Category Archives: Kits

The CR Kits FT8 DSB Transceiver: Some preliminary information

Many thanks to Pete (WB9FLW) who notes:

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!

We’ll post updates as they become available.

Click here to view CRkits.com.

Robert talks uBITX and navigating the world of used radio gear

Robert’s uBITX QRP transceiver kit with fire red chassis.

Many thanks to my buddyRobert Gulley (AK3Q), who shares the following announcement from his blog All Things Radio:

I have posted two new articles in the Reviews and How-Tos section. These were both previously published in The Spectrum Monitor magazine earlier this year.

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.

Four State QRP Group announce the Hilltopper 40

Many thanks to Pete (WB9FLW) who notes that the Four State QRP Group is now shipping the Hilltopper 40 transceiver.

Here are details from the Four State QRP Group website:

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.

Click here to check out the Hilltopper 40.

QRP Labs Announces The QSX Transceiver

The QSX Transceiver

Many thanks to Pete Eaton (WB9FLW) who writes:

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
  • DSP features (selectable sharp filters, AGC, Speech Compression, Noise Reduction etc.)
  • Dual microphone inputs (mobile phone headset with VOX, or RJ45 connector for Kenwood/Yaesu mics)
  • Dual VFO (A/B/Split), frequency and message memories
  • Through-hole assembly only
  • Built-in test equipment features for alignment, debugging and general purpose use
  • Detailed assembly manual
  • Macro facility for user defined sequences of operations, or redefinition of controls
  • Front panel: 16 x 2 LCD (yellow/green backlight), 2 rotary encoders, 4 buttons, mic/earphones socket
  • Soft-power on/off switch, the radio saves its state automatically on switch off, so that it starts up in the same state next time
  • Free firmware updates for life, very simple firmware update procedure via a USB memory stic

QSX is still in development! The above list is subject to change. The following is a FAQ with information about QSX.

More Info on QRP Labs Web Page:

https://www.qrp-labs.com/qsx.html

Check out the following video from YOTA 2018:

Click here to view on YouTube.

Fantastic! Many thanks for sharing this, Pete! This looks like a brilliant little kit for any skill level of patient kit builder.

Black Cat Systems’ 22 Meter Band Part 15 CW Beacon Kit

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).

If you like the idea of building a beacon, you must also check out the beacon Dave (AA7EE) built recently–a true work of art!

The uBITX Transceiver: Pricing and more details

Many thanks to Pete Eaton (WB9FLW) who shares pricing and additional information about the uBITX general coverage QRP transceiver:

Here are the details, if purchased before Christmas $109 delivered!

http://www.hfsignals.com/

From uBITX creator, Ashhar Farhan:

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 farhanbox@gmail.com 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!

Click here to read our other posts regarding the uBITX transceiver.

Click here to order the uBITX transceiver kit.

Please comment if you plan to or have purchased the uBITX. We’d love your feedback!

Videos featuring the QCX Transceiver kit

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:

Click here to view on YouTube.

[And] Roberto IZ7VHF has a much more detailed video of The QCX Transceiver.

Click here to view on YouTube.

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!

QRP Labs’s $49 QCX 5W single-band transceiver kit

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.

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
  • 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)

Pete adds:

Check the manual out, it’s 138 pages! Even a rank beginner can successfully build this rig.

https://qrp-labs.com/images/qcx/assembly_LT.pdf

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.

New kit by NM0S: the 4S-Tuner/Antenna Coupler

(Via the SWLing Post)

4stuner_panelDave Cripe (NM0S) has designed yet another QRP kit for the 4 State QRP Group: the 4S-Tuner/Antenna Coupler.

Description (per Four State QRP Group):

This excellent random wire antenna tuner is the classic T-Match design which is known for wide matching range and smooth operation. Dave has added a nice wrinkle – the SWR indicator employs TWO leds, not the normally seen single red LED. A green one indicates output power with a red one indicating reflected power. The beauty of this arrangement is that the operator sees the output power peaking as the SWR goes down, just like a power meter with dual meters – very intuitive. This makes tuning easier and leaves no doubt that it’s tuned for maximum power output. For a high SWR the red LED is at full brightness and the green LED is off. At 2:1 both are at equal brilliance. At 1:1 the green is full on and the red is off. The small size is perfect for portable operations. Add this dandy little tuner to your portable ops go bag, or use it at home. It’s equally at home on a picnic table, in a tent or camper, as well as on the operating desk in your shack.

Specifications and Design Features

  • Wide tuning range: 80 meters thru 10 meters. Tested on EFHW and 100′ wire.
  • Maximum Power Throughput: tested at 10 Watts.
  • Low loss large toroid
  • Twelve taps for small inductance step selection.
  • Low insertion loss when matched.
  • Enclosure Size: 3″x3″x2″.
  • Pittsburg Construction.

Shipped price is $51.00 (US), $55.00 (Canada), $60.00 (Outside US/Canada).

Dave Cripe designs excellent kits for the ham radio community; they’re easy to build, fun and functional.  If this kit is as popular as his past kits, the first run will most likely sell out in short order.

 Click here to check out the 4S-Tuner/Antenna Coupler at the Four State QRP Group website.