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NUE-PSK Digital Modem
A digital modem for PSK31 field operation ... without using a PC! |
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PHOTO GALLERY
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NUE-PSK Digital Modem The
NUE-PSK Digital Modem comes fully assembled and tested
PLACE AN ORDER
Check on an existing order
UPDATE:
April 19
Custom cables and a few manuals are
still being made and shipped within 7-10 days of the order.
Important Notes 1) Power Supply Modification -- Modems first into production can benefit by applying these simple mods to allow powering the unit from an external supply without removing the batteries. 2) Radio Cable Documentation Correction -- See the linked page here for information concerning the 3-foot radio cable supplied with your modem. It is important to understand if you have a Type A or Type B cable so you know how to attach the connector for your SSB rig. 3) Supplying Power to/from the Modem -- This is a caution note for use in wiring your own connector for the cable to your transceivers ... be careful how you handle the +V line on the end of your cable. Technical Resources | Overview | Schematic | Parts List | GPL Software: dsPIC MC908 | Video Clip: Prototype Operation (5 minutes, 47 MB .wmv file) Video Clip: Battery Installation (2.5 minutes, 20 MB .wmv file) Tips on Installing the Batteries QST Article (March 2008) QEX Article (Mar-Apr 2008) ARRL/TAPR 2007 Digital Communications Conference: (Article and Slides) Operator's Manual QuickStart Guide Radio Cable Guide
Overview 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.
Specifications > 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 displays audio signal spectrum 500 Hz to 2.5 kHz (with backlight) > Tx and Rx buffers and menuing system displayed in lower half of LCD using four 20-character lines of text > Tune controls modem position along audio spectrum > Modes currently supported: BPSK31, QPSK, QPSK reversed > External keyboard jack: 6-pin mini-DIN, PS2-compatible > 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. > Field reprogrammability of internal microcontroller to allow software updating in the field by the owner > Aluminum enclosure provides for rugged portable use while shielding transceiver from digital EMI > Enclosure dimensions: 7" x 4" x 1" > Single 3.75" x 5.25” pc board contains all components and connectors > Lightweight: < 1 lb with batteries. > Control for precise audio level control to transceiver > Cable assembly provided (plug and shielded cable) for connection to the SSB transceiver
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. A complete description of the NUE-PSK Digital Modem design and operation is provided in our cover article in QEX for March-April 2008.
Parts List for Homebrewers:
Download BOM as Excel Spreadsheet
F1 to F7 Play Macros Ctrl-Fn Record Macros-- Enter keystrokes. When finished, Press F9. Alt-Fn Delete Macro associated with Fn. F8 Toggle TUNE mode. May be accessed only in RX or TX (Not in Setup, or Macro Recording.) F11 Display the first few bytes stored in EEPROM. F12 Toggle between RX and TX (again, not in Setup, or Macro Recording) F10 Display the main Setup Screen. (Accessible only in RX mode) # A numeric selection from the Main Menu, selects a submenu, which is then displayed. Another numeric selection activates your selected parameter. Ctrl-M Save keyboard entries into a fixed location in EEPROM (for recording “my callsign”, for use in Macros). Ctrl-T Save keyboard entries into a RAM location (for recording “their callsign”—also for use in Macros). Alt-M Insert “my callsign” into a Macro. Alt-T Insert “their callsign” into a Macro. Ctrl-F Save the current frequency into EEPROM so that it can be restored at the next power-up. Alt-F Retrieve the saved frequency and makes it the current frequency. Ctrl-Tab Displays the current frequency (audio) Ctrl-A Enable AFC Alt-A Disable AFC PgUp Increase PGA gain PgDn Decrease PGA gain Ctrl-L Clears the text area of the LCD Ctrl-K Clears the keyboard buffer (while receiving, keystrokes are not displayed—this allows clearing the buffer, so that callsigns may be entered, or re-entered in case you think that you have entered the wrong callsign) Ctrl-B Clears the internal buffers Ctrl-Q Inserts a TX-OFF control character in the TX buffer, or Macro. Ctrl-O Toggles the display backlight on and off.
Here is a useful combination of macros: F1 CQ F2 Call “them” twice w/ toggle F3 Call “them” once w/o toggle F4 BTU F5 73 F6 Brag File F7 Test message
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Page last updated: April 29, 2008