Tag Archives: General Coverage Transceivers

Sneak peek of the Apache Labs Andromeda 100 watt SDR transceiver

Many thanks to Apache Labs who share the following announcement:

Sneak peek at the Andromeda 100W Transceiver……

10th GEN Intel 6 Core i7, 7 inch built in touch screen and an option to add up to two External HD Monitors.

Windows 10 Powerful PC and an Ultra High performance 100W SDR with PureSignal Goodness in a single compact Box!

Run FT8 and other Digital Modes out of the box!

Coming Soon!

We will post more information about the Andromeda transceiver when we have solid details.

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Help building a general coverage QRP transceiver list

Over the past few weeks, I have been building curated lists of ham radio transceivers. It all started when I needed to learn about multimode VHF/UHF transceivers for my EME project. As I got deeper into the process, I decided to make my master list of VHF/UHF multimode transceivers public. The goal with the list was to familiarize myself with the makes/model numbers and have an easy way to check out any used gear deals.

Next, I started a list of QRP general coverage transceivers–something I had been meaning to do for ages because I get so many inquiries about these from readers.

To be clear, by “general coverage” I mean radios that can receive HF and possibly MW broadcast bands in addition to ham radio bands. By “QRP” I mean radios that have output power of about 20 watts or less–some define the term QRP more strictly, but since our list has less to do with the transmitting function, I’m a little more flexible.

I like QRP general coverage transceivers because they’re often portable, have modest power requirements, and some offer superb sensitivity and selectivity for broadcast listening.

Click here to view the list so far.

Please comment if you note a missing transceiver. I’m certain I’ve left some out. I’d appreciate model numbers and links if possible. If you’ve ever owned one, please consider sharing your thoughts on its performance from the point of view of an SWL as well.

I’ve already started working on a list including all general coverage transceivers. It’s massive so it could be a while before it’s published! I’ll certainly ask for your input then as well.

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The Xiegu G90 as a shortwave broadcast band receiver

After publishing a couple of posts about the Xiegu G90 QRP transceiver, I’ve gotten a number of inquiries from readers asking about the G90’s ability to receive AM broadcasts. Although I’ll address this in detail in my upcoming TSM review, I thought I’d also share a few notes with you.

One of the main reasons I decided to review the Xiegu G90 is I found so little information out there about how well the general coverage receiver worked for HF broadcast listening.  The G90 has a frequency range of 0.5-30 MHz (SSB, CW, and AM), but I couldn’t find a specification showing the maximum width of the AM filter. I had seen a few display photos with the AM filter width indicated as 5.4 kHz–that’s not terribly wide, but workable.

Only moments after opening the box and putting the G90 on the air, I tuned to the Voice of Greece (9,420 kHz) and learned how to change the bandwidth.  I was very pleased to find that in AM mode, the indicated filter width is actually half the actual width. This means, the G90’s AM filter can actually be widened to 10.8 kHz–brilliant!

In addition, the bandwidth adjustment is variable, meaning you’re not locked into pre-determined, stepped bandwidths as with so many other transceivers.

In this short video, I widen the AM filter while tuned to the Voice of Greece:

Here’s another video of the G90 tuned to Radio Exterior de España on 9,690 kHz. Although the REE transmitter is located across the Atlantic Ocean in Spain, they sound like a local here in North Carolina:

Overall, I’ve been very pleased with the G90 on the HF bands.

Of course, there’s no synchronous detector (although users have requested this in a future firmware version) and there’s no notch filter as of yet. While I expect Xiegu may consider adding a notch filter, I doubt they’ll ever add a sync detector as this rig is primarily aimed at QRP ham radio operation. Of course, I could be wrong.

I also haven’t found a way to completely disable the transmitter or set the power level to zero watts. It’s quite possible I simply haven’t discovered the appropriate setting for this yet.  Disabling the transmitter adds an extra level of protection when I use receive-only amplified mag loop antennas, for example. Also, some G90 owners may purchase the rig for listening purposes only and would rather not accidentally key the transmitter or engage the ATU.

Retailers

I purchased my Xiegu G90 from MFJ Enterprises because I wanted to support a US retailer. There are a number of other G90 distributors across the globe. Here’s a short selection:

I’m sure there are many other G90 retailers across the globe.  Before placing an order, I would suggest you double-check availability as some retailers are on back-order.

Post Readers: Have you used the Xiegu G90 on the broadcast bands? Please comment with your thoughts!

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The Yaesu FT-70G: Where the FT line met Milcom

Earlier today, I stumbled upon a very unique transceiver in Universal Radio archives: the Yaesu FT-70G.

Here’s the description from Universal:

The Yaesu FT-70G is a portable HF transceiver covering 2 to 30 MHz transmit. Receive is from 500 kHz to 30 MHz. Frequency selection is via BCD switches to 100 Hz. There is a clarifier for fine tuning. Optional FNB-70 NiCad Battery. Please note that the optional 10F-2.4DL filter is required for LSB opeation.

The Yaesu FT-70F is similar, but is a channelized fixed version offering up to 11 frequencies.

Two hours ago, I was not aware that the FT-70G existed.  Now? I want one!

I’m a real sucker for vintage rugged field radio gear, so I never discovered the FT-70G until today. Turns out, they’re relatively rare. A little light research reveals that it’s a highly-desired transceiver in the world of HF Packers–those radio enthusiast who like “manpack” commercial and military gear.

The FT-70G has a distinct military look and feel with the BCD switches to change frequency, rugged toggle switches, chassis extensions to protect the front panel, and attached screw-on connector caps.

What’s really surprising is that the FT-70G has a general coverage receiver (500 kHz to 30 MHz). Admittedly, it would not be fun band-scanning with those BCD switches…but still!

This website has a number of photos. They also have a product description likely from the original Yaesu/Vertex Standard FT-70G description:

“The FT-70 series HF field portable manpack transceivers are designed to provide reliable communications under rugged conditions in the military and commercial environment. The frequency synthesized, all solid-state circuitry and die-cast anodized aluminum enclosure and battery pack make a highly portable, weatherproof station. Flexible operation for optimum communications under a wide range of propagation conditions are assured by SSB (USB, LSB), semi break-in CW, AM, or audio interfaced Data modes. All controls, antenna, and interface ports are available and selectable via the front panel for maximum effectiveness and ergonomics in field, base, and manpack applications. The companion antenna tuner FC-70 is compatible with walking manpack, field portable, or base configurations. The highly effective vertical tripod mount antenna system YA-70 is deployed and stowed easily and quickly, pulling double duty by converting to manpack whip while on manuevers. High quality handset YH-70 provides communications privacy and clarity.”

Again, check out the excellent photos of the full manpack kit.

As I researched pricing, I discovered this FT-70R with accompanying FC-70M antenna tuner on eBay right now with only 6 hours left of bidding:

At time of posting, the bids are at $520. I fear this will soar well above my comfort level before bidding ends. (Like I need another field radio anyway, right?)

Post readers: Please comment if you’re familiar with the FT-70G and especially if you’ve ever owned one.  I’d love to hear about your experience with this unique rig.

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A Tale of Two Radios: CommRadio CTX-10 vs. Elecraft KX2

The following review first appeared in the February 2020 issue of The Spectrum Monitor magazine.


A Tale of Two Radios: CommRadio CTX-10 v Elecraft KX2

As my blog readers often point out: Why focus on low-power (QRP) ham radio activities when propagation is so dismal…even for high power stations?  A logical argument, I’ll admit, and lately it’s become a common theme in QRP discussion.

But I’ve said it before, and I’ll say it again: despite the current stagnation of the sunspot cycle, we’ve been seeing a very curious uptick in low-power radio innovation. Manufacturers have been churning out QRP transceivers at a rapid rate during this solar lull, and I can assure you, it’s a strategic move that the marketplace rewards.

So, why should this be? I attribute the influx of QRP radios to several factors.

First of all, leveraging innovations in SDR (software defined radio) design, it’s simply become less expensive to produce portable low-power radios with extra features. In other words, manufacturers can now offer more radio bang-for-buck. Similarly, the technology is accessible enough that even smaller manufacturers can produce competitive products.

Secondly, the new-found popularity of field activities––such as Parks On The Air (POTA) and Summits On The Air (SOTA)––fuel the need for field-portable, all-in-one transceivers. Anyone who falls in love with field portable operation, and it’s easy to do, will quickly discover how handy it is to have a dedicated radio for these activities.

However, it’s not always competition that pulls radio operators to the field. With so much QRM (human-generated interference) at home or in built-up areas, many operators and radio enthusiasts now take to the field to escape the noise. Likewise, many operators live in restricted communities that don’t allow for permanent antennas, so it’s in their best interest to make their radio shack…well, portable.

And why not? Weak-signal digital modes like FT-8 have made signal-hopping across the planet with only a few watts of power easier than ever before. I’ve spoken with a number of operators who have––using FT-8––worked DXCC for the first time with stealthy, portable antenna systems, and others who have taken the dare to work DXCC only on individual bands. Such challenges are all in the name of fun.

Finally, in general, QRP transceivers are much less expensive than their 100 watt counterparts. QRP radios gain a competitive edge by omitting pricey amplification in the design, while still offering the operator DX-class features and receiver performance.

Making a choice

With so many new field-portable QRP transceivers on the market, making a choice can be difficult. Still, there are some guidelines that will help you eliminate a number of models.

The Mountain Topper MTR5B

For example, if you only plan to operate CW and don’t need a general coverage transceiver, you can effectively eliminate all of the priciest QRP transceivers. CW-only transceivers like the popular Mountain Topper series are incredibly portable, durable, and half the price of full-featured multi-mode transceivers.

Also, if you use resonant antennas, there may be no need for an internal or external antenna tuner––this can save you upwards of $200. If you prefer using an external battery, there may be no need to purchase a model with an internal battery option.

In this article, however, we’ll be looking specifically at two general coverage QRP transceivers that are very much all-in-one. With an antenna, mic and/or key, these radios will get you on the air in a matter of seconds.

Our competitors

 

Over the past year, I’ve received numerous emails and comments asking for advice choosing between two specific radios: the recently reviewed CommRadio CTX-10 and the Elecraft KX2.

I’m not surprised, because both of these field-portable QRP transceivers sport similar basic features and options, e.g.:

  • Ham band coverage from 80 – 10 meters
  • General coverage receiver
  • Internal batteries
  • Built-in ATU
  • Small and lightweight
  • Designed and built in the USA

Although the CTX-10 and KX2 share the same goal of functioning as an all-in-one, grab-and-go field radio, I believe they have very different appeal. 

Herein lies the key to choosing the right rig for you, and the point I hope to prove in this article: it’s based on your personal operation philosophy.

The Elecraft KX2 is the “Swiss army knife” transceiver. It has an amazing array of capabilities, features, and adjustments, yet is incredibly compact and could easily fit in your jacket pocket. Moreover, the KX2 is backed by Elecraft, one of the most successful amateur radio manufacturers in business.

The CommRadio CTX-10, on the other hand, was designed with a basic feature set in mind, dead-simple operation, and near mil-spec quality inside. The CTX-10 is the transceiver iteration of the popular CR-1 series receiver by CommRadio.

When I’m asked which radio is best, I respond with a series of questions––because I first need to discover what type of operator the potential user is, to give him/her a good recommendation. Below, I’ll break down some of the key questions to help guide you in making a decision between these two transceivers.  Note that these questions are ones that should be asked when purchasing pretty much any transceiver.

Do you plan to engage in more ham radio operation, or broadcast listening?

True, since the CTX-10 and KX2 are both general coverage transceivers, either radio can serve. But if you’re primarily looking for a broadcast listening radio and you might only occasionally hop on the bands to make casual ham radio contacts, then you should give the CTX-10 some consideration.

The CTX-10 is essentially a transceiver version of the excellent CR-1a receiver. It is better equipped for listening to broadcasts than the KX2 because it has three AM filter settings: 5, 7.5, and 15 kHz. In contrast, the KX2 AM filter can only be widened to about 5 kHz. CTX-10 AM audio fidelity is superior to that of the Elecraft KX2.

In addition, the CTX-10’s receiver coverage dips down to 150 kHz and it’s quite capable on the mediumwave band. The KX2’s receiver covers 3 MHz – 32 MHz and  0.5 – 3 MHz with “reduced sensitivity.” In other words, the KX2s receiver architecture is designed for the ham bands, thus mediumwave sensitivity is suppressed on purpose. I’ve certainly listened to mediumwave stations on the KX2, but only to local, strong stations. You could never hop into mediumwave DXing on the KX2 like you can on the CTX-10.

With that said, if you’re primarily looking for a ham radio transceiver for operations in the field, and you might only occasionally do shortwave radio listening, then you should give the KX2 serious consideration. In my opinion, the KX2 is simply a more capable, adaptable ham radio transceiver than the CTX-10. (More details on this point to come.)

The Elecraft KX2 doing a little coastal SWLing.

Now, here’s the irony: Although I had a CTX-10 in my shack for almost a year, I still defaulted to taking the KX2 on trips when I thought SWLing might be my primary activity. Why? The KX2 has a very robust and capable HF receiver. Its only real limitations are a lack of wide AM bandwidths and sub-3 MHz frequency coverage and performance. I find that the KX2’s 5 kHz AM filter sounds pretty good, though; when using headphones, the KX2’s simulated stereo audio effect really makes the audio sound broad and pleasant. I also rarely use ham radio transceivers to do mediumwave or longwave DXing––I use dedicated portables like my Panasonic RF-2200, or an SDR––so mediumwave and longwave reception is never a serious limitation for me.

But, again, if you primarily plan to do broadcast listening, the CTX-10 is the stronger of the two choices.

Are you looking for a feature-packed radio that can be tweaked and adjusted on a granular level?

If so, you’ll definitely want to choose the KX2 over the CTX-10. The CTX-10 has an incredibly basic feature set, while the KX2, like most Elecraft radios, has an abundance of features, functions, and adjustments at your disposal.

If you want a simple, unfussy radio that automatically adjusts most user controls like microphone gain and compression, then the CTX-10 will suit you fine. If you like both automatic and manual control of your radio’s settings, the Elecraft KX2 is your rig.

How important is internal battery operation and ease of recharging?

The CTX-10 has best-in-class internal battery capacity and intelligent charging. You can literally play radio for hours on end without depleting the batteries in the CTX-10. The internal batteries can be charged via the DC power port, or even via USB cable.

The KX2 Battery

The KX2 uses an internal battery pack that must be removed each time to charge. I’ve taken the KX2 to the field more than 100 individual times and find that I can operate at full power for about one hour fifteen minutes (with a heavy amount of transmitting) before the voltage drops, and the output power, as well from about 10 watts to 5 watts. Of course, when in receive, it’ll operate for hours without recharging.

Of course, with a swappable battery pack, you can bring additional pre-charged batteries to the field to eliminate the need to recharge.

I’ve never found recharging or swapping KX2 batteries to be a problem, but internal battery operation via the CTX-10 is certainly its strong suit.

One known issue with some of the CTX-10 units: when charging the internal Li-Ion cells, my initial 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. It was quite annoying because I can still hear frequencies in that range. The second evaluation unit didn’t have this problem. If your CTX-10 has this problem, contact CommRadio for help.

Are you primarily a CW operator?

If you are a CW enthusiast, chances are great that you’ll prefer the KX2 over the CTX-10.

The CTX-10 has very few settings for CW mode. In fact, it doesn’t even (presently) have a side tone control or support iambic operation. The CTX-10 uses a traditional relay for TX/RX switching, but you can’t presently change the hang/delay time. The CTX-10 cannot do full break-in QSK.

Elecraft transceivers are designed by CW operators and sport true benchmark CW performance. The KX2 allows granular control, thus can be tailored to accommodate any operator. The KX2 has silky-smooth full break-in QSK. If you’re a CW operator, you’ll much prefer the KX2.

Are you primarily a digital mode operator?

The CTX-10 body (left) is essentially a large heat sink.

If so, you’ll want to consider the CTX-10, because it can run high-duty cycle modes like FT-8 in the field without ever overheating. This is also one of the CTX-10’s strongest points.

Both the Elecraft KX2 and KX3 will decrease power output after running FT-8, for an extended period of time, to protect the finals from overheating. Operation time can be significantly extended by adding an optional third-party heat sink.  The CTX-10 does not have this issue, however, as the CTX-10 body itself is essentially a heat sink. In all of my testing, I never came anywhere close to overheating it.

Are you primarily an SSB/phone operator?

If SSB is your game, you’ll prefer the KX2.

The CTX-10 essentially has no microphone controls––in fact, it doesn’t even have an adjustable mic gain. The microphone input is completely auto-controlled by the CTX-10, via a limiting pre-amplifier, built-in compressor, and ambient noise gate. The only ways you can really affect how audio is transmitted, in fact, is by changing the distance from your mouth to the mic, and/or changing how loudly you speak into the mic.

If you have a favorite boom headset (like Inrad or Heil), note that it may not work well with the CTX-10, simply because you have no control of the mic inputs.

The KX2, on the other hand, has robust microphone controls; you can, for example, even change the EQ settings of your transmitted audio.

How important to you is the capability of your rig’s internal ATU?

The CTX-10 sports a nifty internal antenna tuner, but it doesn’t match the performance of the KX2’s internal ATU option. In my field work, I found that I needed antennas that were pretty close to resonant for the CTX-10 to match them. The ATU was certainly a handy feature on the CTX-10, but it didn’t allow me the flexibility to, for example, load up a random wire antenna.

Update (23 Mar 2020): Brian Haren informs us that with firmware update 1334 issued by CommRadio on December 18, 2019 “performance of the internal tuner was vastly improved.” This firmware was issued after my review unit was sent back to CommRadio.

The KX2’s internal ATU, on the other hand, is benchmark, and can tune via nearly any antenna––indeed, it would almost tune a metal chair, if you tried to load it. It’s as good at matching antennas as my Emtech ZM-2 balanced line tuner. In fact, I once loaded a 20-meter hex beam on 40 meters with the KX2 in order to work a rare park activation. No other radio in my arsenal could match that (well, frankly, it was asking a lot), but the KX2 not only matched the antenna, but it got an excellent match:  if memory serves, something like 2:1. (And, yes, I worked my park!)

Note that the ATU comes with the CTX-10 package, while the KX2 internal antenna tuner is a worthwhile $200 option.

Are you on a budget?

Everything included in the CTX-10 box.

When you purchase the CommRadio CTX-10 for $999.99, you’re buying an all-in-one package: a transceiver, internal batteries, and an internal ATU. There are no other options to purchase separately. The CTX-10 doesn’t ship with a microphone, but it does include a USB cable, DC power cord, and CD manual. You simply unbox your CTX-10, make sure it’s been charged, plug in your microphone (requires a modular plug type like the Yaesu MH-31A8J or MFJ-290MY) or key, add your antenna, and boom! You’re ready to hit the air.

Unlike CommRadio, Elecraft started as a kit manufacturer. Their philosophy has always been one of purchasing a basic unit, then adding features when you’re ready. In a sense, this gives the customer a lower starting price point. Here’s how the KX2 pricing breaks down:

  • Elecraft KX2 transceiver: $789.95
  • KXAT2-F internal ATU option: $199.95
  • KXBT2 Internal Lithium Battery option: $59.95
  • KXBC2 Lithium battery fast charger: $29.95
  • KXIO2 Real-Time clock: $79.95

To configure the KX2 to be equivalent to the CTX-10––meaning, with ATU, internal battery, and charger––your total price would be $1,079.80. This is the configuration of my KX2.

If you use just an external battery and resonant antennas, the base KX2 might be the only radio you’ll ever need. At $789.95, that’s $210 less than the CommRadio CTX-10. Fully configured, however, the CTX-10 is about $80 less expensive than the KX2.

Apples to oranges, in radio terms

If you haven’t gathered already, although both the CTX-10 and KX2 are general coverage QRP transceivers, they are completely different––like comparing apples to oranges––in terms of the market they wish to reach.

No doubt, CommRadio designed the CTX-10 to appeal to people who love commercial or military channelized radios. Based on my interaction with CTX-10 owners, many are into preparedness and primarily infrequent simplex SSB operations.

The KX2 will appeal to hams who are active operators and who enjoy full control of their radio’s functions and features. Elecraft has a massive and loyal community of users and fans.

Summary

If I haven’t made it clear yet, there’s much more involved in making a purchase decision than simply looking at the specifications of a radio. Often, it’s a truly personal and subjective choice.

Be honest with yourself about your needs, and base your purchasing decision on those. After all, in this case we’re talking about two capable radio transceivers, either of which should provide years of great operation and listening.

Click here to check out the Elecraft KX2 and here for international distributors.

Click here to check out the CommRadio CTX-10 and here to purchase via Universal Radio.


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Mario acquires an Index Labs QRP++ general coverage transceiver

May 1996 QRP Plus ad from QST (Source: WD8RIF)

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN), who shares the following guest post that was originally published on the Delaware Valley Radio Association (DVRA) website:


Amateur Radios from the Past: The Index Labs QRP++

The Index Labs QRP ++ was an intriguing little radio manufactured back in the mid-‘90’s by Index Labs of Gig Harbor, WA.  For those interested in QRP (low power operating, generally less than five watts output) this transceiver filled the bill perfectly.  It supports CW and SSB, transmits on all WARC bands, covers 1.8 – 30 MHz receive, has full break-in CW and a built-in iambic keyer.  It boasts 20 memories, weighs four pounds (perfect for portable operation) and measures 5.5 x 4 x 6 inches.  It’ll run on a 12V 1.5 amp supply or a stout 12 volt gel cell.  The internals (see second pic) are an engineering masterpiece with stacked circuit boards reminiscent of commercial rigs.

Index Labs QRP ++ on the test bench

I recently acquired one of these radios as I was heavily into QRP in the 1970’s while using a TenTec Argonaut 509 and vertical on our apartment house’s roof.  Back then the sunspot numbers scored much higher than today and many contacts were made, most notably a CW contact with Japan with a paltry one watt.  So for nostalgic reasons I had to have one of these QRP++ rigs even though more modern and sophisticated versions are available.

At the moment bench tested is being done prior to sending it into action.  One important component needing replacement was the memory battery which was totally kaput.  Interestingly, this battery not only keeps the 20 memories alive but also brought back to life the CB radio-style S-meter reminiscent of radios from decades ago. Other items on the testing  “to do” list will be checking power output, frequency accuracy, drift, and finally, on-air performance.  The radio will feed a ground mounted 31’ vertical with 53 radials. With the right ionospheric conditions hopefully contacts will be aplenty.

Neatly stacked circuit boards and clean layout of QRP++

Unfortunately, no service manual exists for this gem, but it rates a 4.1 out of 5 on the eham.net Richter scale, and a number of ops have published helpful information on problems, solutions and modifications.  Notably the first run of these radios was later replaced with improved models boasting higher performance via a custom designed mixer, so knowing the serial number of your unit helps to determine if yours was an upgrade.

Rear panel control layout. Power is adjustable and tested at a hair under 5W.

You can read and see more photos from the author, Mario Filippi N2HUN, at https://www.qrz.com/lookup/n2hun

Click here to read this article on the DVRA website.


Thank you, Mario, for sharing this article and many thanks to the DVRA for allowing us to re-post it.

I owned a QRP++ for a few years and absolutely loved it. At the time, it was one of the most portable full-featured transceivers on the market. Although it can struggle in RF dense environments like Field Day or other contests, for daily use it was very effective. I eventually sold mine to fund the purchase of the Elecraft KX1 and, later, KX3.

I always loved the simple front-panel ergonomics of the QRP+ and QRP++. It’s an incredibly easy rig to operate in the field. Plus…it has a bit of a “cute” factor, if you like radios shaped like cubes.

There is a dedicated email discussion group for Index Labs transceivers–currently, they’re on Yahoo Groups but may migrate to another platform by end of year.

In addition, SWLing Post contributor, Eric McFadden (WD8RIF), has an archived webpage with a wealth of information about the Index Labs QRP+ series.

Thanks again for sharing this, Mario! I know you’ll enjoy the QRP++ once you get it on the air!


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Final review of the CommRadio CTX-10 QRP general coverage transceiver

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.

This final review builds upon the initial review––think of it as the  second installment, or “Part 2″––so if you’re considering the purchase of a CTX-10 and haven’t read the previous post about it, please do read the initial review first.

Upgrades

As anticipated, via simple at-home firmware updates, since my initial review the CTX-10 has now been upgraded and tweaked a number of times. [Click here to view all of the documented firmware updates and notes at CommRadio.]

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.

Operating split

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:

  1. Chose the frequency and mode;
  2. Hold the STEP button for one second or more, then release. You’ll then see a split display indicating the TX and RX frequencies.
  3. 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.

ATU flexibility

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, but I consider those ATUs to be some of the most flexible on the market.

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. A perfect combo.

SSB operation?

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.

CW operation

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 faint 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.

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.

All in all, the CTX-10 will serve the CW operator much like a military set in field operations. True, I wish it had a few more adjustments, but it has all of the basics, and I’ve received several great reports regarding signal and tone.

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.

Please note: some of these 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 heartily recommending it in my initial review.

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 values a very simple, straightforward radio. 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.

If, however, you’re looking for a full-featured QRP radio with many of the features and nuanced adjustments you’d expect in the shack, check out the Yaesu FT-818, Elecraft KX2, or Elecraft KX3. All of these excellent rigs are time-tested and very flexible.

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 strong 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
  • HF packs
  • Digital modes like FT-8 and the ability to operate them in the field from internal batteries for extended periods of time
  • The equivalent of a simple portable military/commercial set
  • A well-balanced receiver with few manual adjustments
  • Broadcast listening, as the CTX-10 is also superb broadcast receiver
  • Best-in-class hardware

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––the construction is top-shelf, for sure. It should run for decades without need of repair.

The CTX-10 is built like a tank, and has excellent receiver characteristics for field operation. It’s also designed and manufactured right here in the USA. All the better.

Click here to check out the CTX-10 at CommRadio.

Click here to check price and availability at Universal Radio.


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