain with very low noise figure and excellent dynamic range. The RF preamplifier
is followed by a one-chip quad-FET first mixer, which provides outstanding
rejection of intermodulation. The first receiver IF is at 45.705 MHz, while
the second IF is at 455 kHz, where the main IF selectivity elements are
found.
The receiver front end is the result of hundreds of hours testing, evaluation,
and re-design so as to provide wide dynamic range in the presence of a
large number of strong signals, not just two tones in a testing lab. Devices
to be used in the front end are individually selected and matched after
extensive testing, so as to ensure consistent performance in the field.
Yaesu, the pioneer in the development of the HF transceiver, continues
that tradition with the leading-edge receiver performance of the FT-847! |
| DIRECT
DIGITAL SYNTHESISER PROVIDES ULTRA-LOW NOISE! |
 Replacing
noisy PLL circuits of earlier years, the FT-847 utilises
a new-generation ultra-low-noise DDS (Direct Digital
Synthesiser) in its local oscillator design. The
DDS provides very fine tuning steps (down to 0.1
Hz per step!) for careful tuning of EME signals,
seamless Doppler Shift correction during satellite
work, and effortless Digital mode tuning. Additionally,
the ultra-low-noise design of the DDS does not compromise
the wide dynamic range of the receiver, by ensuring
that the local signals are pure, with noise sidebands
well suppressed. The outstanding Carrier-to-Noise
Ratio of the DDS translates into better Signal-to-Noise
ratio for your FT-847's receiver.
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*
Low-Noise Receive Preamplifiers including HEMT
Device for 430 MHz!
Ensuring best noise figure for
UHF operation, Yaesu's engineers have incorporated a very-low-noise
10 dB HEMT (High Electron Mobility Transistor) preamplifier
for best sensitivity. Especially valuable for the 430 MHz
DX work, the HEMT preamp contributes to the FT-847's industry-best
sensitivity specification of 0.125 uV for 10 dB S/N (SSB
bandwidth). If you have tower mounted preamplifiers you with
to utilise instead, the FT-847 can be configured (independently
on 144 and/or 430 MHz) to bypass the internal preamp in favour
of passing +13.8V DC through your coax line to power your
preamplifier.
*
EXCLUSIVE PUSH-PULL COOLING SYSTEM™!
The FT-847's twin cooling fans
conduct heat away from the critical circuitry of the transceiver.
The front-panel fax provides efficient ingress of cool
air, which is ducted access the control and amplifier circuits.
The rear fan, in turn, forces warm are out the back panel
vents. The extensive thermodynamic design effort had produced
a transceiver which is ready for challenges of digital
mode or contest operation.
* Exciting Receiver
Features Enhance Your Operating Experience!
* EXPANDED RECEIVE FREQUENCY
RANGE 37-76, 108-174, and 420-512 MHz.
So you can check propagation
below 6 meters, monitor the 4-meter band, download
images from weather satellites, or follow the action
on the public safety frequencies!
* IF SHIFT: For adjustment
of IF passband to avoid interference.
* IF NOISE BLANKER:
For reduction of automotive ignition noise.
* INPUT RF ATTENUATOR:
For more comfortable reception of extremely strong
signals.
* FIXED-LEVEL AF OUT
JACK: For connection to tape recorder, WeatherFax
decoder. etc. |
| INNOVATIVE
TRANSMITTER DESIGN CONCEPTS! |
| The FT-847's
unique power amplification design represents a major
breakthrough in the amateur radio industry. For 1.8-54
MHz, the FT-847 uses a pair of rugged 2SC5125 bipolar
power transistors in a push-pull configuration. On
the 144 MHz band a single 2SC5125 is utilised, and
on the 430 MHz band, a 2SC3102 UHF power transistor
is used. Carefully specified and selected devices are
employed in the power amplifier stages of the ultra-compact
transceiver, producing consistent, reliable power output
with low SSB intermodulation characteristics.
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| MICROPROCESSOR
CONTROL PROVIDES OPERATING ENJOYMENT! |
 * Quick
Navigation via SHUTTLE-JOG™ Tuning Ring
First introduced on Yaesu' s
FT-1000MP and FT920, the Shuttle-Jog™ Tuning Ring provides
rapid frequency change by its unique spring loaded design.
Rotating the Shuttle-Jog™ ring slightly to the left
or right begins manual scanning to lower or high frequencies
respectively. Lean the ring further, and the scanning rate
increases. There's no better way to get "feel" for
a band than by using Yaesu's exclusive Shuttle Jog™!
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Separate Sub-VFO Tuning Knob
The Sub-VFO Tuning Knob may be
used in a number of ways. For transceive operation
using the Main
VFO, this knob may function as a CLARIFIER control ("R.l.T.")
for minor frequency offsets. During HF "Split" DX pile-up
operation, it may be used to adjust your transmit VFOs frequency.
And during Satellite operation, it lets you correct your uplink
frequency for Doppler Shift. |
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 *
Channelised VFO/MEM CH Control Gets You Where You
Want to Operate!
For those situations where quick
(but precise) tuning of the band is required, the VFO/MEM CH
switch provides "channelised" tuning via a rotary switch
encoder knob. The step sizes may be changed, via the Menu, independently
for the SSB/CW, AM, and FM modes and independently (on these
modes) for the HF, 50 MHz, 144 MHz, and 430 MHz bands. During
Memory Channel operation, this knob provides selection of your
previously-stored memories. |
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* "SPLIT" Operation
for DX-pedition and Pile-up Operating!
Besides the Satellite and FM Repeater
modes, the FT-847 includes a "SPLIT" operating mode
for DX operation on the 7 MHz SSB band, or for DX pile-ups where
the difference between the TX and RX frequencies is beyond the
Clarifiers +9.99 kHz range. The Sub VFO serves as the VFO for
transmission, and its frequency may be adjusted via the SUB-TUNE
VFO knob. |
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* High-Contrast
Multi-Function Blue Liquid Crystal Display (LCD)
The large (200 mm x 20 mm) blue LCD
provides high resolution and contrast for easy viewing over a
wide range of angles and light levels. Dozens of status indicators
keep you informed of every aspect of your FT-847's operational
characteristics, with the large Sub-VFO field on the right side
being particularly helpful during satellite operation. The LCD's
illumination brightness is adjustable via an 8-level dimmer function.
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10-Key Direct Frequency Entry Keypad!
For quick QSY particular frequency,
the keypad may be used for direct frequency entry on both the
Main and Sub VFOs. The keypad also provides control functions
for repeater, scanning, and band/frequency hopping. |
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* High-Speed
Direct Computer Control Interfacing
Yaesu's CAT System for Computer
Aided Transceiver control is provided via a rear-panel "DB-9" connector,
and it includes a built-in RS232C level converter. Just hook
up your serial data cable, and you're ready for action! Data
may be transferred at speeds of 4800, 9600, or even 57600 bps! |
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* Optional
Voice Frequency Announcement Module (FVS-1A)
For operators with impaired vision,
the FT-847 includes provision for the optional FVS-1A Voice Synthesiser,
which gives you an audible announcement of the current operating
frequency (with resolution to the nearest 100 Hz step) |
| CROSSBAND
FULL DUPLEX OPERATION! |
| The four antenna
jacks on the rear panel of the FT847, in conjunction
with Yaesu's time-proven crossband full duplex design
know-how, bring you effortless satellite operation
whereby you can monitor your downlink signal from the
satellite while you are transmitting. The FT-847 is
ready for operation on Mode A (TX: 145 MHz, RX: 29
MHz), Mode B (TX: 435 MHz, RX: 145 MHz), Mode J (TX:
145 MHz, RX: 435 MHz) and Mode T (TX: 21 MHz, RX: 145
MHz). Independent and display of both uplink and downlink
frequencies is provided. |
