The CR Kits DSB Transceiver prototype (Source: CR Kits)
Many thanks to Pete (WB9FLW) who writes:
Thomas, Adam of CR Kits is now taking orders for his FT8 Transceiver Kit and the price is very reasonable.
From Adam at CR Kits:
FT8 transceiver kit
Folks, I start to take email order now. The introductory price is 39 USD for kit including shipping to worldwide. As in the introductory period, you will get audio cable options for free. The earliest possible shipment date is now improved to May 13.
You can directly PayPal to [email protected] and let me know 40m or 20m (80m not ready yet). I will ship based on the sequence of receiving your payment. I may delay shipment for one week or two due to workload.
This is the spec so far:
Summary: Crystal controlled single frequency DSB transceiver for 20m (14.074MHz), 40m (7.074MHz) or 80m (3.573MHz), other frequencies could be added per requestPower supply: 10-14V DC regulated power supply or battery pack, 12V is recommended, center positive, reverse polarity protection availableCurrent consumption in RX: about 15mA at 12VCurrent consumption in TX: about 300mA at 12VRF output: about 1W for 40m band at 12V, and a bit less for 20m bandSpurious suppression: no worse than -50dBcAntenna connector: BNC connector, 50 ohmAudio in connector: 3.5mm mono, at least 600mV to activate VOX, connects to headphone connector at PC sound card, no dedicated PTT connector is requiredAudio out connector: 3.5mm mono, connects to microphone connector at PC sound cardAmber LED: TX statusGreen LED: RX statusFrequency accuracy: -600 Hz ~ + 200 HzFrequency stability: Okay for FT8 mode per test. If the optional heater resistor R20* is added, after warm up, long term frequency stability in 10 min will be improved at the cost of acceptable short term frequency stability sacrifice in 30 sec. Thanks, Adam
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
Adam BD6CR of CR Kits is getting close to releasing the FT8 DSB Transceiver. Below is some preliminary information:
D4D: A simple QRP transceiver for FT8
Adam Rong, BD6CR
D4D stands for DSB transceiver for Digital modes. It is a Double Sided Band transceiver kit designed for digital modes, especially for FT8. If have chance to try FT8, you will be amazed by the strong decoding capability offered by the communication protocol, digital signal processing and software. I still remember clearly a YouTube video by W6LG who communicated with bulbs. I started to think how much the transceiver could be simplified if you have a moderate antenna like a full sized dipole or EFHW.
A DSB transceiver is much simpler than a usual SSB transceiver, however it was never used for FT8 as far as I know. I did some experiments on my Choc perf board. I started with a direct conversion receiver for FT8 and it worked okay. Then I made a DSB transmitter and the transmitted signal can be decoded. By referring to the designs of AA7EE, VK3YE and ZL2BMI, I combined them using only one NE602 and a PTT switch and it gave me success to make a few FT8 QSO’s.
Personally I really enjoyed it because a manual PTT switch will save power consumption and circuit complexity, but you will need to well sync with computer, although it was not really a problem for me. Per request from a few hams, I found a VOX control circuit and modify the hold time to be compatible with FT8, and I put them together and made a few improvements on the signal purity and frequency stability, and it became our D4D. Do we have to worry about the unwanted Lower Side Band? Maybe, but for a transmitter of 1-watt, it is not really a big problem. Is it just a toy for a transmitter of 1-watt and only half of the power will be effective? Not really, as I can easily make a few QSO’s as far as 1500 miles range for 40-meter band.
Here is the brief specifications I have measured (subject to change without notice):
Summary: Crystal controlled single frequency DSB transceiver for 20m (14.074MHz), 40m (7.074MHz) or 80m (3.573MHz), other frequencies could be added per request Power supply: 10-14V DC regulated power supply or battery pack, 12V is recommended, center positive, reverse polarity protection available Current consumption in RX: 15mA Current consumption in TX: about 260mA(?) at 12V, and about 300mA at 13.8V RF output: about 1W for 20m band at 12V, a bit more for lower bands like 40m and 80m Spurious suppression: no worse than -50dBc Antenna connector: BNC connector, 50 ohm Audio in connector: 3.5mm mono, at least 600mV to activate VOX, connects to headphone connector at PC sound card, no dedicated PTT connector is required Audio out connector: 3.5mm mono, connects to microphone connector at PC sound card Amber LED: TX status Green LED: RX status Frequency stability: Okay for FT8 mode per test. If the optional heater resistor R20* is added, after warm up of about 3 min, long term frequency stability in 10 min will be improved at the cost of acceptable short term frequency stability sacrifice in 30 sec.
Let us briefly go through the circuit: The input audio will activate the VOX circuit of D2 (1N4148), Q5 (2N3906), Q6 (2N3904), Q7 (2N3904) and Relay. The relay is a DPDT type and controls both antenna and power supply. The LPF consists of L2, L3 and surrounding capacitors, and it is switched to either transmitter output or receiver input. The power supply is polarity protected by D1 (1N5817) and switched to either receiver circuit or transmitter circuit. The receiver circuit is only for audio amplifier consists of Q1 (2N3904) and optional heater resistor R20*, while the transmitter circuit is for RX muter Q8 (2N3904), TX driver Q3 (2N3904) and TX final Q4 (BD139). X1 is a filter in the receiver front end to help eliminate strong broadcast interference, and X2 is the crystal for the built-in oscillator in U1 (NE602). U2 (78L05) is the 5V regulator for U1, and Q2 (2N3904) is a buffer amplifier in the TX chain.
Thanks for sharing this, Pete! What a simple transceiver concept!
The first article deals with buying used and new equipment, while the other article is a review of the uBITX QRP transceiver. Thanks go to Ken Reitz for graciously allowing these to be posted after their initial publication!
And thank you, Robert!
Readers, I highly recommend both of these articles. In his used equipment guide, Robert makes practical suggestions for navigating the world of pre-owned radio gear and shares some important tips. His uBITX QRP Transceiver article is essential reading for anyone who has considered building this incredibly affordable kit.
Dave Benson K1SWL, founder of the renown Small Wonder Labs, listened to you and has designed a 40 meter version of his winning Hilltopper design. Four State QRP Group is honored to have been selected to kit the new transceiver. The Hilltopper is a high performance CW transceiver for the 40M meter band. It is the perfect solution to your portable operation needs – small, lightweight, wide 40 meter frequency coverage and low current drain, extending the life of your portable power source. The receiver is adapted from K1SWL’s SW+ Series with minor modifications. The front-end circuitry was revised to replace the now-vanished 10.7 MHz IF transformers. The receiver output is suitable for headphone use.
The transmitter strip is a proven design using three BS170 transistors for the PA. The frequency source for both transmitting and receiving is a DDS VFO employing a Si5351 PLL module. Control for the rig is provided by an Atmel ATmega328P. This runs both the frequency control and the full-featured CW keyer.
A custom silk-screened PCB enclosure is included with the kit. No drilling or cutting required!
There are two pre-installed SMT ICs on the board, but the remainder are ALL THROUGH HOLE parts, and all jacks and connectors are board mounted, the combination making this kit very easy to assemble with no external wiring needed.
QRP Labs has just announced the QSX an All-Band All-Mode Transceiver Kit that should be available later this year. The Target price for the 10 Band Model is $150, also available will be a 40 Meter version for $75.00.
Details from QRP Labs:
QSX (QRP Labs SSB Xcvr) is a 40m SSB transceiver with 10-band (160m-10m) and enclosure options. The kit inherits all the functionality of the famous QCX single-band CW transceiver kit but adds SSB, AM, FM, PSK31 and RTTY. This will be the lowest cost all-HF radio available but also high performance and packed with features. These are the planned features of QSX:
Software Defined Radio (SDR) technology with standalone Digital Signal Processing (DSP), no PC required
Very high performance 24-bit Analog to Digital Converter (ADC) and 24-bit Digital to Analog Converter (DAC)
40m (single band) or 160-10m (10-band, including 60m) versions available
Modes: SSB, CW, AM, FM, PSK31, RTTY, WSPR beacon
Power output: 10W from 13.8V supply (power output is adjustable by the firmware)
Single power supply needed, 12V to 14V
USB host interface and connector, for USB keyboard to allow PC-less operation on PSK31 and RTTY
USB device interface and connector, for PC CAT Control
QSX can appear to a PC as a high performance 24-bit USB sound card and radio – for digital modes from a PC e.g. FT8, either demodulated or as I-Q for PC SDR programs
Built-in CW IAMBIC keyer (or straight keying also possible) with raised-cosine key-envelope shaping
Many thanks to Robert Gulley (AK3Q) who notes that Black Cat Systems has developed a simple 22 meter beacon kit. The price is $20 shipped! A few details:
The kit includes the PCB and components, including a custom programmed microcontroller that will continuously transmit the ID / callsign of your choice, up to 8 characters, at about 13 wpm.
Small size – just 2 7/8 by 1 1/2 inches. Easy to build, just a few components, all through hole, no surface mount.
When ordering you note your callsign/ID to send and it will be pre-programmed.
Black Cat Systems has all kit details including full instructions on their website (click here to read).
1. The ubitx is now available for sale, for $109 dollars (includes the shipping), but only until Christmas. *After Christmas, the price will increase to $129 dollars. for this initial batch, a few ham volunteers and I pitched in to sort the crystals, test the coils, tune-up and box these initial kits, we won’t be able to do that any more. we will have to hire more people (which is not a bad thing) and get them to do it.
2. The ubitx is on sale at hfsignals.com, not hfsigs.com. it is easier to remember. we will soon point hfsigs.com to the new website as well. The new site is in wordpress, that means that we can have volunteers writing and updating it rather than waiting for me to hand code the content in html and vi editor.
3. We need help with proof reading the web content.* If you find any typos, please mail me on [email protected] address (not the bitx20 list),
These apart, the early buyers must be aware that they are beta users of sorts, the firmware will sure get updated. i hope there won’t be any revisions of the PCB.
Pete adds:
Just as an aside the original price of the Heathkit HW-8 was $139.95 (in 1970 dollars) and it became a QRP Classic. The uBITX may become one as well and like the HW-8 there will be (and already are) all sorts of mods/additions one will be able to do. The uBITX is 10 dollars cheaper (after 12/25) works 80-10 M, does SSB in addition to CW, and is a Superhet to boot!
Farhan your hit this one out of the Ballpark!
Very cool, Pete! I am very tempted to purchase the uBITX transceiver before Christmas and have it delivered via DHL service. The only thing holding me back is simply the amount of projects I have on my table at the moment! $109 is an incredibly low price for a full-fledged QRP transceiver!
I’m absolutely amazed that it is also has a general coverage receiver. Perhaps the uBITX could serve the SWL as well as the ham radio operator? I suppose we shall soon find out!
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!
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.
Features
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
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.
QRP radios, product announcements, reviews, news and more. Low power amateur radio fun!
Please support QRPer by adding us to your whitelist in your ad blocker. Ads are what helps us stay online. All of our ads are ham radio related--no junk, we promise! Thank you!
