Tag Archives: QCX

Field Radio Kits, QRP, QRP Radios

Allen’s 22.5 ounce, super affordable, QCX field kit

5 Comments

Many thanks to Allen (N4NN) who writes:

Hello Thomas,

Enjoyed your last video with the QCX-mini as it reminded me of my first portable setup.

Last August, I celebrated my fifth year as a ham and at 74 I’m still able to do some backpacking. This was my first attempt at taking a radio along. The QCX-original was the only model at the time and sold for $49 + shipping. The case is a dollar store pencil box with the radio mounted on stand-offs.

I changed the antenna you see to K6ARK EFHW setup with counterpoise. No coax. I used the on-board key. The throw line was arbor line much like yours and my weight was the tent peg pouch filled with rocks from the camp site. This was my food bag hanging setup. Under $100 for everything.

Before I used it much I discovered POTA from you and purchased a KX2. Haven’t camped much lately but I have activated 70 of Georgia’s 203 parks and having a ball!

[I should note that a] few years back when I made the kit, prices were lower so it may be more difficult to hit that $100 mark. For example, a QCX-mini (no case) runs $57.79 and the QRPGuys EFHW kit is now $30. Adam’s (K6ARK) EFHW kit I changed to is only $20. The “water resistant “ pencil case is still $1! I was more interested in weight rather than cost and as shown the weight is 22.5 ounces.

Thanks Thomas and wish you and yours a Merry Christmas and peace and good health in the coming year.

Allen

72
Allen
N4NN

I love it, Allen! Pure QRP fun on a shoestring budget. Not bad at all! You make a good point here that many kits can be built into a waterproof (or in your case a water resistant) case. I’ve often wanted to do this myself and may very well one day! 

Thank you for sharing!

Hams, News, QRP

Dan’s QRP journey and report on the Venus SW-3B

7 Comments

Many thanks to Dan (KE0ZAR) who writes:

Hi Tom,

I just finished watching your video on resonant/non-resonant antennas and ATUs. I enjoyed it a lot.

For context, I got my ticket in 2020 and got on the air at the end of July 2020. Since that time I have only worked QRP CW using a QCX (the original) on 20 meters and then after September 2021, I got a Venus SW-3B so I have done a bit of work on 40m and 30m now as well.

I really enjoy the challenge of QRP and in a bit over a year, I worked all states, as well as Japan, Canada, several Europe countries, etc, so with good band conditions, QRP really does work and is a lot of fun. My experience working /P stated when I got the SW-3B but I only got out 3 times as the weather up in the hills west of Denver got too chilly very fast; this spring I’ll get back to more /P. Continue reading Dan’s QRP journey and report on the Venus SW-3B →

Homebrew, Kits, News, QRP

How To Convert QRP Labs QCX Transceiver to SSB

3 Comments

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!

(Source: GitHub)

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

Click here for full project details via GitHub.

73, Guido [email protected]

Wow! What a brilliant modification, Pete! Thank you for sharing.

CW, Kits, News, Product Announcements, QRP

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

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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.