Read the QST Review of the IC-7700 here!
*Click the image to view the PDF review.
+40dBm 3rd order Intercept Point (IP3)
The IP3 performance of a radio can be improved by
sacrificing sensitivity, but Icom considers this a poor choice. To achieve
REAL high-performance, Icom reviewed all of the analog receiver circuitry.
The IC-7700 employs mechanical relay BPF switching, a digitally tuned
pre-selector, and three Hi-spec 1st IF filters (roofing filter) in a Dynamic
range characteristics (in 14MHz band) clean and simple double-conversion
superheterodyne design. By balancing the analog and DSP functions, the
IC-7700 provides superior sensitivity simultaneously with a superb dynamic
range of 110dB, and +40 dBm IP3 (even in USB mode with 2.4 kHz filter
Better than +110dBm 2nd order intercept point (IP2)
IP2 point of more than +110 dBm* means
the 2nd order distortion from strong broadcast stations will be completely
eliminated. The endless pursuit of leading analog circuit engineering makes
it possible to achieve this leading edge level of performance.
* Measurements were made using custom equipment,
due to the limits of normal signal generators (SG) and duplexers to +85 dBm.
The IP2 figure is a typical value.
Double conversion superheterodyne system
While multiple IF stages can become a source of distortion products and
spurious responses, the IC-7700 utilizes Icom’s original image-rejection
mixers in a simple double conversion superheterodyne. This reduces
distortion and produces a much cleaner audio signal compared to triple or
quadruple superheterodyne receivers.
High specification inband IMD
In-band IMD (Intermodulation Distortion) creates undesired spurious
signals as a consequence of non-linear processing of multiple signals. All
(2nd, 3rd or even higher) orders of IMD performance are superior in the
IC-7700. The improvement will be especially evident in CW mode. You’ll
notice the difference as you copy weak signals without internal distortion
Inband IMD characteristics
Band pass filter
While some may
lead you to believe that coils and capacitors are all created equal, at Icom
we know design excellence. Rather than using switching diodes that can
introduce distortion, the IC-7700 design utilizes high-grade mechanical
relays along with large capacitors and toroidal coils; resistant to magnetic
saturation, providing superior linearity, and greatly reducing distortion.
DIGI-SEL (Digital pre-selector)
DIGI-SEL (digital pre-selector) is a very narrow, user adjustable, pass band
filter designed to automatically track the operating frequency, attenuating
interference from out-of-band signals. While the pre-selector’s pass-band
remains centered on the operating frequency, on the fly adjustments are
possible via front panel controls. The DIGI-SEL is especially useful for
multi-transmitter operation and near strong broadcast stations by reducing
the 2nd, 3rd, and even higher order IMD components from other stations.
The IC-7700 has a total of 4 pre-amplifiers, two for the HF bands and two
for the 50MHz band. The purpose of pre-amplifiers is to improve receiver
sensitivity for the pursuit of higher gain and a better noise figure. The
IC-7700 employs a noiseless feedback design with push-pull amplifiers. Using
feedback transformers, the pre-amplifiers provide a high IP3 while keeping a
low noise figure.
The 1st mixer stage is driven with a signal from the high-drive Local
Oscillator with excellent C/N. A 16V p-p of high-level LO signal is applied
to the mixer to improve intermodulation characteristics while avoiding a
parasitic oscillation or noise.
Three Hi-Spec 1st IF filters (Roofing Filter)*1
The IC-7700 employs three Hi-Spec 1st IF filters (roofing filters) of
15kHz, 6kHz and 3kHz before the 1st IF amplifier. Icom ordered special
customized high specification devices to improve IMD and achieve better
impedance characteristics. As a result, the 3kHz 1st IF filter provides
approximately 134dB*2 of
blocking dynamic range and allows you to pull out a weak signal in the
presence of strong adjacent signals.
*1 Icom calls the roofing filters
“Hi-spec 1st IF filters”, because their performance is much better than
regular IF filters.
*2 At 14.1MHz receive, with 5kHz separation of interference
2nd-stage image rejection mixer
The 2nd-stage image rejection mixer processes signals to reject spurious
image responses. In conjunction with the Hi-spec 1st IF filters (roofing
filters), image rejection of greater than 100dB is realized. The analog
image rejection mixer’s linearity makes it possible to use a simplified
receiver design. This improves the distortion performance of the receiver.
50MHz band preamplifier and mixer
The IC-7700 was designed with the 6m aficionado in mind. Rather than
sharing circuits used for HF, a separate preamplifier and mixer was designed
especially for 6m. This greatly improves the receiver sensitivity by
reducing intermodulation characteristics, enabling weak signal works without
distortion or interference from strong signals in the band.
Two AGC Loops
The IC-7700 has two AGC loops. The AGC voltages detected in front of and
behind the digital IF filter in the DSP unit. The first AGC loop prevents
the saturation of the 1st IF amplifier from strong signals outside the
pass-band filter, and improves the dynamic range in the presence of strong
adjacent signals. The other AGC loop detects the AGC voltage at the digital
IF filter output which has only passed the intended signal and draws the
full potential from the digital IF filter.
The IC-7700 accommodates both the “on-the-fly” operator as well as the most
avid “tweaker” operator by providing tunable AGC preset and manual AGC level
controls. The AGC time constants can be set in the 3 presets (slow, medium
and fast), adjustable from 0.1–6 sec. (0.3–8 sec. in AM) delay. Then the
addition of the AGC VR control enables the user to “tweak” or fine tune the
AGC reaction time.
High stability OCXO unit
control of the IC-7700 is maintained by the high stability Oven Controlled
Crystal Oscillator. The OCXO achieves frequency stability of ±0.05ppm across
the specified temperature range, meaning that the frequency will deviate
only 5Hz out of every 100 MHz! This specification is equivalent to that of
specialized measuring equipment such as signal generators or spectrum
analyzers. Also, a 10MHz reference signal can be input to the IC-7700 or
output for use by external equipment.
The well-selected components provide premium performance
Mechanical relays using gold contacts have excellent deterioration
resistance and superior conductivity.
1st IF filter
The IC-7700 uses custom made Hi-spec 1st IF filters (roofing filters),
selected especially for excellent IMD characteristics.
To reduce secondary distortion, large coils and capacitors are used in the
high-amplitude filter switching circuits. The use of non-linear
semiconductors is minimized.
The transmitter and receiver use a 32-bit floating point DSP,
offering the high performance of 1800 MFLOPS processing. Also, the spectrum
scope DSP achieves 1200 MFLOPS of peak performance.
The power amplifiers use a combination of push-pull final with two
MRF150 transistors, having proven reliability in ultra professional
communications. These devices generate a stable 200W of output power from HF
7-inch wide color TFT LCD
While Icom’s RF engineering team reviewed receiver designs for how the
IC-7700 hears a signal, close attention was also paid to how the operator
sees a signal. Details such as response time, color, resolution, and
visibility were extremely important. Thus, an active matrix 7-inch (800 ×
480 pixels) TFT color display was selected as the IC-7700’s display. The
display provides superior performance in response time, color, resolution,
visibility and more. The large display shows operating frequencies, various
settings and operating conditions as well as the spectrum scope, S-meter and
RTTY/PSK31 decoded messages. The S-meter shows an analog-like swinging
needle that is smooth and accurate. In addition to the analog like-style
meter, the IC-7700 has a digital multi-function graphic meter and edgewise
meter - chose your favorite style! Further more, the IC-7700 has a VGA
connector for an external monitor and an S-meter connector for an external
USB ports on the front panel
USB ports on the front panel allows you to easily connect a USB type
keyboard or USB memory stick to save transceiver settings, update firmware,
or transfer settings to other IC-7700. Making big scores means keeping your
team fresh on those long DX-peditions or Multi-Operators contests. Swapping
out operators usually involves time-wasting radio tweaks, because each
operator has their own favorite settings to best match their operating
style. This all changes with the USB drives! Prior to a contest, operators
may record their preferred IC-7700 settings such as filter, Digital Voice
Recorder (DVR) memories, antenna settings, etc. When it’s their turn to
operate, simply insert their USB Drive into the IC-7700. In a flash, the
IC-7700 is now “their rig”, and there’s nearly zero down time!
/PSK31 operation without PC connection
The IC-7700 has a built-in RTTY and PSK31 modulator/demodulator. By
simply connecting a USB key-board, you can immediately start enjoying these
modes. In addition, you can pre-program transmit messages in the internal
message memory or a USB memory stick and transmit them even without typing a
message from a USB keyboard. Also, received messages can be stored to a USB
memory stick and transferred to your PC.
4 antenna connectors
The IC-7700 has 4 antenna connectors (ANT1 to ANT4) with an automatic
antenna selector. Once you program the operating bands in each antenna
memory, the IC-7700 will automatically select the antenna as you change the
operating band. The usage type for each antenna can be set for Tx/Rx use, Rx
only* use and off line. The antenna
switch button allows you to change the operating antenna temporarily.
* Rx setting is available for ANT4 only.
Real time spectrum scope
With a dedicated DSP unit, the IC-7700 spectrum scope achieves 80dB of
dynamic range at the signal input level. It also improves the scope response
time and signal resolution, so that it is possible to accurately tune to the
intended signal as you see it on the spectrum scope screen. The spectrum
scope range can be set independently from the receiving frequency. You can
monitor band conditions between the selected sweep edges (Fixed mode), as
well as sweep a selected band width centered on the receiving frequency
(Center mode). In addition, the scope has useful functions including scope
attenuator (10dB/20dB/30dB), 2 types of marker (Transmit, Receiver) and Max
hold function. The mini scope function is convenient for continuous
monitoring even while adjusting the set mode.
Digital twin PBT
The digital twin PBT eliminates interference and noise from signals above
and below your frequency by changing the IF filter bandwidth. The IF shift
function allows you to shift or move the IF passband to either side to more
accurately receive the signal. The passband width, shift direction and steps
(50Hz) are graphically displayed on the LCD. You can reproduce the signal as
you like to hear it.
Digital IF filter
DSP-based digital IF filter of the IC-7700 rejects signals out of the pass
band, and keeps the desired signal free of any distortion or degradation of
quality. Depending on the operating situation, for example handling a
pile-up or receiving a very weak signal, you can flexibly change sharp and
soft filter shapes or reduce or shift the filter width, even while receiving
Manual notch filter and auto notch filter
The manual notch filter controlled by the DSP has extremely sharp
characteristics and provides more than 70dB of attenuation. The notch filter
width is selectable from 3 types, allowing you to select the suitable filter
width for the operating mode and band. It eliminates persistent beat tones
without affecting the AGC loop function. In addition, the automatic notch
filter tracks and eliminates two or more interfering signals such as beat
signals and carriers or tones from digital signals.
Variable noise blanker
The noise blanker provides significant reduction of pulse-type noise. The
noise blanker allows you to change the threshold level as well as blank
duration parameter and attenuation level.
The noise reduction separates the target signal from random noise
components. By using the excellent performance of the 32-bit floating point
DSP, this separation is made immediately without a delay and extracts
signals from noise components. The noise reduction suppression level is
variable in 16 steps to adjust the balance between the S/N ratio and
The digital voice recorder (DVR) is a convenient function for contests,
DX-peditions, portable operation and even regular operation. Record your
callsign, CQ, or other station information into a memory. Easy-to-access
independent “Record (REC)” and “Play” buttons are on the front panel.
audio HPF/LPF setting
The IC-7700 has a separate RX HPF/LPF setting for each mode. The
high-pass filter and low-pass filter are adjustable for each mode.
S/P DIF interface
IC-7700 has the S/P DIF optical digital interface for audio output and
modulation input. By connecting an external digital device* through a
connecting cable, flexible audio tuning is possible, while keeping good
* Third party connecting cable, PC with sound card
supporting S/P DIF, and software are required.
SSB data mode
When you narrow the IF filter passband to 500Hz or less in SSB mode or
SSB-data mode operation, the IC-7700 automatically selects special band pass
filters (BPF). The BPF has a very sharp edge like a CW filter for better
rejection of interfering signals. Along with the BPF setting, the IC-7700
has a 1/4-tuning step function for easier tuning operation.
Firmware upgrade for maintaining the best performance
Icom will always provide the latest firmware for keeping the radio up to
date. Just download the latest firmware from the Icom web site whenever a
new version has been uploaded, and update your IC-7700 via the USB memory.
200W output power at full duty cycle, full power operation
IC-7700 uses two MRF150 power amplifiers connected in push-pull
configuration. The power amplifiers provide a reliable 200W of output power
up to 54MHz. The effective quad cooling fan system makes it possible to
generate 200W full power output even during full duty cycle operation. The
digital PSN modulator using a DSP unit consistently reproduces an
outstanding signal-to-noise ratio, providing clean and clear transmission.
The PA amplifier uses a 48V DC supply to provide output power with low IMD
on all bands.
Microphone equalizer and adjustable transmit bandwidth
The built-in audio equalizer has separate bass and treble adjustments for
a total of 121 combinations, so you can adjust the tonal quality of your
voice as your want. In addition, the transmit bandwidth is selectable from
100, 200, 300, 500Hz at the lowpass edge, and 2500, 2700, 2800, 2900Hz at
the high-pass edge, respectively. Three types of high and low combinations
can be stored in the memory as favorite settings. With this flexibility of
DSP-based waveform shaping, transmit audio quality is adjustable to your
antenna tuner covering HF to 50MHz band
The high speed automatic antenna tuner automatically performs tuning
operations and memorizes the setting in 100kHz steps. Once the tuner
memorizes the setting depending on frequency, the tuner recalls the setting
and matches the antenna instantly. In addition, high-voltage parts allow you
reliable, continuous 200W operation even at high duty cycles.
IC-7700’s memory keyer has 4 channels with 55 characters for CW, 8 channels
with 70 characters for RTTY and 8 channels with 70 characters for PSK31
operation. The memory keyer is convenient for programming station
information, calling CQ and call sign for a DX-pedition or contest. Also,
the CW memory keyer has other time saving functions such as automatic
repeat, serial contest number auto-counter, and Morse cut number functions.
- BNC type RX IN/OUT connectors for receiver antenna or external
- General coverage receiver covers from 30kHz to 60MHz
- 4-step attenuator (6/12/18dB and OFF)
- Twin peak audio filter for RTTY operation
- Low distortion RF speech compressor
- Tx monitor
- 50 CTCSS tone encoder and decoder
- All mode power control
- VOX capability (Voice operated transmission)
- Multi-function electronic keyer with adjustable keying speed, dot-dash
ratio and paddle polarity and bug key function
- DSP controlled CW keying waveform shaping
- Frequency lock function for split operation
- The normal (default) CW carrier point is selectable from USB and LSB
- APF (audio peak filter) function with soft/sharp filter shape
- Double key jack system
- Full break-in function
- CW pitch control from 300 to 900Hz
- CW/AM auto tuning function
- Set mode function for flexible and speedy setting
- Memory pad stores up to 10 (or 5) operating frequencies
- Quick split function enables split operation with a single action
- SSB/CW synchronous tuning
- Single knob control from squelch volume to RF gain
- RIT and ∂Tx variable up to ±9.999kHz
- Quick RIT/∂TX clear function
- UTC/Local Clock and timer function
- 1Hz pitch tuning and 1Hz indication
- 101 memory channels with 10-character comment
- Built-in voice synthesizer announces operating frequency, mode and
receiving signal strength
- Programmed scan, memory scan, select memory scan, VSC scan and ∂F scan
- Auto tuning step function
- Band edge beep
- Main dial tension control and dial lock
- CI-V interface capability and RS-232C connector for PC connection
- BNC type Transverter connector
- Triple band stacking register
- FFT scope wave averaging function
- Screen saver function
Rear Panel View
- Antenna Connectors
- Ground Terminal
- Breaker Switch
- External Display Connector
(D-SUB 15-pin, VGA)
- Ethernet Connector
- CI-V Remote Control Jack
- RS-232C Connector
- Main Switch
- AC Power Cord Receptacle
- Receive Antenna Connector
- Transverter Jack
- External DC Output Jack
- S-meter Output Jack
- External Memory Keypad Jack
- External Speaker Jack
- ACC Sockets A/B
- Tx/Rx Control Jack (Relay)
- ALC Input Jack
- ALC Level Pot
- Key Jack
- S/P DIF In/Out Jacks
- Reference Frequency In/Out Jack