Many thanks to Pete (WB9FLW) who shares the following video from QRP Labs with a detailed overview of the new QCX+ transceiver:
Many thanks to Pete (WB9FLW) who shares the following:
This is truly amazing, Guino PE1NNZ has converted the QRP Labs $49 CW Transceiver to SSB.
Not much to add, a ATMEGA328P plus some firmware and a few component value changes and you’ve got a $50 SSB Transceiver!
This is a simple and experimental modification that transforms a QCX into a (Class-E driven) SSB transceiver. It can be used to make QRP SSB contacts, or (in combination with a PC) used for the digital modes such as FT8. It can be fully-continuous tuned through bands 160m-10m in the LSB/USB-modes with a 2400Hz bandwidth has up to 5W PEP SSB output and features a software-based full Break-In VOX for fast RX/TX switching in voice and digital operations.
The SSB transmit-stage is implemented completely in a digital and software-based manner: at the heart the ATMEGA328P is sampling the input-audio and reconstructing a SSB-signal by controlling the SI5351 PLL phase (through tiny frequency changes over 800kbit/s I2C) and controlling the PA Power (through PWM on the key-shaping circuit). In this way a highly power-efficient class-E driven SSB-signal can be realized; a PWM driven class-E design keeps the SSB transceiver simple, tiny, cool, power-efficient and low-cost (ie. no need for power-inefficient and complex linear amplifier with bulky heat-sink as often is seen in SSB transceivers).
An Open Source Arduino sketch is used as the basis for the firmware, the hardware modification bypasses the QCX CW filter and adds a microphone input in-place of the DVM-circuit; the mod is easy to apply and consist of four wire and four component changes and after applying the transceiver remains compatible with the original QCX (CW) firmware.
This experiment is created to try out what can be done with minimal hardware; a simple ATMEGA processor, a QCX and a software-based SSB processing approach. It would be nice to add more features to the sketch, and try out if the QCX design can be further simplified e.g. by implementing parts of the receiver stage in software. Feel free to experiment with this sketch, let me know your thoughts or contribute here: https://github.com/threeme3/QCX-SSB There is a forum discussion on the topic here: QRPLabs Forum
73, Guido email@example.com
Wow! What a brilliant modification, Pete! Thank you for sharing.
Many thanks to Pete (WB9FLW) who shares the following videos and notes:
Hans Summer G0UPL has released an excellent YouTube Video describing the QCX Transceiver Kit, its Design, and Operating Features:
[And] Roberto IZ7VHF has a much more detailed video of The QCX Transceiver.
Looks like people are catching QCX Fever! What an amazing Radio!
I agree, Pete! It’s simply amazing how self-contained this transceiver is. I like the fact that the kit is through-hole and that the board appears to be high quality. I will soon have one on order. This will be a fun winter project! Thanks for sharing, Pete!
Many thanks to Pete (WB9FLW) who notes:
“QRP Labs has just come out with the full feature CW Transceiver Kit for $49.00!”
(Source: QRP Labs)
The “QCX” is a 5W, single-band, high performance CW transceiver kit with WSPR beacon, and built-in alignment/test equipment. It is available for 80, 60, 40, 30, 20 or 17m bands. See below for the long list of features! This is a kit of parts that you assemble yourself. There are NO surface mount components to solder (two SMD ICs are already factory pre-soldered). We do not currently have any enclosure available for this kit, it may be something we investigate in the future.
- Easy to build, single-board design, 10 x 8cm, all controls are board-mounted
- Professional quality double-sided, through-hole plated, silk-screen printed PCB
- Choice of single band, 80, 60, 40, 30, 20 or 17m
- Approximately 3-5W CW output (depending on supply voltage)
- 7-16V recommended supply voltage
- Class E power amplifier, transistors run cool… even with no heatsinks
- 7-element Low Pass Filter ensures regulatory compliance
- CW envelope shaping to remove key clicks
- High performance receiver with at least 50dB of unwanted sideband cancellation
- 200Hz CW filter with no ringing
- Si5351A Synthesized VFO with rotary encoder tuning
- 16 x 2 blue backlight LCD screen
- Iambic keyer or straight key option included in the firmware
- Simple Digital Signal Processing assisted CW decoder, displayed real-time on-screen
- On-screen S-meter
- Full or semi QSK operation using fast solid-state transmit/receive switching
- Frequency presets, VFO A/B Split operation, RIT, configurable CW Offset
- Configurable sidetone frequency and volume
- Connectors: Power, 3.5mm keyer jack, 3.5mm stereo earphone jack, BNC RF output
- Onboard microswitch can be used as a simple straight Morse key
- Built-in test signal generator and alignment tools to complete simple set-up adjustments
- Built-in test equipment: voltmeter, RF power meter, frequency counter, signal generator
- Beacon mode, supporting automatic CW or WSPR operation
- GPS interface for reference frequency calibration and time-keeping (for WSPR beacon)
Check the manual out, it’s 138 pages! Even a rank beginner can successfully build this rig.
Thank you for the tip, Pete! That’s an amazing amount of transceiver for the price. You’re right, I believe even a new kit builder could build this transceiver.