Category Archives: QRP

Initial impressions of the ALT-512 QRP transceiver

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.

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The new Icom IC-705 QRP portable, backpackable transceiver

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 lab599 Discovery TX-500 ruggedized portable QRP transceiver

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:

View this post on Instagram

Discovery TX-500, Lab599

A post shared by Laboratory599 (@discovery_tx_500) on

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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Hamvention Highlights: The QRP Labs QSX 10 watt, general coverage, low-cost HF transceiver kit

Hans (G0UPL) of QRP Labs holding a QSX transceiver prototype at the 2019 Hamvention

Each year at the Dayton Hamvention I enjoy checking out the latest radio products and services. This year (2019) I found an exceptional number of innovations and will share these in Hamvention Highlights posts. If you would like to check out 2019 Hamvention Highlights as I publish them, bookmark this tag: 2019 Hamvention Highlights

The QRP Labs QSX Transceiver

Hans (G0UPL) of QRP Labs was, without a doubt, one of the most popular guys at the 2019 Hamvention — especially within the QRP community. In fact, at the Four Days In May (FDIM) vendors’ night his table was so busy I didn’t bother trying to force my way through the crowd to speak with him.

As luck would have it, our own table for ETOW was directly across from QRP Labs table at the the Greene County Fairgrounds so, in the end, I spent some quality time with Hans over the course of the Hamvention.

I’ll also make prediction: if the 10 band QSX transceiver delivers what it promises, it will be a serious disruptor in the ham radio transceiver world! This is a good thing. Why?

The QSX is a feature-packed, all-mode, high-performance, affordable, QRP transceiver.

The QSX will have a 24-bit Analog to Digital Converter (ADC) and a 24-bit Digital to Analog Converter (DAC). It will be a fully stand-alone unit and, since it’s an SDR and sports robust DSP, when connected to your PC, it will be recognized as a high-performance sound card. This equates to nearly native digital mode integration without the need for an external sound card interface.

The QSX Prototype Back Panel

The QSX Transceiver will be a through-hole kit with the surface-mounted components pre-installed on the circuit boards. This means the kit should be accessible to anyone with soldering skills.

Hans has even managed to include a mini spectrum display on the front backlit LCD panel.

The price? Around $150 US in total for the transceiver kit, 10 band filter module and enclosure. Unbelievable!

If Hans can pull this off — and I feel pretty confident he can — the QSX will set a new bar for QRP transceiver pricing and performance.

If you’d like more details about the QSX transceiver, check out the following resources sent to me by SWLing Post contributor, Pete Eaton:

The 10 band QSX will sport a general coverage receiver and although though the modes supported currently don’t include AM, Hans plans to add AM for at least reception purposes. This could make for a high-performance stand-alone SDR field radio for HF broadcast listening.

Of course, I also see the QSX transceiver as an accessible entry radio for new ham radio operators who are nervous about forking out $800+ for a new HF transceiver.

I will certainly grab the 10 band QSX transceiver kit when it becomes available and review it here on the SWLing Post. Stay tuned!

If you would like to follow other Hamvention Highlights, bookmark the tag: 2019 Hamvention Highlights


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FT4 digital mode now available in WSJT-X release candidate 5

Joe Taylor presenting FT4 at the Fair Lawn Amateur Radio Club

(Source: Southgate ARC)

The new amateur radio digital mode FT4 is now available for download as part of WSJT-X Release Candidate 5

You can download wsjtx-2.1.0-rc5-win64.exe (or for other O/S) from near the bottom of the page at
http://physics.princeton.edu/pulsar/k1jt/wsjtx.html

FT4 Protocol document
http://physics.princeton.edu/pulsar/k1jt/FT4_Protocol.pdf

See the WSJT Group at
https://groups.io/g/WSJTX/

For more information about FT4, check out this previous post.

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