NUE-PSK Digital Modem

                             Version 5 software adds built-in keyer!
This latest version 5 software adds three huge new capabilities to the NUE-PSK Digital Modem:
     (1) You can now use your favorite CW paddle instead of a keyboard to send digital mode messages;
     (2) A new mode called CW Direct allows your modem to connect to any transceiver to send and receive in CW Mode. (No longer is an SSB transceiver required for CW Mode use!); and
     (3) Keyer Practice Mode is also available to allow you to practice sending with your paddle, at any speed and in any keyer mode.

     You can take advantage of these new capabilities by making a simple hardware mod to your modem (add a 3.5mm jack and four internal wires). Then just sit back, listen to the digital mode traffic in Morse code as it is also displayed to the built-in LCD, and transmit using your paddle to have the ultimate digital mode portable operating experience!

     See the web page describing how to add the paddle jack. A full description of using the paddle for controlling your modem is contained in the extensive Keyer Manual. See also our Keyer Mode QuickStart web page describing how to easily get going with this mode, including tips, techniques and example operating practices.

Thanks once again to Dave Collins, AD7JT for developing this outstanding new software version for us all!

CW Direct Mode being used CW Direct Mode being used
with the KD1JV "ATS-3B" CW Transceiver with the Elecraft "KX1" CW Transceiver
(Click photos to see larger view)

CW Mode supported in version 4
Upgrade to version 4 software to give your modem with the latest feature: CW Mode ... which is a combined "CW reader and Morse Keyboard" capability! Just set the Mode to CW, dial over to a signal of interest on the modem's bandscope, and if it is CW you will see a darned good quality text display of that Morse code signal. The speed of the CW signal being decoded is displayed on the modem's LCD. Then when you go into transmit (press F10 and start typing) your text will be sent over to the SSB rig and transmitted as Morse code! You can set the transmit speed from 1-50 wpm! ... See the CW page for all the details. Also see the slide deck we presented at the TAPR Digital Communications Conference on Sept 16, 2011.

Many thanks to developer Dave Collins, AD7JT for developing CW Mode support for everyone to enjoy! Dave is an engineer extraordinaire and a good friend. Be sure to say hi to Dave when he pops onto the list to help us all out with use of the new CW Mode!

USB+RTCC Card Details
Records QSOs to a USB flash memory device, and loads new modem software from a USB thumb drive or from a computer.
The "Real Time Clock Calendar" feature is available in several forms ... (1) standard on the assembled USB card; (2) standard in the USB Kit; or (3) as an RTCC Upgrade parts kit for adding to existing USB card; See the Ordering page to select the ideal package for you.

Available Accessories:
Custom Flash Drive, USB+RTCC card, interface cables, printed manuals

An easy and portable way to get on the air with PSK-31, RTTY and CW ... no computer required!

The NUE-PSK is a small 7" x 4" x 1" standalone, battery-operated digital modem using a graphic display for transmit and receive text data, as well as for showing band spectrum and tuning. Just plug in a standard PS2 keyboard and connect to an SSB-capable transceiver like the FT-817 or the PSK-xx transceivers from Small Wonder Labs, and you'll have an effective digital mode station that goes absolutely anywhere.

The NUE-PSK modem is an "open" design, with published hardware details and software source code. What this means is that many others can contribute to the modem's capabilities and modes of operation. Already we have a "USB add-on option" that maintains the current time and date, and lets you record the QSO (with a timestamp) to a USB stick for archival or EmComm use.

Further, the modem has the ability to be "field upgraded" by using a serial port (or USB thumb drive) to load new versions of the modem software. The NUE-PSK Modem supports BPSK (PSK-31), QPSK, RTTY and CW. Just download the latest-and-greatest modem software from this website and send it to the modem over the serial port. It's the modem that keeps on growing ... new modes, new features, new add-on accessories!

MODEM NEWS
Updated: April 24, 2012

> Parallax Mini-PS2 Keyboard no longer any good for use with the NUE-PSK modem! Apparently Parallax changed the vendor for the internal controller chip in this keyboard that we had long-recommended for modem users, and the keyboard no longer reliably works. Timing of the serial signals to/from the keyboard is carefully specified, yet some foreign manufacturers do not pay careful enough attention to the spec and timing falls outside the timing tolerance we have in the modem's keyboard controller. (We had a similar condition when the modem was introduced and we widened our tolerance up to far beyond the specifications, and the modem has worked well with all keyboards (including the Parallax one) for the last 4-5 years. Regrettably, Parallax.com changed their supplier and we must caution modem users against getting this one. Another small and inexpensive keyboard that some have found suitable for portable use with the modem is available from www.Frys.com (product # 5874793) with USB adapter (product # 3470833).

> Version 5 software is released ... Adds Keyer and CW Direct modes to any transceiver! See QuickStart Tutorial.

> Newly-updated Operating Manual for v4 now online, and in printed form! ... Two major sections have been added to the existing Operating Manual, now covering details for the Real-Time Clock Calendar option and for CW mode. Now comprising a total of 75 pages, the PDF manual may be downloaded from this page (here and below in the Documents section). Great news too is that we now have the printed version of the manual also available, again in the same convenient, small-sized form factor with spiral binding, plastic front and backsides, and blue divider pages allowing you to easily find the information needed. You can order this Printed Manual online from our Ordering Page.

> CW Mode Version 4.02 ... Download this software and update your modem with the latest capability: CW Mode ... a combined "CW reader and Morse Keyboard" function! Just change the Mode to CW, dial over to a signal of interest on the modem's bandscope, and if it is CW you will see a darned good quality text display of the Morse code being received. The speed of the CW signal being received and decoded is displayed on the modem's LCD. Then when you go into transmit (press F10 and start typing) your text will be sent over to the SSB rig and transmitted as Morse code! (You can set the transmit speed from 1-50 wpm!) This version improves a number of small aspects of modem operation, especially with respect to the RTCC and USB functions. See the Release Notes for all the details. Instructions for loading the software are located here.

> RTCC (Real Time Clock Calendar) now standard on USB cards ... The Real Time Clock Calendar capability is now a standard part of the USB add-on card, providing a way for the modem to maintain the current date and time, even when the modem is turned off! The date and time are displayed on the main LCD, and a timestamp is given to each QSO file recorded to the USB thumb drive connected to the modem. The Date may be set with the CTL-D keyboard command, and Time is set with the ALT-D command. When the RTCC circuits are not present, the v3 software still displays the "time" starting at 00:00:00 since powering on the modem, thus acting as an elapsed time counter when using the modem. The Time may still be set (ALT-D) without the RTCC hardware being present. Pretty handy for use in logbooks, emergency traffic radiograms, and more.

> Summary of recommended hardware mods ... Just a couple mods to the modem pcb are recommended for optimum performance. Easy to do and provides better immunity to external RFI and internal EMI.

> SDR Cube ... an SDR transceiver option that is optimized for digital mode operation with the NUE-PSK Modem � Want another easy way to take your digital mode operation to the field? Check out this recent companion to the NUE-PSK modem: a portable, Software Defined Radio transceiver that also does not need a PC to work! It's a fully self-contained CW/SSB/AM transceiver with some amazing features that make it great for the digital modes when used with the NUE-PSK.

Overview
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 showing 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 amateur bands.

> Standalone, half-duplex modulator/demodulator for amateur radio digital mode communications

> 128 x 64 pixel graphic LCD displays audio signal spectrum 500 Hz to 2.5 kHz (with backlight)

> Tx and Rx buffers and menu system displayed in lower half of LCD using four 20-character lines of text

> Standard PS2-style or dual-mode USB/PS2 keyboard (user-supplied) 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 two internal 9V batteries (not included) or an externally-applied supply via 2.1mm coaxial jack

> Power requirements: 9-18V DC. Current at 12V is 60 ma without backlight, 80mA with backlight. The current decreases as input voltage is increased.

> Aluminum enclosure provides for rugged portable use while shielding transceiver from digital EMI

> Cable assembly provided (plug and shielded cable) for connection to the SSB transceiver
> Optional USB Card provides ability to record transmit and receive text from QSOs for archival and printing. Also serves as serial adapter port for connection to PC for upgrading modem software, and for uploading/editing/downloading file with modem settings and macro text strings.

As illustrated below, a dsPIC33F is at the heart of the project design. This highly-integrated dsPIC33F device employs a powerful 16-bit architecture that seamlessly integrates the control features of a Microcontroller (MCU) with the computational capabilities of a Digital Signal Processor (DSP). The resulting functionality is ideal for applications that rely on high-speed, repetitive computations, as well as control � just perfect for the NUE-PSK Digital Modem.