Field Portable PSK without a Computer – AmQRP’s NUE-PSK Digital Modem

One of the downsides of doing portable Digital Modes is dragging the computer with you. Personally I have had poor luck with bringing laptops to the field for digital work – a Dell Laptop on one occasion decided the outside cold would finish off its battery and didn’t work, the Macbook had a physically self-destructed hard drive within hours of arriving on an Island and an older Windows machine decided that its USB ports which worked wonderfully at home were not recognized once in the field. has announced what looks to be an elegant solution, the “NUE-PSK Digital Modem
AmQRP’s NUE-PSK Digital Modem

click on picture for larger version

From their website:

NUE-PSK Digital Modem

Improved since the design prototypes …
aluminum enclosure
single graphic display

The NUE-PSK Digital Modem comes fully assembled and tested
… just plug in your keyboard and SSB transceiver, and start operating!
(Kits and partial kits will be avalable for sale later in 2008.)

Place an “Early Bird” Order
Limited-time, special pricing provided for pre-availability orders.


PSK31 is one of the latest communications modes to capture the interest of hams worldwide. Its inherent ability to dig out low, near-inaudible signals is ideally suited for low power QRP enthusiasts. The PSK31 digital modem engine, however, requires intense DSP processing that is only commonly available in PC sound card. Thus the PSK operator desiring portability for field operation is locked into using a laptop computer as a controller, which results in a cumbersome station. But there’s hope!

The NUE-PSK is a standalone, battery-operated digital modem using a Microchip dsPIC33F microcontroller. The project uses a single graphic display for: transmit and receive text data, band spectrum, and tuning indication. When coupled with an SSB-capable transceiver and a standard PS2 keyboard, the NUE-PSK Digital Modem forms an effective, compact, and portable station for working the digial modes on the amatuer bands.


> Standalone, half-duplex modulator/demodulator for amateur radio digital mode communications
> Handheld unit … no PC required
> Menus select operating modes, Squelch Thresh, PGA Gain, CW ID
> 128 x 64 pixel graphic LCD shows audio signal spectrum 500 Hz-to-2 kHz (with backlight)
> Tx and and Rx buffers and menuing system shown in lower half of LCD using four 20-character lines of text
> Rotary encoder adjustment of modem position along audio spectrum
> Modes currently supported: BPSK31, QPSK (RTTY and MFSK coming next)
> External keyboard jack: 6-pin mini-DIN, PS2-compatible
> Keyboard provides text input for Tx entry, command/mode selection and modem frequency adjustment
> Connection to SSB transceiver: 8-pin mini-DIN (audio in, audio out, PTT, power)
> Powered by internal battery (9V) or externally applied via 2.1mm coaxial jack
> Power requirements: 8-13.5V DC at 80 ma (typical)
> On board trickle charge circuitry provided for internal NiMH battery (only)
> Field reprogrammability of internal microcontroller (dsPIC33F) to allow software updating in the field by the owner
> Aluminum enclosure provides for rugged portable use while shielding transceiver from digital EMI
> GPL open source – software freely available
> Simple/inexpensive development platform (Microchip ICD2 or PICKit2) for experimenters
> Programmed in C
> Enclosure dimensions: 7″ x 4″ x 1″
> Single 3.75″ x 5.25” pc board contains all components and connectors
> Lightweight: Control for precise audio level control to transceiver
> Cable assembly provided (plug and shielded cable) for connection to the SSB transceiver


The AmQRP group is running a special until December 31st which will save a person some money while giving the group the funds to cash flow the project. I’ve just put my order in, paying by Paypal to make sure I made the deadline.

Check out their website for more information – they have flyers and video for download.



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9 thoughts on “Field Portable PSK without a Computer – AmQRP’s NUE-PSK Digital Modem

  1. Pat NØHR says:

    Looks cool.

    While not for everyone, another alternative might be the (freeware) PocketPC PDA PocketDigi. It runs on PocketPC PDAs and PocketPC Phones.

    PocketDigi is a PDA app that runs PSK, RTTY and even decodes CW. Worth a look if you have a PocketPC.

    Pat NØHR

  2. k9zw says:

    AmQRP has closed the pre-orders with some 280 or so units prepaid. The website reflects a February 15th +/- ship date.



  3. Jim says:

    The very first time I heard of this piece of gear was in the March issue of QST. Since your special pricing ended in December, ’07, why wasn’t the article sent to be printed in QST by November or December issues?


  4. k9zw says:

    Hi Jim K2YSR

    Not being part of the project I can only guess the reasons for the small window for discounted early orders. I know in my case I read the offer and had to decide to “wing it” not knowing how well the device would perform and in honesty would it actually happen.

    My guess is the modest discount reflected that uncertainty – remember there was no actual product to be reviewed by QST and QEX at that point – and to gather the seed money to make teh project happen.

    Again this is my guess only.



  5. […] K9ZW, NUE-PSK, PSK31, QEX, QRP, QST trackback AmQRP’s  “NUE-PSK Digital Modem“ which I have written about before, is again in the […]

  6. […] Field Portable PSK without a Computer – AmQRP’s NUE-PSK Digital Modem […]

  7. […] Field Portable PSK without a Computer – AmQRP’s NUE-PSK Digital Modem  […]

  8. Dennis L. Cooper says:

    Amateur Friends,
    I have a Kenwood TS480SAT and a Elecraft K2.
    Problem: Cannot intergrate to my Toshiba Laptop A15.
    >>Had a Rig Blaster, but had a serial port, my laptop has only a USB port. Tried several Serial to USB adapters; yet to find one that works.
    >>I can receive okay, but cannot trigger transmit from keyboard keys!

    Will your moden work with my TS480 or? K2??!
    Sure looking for something that will WORK!.
    Thanks,.. Dennis K3NVI York, PA

  9. k9zw says:

    Hi Dennis K3NVI

    My understanding is that the NUE-PSK should work with the K2 and TS-480

    Might be best to ask the question on how the hookup would work on the NUE-PSK Yahoo Group reflector.

    West Mountain now has native-USB versions of their interfaces, which you might look into, as it may be a wait to get a NUE-PSK Modem while they resupply.



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