All posts by k4swl

2019 Homebrew Heros Award Winner

Many thanks to Pete Eaton who notes that Hans Summers has won the 2019 Homebrew Heroes award. Congratulations, Hans!

Click here to view on YouTube.

QRPGuys new DSB Digital Transceiver kit

Many thanks to QRPer, Pete (WB9FLW), who writes:

QRPGuys has just introduced a new Multiband DSB Digital Transceiver for FT8.

At $40 it introduces a new price point for such Rigs as it includes band modules for 40/30/20 Meters! For those wanting to experiment with different Bands extra bare boards are available for sale.

The rig as it comes is crystal controlled for FT8 but fear not the main board includes connections for an external VFO. As an example one could use one of the very popular Si5351 VFO Kits and be able to QSY to operate the different modes available to the Amateur Community today.

Let the fun begin 🙂

Pete WB9FLW

Thanks so much for the tip, Pete! What a great little project!

Click here to check out the DSB Digital Transceiver at QRPguys.

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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QHR Kits: A QRP kit maker in Spain

Many thanks to Dan Sloss (VK2NAD / KJ7AKC) who writes:

G’day,

Thank you for the work on your website. I happened across another QRP kit maker and thought you might want to share the link:

https://www.qrphamradiokits.com/

All the best,

Thanks for sharing the tip, Dan!

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.

Icom Introduces the IC-705 portable QRP transceiver

Note: this is a cross-post from our other radio blog, the SWLing Post.

This weekend at Tokyo’s Ham Fair 2019, Icom announced an innovative transceiver to their line-up: the Icom IC-705 QRP transceiver.

The IC-705 introduces several industry firsts for a backpack portable radio:

  • It uses the same BP-272 Li-ion Battery pack as the ID-51 and ID-31 series D-Star handy talkies. To my knowledge, this is the only HF transceiver that uses battery packs that can be swapped so easily in the field–like one would swap an HT battery pack
  • It has a general coverage receiver that spans a whopping 0.5 to 148 MHz
  • It sports a full color, touch screen with spectrum and waterfall displays
  • It includes the D-Star digital voice mode
  • A GPS receiver
  • Bluetooth connectivity
  • A MicroSD card slot for memory storage, screen captures and recordings

All of this appears to be included, not add-on options.

The only IC-705 omission, in my opinion, is an internal ATU (antenna tuner). Something I would have expected, but not a deal-breaker for those of us who could really benefit from the amount of features this radio offers.

Side and back panel view noting ports and connections.

There is no word yet on pricing or availability, but you can count on us to post these details once they’re available. If you would like to follow updates, bookmark the tag: IC-705

We will also review on the Icom IC-705 as soon as it’s available.

Video from Amateur Logic/Ham College

Ray Novak (N9JA) with Icom America did a live video interview with Amateur Logic/Ham College TV yesterday. The video includes a full announcement in English from the Icom Booth:

Click here to view on YouTube.

IC-705 Pre-Release brochure

Many thanks to Ray Novak for snapping a few photos of the pre-release brochure:

Update: click here to download the full IC-705 brochure. Hat tip to Dave Zantow!

A surprise from one of the “Big Three”

The “Big Three” transceiver manufactures–Icom, Yaesu and Kenwood–have not shown a lot of interest in backpackable QRP radios over the past two decades.

By “backpackable” I mean QRP transceivers specifically designed for portable use in the field–radios that typically have built-in battery options, internal ATUs, and designed to be lightweight shack-in-a-box units.

Yaesu introduced the FT-817 almost twenty years ago and it lives on today (with modest upgrades) as the FT-818. Kenwood has no portable/backpackable HF QRP radio at this point.

I bet the IC-705 is being introduced today because Icom sees a strong market among field-portable operators who enjoy travel and outdoor radio activities like SOTA (Summits On The Air) and POTA (Parks On The Air).  In addition, many ham radio operators live in neighborhoods that are either plagued with radio interference (RFI) or don’t allow antennas to be installed outdoors. Portable radios liberate ham radio ops from their shacks and allow them to set up a station far away from noise or home owner’s associations.

Looking forward…

Again, I’ll be in touch with Icom about the IC-705 and will share updates here when they’re available. I’m looking forward to evaluation this rig when it hits the market!


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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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CW Club lookup for logging programs

Many thanks to Paul Evans (W4/VP9KF) who writes:

If you’re using a logging program and you need instant look-up of who is in what CW Club, you can use the following page, which I look after:

CW Club Call History files: http://www.g4bki.com/club_call_history.htm

These files are kept up-to-date on a daily basis. You’ll see that this currently lists memberships of 69 different clubs, including the vast majority of QRP clubs, a surprisingly high number.

One exception: G-QRP [who] told various sites that used their (previously open) membership list to cease using it.

Thank you, Paul!

Initial impressions of the Mission RGO One 50 watt transceiver

On Monday, I took the new Mission RGO One transceiver to the field and attempted a POTA (Parks On The Air) activation.

I just published a detailed post including a number of RGO One photos on my other radio blog, The SWLing Post.

In short? Although it’s early days, the RGO One is a promising rig and I’m very pleased with the ergonomics, functionality, and features. It’s very well suited for field operations weighing in at only five pounds and can comfortably operate up to 50 watts if you need a little extra power. I’m looking forward to activating a number of parks this year with the RGO One!

Click here to read about the Mission RGO One on the SWLing Post.

Elecraft introduces the K4 high-performance direct-sampling SDR

The following is a cross-post from my other website, The SWLing Post:

Click to enlarge (Source: K4 Product Brochure)

Today we learned about the latest addition to the Elecraft product line, the Elecraft K4.

This fills a niche in the Elecraft product line and is certain to directly compete with the likes of the Icom IC-7610 and a number of Flex Radio transceivers, among others.

Elecraft describes the K4 as having a “modular hybrid architecture”. Below, I’ve pulled the text and images from the Elecraft product brochure.

Wayne Burdick (N6KR) of Elecraft notes that tomorrow (Friday, May 17, 2019) the Elecraft site will (re)launch a K4 product page with pre-order/reservation page.

I plan to learn more about the K4 and report back during Hamvention this week. Stay tuned by bookmarking the tag Elecraft K4:

Elecraft K4 Product Information

(Source: Elecraft K4 Product Information Sheet via Lutz Electronics, Switzerland)

Click to enlarge (Source: K4 Product Brochure)

A direct-sampling SDR you’ll love to use

Our new K4 harnesses the latest in signal processing while retaining the best
aspects of the K3S and P3. The resulting user interface makes the technology
transparent, allowing you to focus on working the world.

160-6 meter, all-mode coverage & dual RX

The K4 includes dual receive over 100 kHz to 54 MHz. Since it utilizes direct
sampling, there’s no need for crystal filters in the K4 or K4D (see Models, back
page). For extreme-signal environments, we offer a dual superhet module
(standard in the K4HD). An internal VHF/UHF module is also planned.

High-resolution mini-pan for each receiver

Our advanced fine-tuning aid, with its resampled bandwidth as narrow as +/- 1
kHz, is displayed separately from the main panadapter. You can turn it on by
tapping either receiver’s S-meter or by tapping on a signal of interest.

Simple operation and setup

The K4 features a large, full-color touch display, combined with a rich set of real
controls. Per-VFO transmit metering makes split mode completely foolproof.
Band-stacking switches and per-receiver controls are both intuitive and versatile,
adapting to operating context. Usage information on these and other features
is just one tap away, thanks to our built-in help system.

Click to enlarge (Source: K4 Product Brochure)

Rich I/O complement

The rear panel includes all the RF, analog and digital I/O you’ll need to complete
your station. All K-line accessories are supported, including amps, ATUs, and our
K-Pod station controller. The HDMI video output supports an external display
with its own user-specified format.

Full remote control from multiple devices

The K4 can be 100% remote controlled, via Ethernet, from a second K4 as well as
a PC, notebook, or tablet. Panadapter data is included on all remote displays.

Modular hybrid architecture

The K4 adapts to your needs, with three models to choose from:

  • Basic K4 with wide-range dual receive
  • K4D with diversity receive
  • K4HD with a dual superhet module for exceptional dynamic range

You can upgrade or add options as desired, or as new technology becomes
available. This extensibility applies to software as well. The K4’s powerful, fast-starting CPU provides unlimited expansion opportunities.

Fast signal processing

The RF signal chain in the K4 incorporates parallel hardware processing of data
streams, including a dedicated DSP subsystem. This, combined with silent,
PIN-diode T/R switching, ensures fast CW break-in. Data and speech-processing
delays are also minimized.
Standard DSP features include easy-to-adjust, per-mode RX/TX EQ; clean,
punchy RF speech processing; full DVR capabilities; and several built-in data
decode/encode modes. Direct-sampling technology results in an ultra-flat
passband response for clean RX and TX audio. Since the signal chain is softwaredefined, the DSP can be field upgraded to add new algorithms and operating
modes.

KAT4 ATU

The KAT4 ATU has a nominally 10:1 matching range. It includes 3 antenna jacks,
any one of which can be selected as an input for one or both receivers.

Internal VHF/UHF module (future option)

An expansion slot is reserved for a high-performance VHF/UHF module, with
output of approximately 15 W. This module will support all modes.

Kit version

A no-soldering kit version of the K4 is planned for later release. Builders will learn
about advanced radio technology as they proceed. All modules are pre-aligned
and tested.

K4 Key Specs and Features

  • Size: 4.5”Hx13.5”W,10”D
  • Weight: Approx.10lbs
  • SupplyVoltage: 12-15VDC
  • Current: ~2ARX,~18-23ATX
  • FrequencyRange: 100kHz-54MHz(VHF/UHFrangetobe determined*)
  • Stablility: +/-0.25ppm(TCXO) Modes: CW, SSB, AM, FM, Data
  • LCD: 7”color;touch&mousecontrol Text modes: CW, PSK31/63, RTTY KAT4ATU:
  • 10:1+range;3ant.jacks RXantennasources: Upto5
  • A-to-D Converter(s): 16 bits
  • I/O: USB-Ax3,USB-B(twovirtualcomports+audio),RS232(DE9), Ethernet, HDMI. front/rear mic, front/rear phones, LINE in/out, speakers,PTTin,KEYout,paddle,key, ACC,12Vout.
  • CWQSK: Silent,PIN-diodeswitched
  • Other: RX/TX EQ, real-time clock,100% remote control including panadapter data, remote antenna switch control*, custom in-box software apps*

Models (K4 & K4D upgradeable by the user at any time)

  • K4: Basic K4 transceiver provides 160-6 m, all-mode coverage; 100 W output; five receive RF sources; and wideband dual watch, allowing the main and sub receivers to be set for the same or different bands.
  • K4D: Adds KDIV4 option, with a second set of band-pass filters and additional direct- sampling ADC module. This allows the two receivers to use different antennas – a requirement for diversity receive. Having two sets of band-pass filters also optimizes signal handling when the receivers are on different bands and/or antennas.
  • K4HD: Includes all of the above, plus our dual superhet module, the KHDR4. Ideal for competitive field day, contesting, and DXpedition stations. Each superhet receive section includes two crystal filters: one SSB/data bandwidth, one CW bandwidth. The superhet’s 8 MHz IF has excellent dynamic range, so additional crystal filters are not required.