iCOM IC-7300 HF and 6 Meter Transceiver Owner’s Manual
- June 9, 2024
- ICOM
Table of Contents
Product Review
Icom IC-7300 HF and
6 Meter Transceiver
Icom’s software defined radio (SDR) in a box with knobs.
IC-7300 HF and 6 Meter Transceiver
Reviewed by Steve Ford, WB8IMY QST Editor
wb8imy@arrl.org Calling a piece of technology a
“gamechanger” is to invoke a cliché of the highest order, but it’s dif- ficult
to avoid when discussing the Icom IC-7300. A gamechanger is usually defined as
a product that has the potential to disrupt a market. When a game-changer
appears on the scene, competitors are challenged, buying preferences change,
and the market veers off in a new direction (the introduction of the Apple
iPhone is a classic example).
The game-changing aspect of the IC-7300 is not the fact that it is a software
defined radio (SDR). Hams have been exposed to SDR technology for more than a
decade, and QST has reviewed several highly competent SDRs from other
manufacturers. Instead, what makes the IC-7300 disruptive is that it offers
the performance and flexibility of SDR with a touchscreen in a user-friendly
package that is unlike any other — and it does this at a price point that is
guaranteed to be attractive to a large segment of the amateur community. It’s
similar in concept and price point to Icom’s previous generation IC-7410, but
offers more features and better performance in many areas.1
SDR with Knobs
For those who may be unfamiliar with the technology, a software defined radio
takes the analog signal arriving at the antenna 1R. Lindquist, WW3DE, “Icom
IC-7410 HF and 6 Meter Transceiver,” Product Review, QST, Oct 2011, pp 49 —
54. input and “samples” it at an extremely high rate, effectively converting
the analog signal into a stream of digital information. Once a signal has been
converted to data, it can be processed by software in ways that are not os-
sible — or at least practical — with analog technology. Any form of modulation
can be decoded, noise can be removed (or greatly suppressed), and
extraordinarily sharp filters can be applied to the result. To transmit, the
process is essentially reversed. Software massages the desired signal, which
is then converted to analog and amplified.
In the early days of Amateur Radio SDR, a receiver board performed quadrature
mixing on the incoming RF signal, creating in-phase (I) and quadrature (Q)
analog
Bottom Line Icom’s IC-7300 is a 160 — 6 meter, 100 W, software defined
radio (SDR) in a conventional package. Aimed at the “entry level” segment of
the market, it offers a wide range of features and excellent performance often
found in higher-priced transceivers.
Figure 1 — The IC-7300’s rear panel has connections for a CW paddle for the
internal keyer or external key/keyer; an external speaker; ALC and TR
switching for an amplifier; remote control via the optional RS-BA1 software or
an Icom CI-V device; a USB port for radio control and digital mode operation;
an ACC socket for connecting a TNC or PC for digital modes, and a jack for
connection to any of Icom’s accessory antenna tuners or tuned antennas.
Key Measurements Summary
Icom IC-7300 HF and 6 Meter Transceiver
Table 1 Icom IC-7300, serial number 02001161
Manufacturer’s Specifications Frequency coverage: Receive, 0.03 – 74 MHz;
transmit, 160 – 6 meter amateur bands. Power requirement: Receive, 0.9 A
(standby), 1.25 A (maximum audio); transmit, 21 A at maximum power output at
13.8 V dc ±15 %. Modes of operation: SSB, CW, AM, FM, RTTY.
Receiver
CW sensitivity, <0.16 µV (1.8 – 29.999 MHz, preamp 1 on), <0.13 µV (50 MHz
preamp 1 on), <0.16 µV (70 MHz, preamp 1 on).
Noise figure: Not specified.
AM sensitivity: 10 dB S/N, <12.6 µV (0.5 -1.8 MHz preamp 1 on); <2.0 µV (1.8 –
29.999 MHz, preamp 1 on); <1.0 µV (50 and 70 MHz preamp 2 on).
FM sensitivity: 12 dB SINAD, <0.5 µV (28 -29.990 MHz, preamp 1 on), 0.25 µV
(50 and 70 MHz, preamp 2 on).
Spectral sensitivity: Not specified.
Blocking gain compression dynamic range:
Not specified.
Reciprocal mixing dynamic range: Not specified.
ARRL Lab Two-Tone IMD Testing (500 Hz bandwidth) Measured
Measured in the ARRL Lab
Receive and transmit, as specified;
(5.255 – 5.405 MHz, 60 meters).
At 13.8 V dc: Receive, 1.05 A (maximum
volume); transmit, 18.5 A (typical);
5 mA (power off).
As specified.
Receiver DynamicTesting
Noise floor (MDS), 500 Hz bandwidth:
With IP+ (Dither) Off (See text)
Preamp ‘
| Off ‘| 1|
‘ 2
---|---|---|---
0.137 MHz| -85| -83| 82 dBm
0.475 MHz| -96| -116| 118 dBm
1.0 MHz| -114| -123| -125 dBm
3.5 MHz| -133| -141| -143 dBm
14 MHz| -133| -141| -143 dBm
28 MHz| -132| -141| 143 dBm
50 MHz -130 -139 . -141 dBm
With IP+ (Dither)
| On (See|
text
3.5 MHz| (See text)| -123| -135 -139| dBm
14 MHz| -124| -136 -140 dBm
28 MHz| -122| -135 -138 dBm
14 MHz, IP+ off, preamp off/1/2:
14/6/4 dB; 50 MHz, 17/8/6 dB.
10 dB (S+N)/N, 1-kHz, 30% modulation,
9 kHz bandwidth:
Preamp | Off | 1 | 2 |
---|---|---|---|
1.0 MHz | 12.2 | 4.16 | 3.71 µV |
3.8 MHz | 1.64 | 0.61 | 0.56 µV |
29 MHz | 1.82 | 0.66 | 0.58 µV |
50.4 MHz | 2.19 | 0.76 | 0.66 µV |
12 dB SINAD, 15 kHz bandwidth:
Preamp | Off | 1 | 2 |
---|---|---|---|
29 MHz | 0.5 | 0.17 | 0.16 µV |
52 MHz | 0.62 | 0.21 | 0.17 µV |
Blocking gain compression dynamic range,
500 Hz bandwidtht:
20 kHz offset
5/2 kHz offset
Preamp off/1/2 Preamp off
3.5 MHz | 123/118/116 dB | 123/123 dB |
---|---|---|
14 MHz | 123/118/116 dB | 123/123 dB |
50 MHz | 122/118/116 dB | 122/122 dB |
14 MHz, 20/5/2 kHz offset: preamp off, IP+ off: 114/107/101 dB; preamp off, IP+ on, 114/108/102 dB.
Band (Preamp/IP+)
3.5 MHz (off/off)| Spacing 20 kHz| measured IMD Level -133 dBm
-97 dBm| measured Input Leve!t
-53 dBm
-16 dBm| IMD DR
80 dB
---|---|---|---|---
3.5 MHz (off/on)| 20 kHz| -123 dBm -97 dBm| -33 dBm
-16 dBm| 90 dB
14 MHz (off/off)| 20 kHz| -133 dBm -97 dBm| -56 dBm
-16 dBm| 77 dB
14 MHz (two/on)| 20 kHz| -140 dBm -97 dBm| -38 dBm
-38 dBm| 102 dB
14 MHz (off/off)| 5 kHz| -133 dBm -97 dBm| -56 dBm
-16 dBm| 77 dB
14 MHz (two/on)| 5 kHz| -140 dBm -97 dBm| -40 dBm
-39 dBm| 100 dB
14 MHz (off/off)| 2 kHz| -133 dBm -97 dBm| -56 dBm
-21 dBm| 77 dB
14 MHz (off/on)| 2 kHz| -124 dBm -97 dBm| -29 dBm
-21 dBm| 95 dB
Manufacturer’s Specifications
Measured in the ARRL Lab
14 MHz (one/off)| 2 kHz| —141 dBm
—97 dBm| —63 dBm
—34 dBm| 78 dB
---|---|---|---|---
14 MHz (one/on)| 2 kHz| —136 dBm
—97 dBm| —36 dBm
—34 dBm| 100 dB
14 MHz (two/off)| 2 kHz| —143 dBm
—97 dBm| —64 dBm
—34 dBm| 79 dB
14 MHz (two/on)| 2 kHz| —140 dBm
—97 dBm| —40 dBm
—39 dBm| 100 dB
50 MHz (off/off)| 20 kHz| —130 dBm
—97 dBm| —41 dBm
—15 dBm| 89 dB
50 MHz (two/on)| 20 kHz| —139 dBm
—97 dBm| —41 dBm
—30 dBm| 98 dB
Second-order intercept point: Not specified.
DSP noise reduction: Not specified.
Audio Output: >2.5 W into 8 0 at 10% THD.
FM adjacent channel rejection: Not specified
FM two-tone third order dynamic range:
Not specified.
Squelch sensitivity: SSB, 5.6 µV, FM, <1 µV.
Notch filter depth: Not specified.
S-meter sensitivity: Not specified.
Audio filter response: Not specified.
Preamp off/1/2:t
14 MHz, +69/+45/+41 dBm;
21 MHz, +654671+67 dBm;
50 MHz, +71/+71/+71 dBm. 15 dB (maximum).
At 10`)/. THD, 2.4W into 8 0..
THD at 1 VRms, 0.2%.
29 MHz, 82 dB; 52 MHz, 79 dB.
20 kHz spacing, 29 MHz, 82 dB;
52 MHz, 79 dB. 10 MHz spacing,
29 MHz, 97 dB; 52 MHz, 99 dB.
At threshold: 1.58 µV 14 MHz (SSB, preamp off); 0.08 µV (29 MHz, p2 on).
Manual notch, 52 dB; auto-notch, 52 dB (45 dB two tones). Attack time, 198 ms
(single tone), 2080 ms (two tones).
S-9 signal, (preamp off/1/2):
14 MHz, 70.7/31.2/18.8 µV;
50 MHz, 78.4/37.5/24.5 µV.
Range at —6 dB points:**
CW (500 Hz): 342 — 860 Hz (518 Hz);
Equivalent Rectangular BW: 514 Hz;
USB (2.4 kHz): 234 — 2632 Hz (2398 Hz);
LSB (2.4 kHz): 250 — 2656 Hz (2406 Hz);
AM (9 kHz), 166 — 4477 Hz (8622 Hz).
Transmitter
Power output: 2 — 100 W; 1 — 25 W (AM).
Spurious-signal and harmonic suppression:
50 dB (1.8 — 28 MHz); >63 dB (50 MHz).
SSB carrier suppression: >50 dB.
Undesired sideband suppression: >50 dB.
Third-order intermodulation distortion (IMD)
CW keyer speed range: Not specified.
CW keying characteristics: Not specified.
Transmit-receive turn-around time (PTT release to 50% audio output): Not specified.
Receive-transmit turn-around time (tx delay):
Not specified.
Composite transmitted noise: Not specified.
Size (height, width, depth, including protrusions): Price: $1500.
Transmitter Dynamic Testing
HF, 0.7 — 104 W typical; 50 MHz, 0.5 — 97 W. 70 W typical at minimum specified
dc voltage input.
HF, typically 64 dB, 57 dB (worst case 160 m), 50 MHz, 76 dB. >70 dB. >70 dB.
3rd/5th/7th/9th order, 100 W PEP: HF, —42/-38/-46/-57 dB (typical)
—30/-37/-44/-58 dB (worst case, 10 m);
50 MHz, —26/-37/-39/-44 dB (100 W); 50 MHz, —33/-37/-44/-62 dB (80 W) 6 to 48
WPM, iambic mode B.
See Figures 2 and 3.
S-9 signal, AGC fast, 15 ms.
QSK transmit to receive time, 35 ms.
SSB, 14. ms; FM, 15 ms (29 MHz and 52 MHz). See Figure 4.
Size (height, width, depth, including protrusions): 4.0 x 9.4 x 10.7 inches.
Weight, 9.3 lbs.
Price: $1500.
tBlocking occurs at ADC overload threshold. Blocking level is same for IP+ on
or off.
tThere was no intercept of the IMD input signal and receiver IMD at the S5
(-97 dBm) level.
Figures are at threshold of ADC overload or spurious receiver response.
Second-order intercept points were determined using S5 reference.
*Measurement was noise limited at the value indicated.
**Default values; bandwidth is adjustable.
Figure 2 — CW keying waveform for the Icom IC-7300 showing the first two dits using external keying. Equivalent keying speed is 60 WPM. The upper trace is the actual key closure; the lower trace is the RF envelope. (Note that the first key closure starts at the left edge of the figure.) Horizontal divisions are 10 ms. The transceiver was being operated at 100 W output on the 14 MHz band.
Figure 3 — Spectral display of the Icom IC-7300 transmitter during keying
sideband testing. Equivalent keying speed is 60 WPM using external keying.
Spectrum analyzer resolution bandwidth is 10 Hz, and the sweep time is 30
seconds. The transmitter was being operated at 100 W PEP output on the 14 MHz
band, and this plot shows the transmitter output ±5 kHz from the carrier. The
reference level is 0 dBc, and the vertical scale is 10 dB/division. Figure 4
— Spectral display of the loom IC-7300 transmitter output during phase noise
testing. Power output is 100 W on the 14 MHz band (red trace) and 50 MHz band
(green trace). The carrier, off the left edge of the plot, is not shown. This
plot shows composite transmitted noise 100 Hz to 1 MHz from the carrier. The
reference level is 0 dBc, and the vertical scale is in dBc/Hz. baseband
signals.
This IQ baseband signal was converted to digital information by a computer
sound card, and software was used to demodulate the received signal. As
technology improved, the signal mixing and IQ digital conversion stages were
combined in a single box, and the resulting data was streamed to the computer
for processing, typically over a USB connection.
Today, most software defined transceivers do not rely on outboard computers
for processing; all conversion and processing takes place within dedicated
circuitry that functions as a complete transceiver.
The computer merely functions as an interface between the transceiver and its
human operator.
The IC-7300 takes the next step by eliminating the computer interface
completely and substituting knobs, buttons, and a screen. As a result, if you
are comfortable operating a conventional transceiver, you can operate an
IC-7300 just as easily. You’ll find buttons and knobs that are entirely
familiar.
Best of all, the complicated menu systems found in other transceivers have
been greatly streamlined in the IC-7300 through the use of the touchscreen.
Navigation is as simple as tapping your finger on a screen icon or “button.”
Some amateurs may miss the ability to directly tap into the IQ stream (the
IC-7300 does not offer an IQ output), but the IC-7300 is clearly designed to
appeal to a different audience. The hams who embrace the IC-7300 are those who
desire the performance of an SDR, yet are put off by the need to have a
computer or some other interfacing device between them and the radio.
The Basics The IC-7300 is a 100 W output, 160 through 6 meter transceiver
capable of operating SSB, CW, FM, AM, and digital modes. The chassis is
compact at 9.4 inches wide, 3.7 inches high, and 9.4 inches deep. It is
somewhat light at only 9.3 pounds, of interest for portable operation as well
as home station use.
All of the knobs and buttons have a high-quality feel. The transceiver comes
with a handheld microphone and a printed “basic” manual. An accompanying CD-
ROM contains a much more detailed manual and a complete set of schematic
diagrams.
Looking over the schematics, it’s obvious that the IC-7300 wastes no time
getting from analog to digital. Received signals are filtered, amplified, and
then sent to an analog-to-digital converter (ADC). Then they are fed to an
FPGA (field programmable gate array) for conversion and processing. All of
this is transparent to the user, though…if you sat down in front of an IC-7300
without knowing about its architecture, you’d never guess that you were
looking at an SDR.
The “No Manual Test ” When a transceiver makes the claim of being “user
friendly,” that’s my cue to perform the No Manual Test. I simply leave the
manual in the box and attempt to set up
The IC-7300 takes the next step by eilminating the computer Interface
completely and substituting knobs, buttons, and a highly responsive
touchscreen. and operate the radio without any assistance other than my own
experience.
It took less than 5 minutes to plug in the dc power cord (the radio draws 21 A
maximum) and connect the coaxial cable from my antenna to the IC-7300’s single
tenna to the IC-7300’s single SO-239 port.
That antenna port is used for all bands from 160 through 6 meters, and also 4
meters — 70 MHz — in other markets. There’s no provision for a separate
receiving antenna such as a Beverage for the low bands. The rear panel (see
Figure 1) also has connections for a CW paddle for the internal keyer or
external key/keyer, an external speaker, digital mode interfaces, and other
accessories.
I pressed the POWER button and the large touchscreen came to life with a
frequency display and a bright spectrum scope and waterfall. The audio and RF
gain knobs operated as expected, as did the passband tuning.
I noticed the TUNER button and assumed that it operated the built-in antenna
tuner. I held it down for about a second and was rewarded with rapid clicldng
noises as the tuner went to work. A few seconds later, the IC-7300 had tuned
to a flat 1:1 SWR. You can’t miss the large VFO knob, so I gave it a spin
across the signal peaks appearing in the spectrum scope. Being in the SSB mode
at the time, I marveled at how good the received audio sounded.
But how would I change bands? There were no mechanical band buttons to be
found, so I knew I had to resort to the touchscreen. Being on 20 meters, I
tapped my index finger on “14” on the frequency display. Sure enough, an array
of band-button icons appeared. I tapped on “7” and was immediately transported
to 40 meters.
Through this exercise, I also discovered that tapping on various portions of
the frequency display also effectively altered the tuning rate of the VFO.
Direct frequency entry is also possible through the same window. I plugged in
the microphone, and within a couple of minutes I found a fellow calling CQ.
I answered and received an outstanding signal report (he remarked that my
audio sounded particularly good). The elapsed time from power application to
conversation was less than 10 minutes. The IC-7300 had passed the No Manual
Test with high marks. Of course, you will probably want to peruse the full
version (PDF format) of the manual at some point to look a bit deeper into
what the IC-7300 can do.
The manual is well organized and well written, with illustrations and helpful
hints throughout. The manual is also available for download from Icom’s
website.
On the Air in Depth
The SDR aspects of the IC-7300 become apparent as you spend more time
listening to signals and using the various features. The sensitivity and
selectivity of the radio never failed to impress. Even in crowded conditions,
the IC-7300 clearly outperformed my older analog transceiver.
The manual wares that the IC-7300 could diston in the presence of very strong
signals. The receiver is indeed very “hot” — so hot that I found myself
turning off the dual preamps and even switching in the attenuator on occasion.
Receiver sensitivity without the preamps is adequate virtually all of the
time. The IC-7300 has an IP+ feature, which inserts a dither signal when you
activate it. You could say this is somewhat like adding a strong signal off
frequency, which has the clever effect of reducing the intermodulation
distortion (IVID) products. The dither signal is noise and it raises the noise
floor a bit. As shown in Table 1, the best possible measured performance is
with IP+ and Preamp 1 on. However, as with other radios,
Lab Notes: Icom IC-7300
By Bob Allison, WB1 GCM
Assistant Laboratory Manager
Starting with this review, the ARRL Lab will offer comments and observations
about HF transceivers tested. The Icom IC-7300 uses an RF direct sampling
system. Analog signals are picked up via the antenna and go through the
appropriate band-pass filter.
Then all incoming analog signals are digitized, processed, and manipulated by
software and then converted back to analog audio for listening with the
speaker or headphones. This is quite different from current traditional
receiver architecture, in which the signal path stays analog until the digital
signal processing stage is reached.
A key component of an RF direct sampling system is the analog-to-digital
converter (ADC). The digitization of an analog signal is done in small steps.
These steps are a type of non-linearity that forms intermodulation (IMD)
products at low signal levels that can coherently add up.’
To prevent this unwanted effect, a dither signal (random noise) is added. The
result is an improved two-tone third-order intermodulation distortion dynamic
range (3 IMD DR). The dither signal inside the IC-7300 can be turned on and
off by using the IP+ key. With IP+ on, the sensitivity is reduced by the
dither signal, but the overall 3 IMD DR is improved.
Table 1 shows the minimum discernible signal level and the 3 IMD DR with and
without the dither signal. All ADCs have an input signal limit.
If a high enough signal level is present at the antenna jack, the ADC can go
into an overload state. The signal level at which the overload state is
attained is known as the ADC threshold. At this signal level, the receiver is
not usable. Fortunately, the ADC threshold is high in the IC-7300 — an in-
passband signal does not overload, even at >10 dBm. No signal blocking appears
until the ADC threshold level from an adjacent signal is reached. The
reciprocal mixing dynamic range (RMDR) and gain compression (blocking) dynamic
range figures are very good.
RMDR in particular shows the benefit of Icom’s new synthesizer design. At 2
kHz spacing, it is nearly 25 dB better than the previous generation IC-7410.
Note that these dynamic ranges are measured with the AGC off. With the AGC on,
no blocking is observed, but the background noise increases as the ADC
threshold level is approached with an adjacent signal 2 kHz away. Stilt,
overall performance is excellent for an entry-level transceiver.
For decades, it’s been generally accepted that an S-meter reading of S-9
corresponds to an input signal level of 50 µV (-73 dBm), and that each Sunit
represents a change of 6 dB (S-8 = —79 dBm, S-7 = —85 dBm, and so on). Our
measurements indicate that some manufacturers do a good job of hitting the
S-9/50 µV level, but many ARRL members have told me that they wish there were
more uniformity with the rest of the S-meter scale.
Unfortunately, in most transceivers the S-meter scale does not accurately
report 6 dB/S unit. The Icom IC-7300 uses a 3 dB/S unit scale, for example. I
hope that manufacturers will improve upon this by adding a dBm signal level
scale for more accurate reports, and also make the meter read the same level
with the preamp(s) on or off. Turning the preamp on does not magically add
voltage at the antenna jack! The transmitter of the IC-7300 is clean, with low
phase noise and reasonable keying sidebands. On most HF bands, the transmit
IMD third-order products are excellent, among the best we’ve tested in 13.8 V
transceivers, but the fifth and seventh order products are on the high side.
On 6 meters, all transmit IMD products are high at full RF power output.
Reducing the RF output to 80 W PEP reduces odd order products considerably.
I did not see any power overshoot in CW mode but did find some in SSB mode. It
happens very quickly, for less than 2 ms, and can only be seen on a scope with
screen persistence. I tested the IC-7300 with an amplifier that has protection
circuitry that is sensitive to overshoot.
The amplifier’s peak power meter does indicate a higher power on the first
syllable — 1800 W — then it settles down to 1500 W. This very brief overshoot
did not trip the amplifier’s protection circuitry, and appears to be of no
concern. loom recommends operating the IC-7300 with the speech compressor off
to minimize the probability of overshoot when using an external power
amplifier.
A concern pointed out by a member is the appearance of RF output at the
antenna jack for 3 ms, after the amplifier key line opens (confirmed in the
ARRL Lab).
If used during QSK (full break-in) CW operation with an amplifier with very
fast PIN diode TR switching, it is possible that the amplifier could switch
back to receive mode while RF is still flowing from the IC-7300. In such a
case, hot-switching can cause key clicks. At the beginning of the
transmission, there is an adjustable transmit delay for RF to start flowing
after the key line closes. The delay is 6 ms with the default setting.
If you use the IC-7300 with an amplifier, check the amplifier switching time.
You will probably need to set the delay to 10 or 15 ms (or longer), to avoid
hot-switching and subsequent damage to amplifier switching circuitry. tSee
OST, February 2010, page 52 for more information. it is best to leave the
preamp off unless needed. For the weakest signals, I would turn off the IP+
for maximum sensitivity. Speaking of noise, the IC-7300’s noise blanker is a
thing to behold. I’ve never experienced this level of noise blanker
performance in a radio in this price clans.
All but the worst clicks and pops were completely eliminated.
The noise reduction feature was equally impressive. It manages to greatly
reduce background kiss and statie without introducing excessive distortion of
its own.
AGC is highly adjustable. FAST, MID, and SLOW settings are available with
separate settings for SSB, CW/RTTY, and AM modes. Time constants are
adjustable from 0.1 — 6 seconds for SSB and CW/RTTY, and up to 8 seconds for
AM. FM is fixed at a 0.1 second FAST setting.
At the default setting of 6 seconds, on SSB the AGC is very slow
to recover in thepresence of a strong signal. As noted in the manual, a
faster setting works better when receiving weak signals if strong signals are
also present. As with many current transceivers, any kind of impulse noise
captures the AGC when the noise blanker is off. As with all SDR rigs, you can
adjust the filtering to whatever parameters you desire. In the IC-7300, this
is accomplished through the touchscreen. Each operating mode provider three
filter selections and
Figure 5 — The built-in RTTY decoder features a window on the lower right
with a visual tuning aid — just line up the mark and space signals with the
vertical bars. Up to our lines of decoded text are displayed at the lower
left.you can change the bandwidths of each one, as well as the shape between
“sharp” and “soft.” When operating CW, it was a pleasure to select a sharp 250
Hz filter and just slowly tune through crowded bands, listening to individual
signals without a hint of ringing.
When it comes to sending CW, earlier SDRs occasionally had latency issues (a
lag between pressing the key and sending or receiving the CW), but none of
this is present in the IC-7300.
I quickly found that I could send CW every bit as well as I could with my
analog rig. Break-in operation is selected by a front panel switch, either
with full break-in (QSK) or an adjustable delay for semi break-in. Note that
in QSK operation, the turnaround time is 35 ms, which is slower than, for
example, the IC-7100, which is 29 ms. This limits QSK operation at higher
speeds.
The AUTO TUNE button can help you to tune in a CW signal to the proper pitch.
The IC-7300 includes a CW keyer with adjustable speed, weighting, and so
forth. You can program up to eight memories to send your call sign, signal
reports, contest exchanges, and other information. Once recorded, memories can
be played back using buttons on the lower portion of the screen or with an
external keypad. (Icom doesn’t offer a keypad, but the manual shows the
connections needed.)
There’s a similar “voice keyer” provision for recording and sending up to
eight short voice messages. Split frequency operation is similar to other Icom
transceivers. With QUICK SPLIT enabled, simply press and hold the SPLIT
button. The transceiver turns on the split function and sets VFO A and B to be
equal.
The VFO B frequency (which will be used for transmitting) is displayed near
the bot prefer to continue using it instead, don’t worry. The IC-7300 still
offers a multipin accessory port on the rear panel to accommodate your
interface connections. About that Screen goantha ital I quickly learned to
love the IC-7300’s touchscreen. It is bright and easy to read, including the
waterfall and spectrum scope (see Figure 6).
Both scopes are adjustable and you can even zoom in for a closer look at
individual signals, or select an additional display of the audio
characteristics of the signal. (This was particularly helpful when sending
PSK31. I could see the modulation characteristics of my transmit signal right
there on the screen.)
Tapping a signal on the scope tunes the transceiver to that frequency. Even
passband tuning is rendered graphically. When you twist either of the passband
tuning knobs, you see the result as an animated graphic that shows the ef-
Oneyothsotrsccath fect of what you are doing. While exploring the myriad
features, I also ran across a very cool SWR graphing function that behaves
like an antenna analyzer. You set your frequency parameters and then
repeatedly press the TRANSMIT button. With each press, the SWR is measured and
plotted on the graph (see Figure 7).
This is agood time to mention that while the built-in antenna tuner is
designed for mismatches that result in a maximum 3:1 SWR, it offers a so-
called “Emergency Mode” that allows it to grapple with SWRs as high as 10:1,
albeit at reduced RF output. Overall, the screen was well suited to my needs,
even with my aging vision, but if you want something bigger, Icom offers the
optional $100 RS-BA1 remote control software.
With this software you can control the transceiver and display the entire
screen on your computer monitor. You can even control the IC-7300 remotely via
the Internet.
Figure 6 — The IC-7300’s real-time spectrum scope shows both panadapter and
waterfall displays. The frequency span is adjustable in several steps and can
be set to show a fixed portion of the band or centered around the operating
frequency.tom of the screen.
Use the XFC button to set your transmit frequency, or to listen on the
transmit frequency. Audio can be tailored with the TONE CONTROL menu. Bass and
treble are adjustable separately for each voice mode (SSB, AM, and FM), with
separate adjustments for receive and transmit. Other adjustments include high-
pass and low-pass filter cutoff frequencies for receive audio for each mode
and transmit bandwidth for SSB.
The rear panel includes TR switching and ALC connections for using an external
power amplifier.
Transmit delay is adjustable in several steps up to 30 ms to allow amplifier
relays to settle and avoid hot switching. The Lab did observe that RF output
appears at the IC-7300’s antenna jack for about 3 ms after the amplifier key
line opens so hot-switching an amplifier is possible at the end of
transmission during full break-in (QSK) operation if the amplifier uses fast
switching (see the accompanying sidebar). Once you have the IC-7300 configured
to your liking, you can save the configuration to the SD memory card (the
memory card is not included). In this way, you can store different
configurations for different types of operating. The SD card will also store
many other types of information, including received audio and transmit voice
keyer audio.
Digital Modes The IC-7300 offers a built-in RTTY decoder (see Figure 5). I
tested this function, along with the “twin peaks” RTTY filtering, and it
performed quite well. The text appears in a small window within the main
display. The radio can also save the decoded text to the SD card for later
review. The RTTY feature includes transmit
Figure 7 — The SWR graphing function offers a visual indication of
antenna system SWR over an adjustable frequency range.memories for various
“canned” messages. These would be highly useful for DX hunting, especially in
pileup situations. You could program your call and response, and simply tap
the touchscreen to send. For most digital operating generally, the IC-7300’s
USB connection is the way to go.
Transmit and receive audio, and transmit/receive keying, are all handled
smoothly over a single cable between the radio and your computer — no hardware
interfaces required. You only need to keep in mind that the IC-7300 presents
itself as a “sound device” (USB Audio CODEC), which you’ll have to select in
your software setup.
For transmit/receive keying, the IC-7300 appears as a virtual serial COM port.
To hunt down the assigned COM port number, I had to access Device Manager in
Windows 10 and open the list of ports. In my computer, the IC-7300’s interface
appeared as “Silicon Labs CP210x USB to UART Bridge” and had been assigned. to
COM 9 (the COM port number will likely be different in your computer). So,
once I configured my software to use COM 9 for rig keying, all was right with
the world. I operated the IC-7300 on several digital modes with ease — exactly
as I would with a conventional transceiver.
With RTTY contesting in mind, I used the IC-7300’s USB connection to handle
receive audio and FSK keying with the popular MMTTY RTTY software and did a
little searching and pouncing during the Alessandro Volta RTTY competition.
Once again, the IC-7300 performed perfectly. Rich Donahue, KOPIR, has a video
on YouTube at https://youtu.be/ZCkiuzAMuZI that shows you how to set up
MMTTY for use with the IC-7300. If you already own a digital interface, and
Conclusion So is the IC-7300 really a game-changer? In my opinion, it clearly
meets the criteria. The IC-7300 takes the familiar ergonomic design of an
analog transceiver and blends it seamlessly with software defined radio
technology — all at a moderate price.
I have a feeling that this approach to amateur transceiver design is likely to
spread rapidly, even to lower-end models. Years from now we may look back at
the IC-7300 and see its introduction as the moment when everything changed.
Manufacturer:
Icom America, 12421 Willows Road NE, Kirkland, WA 98034; tel
800-872-4266;
www.icomamerica.co
Click here for a video overview of the Icom IC-7300 HF and 6 meter transceiver.
THE NETHERLANDS | Roermond
Tel. +31 (0)475-327390
www.classicinternational.eu
GERMANY | Mönchengladbach
Tel. +49 (0)2166-33061
www.classicinternational.eu
Mark J. Wilson, K1RO, klro@arrl.org
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>