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December Features
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NUE-PSK Digital Modem
The design team of Milt Cram, W8NUE and George
Heron, N2APB has introduced a new, handheld, battery-operated digital
modem that conveniently provides for PSK31 communications ... without
using a PC!
Presented at the recent ARRL/TAPR DCC 2007 conference,
and described in the March 2008 QST and Mar-Apr 2008 QEX magazines, the NUE-PSK digital modem will work with any SSB transceiver to finally
allow PSK31 to be easily done in the field ... "portable PSK".
See the NUE-PSK web
page here on the AmQRP website for overview, technical details, photos and
more. Also available are the QEX and QST articles overviewing the
project.
>
Micro908 Kit
The Micro908 "Antenna Analyzer"
capabilities have really matured in the 2.5 years since first
introduction, and we continue to add real useful features on a regular
basis. For example, recent improvements include: computational accuracy,
automatic calibration, ability to calibrate the generated frequency to a
known standard, startup frequency selection, and some coax measurements.
This is in addition to the standard base features of Z, R, X, L, C
measurements up to 60 MHz, a VFO mode, battery operation for field use, a
DSP engine with additional programs able to be run, and optional remote
control of the instrument for plotting measured values on a PC. This
is quite a kit, and with open source and full documentation the Micro908
has "legs" way into the future for new applications coming
downstream like Portable-SDR and Portable-PSK.
> DDS-60
Daughtercard Kit
The
self-contained DDS-60 functional module generates a good-quality RF signal
from 1-60 MHz using a small 1"x2" pc board with the DDS essential circuits –
an Analog Devices AD9851 DDS chip, a clock oscillator, a 5th-order
elliptic filter and an adjustable-level RF amplifier.
Additionally, an onboard 5V regulator is provided so you need only
provide a battery or power supply ranging from 8-12V DC. The three digital
control lines, the power supply, and the output signal are all available
on a pin header at the board edge. The DDS-60 is even pin-compatible with
the original DDS Daughtercard; only a few simple changes are needed in the
software projects controlling the DDS-60. See the full details inside.
>
Rookey Kit
The Rookey
is a small-yet-powerful building block of a remote control system
utilizing audio tones. The kit consists of the audio Decoder pc board,
a small FM receiver, an audio patch cord, ear buds and a 9V battery clip.
The microcontroller IC supplied with the Decoder board is preprogrammed
with the BASIC software program that decodes the incoming audio pulses
to illuminate any one of the four LEDs.
An extra (blank) Rookey pc board is also supplied in
the Rookey Kit and is easily modified for use as a mating Encoder board
to generate the coded audio signals that would be sent (with a
user-supplied FM transmitter) over the "transport medium" of the FM
band. Alternatively, the Encoder's audio pulses could be sent to the
Rookey using IR, Bluetooth, hf/vfh ham band or ultrasonic transceivers.
You could even just connect the Rookey Encoder and Decoder board pair
with a long run of ordinary twisted pair wires to deliver multi-function
control to the end-point. A blank Rookey pcb is also available.
The Rookey Encoder and Decoder boards use the simple
and reprogrammable PICAXE microcontroller, thus allowing you to easily
customize the project by changing the codes and adding other features to
suite your remote control project ideas. All encoder/decoder software is
freely available on the web page.
Additional software is available for the Rookey boards,
provided by PICAXE-enthusiast David Gwillim, KB2TQX (SK). Dave's programs
allow the Rookey board to function as a Randon Morse Generator, Iambic
Keyer, Koch Method Generator and a temperature controller. This source
code is also freely available here, and we have a limited number of "KMMT
Kits" made up with the pcb and components needed to make up the KB2TQX
circuits.
>
Homebrewer Sprint Results
Check out
the latest results from our popular and long-running QRP
Homebrewer Sprint:
2007:
Spring
and Fall (results currently coming in)
2006:
Spring
and Fall
2005: Spring
and Fall
2004: Spring
and Fall
2003: Spring
and Fall
2002:
Spring
and Fall
2001:
Spring
and Fall
> HC908
VFO Software & Reference Design
Here's
yet another DDS VFO for homebrewers to try out ... but this one is
different from all the rest. It's a derivative of the Micro908
running on a minimal set of daughtercards: either the DDS-30 or DDS60, and the powerful HC908
microcontroller daughtercard. This small and standalone approach gives the
builder flexibility in constructing the application, the advantage of
using a ton of tested/proven VFO software, and the tremendously convenient
capability of downloading new software updates from the website to provide
new features as they become available. Other nifty features such as LCD
backlight timeout control, built-in debugger and terminal control, and
programmable scanning capabilities all conspire to make this the most
flexible and singularly-powerful VFO module available on the homebrew
market today.
By the way, this project is not a kit but instead is
software that is designed to run on existing daughtercards that many
builders already have, or that can be obtained as kits/modules from the
AmQRP. Using the "reference design" schematic and parts
list, simply wire together the daughtercards and a few extra components,
load up the software from the web page, and you'll have yourself this
great little HC908 VFO.
>
Software for PIC-EL supports 60 MHz operation with DDS-60 Kit
> Assembly
Help
Need help soldering all those small parts onto the pc board of
your kit? Check out "KitBuilders"!
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