Gear Review ALX-SSB low power, portable, HF radio

Discussion in 'Functional Gear & Equipment' started by DKR, Sep 10, 2018.

  1. DKR

    DKR Raconteur of the first stripe

    Review - ALX-SSB transceiver.

    ALX-SSB transceiver – Front panel view.


    ALX-SSB transceiver rear panel

    What this review covers:
    This review covers a 'new' to the North American market portable, low power SSB radio set. QRVtranics, out of Sugar City Idaho, sells the ALX-SSB radio. See

    What is this radio?
    The ALX-SSB is based on a modified board, sold as the CS series by QRVtranics. See, KN-Q7A Kit.

    The base radio is the CS series from CRkits in China. See

    What's the difference?
    The CS series from CRkits has a digital VFO, but no display - past a simple tri-color LED. In other words, very hard to track your actual frequency.

    The CS series from QRVtranics has a digital VFO and the option of a digital display, two different types, in fact. More on this later.

    The ALX-SSB is the CS main board, a new digital VFO and display as shown above. Multiband operation is possible.

    Any of these versions of the radio may be purchased as a kit or as a fully assembled and tested radio.
    Notethere are no SMD parts – this is fully thru-hole. Anyone that would have tried a Heathkit of old can easily build this radio set. There is less point-to-point wring on this rig than in my old HW-7 or HW-8.

    Full disclosure, I have no interest in QRVtranics, but I have provided some suggestions to the vendor for the documentation of the radio set. As an aside, I wrote a 60 page operations and technical manual for the MFJ-9296 (-9200) travel radio a couple years back. The radio has since neem discontinued and replaced by the You Kits HB-1B (2018) radio set – which sells for $299, is CW only, 5 watts and has almost no documentation.

    Alright already, what's the deal on this rig?
    I'm glad you asked. This is a small, HF radio that has full band coverage out of the box for any one band and up to five bands within the US Amateur Radio Service. Power out is 10 watts (slightly lower in the higher bands). The rig can be had as a kit or fully built by the vendor. It has full, English language, technical documentation. Yup – Native English, not the transliterated Chinese (Chinglish) crud normally seen on the low end market.

    Pretty cool, but the clincher for me is that the VFO is based on an Arduino chip and the software is open source!

    One of the big concerns most hams have with the low cost QRP rigs seen on the market today is the proprietary MCU (control chip). Lose this and you own a brick. Add in densely packed SMD parts, parts that are unmarked for the most part, no technical documentation or schematics and you have a radio that - if it faults, goes into the trash.

    The ALX-SSB radio is available as a kit, with full documentation. Repair, maintenance and hacking (more on this later) are a breeze as all the data needed is available. The parts are quality, not take-offs and are well marked.

    Cost for the kit as a single band, with the speaker/mike is $150 US dollars, plus shipping. All manuals are on line as PDF document with illustrations. Full band coverage and up to 10 watts output. This is available as 80/75 Meters, 40, 20, 17 or 15 meters. Ask for a quote for the multiband unit, as several options are available.

    The radio is a common, single conversion, NE602/LM386 kind of setup. The final PA transistor is a IRF-510, which is noted for being more tolerant of high SWR at the antenna. The radio has a reverse polarity protection diode as well.

    If you want to use this in the field, my suggestion is to add the QRPQuys antenna tuner (EFHW Mini Tuner - QRPGuys). I have and use this paired to the rig. The tuner is sold as an easy kit, taking less than an hour to assemble.

    Dimension: 6.0 x 3.75 x 2.0 inches including feet not including connectors and knobs.
    Weight assembled: 12 oz., not including microphone. The dual/multi band version is slightly heavier.
    . Power Supply: 12 to 13.8 V, 3 A
    . Current consumption: 70 mA in RX and about 2 A in TX @ 13.8 V
    . RF output: about 10 W PEP @ 13.8 V typical
    . RF output for 15, 17 and 20 Meters will be lower
    . Sandwich digital VFO integrated with the LED hole pre-drilled
    . Stable and accurate frequency like a crystal
    . Both USB and LSB are be supported by changing BFO frequency in calibration mode
    . Sensitivity: about 0.5 uV at 10 dB SNR – or 0.1 uV for MSD.
    . UNBAL jumper added to intentionally break the balance of NE602 to allow more convenient TX power peak alignment and antenna tuning (more on this later)
    . Low dropout diode is used to allow a bit more battery life
    . Final power amplifier IRF510
    . Speaker microphone available
    . IF filter: 6 pole crystal ladder filter + 1 pole post IF amplifier crystal filter
    . IF bandwidth: about 2.0 KHz
    . IF frequency: 8.467 MHz
    . Connectors: Speaker, Microphone and Antenna
    . Antenna Connector is: BNC type

    My bench testing showed that full band overage and power output specs were easily met on my rig. The sensitivity levels were met with no problem. Actually, it took some tweaking to get my SIGEN to that low a power level.

    NOTE - power output is input voltage dependent. On my 8xAA NiMH battery pack, power was 8 watts on 40M and just under 4 watts on 20M. On a fully charged AGM battery, full power was no problem. My new (Thanks to SM) 10 x AA battery packs work the treat with this rig.

    The controls are basic. On/Off. Volume. VFO tuning. No Receiver Incremental Tuning (RIT) or Clarifier. The VFO does provide for very fine tuning. Just no offset.
    USB'LSB selection is baked into the software and cannot be shifted on the fly. The software can be modified for USB on 40 meters for running PSK-31, for example.

    The display may be either an OLED or LED. I chose OLED for the lower power use.
    Attach battery, antenna, speaker/mike.
    Turn the rig on. Set VFO. Communicate. Hard to get any easier than that.

    The radio receiver has no ALC loop. The rear panel connector labeled "Speaker" means just that - use a speaker. Use of headphones is something I would strongly discourage. A near-frequency tuner-upper will leave your ears ringing…

    The speaker/mike is a modified commercial unit with matching 8-pin connector. You can roll your own, but I doubt you could do this for $10 – your call.

    Transmitter is clean and puts out enough power to be heard with a NVIS antenna setup for nearby (up t0 300 Miles) communications. This is a solid state, broad-band, no tuning required transmitter. If you are using a non-resonant antenna, an external tuner is required. With 10 watts output, you will need the distant station to do the heavy lifting, but the rig has more than enough power to work DX, if that is your thing. For disaster comms, 10 watts is a good compromise between power out and power consumption.

    The rig can be had with up to five bands in this new ALX layout. I have the older two band setup for 40 and 20 meters, a good choice for Alaska.


    Dual band filter board. That empty real estate on the side of the board is used for additional filters.

    I have to give Larry, the owner of QRVtronics, a lot of credit. He took a basic kit and modified it for multiband use, with both filers and software to make that possible and added a nice digital display. Which is my Segway onto the 'hacking' part of this review.

    Digital VFO
    The VFO runs on a Si5151 chip, controlled by an Arduino computer.


    You can see the Arduino parks nicely on, the (modified) VFO board. It has on-board power conditioning (3.3VDC) to it is truly self-contained.

    The software is simple and easy to modify…let me explain. The rig comes with full band coverage for the US ham bands.

    I, on the other hand, want to read the mail on 30 Meters and have access to WWV for use as a propagation aid. Having the remaining SW broadcast stations is a good deal as well. In addition, the 40 Meter band is different for Alaska than in the L-48. I wanted the rig to come up in the middle of the Alaskan 40 meter band.

    For that, I had to modify the software. Fortunately, that was fairly simple. The Arduino IDE (integrated development environment) software is a free download and the code for this rig is heavily commented.
    Here is a sample of the code:

    Si5351 si5351;
    // Wiring: Connect common pin of encoder to ground.
    // Connect pin A (one of the outer ones) to a pin that can generate interrupts (eg. D2)
    // Connect pin B (the other outer one) to another free pin (eg. D4)

    volatile boolean fired;
    volatile boolean up;
    volatile boolean khz = true; //tuning step in 1k Hz or 100 Hz in normal mode. calibration mode is not affected by this.
    volatile boolean mode = true; //true = normal mode; false = calibration mode. To enable the calibration mode, press and hold the encoder switch and power on
    volatile boolean CALIBMODE = true; //true = bfo adjustment in 100 Hz step in calibration mode; false = crystal calibration in 20 Hz step in calibration mode.

    If this seems like gibberish to you, there are a ton of sites that will walk you thru the code. Or, you can just save the code in case of a VFO problem. For the most commercial gear, and almost all the low-end stuff from China, this kind of modification is not an option. This software for the rig is available for download, if you wish to look at the entire package. Se, CRK-10A, ALX-SSB TRANSCEIVER, KN-Q7A Kit.

    Bottom line:
    This is a good quality, but relatively inexpensive SSB HF rig with 10 watts out. It's simple interface is so basic, a child can operate it. In a disaster situation, simple is better. No menus, no memories, no hassle. You can listen to AM SWBCB, with some care in tuning.

    The rig offers the opportunity to modify the code for listening out of band, is made with through hole parts, so local repair is at least possible. Full documentation makes identification of parts simple. And the parts are both common use and are obtainable from any numbers of vendors on line. The kit assembly instructions offer trouble-shooting tips as well. Use the supplied links to check any details where you would like to know more.
    3M-TA3, Bandit99, Brokor and 7 others like this.
  2. duane

    duane Monkey+++

    Thank you, you do as well with tech as you do with your other writing. Looks like a slightly more expensive alternative to the walky talky Chinese lower end with the ability to repair, program and customize.
    techsar and sec_monkey like this.
  3. DKR

    DKR Raconteur of the first stripe

    The cool part is the open source code running on the Arduino that controls the VFO.

    I'll admit to spending a lot of my paid work time dealing with uncomplied COBOL and Unisys Workflow Language (WFL) programing. The Arduino code is 'Playskool' level coding, and the IDE lends itself well to 'cut and paste' programing. Any good text editor can be used for working up new text - such as KOMODO Edit 8.

    For example -

    /* Dual band section */
    if (digitalRead(JP)) //Frequency select: HIGH - 20 Meter, LOW - 40 Meter
    { //20 meter
    op_freq = 14300000; //set op_freq default
    band_high_limit = 14350000; //set band high limit to 14.35 MHz
    band_low_limit = 14000000; //set band high limit to 7.0 MHz
    bfo_freq = 8190100;
    bfo_low_limit = 8189500;
    bfo_high_limit = 8193500;
    { //40 meter
    op_freq = 7200000; //set op_freq to higher portion of the band
    band_high_limit = 7300000; //set band high limit to 7.3 MHz for region 2, like America
    band_low_limit = 7000000; //set band high limit to 7.0 MHz
    bfo_freq = 8190100; //historical reason: for KN-Q7A kits covering 7145-7165, 7200-7220, 7280-7300, IF freq = 8192 kHz
    bfo_low_limit = 8189500;
    bfo_high_limit = 8193500;

    band_high_limit = 7300000; //set band high limit to 7.3 MHz for region 2, like America
    could be re-written as
    band_high_limit-1010000,//reset to rx WWV or even (1020000) for 30M reception.

    When you upload to the Arduino, the IDE app compiles the code as it loads to memory.
    The web is full of basic level programming for ham based Arduino projects, no just digital VFOs.
    Last edited: Sep 12, 2018
    duane likes this.
  4. DKR

    DKR Raconteur of the first stripe

    Well, this radio needs an external tuner unless you plan on carrying a resonant dipole (a good idea BTW)-

    And since it is a kit, it seems natural to look at a few of kit type tuners....
    [​IMG] [​IMG]
    No tune, end fed, half wave. Small, simple and requires a wire cut to a specific length. Designed as a single band tuner, the innovative PCB serves as wire storage, clever! Cost - $15!
    For more - see QRPGuys Portable No Tune End Fed Half Wave Antenna - QRPGuys

    [​IMG] [​IMG]
    Minituner with built in dummy load. 4 watts continuous, 10 Watts on SSB - a good fit for a dual band radio and this is the one I have to support my little radio. Has a visual SWR indicator. I have attached this to an acurate SWR meter and it will tune to 1:1 quickly. See EFHW Mini Tuner - QRPGuys Cost $25 + shipping. for the build.

    This Minituner uses the same circuit s the Pacific Antenna SOTA tuner ($40) (below)
    I built this - but sold it along with another radio. OK, but the QRPGuys tuner is the better deal.

    Now - to up the game, there is the 4 States QRP club tuner.
    A classic T-match, this will give the maximum flexibility for that off piece of wire. The tuner is unique, the red glows with HI SWR, the green when the antenna is resonant.for the RF @ the input. Cost is $51 and the
    size, 3 x 3 x 2, so will work with the ALX See Four State QRP Group for more.

    So, there you have it. Some kit-based tuners. All have a few YT vids for both building and using each of these.

    Have fun!
  5. DKR

    DKR Raconteur of the first stripe

    Even with a tuner, you will need an antenna wire to go with this little radio - enter the NVIS - Near Vertical Incidental Sky wave antenna. Good "up to" 10 Mhz or 30 Meters. The reality is 80 Meters (3.5 to 4 Mhz) or 40 Meters (7 Mhz) are the only real choice of you expect to communicate.

    NVIS works like this:

    Based on this data
    75M Dipole @ 20ft above ground.

    I used NVIS antennas for years while active duty - I would love to own a AS-2259 ant system. (Costs start at $350 and up for well used systems.

    Fortunately, home made is cheaper.

    There is this, using a vehicle
    (H/T to K6SOJ - Quick, Easy, Cheap, NVIS Antenna for Roadside Operating.)

    which describes a simple, easy to use NVIS using your vehicle as support system/power source. I use this with my VW Eurovan and have the bonus of inside seating and a nice seat to boot! Minmum coax required and you really don't need a connector at the antenna end. I use my QRPGuys tuner and it works the treat.

    Alternatively there is this for folks who have a Hustler/Screw ant If you use a 108 in whip and a tuner, this can work....

    A dipole antenna near the ground will also work

    for small yards or temporary setups, this is a good choice. ( as source)

    Mounted low to the ground, they look like this in the real world:

    If this of interest, use the links for learn more...
    Last edited: Sep 17, 2018
    ghrit likes this.
  6. WastedDaze

    WastedDaze Monkey+

    Been absent from the site here. Glad to see this review, good info. Might have to pick up one of the multiband kits.
    And for a good tuner there's nothing like the old "L" network tuner.
    BTPost likes this.
  7. DKR

    DKR Raconteur of the first stripe

    Adding a postscript to the piece

    QRVtranics has gone dark. These radios will show up from time to time as used, so, there is the possibility to find one still.
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