Tag Archives: QRP Transceivers

The Elecraft KX1: Reunited and it feels so good.

The Elecraft KX1

A few weeks ago, I published a post about radios I’ve regretted selling or giving away.

Number one on that list was the Elecraft KX1.

Within a couple hours of posting that article, I had already purchased a KX1 I found on the QTH.com classifieds. It was, by any definition, an impulse purchase.

The seller, who lives about 2 hours from my QTH, described his KX1 as the full package: a complete 3 band (40/30/20M) KX1 with all of the items needed to get on the air (save batteries) in a Pelican 1060 Micro Case.

The KX1 I owned in the past was a four bander (80/40/30/20M) and I already double checked to make sure Elecraft still had a few of their 80/30 module kits available (they do!).  I do operate 80M in the field on occasion, but I really wanted the 80/30 module to get full use of the expanded HF receiver range which allows me to zero-beat broadcast stations and do a little SWLing while in the field.

The seller shipped the radio that same afternoon and I purchased it for $300 (plus shipping) based purely on his good word.

The KX1 package

I’ll admit, I was a bit nervous: I hadn’t asked all of the typical questions about dents/dings, if it smelled of cigarette smoke, and hadn’t even asked for photos. I just had a feeling it would all be good (but please, never follow my example here–I was drunk with excitement).

Here’s the photo I took after removing the Pelican case from the shipping box and opening it for the first time:

My jaw dropped.

The seller was right: everything I needed (and more!) was in the Pelican case with the KX1. Not only that, everything was labeled. An indication that the previous owner took pride in this little radio.

I don’t think the seller actually put this kit together. He bought it this way two years ago and I don’t think he ever even put it on the air based on his note to me. He sold the KX1 because he wasn’t using it.

I don’t know who the original owner was, but they did a fabulous job not only putting this field kit together, but also soldering/building the KX1. I hope the original owner reads this article sometime and steps forward.

You might note in the photo that there’s even a quick reference sheet, Morse Code reference sheet and QRP calling frequencies list attached to the Pelican’s lid inside. How clever!

I plan to replace the Morse Code sheet with a list of POTA and SOTA park/summit references and re-print the QRP calling frequencies sheet. But other than that, I’m leaving it all as-is. This might be the only time I’ve ever purchased a “package” transceiver and not modified it in some significant way.

Speaking of modifying: that 80/30 meter module? Glad I didn’t purchase one.

After putting the KX1 on a dummy load, I checked each band for output power. Band changes are made on the KX1 by pressing the “Band” button which cycles through the bands one-way. It started on 40 meters, then on to 30 meters, and 20 meters. All tested fine. Then I pressed the band button to return to 40 meters and the KX1 dived down to the 80 meter band!

Turns out, this is a four band KX1! Woo hoo! That saved me from having to purchase the $90 30/80M kit (although admittedly, I was looking forward to building it).

Photos

The only issue with the KX1 was that its paddles would only send “dit dah” from either side. I was able to fix this, though, by disassembling the paddles and fixing a short.

Although I’m currently in the process of testing the Icom IC-705, I’ve taken the KX1 along on a number of my park adventures and switched it out during band changes.

Indeed, my first two contacts were made using some nearly-depleted AA rechargeables on 30 meters: I worked a station in Iowa and one in Kansas with perhaps 1.5 watts of output power.

I’m super pleased to have the KX1 back in my field radio arsenal.

I name radios I plan to keep for the long-haul, so I dubbed this little KX1 “Ruby” after one of my favorite actresses, Barbara Stanwyck.

Look for Ruby and me on the air at a park or summit near you!

Guest Post: Steve builds a DC30B QRP Transceiver

DC30B QRP Transceiver ProjectMany thanks to Steve (KZ4TN) who shares the following guest post:


DC30B QRP Transceiver Project

by Steve Allen, KZ4TN

I wanted to build a lightweight backpackable transceiver I could take hiking and camping. I chose the 30 meter band as it is specific to CW and the digital modes. I am also in the process of building Dave Benson’s (K1SWL) Phaser Digital Mode QRP Transceiver kit for the 30 meter band. Also, a 30 meter antenna is a bit smaller than one for 40 meters and the band is open most anytime of the day.

I sourced the DC30B transceiver kit, designed by Steve Weber KD1JV, from Pacific Antennas, http://www.qrpkits.com. It appears that they are now (10-11-20) only offering the kit for the 40 meter band. The following information can be used for the assembly of most any kit that lacks an enclosure.

Lately I have been finding extruded aluminum enclosures on Amazon.com and eBay.com. They come in many sizes and configurations. I like to use the versions with the split case which allows you to access the internal enclosure with the front and rear panels attached to the lower half of the enclosure. Most of these enclosures have a slot cut into the sides that allow a PCB to slide into the slots keeping it above the bottom of the enclosure without having to use standoffs. The one requirement for assembly is that the PCB needs to be attached to either the front or rear panel to hold it in place.

DC30B QRP Transceiver Project

As the enclosure is anodized, I didn’t want to rely on the enclosure for common ground. I used a piece of copper clad board that I cut to fit the slot width of the enclosure and attached it to the back panel. I was then able to mount the transceiver PCB to the copper clad board with standoffs. This basic platform of the enclosure with the copper clad PCB provides a good foundation for any number of projects. All you have to do is mount the wired PCB on the board, install the components on the front and rear panel, then wire it up.

DC30B QRP Transceiver Project

I wanted to have the choice of a few frequencies to operate on so I searched eBay for 30 meter crystals and found a source for 4 different popular frequencies. I installed a rotary switch on the front panel and added a small auxiliary PCB with two, 4 pin machined IC sockets. This allowed me to plug the crystals into the sockets. I wired the bottom of the socket PCB first using wire pairs stripped from computer ribbon cable leaving extra length. I marked the wires with dots to indicate which sockets each wire pair went to so I could solder them onto the rotary switch in the correct order. It was tight but I always work with optical magnification so I can see exactly what I’m doing. I have used this crystal switching method in the past with good success.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe rest of the assembly was straight forward. I find that most kits are well designed and documented, and if you take your time and follow the directions carefully all should go well. The two most common speed bumps seem to be soldering in the wrong component or bad soldering technique. I double check all component values and placements prior to soldering, and I always use optical magnification while working. I inspect each solder joint and look for good flow through in the plated through holes, and make sure there are no solder bridges.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe finished product. I bought a Dymo label maker and it works very well for projects like this. I love using these enclosures and they are a leap forward from the old folded aluminum clam shells I used in the past. I could stand on this without causing any damage. Power out is 1-3 watts depending on the DC power in. The receiver is sensitive and the ability to choose from four frequencies is a real plus.

73 de KZ4TN

Steve Allen
Elizabethton, TN


Wow, Steve! What a top-shelf job on this build! I’ll have to look for those aluminum enclosures as well. Beautiful little rig you’ve made there and I think it’s fantastic you’ve a few crystal frequency options! Thank you for sharing!

Have you ever regretted selling a radio? I have. More than once.

The Elecraft KX1

I’ve been a ham radio operator since 1997. In the first decade of my amateur radio life, I only owned three HF radios (Icom IC-735, Yaesu FT-817, and a Ten-Tec OMNI VI+).

As I got into writing, blogging, and evaluating/testing radios, that number increased. Quite often, radios are only in my shack for a short period of time as I alpha/beta test and/or review production run units.

I try not to get attached to radios because I know they’re often only temporarily in the shack.

Over the years, there have been a few radios I’ve sold for…let’s say “pragmatic” reasons. It’s very rare that I purchase a radio with the intention of keeping it only to find that I want to sell it shortly thereafter. More likely than not, I sell because the radio is redundant (how many field radios does one need–?) or because I’m raising money to make a larger purchase.

Here’s a short list of transceivers I regret selling/trading:

Elecraft KX1

I sold my Elecraft KX1 in 2016 in order to help purchase my Elecraft KX2. It was a solid decision. The KX2 has become my favorite field radio (here’s my review) and was SO much more versatile than the KX1. Still: I really miss the KX1. I loved how bare-bones it was, I loved the top-mounted controls and the fact I often operated it while simply holding it in my hands. The controls were super easy to use even with gloves on in the winter. Plus, it was “cute” in a boxy Elecraft sort of way. If I ever find a deal on another one, I might grab it!

Elecraft K2

I’ve owned both the Elecraft K2/10 and K2/100. Funny story: I acquired a K2/10 in 2008 or so and absolutely loved the radio. After I purchased my KX3 in 2013, however, it was rarely used and sat on my shelf as a “back-up” radio. Eventually, I decided to sell it and did so with ease. Within a week of selling it, a local ham posted on our club email list that he was selling a K2/100 in an SK sale. He wasn’t sure of all of the upgrades, but knew it was a K2/100. The price was very low, but there were no takers after a few days, so I bought it. I used the K2/100 for a few years and it served as a back-up 100 watt radio. I eventually sold it, though, to purchase a KXPA100 used. Now, of course, I do miss that radio. In truth, I’ll likely never purchase one again, because I own so many other transceivers–and the KXPA100 is truly a genius compliment to the KX2 and KX3–but I do have an affinity for that fine rig.

Index Labs QRP++

QRP+ ad from the Dec 1995 issue of QST. Source: WD8RIF

My buddy Eric (WD8RIF) is to blame for this radio. He owned an Index Labs QRP+ for years. He loved operating it in the field and at home. It was the first QRP radio I ever saw in action (at this particular field event). More than 10 years ago, I happened upon a great deal on a QRP++ and instantly bought it. It was SO much fun to operate—super simple, yet had pretty much every feature you’d want in a basic transceiver. I sold it because, frankly, performance was sub-par especially if you ever planned to use it in an RF-dense environment. The receiver front end would simply fall apart, for example, during contests or events like Field Day. Otherwise, it was a pretty sensitive radio. It was incredibly portable and had that awfully “cute” cube form factor. Another fear I had was availability of replacement parts. Index Labs was no longer in business and there were quite a few obsolete parts in the radio. Perhaps it’s a stretch to say I “regret” selling it because, in truth I don’t. But when I see them at hamfests, I’m still tempted to grab one if for no other reasons than nostalgia.

Yaesu FT-817

I purchased an ‘817 shortly after they were introduced in…what…2000? At the time, there wasn’t a radio like it on the market: it was the most compact full-featured HF/VHF/UHF radio in the amateur radio world. Back then, I was living in the UK and travelling all over Europe. I purchased the FT-817 with the idea that I could play radio while, say, working in Hagen, Munich, Chartres, Berlin, Torino, Pescara, or any of the other fabulous sites I regularly visited. I did pack the FT-817 on a number of occasions but since I’m a one-bag traveller, it was scrutinized to some degree at most airports—especially post-9/11. Also, my first production run model blew its finals within the first two years of ownership (a common problem that was addressed by Yaesu shortly after that production run).

I had the finals replaced by Burghardt Amateur Center but rarely used the FT-817 after that. Truth was, I found the radio’s front panel to be too compact and the embedded menus really frustrated me. But back then, I wasn’t as much of a field op as I am now and I could really appreciate a compact, affordable radio that also sports VHF/UHF operation—especially for SOTA activations. Plus, few transceivers have enjoyed a product life like the FT-817/818 which is now pushing 20 years on the market. While the 817/818 lacks a number of features I’ve grown to love (like memory keying) I do believe I may purchase an FT-818 next time they go on sale. In the end, I miss the rig.

How about you? Any regrets?

Please feel free to comment with any radios you regret selling, trading, or giving away over the years and tell us why you miss it! Inquiring minds want to know!

An Introduction to the uSDX transceiver kit

Many thanks to Pete (WB9FLW) who shares the following article by Bob (KD8CGH) regarding the uSDX transceiver kit.

I reached out to Bob who has kindly given me permission to share his article on QRPer:


An Introduction to the uSDX

by Bob Benedict (KD8CGH)

There is a new open source, home brew multi band, multi mode QRP transceiver that grew out of the QRP Labs QCX. Through some serious wizardry  it retains an efficient class E RF amplifier for SSB and digital modes. It crams impressive SDR capabilities into an Arduino.

This has an interesting international development process conducted on  https://groups.io/g/ucx/topics with contributions by many, including the usual gang of suspects: Hans Summers G0UPL, Guido Ten Dolle PE1NN, Barbaros Asuroglu WB2CBA , Manuel Klaerig DL2MAN, Kees Talen K5BCQ, Allison Parent KB1GMX, Jean-Marie T’Jaeckx ON7EN, Ashhar Farhan VU2ESE,  and Miguel Angelo Bartie PY2OHH. I apologize to the many others whose names I didn’t list. A summary is in the WIKI https://groups.io/g/ucx/wiki.

The basic work uSDX appears to have been accomplished by Guido Ten Dolle PE1NNZ. It uses pulse width modulation of the PA supply voltage to transmit  modes other than CW while retaining class E efficiency and uses a direct conversion SDR receiver.

The basic idea behind Class E nonlinear amplifiers is that transistors have little loss when they are switched fully on or off. The losses occur when devices are limiting power flow in linear amplifiers. The idea behind a Class E amplifier is to use transistors in a switching mode to generate a square wave to drive a resonant circuit to generate RF power.

This method is used in the popular QCX QRP CW transceiver kit line developed by Hans Summers and sold through QRP Labs  https://qrp-labs.com/.  More than 10,000 of these great transceiver kits have been sold (I built one). There is a good discussion of the circuit and particularly of the class E amplifier in the excellent QCX documentation https://www.qrp-labs.com/images/qcx/assembly_A4-Rev-5e.pdf.

The QCX was the base for the QCX-SSB which starts with a QCX and modified the circuit and software to add SSB capabilities. The wizardry that  Guido accomplished uses pulse width modulation of the PA supply voltage to control the amplifier in an Envelope Elimination and Restoration (EER) technique  https://core.ac.uk/download/pdf/148657773.pdf. To generate SSB a DSP algorithm samples the  audio input and performs a Hilbert transformation to determine the phase and amplitude of the complex signal.  The phase changes are transformed into temporary frequency changes which are sent  to the  clock generator. This result in phase changes on the SSB carrier signal and delivers a SSB-signal with the opposite side-band components is attenuated.

On the receive side a direct conversion SDR receiver is used with the I and Q signal digitized and all further processing carrying out digitally. Attenuators are included to help not overload the ADC range.  Documentation is at  https://github.com/threeme3/QCX-SSB .  In addition to a good description of the theory and hardware mod there is also a good description of the software command menu.

From there development took off in several directions. One is by Barbaros Asuroglu WB2CBA  and Antrak that uses through hole components (mostly) and replaceable band boards that  hold the low pass filter and band dependent class E amplifier components (an inductor and capacitor). Barb also includes boards designed to be a case top and bottom, battery pack and a PA.

Another development track by Manuel Klaerig DL2MAN uses SMT components in a stacked board layout and has a relay switched band pass board https://groups.io/g/ucx/message/1596  and  https://groups.io/g/ucx/files/DL2MAN uSDX-Sandwich Files. A new revision has been released that uses serial resonance class E amp design and easier to obtain relays, https://groups.io/g/ucx/files/DL2MAN uSDX-Sandwich Files with new Serial Resonance Class E Multiband Circuit .

Other development streams include one by Kees Talen K5BCQ https://groups.io/g/ucx/files/K5BCQ uSDX Board Schematics and Jean-Marie T’Jaeckx ON7EN https://groups.io/g/ucx/files/QCXV4.zip.

I built the variant designed by Barbaros Asuroglu WB2CBA   and I’m pleased with it’s performance. I ordered 10 main boards and 40 LP filter band boards PCBs from PCBWAY, but now you can also purchase single boards sets from https://shop.offline.systems/.

I also designed and 3D printed a case for the transceiver and a small box to carry band boards. Info at https://www.thingiverse.com/thing:4582865 and at https://www.thingiverse.com/thing:4587868 and also in the files section https://groups.io/g/ucx/files/3D printed case for Barb WB2CBA V1.02.

In an example of hams collaborating at its finest, Hans Summers  announced on 9/11/2020 that his new QCX mini product, a QCX in a smaller package,  will include a daughter board that can be used to give the QCX mini a uSDX like SSB capability. The QCX mini has the same circuit as the QCX but uses SMD components packaged it into a two board stack that is less than half the volume of the original QCX. The mod is unsupported by QRP-LABS but may be supported by the uSDX group.

http://qrp-labs.com/qcxmini.html 

More information at https://groups.io/g/ucx/topics and don’t forget the WIKI https://groups.io/g/ucx/wiki.

73

Bob,  KD8CGH


Many thanks again, Bob, for sharing this excellent uSDX introduction. Thanks again for the tip, Pete!

Pete also notes that there is a very active uSDX experimenters discussion group on Groups.io with over 100 members: https://groups.io/g/ucx

From the SWLing Post: A final review of the CommRadio CTX-10 QRP transceiver

The following article was originally posted on my other radio blog, the SWLing Post.

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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Initial impressions of the ALT-512 QRP transceiver

(Note: This is a cross-post from my other radio blog, the SWLing Post.)

So the ALT-512 QRP SDR transceiver has landed at SWLing Post HQ. This little rig is on loan from Aerial-51 and I’ll be spending the next month or so putting it through the paces.

I can already tell that the ALT-512 has some strong points:

  • It’s incredibly portable and easy to take to the field, providing you have a battery and resonant antenna (or external ATU).
  • The color backlit display is quite readable at any angle despite being rather information-dense.
  • I really like the waterfall display. It’s large enough to be quite useful.
  • The ALT-512 can connect directly to your computer for digital modes like FT-8. No external sound card needed.
  • The menu system contains a wide array of features and options for granular tweaks and modifications.
  • The ALT-512 includes the European 4 meter band.
  • Although I prefer using headphones with small radios, the ALT-512’s small internal speaker does a fine job.
  • Rob Sherwood tested the ALT-512 (indeed, this very unit) recently and added it to his receiver test data. It performed quite well especially considering the price.

Any negatives so far?  Nothing major:

  • No internal ATU or battery options. At this price point (799 EUR), I wouldn’t expect either of these.
  • The ALT-512 is not general coverage. This is a negative for those of us who like SWLing, but a positive for ham radio use as the ALT-512 sports band-specific bandpass filters to reject out-of-band strong stations. You can tune to some stations above the 40M band and also the full mediumwave band and below (down to 100 kHz), although I wouldn’t expect stellar performance in those regions.

So far, I’m very pleased with the ALT-512’s performance.

Next, I’ll be taking it to the field and see how easily I can activate a few POTA (Parks On The Air) sites! Stay tuned!

Click here to check out the ALT-512 at Aerial-51.

The Discovery TX-500 QRP Transceiver

Please note: This is a cross-post from our other radio site, the SWLing Post.

Many thanks to SWLing Post contributor, Vlad, who shares some images and a video of a new QRP transceiver in development: the Discovery TX-500 by a company called lab599.

Specifications have not been published yet, but we have confirmed a few details from the manufacturer:

  • 10 watts PEP
  • HF plus 6 meters
  • Weight 570 grams (1.25 pounds)
  • Voltage 9 – 14 VDC
  • 105 milliamps at 13.8 VDC and with backlit display on
  • CAT control via USB and using Kenwood codes
  • I/Q outputs
  • Weatherized
  • Expected availability autumn 2019
  • Target retail price is $700 US
  • Product website is forthcoming

All of the following images came from the Discovery TX-500 gallery on Instagram:

Here are a few videos:

Click here to view on Instagram.

Click here to view on Instagram.

Click here to view on Instagram.

For someone, like me, who loves playing radio in the field (Parks On The Air and Summits On The Air) this looks like an ideal rig. It’s one of the only ham radio transceivers I’ve seen that is weatherized to some degree (how much, we don’t know yet).

I don’t see a speaker on the TX-500, so I’m guessing it might require a mic/speaker combo or an external speaker of some sort? I also don’t see a built-in ATU, but at $700, I certainly wouldn’t expect one.

With a power consumption of 110 milliamps at 13.8 VDC, this little transceiver should run for ages on a modest battery pack.

This is certainly a fascinating prototype QRP transceiver. If the Discovery TX-500 transceiver can be produced and marketed at $700 with all of the features mentioned so far, it should certainly fly off the shelves. They can certainly take my money!

Of course, I will plan to grab one of these for review. I’m also eager to see how this little SDR transceiver might perform on the broadcast bands.

We will post post TX-500 updates and details as they become available. Bookmark the tag Discovery TX-500 and stay tuned!


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The ALT-512: A new general coverage QRP transceiver

Note: The following has been cross-posted from our other radio site, the SWLing Post.

There’s a new QRP transceiver on the market: the twelve band ALT-512 by Aerial-51.

At first glance, you’ll see a similarity between the ALT-512 and the LnR Precision LD-11/Aerial-51 SKY-SDR. The LD-11 and SKY-SDR, are very similar, save the LD-11 is marketed to North America (via LnR) and the SKY-SDR to Europe. The SKY-SDR had several iterative upgrades, most importantly the dual-threaded software used in the firmware, which cut CPU latency in half. Both the LD-11, SKY-SDR and now the ALT-512 are made in Europe.

Click here to read my review of the LnR Precision LD-11.

ALT-512 Waterfall display (Photo: DJ0IP)


According to Aerial-51, the new ALT-512 is built on the LD-11/SKY-SDR platform, has the same chassis design but has many improvements over the SKY-SDR:

  • 4m Band
  • 4.5 in. Color Display
  • Improved receiver pre-amplifier
  • 2 transistors in the transmitter PA (was 1)
  • Waterfall in addition to the Pan-Adapter Bandscope
  • 4 additional front-panel buttons
  • User friendly front-panel adjustment of often used parameters (formerly embedded within the software menu)
  • FULL TS-2000 command set implementation
  • Built-in Sound Card; Digi Modes run using only one USB-2 cable connected to the PC. No additional hardware required.

If the ALT-512 performs as well as or better than its predecessor, it’ll certainly be a great little QRP radio and an excellent general coverage receiver for HF broadcast listening.

Pricing has not yet been posted, but Aerial-51 plans to make this transceiver available in the next few weeks.

Click here to check out the ALT-512 on the Aerial-51 website.

The HobbyPCB IQ-32: A general coverage portable QRP transceiver with color touch screen now shipping

Many thanks to Pete (WB9FLW) who shares the following information regarding HobbyPCB’s much-anticipated portable transceiver which is now shipping.  The price is a competitive $529.00.

The following information comes from the HobbyPCB website:

The IQ32 is 5W output, 80-10M Amateur Radio transceiver with powerful 32 bit processing providing high-end features at an entry level price. The IQ32’s 3.2″ color LCD touch-screen display and dual control knobs provide an enjoyable operating experience in a robust package.

Available for immediate delivery!

Introducing the HobbyPCB IQ32 HF transceiver, based on the high performance RS-HFIQ RF system, the receiver in the IQ32 consists of 5 band-pass filters to reject out-of-band signals, an LNA with frequency dependent gain and a conventional quadrature down-converter. The transmitter features a Class A, 5W power amplifier with individual low-pass filters for each band to exceed FCC requirements for spectral purity.

The IQ32 features a large, color, touch-screen display providing an enhanced user interface and informative spectrum and waterfall displays found on radios costing much more. With a powerful STM-32 DSP processor, the IQ32 transceiver has variable filtering, multi-mode AGC, memory functions, built-in PSK encode/decode with keyboard support.

5W not enough power? Add a HARDROCK-50 to your station to boost up to 50W. The IQ32 and HARDROCK-50 seamlessly integrate together for a powerful mobile/base station!

Simple upgradeable firmware, no connection to a computer required, no drivers, no cables. Simply insert a thumb-drive with the appropriate file and the IQ32 updates its own firmware.

Specifications

  • Frequency Range: 3-30MHz (performance guaranteed on 80/60/40/30/20/17/15/12/10M ham bands)
  • Sensitivity: MDS < -128 dBm on 80M dropping to < -135 on 10M
  • Noise Figure: < 8 dB
  • TX Power: 5W typical, 4W minimum
  • LO Feed-thru: < -50 dBc @ 5W output
  • Spurious and Harmonics: < -50 dBc typical
  • DC Power: 13.8VDC, 2 amp max
  • Size: 172mm x 105mm X 75mm
  • Weight: < 700 grams
  • Display: 3.2″ Color LCD Touchscreen
  • Modes: USB, LSB, CW, PSK 31
  • DSP Processor: STM-32, 32 Bit

Click here to download the manual.

Pete also notes:

If one already has the RS-HFIQ board fear not an upgrade kit is available:

https://hobbypcb.com/products/hf-radio/iq32-upgrade

Thank you for sharing this, Pete!

I may see about grabbing an IQ-32 to evaluate. I’m very curious how its receiver might stack up to the Elecraft KX2, the CommRadio CTX-10 and the LnR Precision LD-11. (Please note that these links lead to my other radio site, the SWLing Post.)

It doesn’t appear that the IQ-32 has an AM mode, but I would still like to see how it might handle broadcast listening on the shortwave meter bands using ECSS.

Video

Check out WA2EUJ’s IQ-32 presentation at the 2018 Hamvention on YouTube:

Click here to check out the IQ-32 product page at HobbyPCB.

Have any readers purchased the IQ-32?  Please comment!

The uBITX Transceiver: An Update

Many thanks to Pete Eaton (WB9FLW) who shares the following post:

Last March Ashhar Farhan VU2ESE the designer of the very popular BITX20 and BITX40 series of mono-band HF Transceivers announced a new low cost Rig called the uBITX (micro BITX) a full blown 80-10m 10 Watt SSB/CW Transceiver. Now comes word that after many months of very hard development work by Ashhar this much anticipated Rig will soon be available.

For those not familiar with the Project this is *not* a kit, rather like its sibling (the BITX40) it consists of two assembled and tested Circuit Boards. The RF board measures 5.5 x 6 inches and a second small plug in daughter card that takes care of the digital portion of the design including the 2X16 LCD, Arduino Nano, and Si5351 which are used in the VFO. Add a Cabinet, Knobs, and Connectors and you have a full blown HF Rig. An added plus is that except for the Gerber PCB files everything else (including the firmware) is Open Sourced!

The original description can be found here:

http://www.phonestack.com/farhan/ubitx/ubitx.html

Farhan has just released the Firmware, Schematics, and Wiring Diagram for the production version on GitHub

Arduino Sketch:

https://github.com/afarhan/ubitx

RF Board Schematic:

https://github.com/afarhan/ubitx/blob/e481ea2a2457fc4e7be7a6a4bc9a0fba12bf2cde/ubitxv3.pdf

Digital (Raduino) Board Schematic:

http://www.phonestack.com/farhan/ubitx/raduino.pdf

Wiring Diagram:

https://github.com/afarhan/ubitx/blob/e481ea2a2457fc4e7be7a6a4bc9a0fba12bf2cde/ubitx_wiring.png

Farhan has a social conscience as well giving several local Ladies much needed employment for final assembly and checkout of the Rigs.

There are still a few final tweaks being done to the design so pricing is still to be determined. But if it’s offered at a similar price point as his earlier Transceivers it should sell like Hotcakes!

For the latest info check out the BITX User Group at:

https://groups.io/g/BITX20

Wow!  Amazing project!  Thanks for the tip and updates, Pete!