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Ultimate3: QRSS Labs Multi-mode QRSS Beacon Kit
1. Introduction
Thank you for purchasing my third generation "Ultimate3" Multi-mode QRSS beacon kit. This kit is capable
of automated transmission of a range of weak signal modes that are capable of worldwide HF propagation
using a fraction of a watt of RF output power. The DDS module permits accurate, stable operation
anywhere on HF whilst plug-in low-pass-filter modules allow easy band changing.
Recommended approach to building the kit: This is a simple design but there are a large number of
features which provide a great deal of flexibility. Read this WHOLE manual and understand it! Follow
the construction section to build the kit. Use a receiver connected to your PC, with a slow-signal decoding
program such as Argo, to monitor your signal, experiment and understand the various features before
connecting an antenna! Good performance depends on proper set up:, see the calibration section.
Please read the DDS module stability section 7! Do not miss this section, or your output signal may
be unstable and look horrible!
This assembly manual is to be read in conjunction with the operation manual!
The kit supports the following modes:
QRSS mode (plain on/off keyed slow CW)
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FSK/CW mode (frequency shift keyed slow CW)
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DFCW mode (dual frequency CW, dit's and dah's on different frequencies)
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WSPR and WSPR-15 modes (Weak Signal Propagation Reporter)
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Slow-Hellschreiber (frequency shifted slow Hellschreiber)
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Hellshreiber (full-speed standard Hellschreiber, and half-speed Hellshreiber)
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CW (plain CW) and fast FSK mode
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Transmitter mode
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Customisable FSK patterns
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Other features:
DDS-controlled output frequency (through-pin DDS module, no SMD soldering required)
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Plug-in low pass filter boards (available for 10 HF and 2 LF bands)
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16-column x 2-row LCD with backlight, and two-button user interface
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User-programmable (callsign, message, speed, FSK, mode, etc.), settings stored in EEPROM
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GPS interface, for locking the frequency, timing and location information
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On-chip generation of WSPR encoded message (no PC required)
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WSPR maidenhead locator can be generated from GPS-derived latitude/longitude
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Selectable "frame" size, for stacked QRSS reception
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Plain CW callsign identifier at selectable interval
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Produces approximately 150mW RF output on 30m (lower output on higher frequency bands)
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Higher output power by fitting additional PA transistors and/or higher PA supply voltage
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PCB Revisions 3 and 4
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Summary of Contents for QRP Labs Ultimate3
- Page 1 PCB Revisions 3 and 4 1. Introduction Thank you for purchasing my third generation “Ultimate3” Multi-mode QRSS beacon kit. This kit is capable of automated transmission of a range of weak signal modes that are capable of worldwide HF propagation using a fraction of a watt of RF output power.
- Page 2 The transmitter is designed to be powered with 5V DC, which could come from a mobile phone charger, wall wart, or even four 1.5V batteries connected in series with a suitable low dropout regulator. Do not use more than 6V: this may kill the microcontroller; the LCD may not work properly with more than 5V. Best results will be obtained with a well-regulated and well-smoothed 5V supply.
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Page 3: Parts List
The ATmega328 AVR microcontroller (IC1) is pre-programmed with firmware to control the LCD, buttons, and GPS interface. The AD9850 Direct Digital Synthesis (DDS) module includes its own on-board 125MHz crystal reference oscillator, and reconstruction filter components ready-mounted. On/off keying is provided by the BS170 transistor Q1, and power amplification by another BS170 transistor, Q2, producing over over 150mW from a 5V supply on 30m. - Page 4 4. Construction 4.1 General construction tips The kit comes as a main board, with pre-assembled DDS module, and a plug-in low-pass-filter module for the desired band. Since the low-pass filter module is a separate kit in its own right, please refer to the separate instructions for constructing that kit.
- Page 5 NOTE: Photos below show PCB revision 1, but they are very similar! 1) Solder in the socket for IC1. To avoid confusion or mistakes later, align the dimple at one end of the socket, with the dimple illustrated on the PCB. The dimple should be at the end nearest the right-hand edge of the PCB.
- Page 6 use the DDS and LPF boards plugged into the sockets, then solder the pins, to ensure correct alignment. 6) Fit and solder R1, the preset potentiometer that sets the LCD contrast. It is a slightly tight fit but apply pressure carefully and evenly, and the pins of the potentiometer will fit into the PCB perfectly.
- Page 7 Also pay attention to the jumpers at R3 and R4 on the right-hand side of the diagram. R3 is an optional resistor, to be fitted to enable in-circuit-programming for those wishing to update their own firmware and having the necessary equipment. If you do not fit a 100K resistor for R3, then you must fit a wire jumper here as shown.
- Page 8 soldered, then you will be able to ensure perfect alignment. Use the eight 6mm M3 screws, and four 12mm nylon hex spacers, to bolt the PCB to the LCD. The combined 16-way plug and socket when mated together, have a height of a little under 12mm.
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Page 9: Hardware Options
c) It is normal for the 125MHz reference oscillator (metal can on the right) to get hot in operation. 5. Hardware Options Label Group Description +5V supply to GPS module 5.1 Explanation of connections Ground connection to GPS module Serial data input from GPS module The table to the right details the 1 pulse per second input from GPS module purpose of the connection points... - Page 10 5.4 Optional connection of GPS module A GPS module may be connected to the kit, to provide frequency stability, accurate time, and latitude and longitude which can be converted to Maidenhead locator format for encoding in the WSPR message transmission. Check that your module is powered from 5V.
- Page 11 Another possible way to use the AF output is to rectify it (diode + capacitor) and use that as a plain on/off keying signal to a CW transmitter. This would be suitable for CW and Hellschreiber modes, but not modes where a frequency shift encoding is involved.
- Page 12 5.10 Higher sensitivity contrast potentiometer adjustment The contrast voltage required by the LCD is typically under one volt, but the potentiometer R1 is connected between +5V and Gnd. Therefore most of the available travel of the potentiometer adjustment is redundant, and the contrast adjustment is rather sensitive. If you wish to improve this, you may fit a 220K resistor at R4 instead of the wire jumper.
- Page 13 Once you have measured the actual output frequency, you can calculate the required correction to the 125MHz reference frequency and enter it in the “Ref. Frq.” configuration setting. For example, suppose you set the output frequency to 12.500000 MHz but you actually measure 12.500075. Your output frequency is 75 Hz too high.
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Page 14: Version History
8 Resources Please see the kit page http://www.hanssummers.com/qrssultimate2 for any information on latest updates and issues. Further references are listed in the Operation manual. Analog Devices DDS information: http://www.analog.com/en/rfif-components/direct-digital-synthesis- dds/products/index.html 9. Version History 15-Oct-2013 Initial draft version • 11-Nov-2013 First official version •...