Earlier this year I published what I called an “initial” review of the CommRadio CTX-10 QRP transceiver, promising an eventual final review. The reason for this is that I sensed there were important CTX-10 updates on the horizon, and I wanted to re-evaluate the rig once the upgrades had been implemented through firmware.
I’ve been very pleased with the attention CommRadio has paid to their customer feedback on some of the most important requests.
Instead of reiterating what I wrote in the initial review, I’ll jump straight into the upgrades.
At time of posting my initial review, the CTX-10 didn’t have A/B VFOs. This was my primary gripe about the CTX-10, because without A/B VFOs, there was no way to operate split, which meant that you could not work DX stations that use split to manage large pileups. This is actually a really important feature for a QRP radio because during split operation, a pileup is pulled apart across a few kHz of bandwidth, thus giving a 10-watt signal a better chance of being heard through a collection of legal-limit signals.
On June 10, 2019, CommRadio released a firmware package that added A/B VFOs and the ability to operate split to the CTX-10.
Even though there are only a limited number of buttons on the front panel, it’s incredibly simple to enter into split mode:
Chose the frequency and mode;
Hold the STEP button for one second or more, then release. You’ll then see a split display indicating the TX and RX frequencies.
Use the left arrow key [<] to toggle between them.
I do like the clear TX and RX lines, which leave no doubt in the user’s mind what the frequency used for transmitting and receiving is. On some radios, this can be a bit confusing.
Split operation is simple and effective, thus I consider this issue fully resolved.
In my initial review, I noted that the CTX-10 ATU needed near-resonant antennas for the ATU to make a strong 1:1 match. Indeed, a number of times I actually used a near-resonant antenna in the field––the EFT Trail-Friendly, for example––and the ATU couldn’t get below a 3:1 match. For what it’s worth, CommRadio states that the CTX-10 can easily handle 3:1.
Making a Parks On The Air activation at Tar Hollow in Ohio.
CommRadio has made modifications to the ATU function, improving the performance of the antenna-tuner algorithm, which had a significant impact on 80 and 60 meters. I’ve also had better luck with a number of field antennas I’ve tried on 40 and 20 meters. Is it as good as the Elecraft KX-series ATUs? No.
Having a built-in ATU on the CTX-10 is certainly a valuable feature in the field. When I need to match a challenging antenna with the CTX-10, I bring my Emtech ZM-2 manual tuner along for the ride.
There still is no way to adjust the microphone gain control nor microphone compression on the CTX-10. Much like a military or commercial radio, the CTX-10 is optimized for just one style of mic: in its case, the modular MFJ-290MY or Yaesu MH-31A8J handheld mic.
The CTX-10 microphone input has a limiting pre-amplifier with built-in compressor and ambient noise gate–in short, the CTX-10 handles all microphone settings automatically.
Through firmware updates, a number of positive adjustments have been made to the microphone settings:
the microphone-decay timer has been tweaked so that audio clipping is less of a concern
audio clarity and gain have been improved
audio power has been improved resulting in .5 to .75 watts of additional peak power
microphone audio leveling has been improved
VOX attack and decay timing has been improved
These are all welcome adjustments.
I would note here, though, that if you plan to use a mic other than the MFJ-290MY or Yaesu MH-31A8J handheld mics, you will have a limited means of adjusting the mic parameters unless you have an external mic EQ. A number of readers, for example, have asked about using their Heil boom headset with the AD-1-YM cable adapter on the CTX-10. Boom headsets are a wonderful tool for field operation because they free your hands to log contacts. As for using boom headsets on the CTX-10, since I don’t have the appropriate adapter, I can’t speak to this. But since you can’t control mic gain, it might take time to learn how to position the boom mic and adjust your voice level for optimum performance.
As mentioned in our initial review, the CTX-10 does not support QSK/full break-in operation. Rather, the CTX-10 uses a traditional relay for switching between transmit and receive. During CW operations, you’ll hear a relay click when switching from TX to RX and back again.
The CW hang time delay on the CTX-10 is not currently adjustable. For high-speed CW ops that prefer a faster relay recovery, I suspect this could be an annoyance.
There have been recent CTX-10 firmware upgrades that have helped solve issues found with CW keyer timing in early units. I found the timing issues were mainly present while sending high-speed CW (25 WPM+). My buddy Vlado (N3CZ) put the CTX-10 through some high speed tests, and was pleased with the results overall.
I will reiterate here that the CTX-10 lacks other controls many CW operators appreciate. Currently, the CTX-10 lacks a sidetone control; as a result, you cannot change the sidetone volume/tone, nor can you turn it off. I continue to hope that CommRadio will fix this quirk via a future firmware upgrade.
The CTX-10’s built-in CW keyer does not currently support iambic keying. Meaning, when both levers of a dual paddle are closed simultaneously (squeezed), it will not send a series of alternating dots and dashes. I imagine this could be addressed in a future firmware update.
Additionally, without re-wiring your paddle, you can’t change which side of your paddle sends ‘dits’ and which sends ‘dahs.’ A minor con, for sure–still, most modern QRP transceivers allow you this flexibility.
Revisiting the basic feature set
Let’s be clear: as I stated at length in my initial review, the CommRadio CTX-10 was designed around simple operation, like one might expect from a military or commercial channelized radio. I know ham radio operators and preparedness enthusiasts who prefer this approach to gear design, and they will appreciate this CTX-10 design philosophy.
Still, the CTX-10 lacks many of the features and adjustments you’d typically find on a QRP transceiver in its price class. Instead, the CTX-10 was designed to handle many of these adjustments automatically.
The CTX-10 still has no separate RF gain control. The CTX-10’s RF gain is directly tied to the three AGC settings (slow, medium, and fast). While I believe it does a fine job of adjusting RF gain, I do ride an RF gain control a lot during noisy summer conditions, and miss this feature.
The CTX-10 still has no passband (PBT) control, notch filter, or noise blanker––all features I’d normally expect in a QRP radio at this price level.
There are no CW (os SSB) memory keyers. I wouldn’t expect these, as I believe only the Elecraft KX2 and KX3 sport this feature in this price class of QRP radios.
Also, the ARRL lab reports of the CTX-10 are found in the July 2019 issue of QST (Bob Allison, WB1GCM) noted:
Though adequately sensitive, its third-order IMD and blocking gain compression dynamic ranges, as measured in our laboratory, are more suited to casual operation with antennas of modest gain.
Even with the AGC disabled, one or more strong, adjacent signals will result in the reduction of speaker volume, and I was unable to measure the reciprocal mixing dynamic range (RMDR).
The dynamic range was reported as 58 dB, which is a very low number. Blocking was 65 dB.
Out of his comprehensive table which includes vintage radios, the CTX-10 scored the lowest of all of them sorted by third-order dynamic range narrow spaced. It is literally at the bottom of his list: at time of posting, number 146 out of 146 tested radios. Rob concluded that an out-of-passband signal that is approximately S9 will start blocking the radio. Click here for his full notes (PDF).
The CTX-10 doesn’t really have the tool set or receiver performance to cope well with contests or DX conditions.
Please note: as with most firmware-based radios, some missing features could potentially be added in future firmware upgrades. If one of these items is keeping you from purchasing the CTX-10, please contact CommRadio and inquire.
Is the CTX-10 for you?
The CTX-10 on air at the W4DXCC conference
With the most recent upgrades, CommRadio has solved the major issues that kept me from recommending it in my initial review. I still feel there are more capable portable transceivers for the $1,000 US price.
The addition of split operation was especially key for me, as I do operate split. The more nuanced adjustments to the CW keyer, an extra feature to prevent the radio from accidentally turning on while in transit, and the adjustments to the mic algorithm, all make this radio more pleasant to operate at home or (especially) in the field.
As I mentioned in the initial review, the CTX-10 owner is one who operates casually and values averysimple, straightforward radio. Those who want a sturdy, no-frills, set-it-and-forget-it rig. If that’s you, take a closer look at the CTX-10: it may just suit your needs if you’re not planning on using it on Field Day or during RF-dense contest environments.
The two major advantages of the CTX-10 over competitors are:
the ability to charge the internal batteries from almost any voltage source, and
a higher TX duty cycle (without needing to add external heat sinks).
I believe the CTX-10 will have appeal for radio enthusiasts who value these characteristics:
All-in-one-box portability with no extra wired accessory components
Best-in-class internal battery life
Best-in-class intelligent battery charging
Digital modes like FT-8 and the ability to operate them in the field from internal batteries for extended periods of time
Very few manual adjustments
Broadcast listening, as the CTX-10 is also a broadcast receiver
The CTX-10’s overall construction and components are, as I’ve said, near mil-spec. While the CTX-10 isn’t weatherized or waterproof––no more than any of its current competitors (save the TX-500)––the construction is top-shelf, for sure. It should run for decades without need of repair.
Although I can’t recommend to the CTX-10 for serious radio operators, it is built like a tank, and has a simple feature set for field operation. It’s also designed and manufactured right here in the USA. All the better.
[Update: Please note that we’ve now posted a final review of the CTX-10 which builds upon the review below. Think of of the final review as the second installment, or “Part 2? of this review. If you’re considering the purchase of a CTX-10 please read this initial review first.]
In the past two years few QRP transceivers have generated the interest of the CommRadio CTX-10. I’ve gotten no fewer than two dozen emails from readers asking about the CTX-10 after learning I had one here at SWLing Post HQ. And, I’ll freely admit, I was among those people who couldn’t wait to give this promising little radio some on-air time––and, as a result, a proper evaluation.
Fans of the US-made CR-1 and CR-1A appreciated the approach to the CommRadio design: simple operation, clever engineering, near-mil spec components and construction, superb receiver characteristics, as well as excellent audio. The classic CR-1 has all the essentials––multiple modes, filters, and the like––yet offers relatively few features when compared with other tabletop radios in its price class. It’s a simple get-on-the-air rig that feels like it’s engineered to last forever. Indeed, its design approach reminds me of the Lowe receivers of days gone by.
Since then, there have been very few CTX-10 reviews posted…hence all of the email questions.
In early October 2018 Don Moore, President of CommRadio, sent me a loaner CTX-10 which I’ve been using regularly since, testing all aspects of this little 10-watt transceiver.
Even though I’ve had the radio for a while, I plan to post a final CTX-10 review in the SWLing Post in coming months. As you may know, I typically only keep a review unit two months before publishing an evaluation, so why the delay? In short: I feel like the CTX-10 has some important updates/upgrades that need to come down the line, and I’m allowing time for these to be developed and tested before I issue a full and final review. So, if this is a rig that interests you, you’ll want to stay tuned for that.
In fact, due to a couple of quirks that only affected the first twenty production units, CommRadio has already replaced my initial review unit. I’ll detail these quirks below.
In the meantime, what follows is an initial review of the CommRadio CTX-10 with the most current firmware as of time of posting (1311). This review format is a departure from previous reviews as I’m only focusing on the pros and cons that might help future CTX-10 owners make a purchase decision.
Consider this initial review just a taste of the CommRadio CTX-10, not the full course.
CTX-10: The Pros
First of all, much like the CR-1 and CR-1A, the CTX-10 is an all-in-one unit that takes fewer than five seconds to get on the air if you have an antenna at the ready. Seriously. Other than a key, and/or microphone and antenna, there are no other external attachments needed. It’s field-ready from the moment you remove it from the package.
True story: it took me all of thirty seconds to remove the CTX-10 from the box, plug in a key, an antenna, and have it on the air. This is a major pro, in my radio world.
The CTX-10 has a built-in automatic antenna tuner that seems to do a great job making 1:1 matches on near-resonant multi-band antennas. I have a large horizontal multi-band delta loop here at the QTH, and the CTX-10 does a fine job finding a match on most ham bands.
Can it match the performance of the Elecraft KX-series ATU? I haven’t done an A/B comparison yet, but I don’t expect so—not on random wire antennas, at least. I do think, however, it will easily match any proper field antenna you pack in your go-kit.
Another minor plus worth mentioning? The ATU is very quiet in operation.
The CTX-10 ships with three built-in #18650 3.7V 2600 mAh rechargeable Li-ion batteries that are user-replaceable. These are high-capacity cells—in fact, the same type of cells used in the Tesla Model S.
But how do they work? In short: brilliantly. They power the CTX-10 for a much longer period of time than the battery pack in my Elecraft KX2.
After a full charge, these cells will support casual operation for up to eight hours. If you’re using the CTX-10 in a contest or on Field Day where operation is intense––that is to say, near-constant transmitting––it should last the better part of an hour. Don Moore actually produced a video early on of the CTX-10 running a full 10 watts and transmitting dits in CW for forty solid minutes before the batteries depleted to the point of shutting down. That’s certainly a new benchmark for portable rigs with internal batteries.
The CTX-10 has an intelligent charger that will recharge the internal cells when any voltage over 5 VDC is applied. This means, in a pinch, even a typical USB charger will work. If the power supply can deliver up to ten watts, it’ll charge the batteries rapidly––anything below that will take a longer.
Elecraft KX2 (left) and the CommRadio CTX-10 (right)
I also own the Elecraft KX2 and have used it in the field more than any other portable transceiver I’ve owned up to this point.
The KX2’s battery charging routine is more involved than that of the CTX-10. The KX2’s pack must be removed from the radio (by opening the bottom plate of the chassis with two thumb screws, and unplugging the coaxial connector), then it must be hooked up to an external battery charger, charged, and then re-inserted in the KX2.
In contrast, the CTX-10 only requires plugging it into a power source that can provide anything from 5 – 20 VDC––in other words, pretty much any power source. All of the intelligent charging is built into the CTX-10.
Without a doubt, the CTX-10 has the most robust and well-designed internal battery charging system I’ve ever found in a portable radio. Period.
Best-in-class duty cycle
If you’re a fan of FT-8 and other high-duty cycle digital modes, you’ll be very pleased with he CTX-10.
Like many other hams, I was bitten by the FT-8 bug. FT-8 is an amazingly efficient digital mode that somehow manages to defy propagation—even when transmitting at low power. In the past, I’ve worked all time new countries on five watts!
The CTX-10 back panel.
At home, I designated the Elecraft KX3 as my primary FT-8 rig. First time putting it on the air, I found to be fairly effortless. However, after operating perhaps 15-20 minutes, I found that power levels decreased significantly. This is because taxing the finals with FT-8 produces a lot of heat, and the KX3 protects the finals by lowering the output power. KX3 owners wishing to play FT-8 for extended periods at 10 watts or higher know how important it is to purchase an aftermarket heatsink to give the KX3 more transmitting time.
The CTX-10, in contrast, needs no aftermarket additions—if anything, it’s over-engineered. The entire chassis of the radio is essentially a heat sink, and because of this, it requires neither additions nor a fan to cool the finals, leading to comparatively effortless operation. Plus, as a result, operation is completely quiet.
In short? No overheating finals with the CTX-10: it’s an FT-8 beast!
Overall receiver performance is what I expected: nearly identical to the CommRadio CR-1/CR-1a receiver series with the added benefit of an internal ATU that helps tweak the antenna match on the ham bands.
You can tell that CommRadio has a legacy in designing equipment for the military, as well as for commercial and aviation industries. The CTX-10 smacks of a channelized commercial radio. There are relatively few features and adjustments as compared with, say, the Elecraft KX2 or the LnR LD-11. For those who like basic controls, the CTX-10 should please. On the other hand, if you like more granular control of your transceiver, you might prefer more refinements.
Quality engineering and construction
Like the CR-1A, the CTX-10 enclosure is aluminum with machined aluminum knobs. The boards and internal components are near (if not) mil-spec––brilliant quality that is found in few other radios.
The OLED display is easy to read at any angle and under almost any conditions you might experience at home or in the field––truly best-in-class in this regard. It is a relatively small display, but crisp and high-contrast, so quite easy on the eyes.
The circuit boards inside are of the highest quality, and so are the components. Don Moore sourced them from the same suppliers he uses for commercial-grade equipment.
My good friend, Vlado (N3CZ)––radio engineer and repair technician––took a look inside the CTX-10 chassis; he was sincerely impressed by the quality of the construction and board design. It’s worth noting that Vlado isn’t easily impressed, as he looks at the internals of commercial and military grade communications equipment every day: thus it says something that he remarked on this rig’s quality.
CTX-10: The cons
I’ve covered the obvious positives, so what about the negatives?
What follows are the cons I’ve noted while operating the CTX-10.
Keep in mind, some of these cons may disappear with future CTX-10 firmware updates. Again, I plan to hold off on my full and final CTX-10 review until I feel CommRadio has essentially finished planned upgrades.
Herein lies my biggest gripe with the CTX-10 and what I would consider a glaring omission on a $1,000 modern SDR transceiver. However, it’s worth noting that CommRadio has committed to address this in an update–see below.
At time of posting, the CTX-10 doesn’t have A/B VFOs like almost all modern transceivers––certainly like all of its direct QRP competitors, like the Elecraft KX2/KX3, LnR LD-11, and Yaesu FT-818/817ND.
So, how does a lack of two VFOs impact operation? First of all, there is no way to operate split on the current version of the CTX-10. Ouch.
The first time I put the CTX-10 on the air it was at the QTH of Vlado (N3CZ). We put the CTX-10 on 40 meters, and one of the first stations we heard was in Vanuatu, due to a brilliant opening into the Pacific. Vlado was positive he would work them with 10 watts on his 40M Steppir Yagi––I was, too. This being the first time either of us attempted DX on the CTX-10, we plugged in Vlado’s Bencher paddles and quickly tried to sort out where the DX station was working his pileup.
It was then we realized that the CTX-10 had no second VFO to work split, and, hence, we couldn’t work the Vanuatu station––because, like pretty much any desirable DX, he was operating split. Frankly, I was in disbelief and quickly downloaded the latest CTX-10 manual to find out how to engage split, but there was no mention of it in the manual.
The only other option was to operate split using a RIT control to shift the receive frequency. Again, we couldn’t locate a RIT control and a search of the manual proved no mention of RIT because, alas, there is no RIT control.
Again, we couldn’t work Vanuatu on the CTX-10 because, like all good DXers, the Vanuatu team were operating split.
Update: CommRadio has informed me they will be adding A/B VFOs as soon as possible, certainly before the 2019 Hamvention in mid-May, but hopefully sooner.
Update 2: Split operation added June 2019. Please read our final review for details.
Features may be too basic for some ham radio operators
It’s no secret: most of us hams like to fiddle with controls to tweak a transceiver’s performance. This is why ham radio transceivers often feature even more controls than their commercial/military counterparts.
The CTX-10 support feet are easy to flip up. The operating angle is excellent.
Still, some operators do appreciate a simpler rig, as they prefer simply to get on the air and get the job done. I appreciate this, too, especially when engaged in field operations where I’m less inclined to tinker with settings. So there’s some appeal in the CTX-10 approach.
At present, the CTX-10 feature set is very basic. Here’s a list of common controls the CTX-10 lacks––many that I’d typically expect in a radio of this price class:
No RF Gain control. The CTX-10’s RF gain is directly tied to the three AGC settings (slow, medium and fast). I know operators who never reach for the RF gain control, but I do, especially in the summer when it’s such an effective tool to lower QRN levels and help DX pop out of the background.
No microphone gain control. The CTX-10 lacks a mic gain control. The microphone input has a limiting pre-amplifier with built-in compressor and ambient noise gate. Problem is, at present, these settings are fixed and cannot be manually adjusted by the user. The CTX-10 was designed to work with handheld mics positioned closely to one’s mouth. Early feedback from users indicated that the CTX-10 was a little too aggressive, cutting off speech; a recent update did address this concern. Some users might never notice the lack of a mic gain control if they stick with the suggested modular MFJ-290MY or Yaesu MH-31A8J handheld mic. Personally, though, I like having a little more control of my microphone performance.
Keep in mind, there’s a plus side to the CommRadio ANG (Ambient Noise Gate): extended battery life. If you have the microphone keyed down, yet aren’t speaking for longer than a second or two, the output will be gated OFF, preventing background ambient noise from being transmitted. The on/off gating happens very quickly and isn’t noticeable.
The CTX-10 currently has no passband (PBT) control, notch filter or noise blanker.
Microphone compression is also pre-configured, and there’s currently no way to manually adjust it. This is a design choice typical of commercial communications gear.
No QSK/full break-in operation. The CTX-10, like the LnR LD-11, uses a traditional relay for switching between transmit and receive. Some CW ops like to hear the received audio between the dits and dahs of their sent CW. Elecraft radios, for example, use PIN diode T-R switching to eliminate relays during QSK. The CTX-10 uses a relay, so during CW operations, you’ll hear the relay click when switching from TX to RX and back again. This isn’t a problem for me, as I rarely set my CW rigs for full break-in, but the CW hang time delay on the CTX-10 is not currently adjustable. For high-speed CW ops that prefer a faster relay recovery, I suspect this could be an annoyance.
Limited CW adjustments. The CTX-10 lacks other controls many of us CW operators appreciate. Currently, the CTX-10 lacks a sidetone control––you cannot change the sidetone volume, nor can you turn it off. I believe CommRadio plans to fix this quirk in a future firmware upgrade. Additionally, you (currently) can’t change which side of your paddle sends dits and dahs without re-wiring your paddle. A minor con, for sure. Still, most modern QRP transceivers allow you to change this from the radio––I imagine CommRadio could add this feature in the future if their customers want it.
In addition, when operating the built-in CW keyer at speeds north of 25 words per minute, both Vlado and I noticed that immediately following a TX-RX-TX relay recovery, CW keyer timing was a little flaky. We assumed there was a problem with our paddles (perhaps dirty contacts?), but that turned out not to be the problem. Difficult to characterize, but essentially: immediately after a TX-RX-TX relay recovery, it’s hard to form a word correctly. The letter “Y” might come out as a “K” or “X” and a “Q” might come out as a “Z.” Both Vlado and I believe this might have something to do with keyer timing, which is possible. Nonetheless, I’m confident this can be fixed with a firmware update. In addition, we worked my friend Mike (K8RAT) and while he had very positive comments about the CW tone in general, he did notice truncated elements following a TX recovery. He also noticed an occasional slight tone spike on the first element which seems to coincide with an audio pop we hear in the sidetone. Note: CommRadio fixed this issue in a 2019 firmware update. Read our final review for details.
Accident-proof ATU activation. As with the CR-1A receiver, most of the CTX-10’s features and options are controlled by accessing the menu system by pressing the volume control knob. To make ATU activation easy, CommRadio place the ATU function first in the menu––with one knob press, the ATU item appears, and with one more press the ATU activates and tries to find a match. Engaging the ATU, in my opinion, is just a little too easy. With two presses of the volume knob, the ATU engages––great, but I find this happening by accident simply by normal handling of the radio. Instead of two short presses to engage ATU, I feel it might be best when making one short then one long press.
One other minor note: the CTX-10 ATU configuration cannot be adjusted manually like it can on the Elecraft KX series ATU.
No keylock to prevent powering up and engaging ATU. The CTX-10 does have a keylock to prevent the encoder from shifting during operation (a great feature for FT-8, for example), but it lacks a keylock to prevent the main power button from being pressed and turning on while in transport. Even more worrisome would be turning on the unit and engaging the ATU while in a pack––I’m guessing this could eventually damage the radio’s finals. The current solution for this? CommRadio suggests tying a shielded wire around the post of the volume control. This prevents accidental pressing while in transport and the CTX-10 ships with one of these around the volume knob (to prevent it turning on in shipment). I feel a more elegant solution would be to design it so that, in order to power up the CTX-10, you’d press two buttons simultaneously: for example, the volume control and the STEP buttons. I’ve make this suggestion to CommRadio. Update: Via a 2019 firmware update, CommRadio added a feature that automatically turns off the radio if accidentally turned on during transport. This is not a keylock and will not prevent the ATU from activating of the power button is accidentally pushed twice, but it will prevent the radio from being powered on in a pack until the batteries have been depleted.
Minor concern: no noise reduction control. In truth, this is a very minor con in my opinion. I’m not a big user of DSP noise reduction, but some users expect it on modern transceivers. I feel like the CTX-10’s receiver is well-balanced so I wouldn’t reach for a noise reduction control under normal operating conditions. That said, since there is no manual RF gain control, a variable noise reduction control could come in handy when QRN is heavy.
Size comparison: My ultra-compact C. Crane CC Skywave SSB sitting on top of the CommRadio CTX-10.
Minor concern: limited power output levels. This is a very minor gripe for me, but again could be important for other ops. At present, the CTX-10 has only three power output levels: 1, 5, and 10 watts. Thus for low-power contests, there is no way to lower the CTX-10 below one watt and no adjustment to zero watts. A couple of years ago my radio club had a DXCC 500 mW challenge to see who could work 100 countries with 500 mW or less. Most other modern QRP transceivers in this class have more nuanced control of power output and can be set to 1/2 watt. At present, the CTX-10 cannot. This is truly a minor complaint––perhaps only important to 10% of CTX-10 owners at best––but I’m willing to bet this could be added via a firmware upgrade.
Early production run quirks now resolved
Fortunately, however, the CTX-10 is listening to their market, and has resolved a number of early production run quirks. My initial evaluation loaner unit was serial number #19. Turns out, some of the first production run units (including mine) had a couple of hardware quirks. CommRadio has replaced or fixed these issues when customers report them, and units currently in inventory aren’t affected. I list them here simply to document:
Resolved: Intelligent charger whine. When charging the internal Li-Ion cells, my evaluation unit produced a high-pitched audible whine. I measured the audio frequency with a simple smartphone app and determined that it hovers around 10.5 kHz. The replacement unit doesn’t have this problem.
Resolved (or repairable): Internal speaker distortion. The internal speaker on some of the early units was prone to vibrate against the bottom plate of the radio’s chassis. This produced a buzzing distortion on loud sounds or when the volume was increased above, say, 50%. Again, this only affected some of the initial production run units. The fix for this is quite easy, and either CommRadio will do this for you or you can do it yourself and get a warranty extension, so if you find this to be a problem with your early unit, contact CommRadio.
To my knowledge, the CTX-10 is CommRadio’s very first ham radio transceiver. But it’s not the company’s first foray into transceiver equipment, as they’ve a solid history in commercial, aviation, and military electronics.
My biggest criticism of the CTX-10 is that I feel it should have never been released without A/B VFOs. Fortunately, this was addressed in a 2019 firmware update. I trust this company, so I know they will follow through; I’ve even offered input on how split operation might be implemented with the A/B VFOs. Personally I wish the rig sported a little more in the way of CW controls, mic gain, and an RF gain control, too––but that’s my preference, controls I like to use. Again, the CTX-10 feature set might be a little too thin––too simplistic––for some hams.
That said, I never expected the CTX-10 to have the number of features that, say, the KX2 has––the CTX-10 isn’t intended to be a “Swiss Army Knife” radio like the KX2/KX3. In fact, CTX-10 development actually began around the same time the KX2 was introduced to the market, and its introduction didn’t deter CommRadio.
CommRadio firmly believes that the CTX-10 will still have appeal to current KX2/KX3 owners and QRPers who value their design philosophy of simplicity. And, what’s more…they have a point.
So, who is the CTX-10 for?
When I check out a new-to-the-market radio like the CTX-10, I always try to sort out who the customer is––what type of ham radio operator would reach for the CTX-10 over other transceivers.
After having spent the past few months with the CTX-10, I can tell you that the CTX-10 owner is one who values a very simple, straightforward radio––one that appears and functions more like a commercial or military channelized set. Perhaps someone who began operating in a commercial, military, or aviation field, and/or who likes the “get on and get the job done” approach. Someone more interested in making contacts than in radio operations and refinements. Those who want a sturdy, lasting, no-frills, set-it-and-forget-it rig. If that’s you, take a closer look at the CTX-10–it may just suit your needs to a T.
The CTX-10’s overall construction and components are, as I’ve said, near mil-spec. The CTX-10 isn’t weatherized or waterproof––no more than any of its competitors––but the construction is top-shelf, for sure. It should run for decades without need of repair.
The whole body of the CTX-10 is essentially a heat sink.
I believe the CTX-10 will have strong appeal for radio enthusiasts who value:
All-in-one-box portability with no extra wired accessory components
Best-in-class internal battery life
Best-in-class intelligent battery charging
A high duty cycle and no cooling fan noise or third-party heat-sink add-ons
Digital modes like FT-8 and the ability to operate them in the field from internal batteries
The equivalent of a simple portable military/commercial set
Robust audio from a radio’s internal speaker or headphones
A well-balanced receiver with few manual adjustments
Broadcast listening (the CTX-10 is also superb broadcast receiver)
The CTX-10 is built like a tank, and has brilliant receiver characteristics. It’s also designed and manufactured here in the USA, and I find it’s easy to get good support from CommRadio.
I will add that CommRadio has been very receptive to my constructive and frank criticism. A good thing, in my book, as lesser companies might take offense or simply be dismissive.
If you’ve been waiting to purchase the CTX-10, I hope I’ve given you enough information that you can make a decision.
If you have any specific questions, please contact CommRadio or comment, and I’ll do my best to answer. I hope to post a few videos of the CTX-10 in action within the next few weeks when my rather busy schedule permits.
In August 2015 at the Tokyo Hamfair, Icom debuted a new type of transceiver in their product line––one featuring a direct RF sampling receiver. Essentially, it was an SDR tabletop transceiver.
At about the same time that the IC-7300 started shipping around the world, Icom pulled their venerable IC-7200 off the market. Yet the IC-7200 was established as a well-loved product, due to its highly sensitive receiver, its relatively robust front end, and its quality audio. Moreover, it was simple to operate, which made superb as a Field Day or radio club rig.
Therefore, even though the IC-7300 promised much more versatility than the IC-7200, for its price point it had a tough act to follow.
So, of course––even more so than with any other radio Icom has introduced in the past few years––I was eager to get my hands on a IC-7300. I’m very fortunate that my good friend, Dave Anderson (K4SV) was one of the first purchasers of the IC-7300, and that he didn’t mind (after only having the rig perhaps one week!) allowing me to borrow it for a several weeks for evaluation.
Note: I should state here that since this rig was loaned to me, I evaluated it based on the firmware version it shipped with, and made no modifications to it.
This review primarily focuses on the receiver’s performance, functionality and usability.
Introducing the Icom IC-7300
In recent years, the “big three” ham radio manufacturers have been using color displays, and––Icom most especially––touch screens. While I’m no fan of backlit touch screens in mobile applications, I think touch screen displays make a lot of sense in a base radio. If carefully designed, a touch screen can save an operator from heavily-buried menus and decrease the number of multi-function buttons on the front panel.
The challenge, of course, is making a display with intuitive controls, and one that is large enough, and with sufficient resolution, to be useful to the operator. In the past, I’ve been disappointed by many displays; the most successful have been incorporated in DX/Contest-class (i.e., pricier) transceivers, meanwhile, entry-level and mid-priced transceiver displays often seem half-baked. While the graphics may be crisp, spectrum displays at this price point are often too compressed to be useful, and if not a touch display, force the user to pause operation in order to find the correct knob or button to change settings. In such cases, I find myself wondering why the manufacturer went to the expense of a color display at all––?
But what about the C-7300 display? I’m thoroughly pleased to report that Icom did a fantastic job of balancing utility and function in design of the IC-7300’s color touch display and front panel. There are number of ways you can chose to display and arrange elements on the screen–since I’m an SDR fan, I typically chose a display setting which gave the waterfall the most real estate. Of course, one can chose to give the frequency display priority or a number of other arrangements.
I can tell that Icom built upon their experience with the IC-7100––their first entry-level touch screen display transceiver.
I was able to get the IC-7300 on the air in very little time. Within five minutes of turning on the IC-7300, I was able to:
change the display to feature a spectrum waterfall;
change the span of the waterfall display;
adjust the TX power output;
change the filters selection and the transmit mode;
change bands and make direct-frequency entries;
adjust notch, passband, and filter width;
adjust AF and RF gain;
set A/B VFOs and operate split;
change AGC settings;
turn on Noise Reduction/Noise Blanker, and
Basically, I found that all the essential functions are clearly laid out, accessible, and highly functional. Impressive.
The IC-7300 ships with a manual–– aptly titled, the “Basic” manual––and a CD with the full and unabridged operations manual. The Basic Manual covers a great deal more than the manual which accompanied the Icom ID-51a, for example. If you read through the manual, you’ll readily familiarize yourself with most of the IC-7300’s higher function operations, and especially, you’ll be able to adjust the settings to your operation style. The Manual is written in simple language, and includes a lot of diagrams and graphics.
If you’re like me, you will find you’ll also need to reference that unabridged manual, so hang on to the CD, too.
Still, I imagine there’s a large percentage of future IC-7300 owners that will never need to reference the manual––especially if they don’t care about tweaking band edges or similar settings. Yes, believe it or not, it’s that easy to use.
While I spent a great deal of time listening to CW and SSB in various band conditions and at various times of day, I spent less time on the air transmitting.
With that said, all of my transmitting time was in CW since the IC-7300 mic was accidentally left out when my friend loaned me the rig.
I’m please to report that CW operation is quite pleasant. All of the adjustments––RF Power, Key Speed, and CW Pitch––can be quickly modified using the multi-function knob. While in CW mode, you can also toggle full break-in mode, which is quite smooth, via the function button and touch screen.
SSB functions are similar. While in SSB mode, the multi-function knob allows you to change the tx power, mic gain, and monitor level. The function button opens an on-screen menu with VOX, compression, TBW, and the monitor toggle.
Of course, my smartphones’s microphone can’t accurately reproduce the audio from the IC-7300, but you probably get the idea.
The only annoyance I noted––and perhaps I’m more sensitive to this, being primarily a QRPer––is that the 7300’s cooling fan starts up each time you key up. It even comes on when transmit power is at its lowest setting. I find this a little distracting in CW. Fortunately, however, the 7300’s fan is fairly quiet and operates smoothly.
This result was almost tied. The Excalibur’s audio––without any adjustments––has a fuller and “bassier” sound. The ‘7300 can be adjusted to have similar characteristics, but the default EQ settings produce very flat audio. Many of you commented that the IC-7300 more faithfully produced audio optimized for SSB.
Shortwave Broadcast recordings
The following recordings were made on the 31 meter broadcast band in the evening. Both radios had the same filter width: 9 kHz and 8.2 kHz.
Weak Shortwave AM (Radio Bandeirantes 31 meter band)
There was a noticeable preference for the WinRadio Excalibur in this particular audio set. Even though the Excalibur’s audio splattered a bit, the content was more interpretable. The IC-7300’s audio sounded flat in comparison––again, something that can be adjusted quite easily in the ‘7300’s audio settings.
Strong Shortwave AM (Radio Romania International, French 31 Meter Band)
Once again, the Excalibur won favor, but I imagine results would have been closer had I adjusted the ‘7300’s audio EQ.
Mediumwave Broadcast recordings
Note that the following mediumwave recordings were made during the morning hours (grayline). The strong station is the closest AM broadcaster to my home; it’s not a blow-torch “Class A” type station, merely the closest local broadcaster.
In the “weak” sample, I tuned to 630 kHz where multiple broadcasters could be heard on frequency, but one was dominant.
In this particular example, the IC-7300 could not pull the strongest broadcaster out of the pile as well as the WinRadio Excalibur. In fairness, the Excalibur was using AM sync detection, something the IC-7300 lacks.
Icom IC-7300 vs. Elecraft KX3
I also decided to pit the IC-7300 against my well-loved Elecraft KX3.
These results were spilt in the middle. Again, I believe this comes down to personal preference in the audio. And again––in both radios––the audio EQ can be adjusted to suit the operator.
Receiver performance summary
I enjoy producing audio clips for readers to compare and comment upon. Each time I’ve done so in the past, I’ve had listeners argue the virtues of a particular audio clip while others have the complete opposite reaction to that same clip. Not all of us prefer our audio served up in the same way. No doubt, there’s a great deal of subjectivity in this sort of test.
I’ve had the IC-7300 on the air every day since I took possession of it. I’ve listened to SSB, CW, and lots of AM/SW broadcasters.
And here’s my summary: the IC-7300 is an excellent receiver. It has a low noise floor, superb sensitivity and excellent selectivity. I even slightly prefer its audio to that of my Elecraft KX3, and I’m a huge fan of the little KX3.
I’ve written before about how difficult it is to compare SDRs; the problem is that there are so many ways to tweak your audio, filters, AGC, noise reduction, etc. that it’s hard to compare apples with apples.
In the audio samples above, the IC-7300 and WinRadio Excalibur were both set to their default audio settings. In SSB and CW, the IC-7300 excels, in my opinion. CW seems to pop out of the noise better and SSB is more pleasant and interpretable. The Excalibur has a better audio profile for AM broadcasters, though. Its default audio simply sounds fuller–more robust.
The audio from the IC-7300 on AM sounded absolutely flat. However, if I tweak the audio of the ‘7300, adding more bass, it instantly sounds more like a dedicated tabletop receiver.
I should also mention that while the IC-7300’s built-in digital recording is a fantastic and effective feature, it doesn’t produce audio true to what’s heard through headphones live. This is especially the case when you add more bass and treble response as in the RRI example above. When the audio EQ is set to a default flat, it’s quite accurate.
Cooling fan immediately starts up on CW/SSB transmit at any power setting (see pro regarding fan noise)
Occasionally you may get lost in deeper customized functions
Supplied printed basic owner’s manual, while well-written, doesn’t fully cover the IC-7300s functions and options; you must explore the digital owner’s manual in supplied CD.
In a nutshell: Icom has hit a home run with the IC-7300.If I didn’t already have an Elecraft KX3 and K2, I would buy the IC-7300 without hesitation.
Though the price point is a little high for an “entry level transceiver,” it’s worth every penny, in my opinion. For $1500 US, you get a fantastic general-coverage transceiver with an intuitive interface, nearly every function you can imagine, and performance that would please even a seasoned DXer.
Though I haven’t done and A/B comparison with the IC-7200, I imagine the IC-7300 would prevail in a test. The IC-7300 would certainly wipe the floor with it’s more economical brother, the IC-718.
Radio clubs, take note:
In my view, the IC-7300 has the makings of an excellent radio club rig in which performance, functionality, as well as ease of use are important. I expect that the IC-7300 will not only cope very well with crowded and crazy Field Day conditions, but it will also give any newcomers to the hobby a little experience with a proper modern transceiver. The fact that you can view signals so easily on the spectrum display means that it will be easier to chase contacts and monitor bands as they open and close. Indeed, what better way to mentor a newly-minted ham in modes, contacts, carriers, QRN, QRM, and so forth, than to simply point these out on the IC-7300’s bright, clear display––?
If your club is considering a transceiver upgrade or purchase, do seriously consider the IC-7300. I think you’ll find this rig is up to the task.
And for home? The Icom IC-7300 may be all of the rig you’ll ever need.
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