Thursday, October 12th, 2017
DuWayne Schmidlkofer has a nice write-up on building a two channel SI5351 signal generator: After getting the sketches written for the SI5351 board written to support multiple display types, I decided I need to write one more. Now that Pete is moving the Simpleceiver to a single conversion super-het, I...Tags: build log, Si5351, signal generator
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Friday, September 29th, 2017
Henrik Forstén has a nice build log on his newest version of this homemade 6 GHz FMCW radar: Frequency Modulated Continuous Wave (FMCW) radar works by transmitting a chirp which frequency changes linearly with time. This chirp is then radiated with the antenna, reflected from the target and is received...Tags: FMCW radar
Posted in RF | 1 Comment »
Wednesday, August 9th, 2017
Agilent 53152A 46GHz frequency counter teardown and repair from The Signal Path: In this episode Shahriar investigates a faulty Agilent 53152A 46GHz frequency counter. The instrument does not power on and shows no sign of internal voltage presence. Teardown of the instrument reveals a large PCB where all analog and digital circuity...Tags: analog, repair
Posted in RF, Teardowns | No Comments »
Friday, June 2nd, 2017
Tutorial, experiments and teardown of a 77GHz automotive FMCW radar module from The Signal Path: In this episode Shahriar explores the principle operation of automotive FMCW radars. Thanks to a donated automotive radar module, various components of the system can be examined and explored. The PCB reveals three die-on-PCB ASICs responsible...Tags: teardown, tutorial
Posted in RF, Teardowns | No Comments »
Monday, March 20th, 2017
[embed]http://www.youtube.com/watch?v=1sq8Cvju2Oo[/embed] Craig writes, "RF filter design is a piece of cake these days thanks to computer design and simulation tools. But actually realizing the simulated filter response in the real world can be a completely different matter! This video provides an introduction to practical RF filter design by building, testing,...Tags: analog, circuit
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Monday, January 16th, 2017
Pete Juliano's (N6QW) Shirt Pocket Transceiver with the Si5351 and OLED display: In 2011 I fulfilled a dream of building a shirt pocket sized QRP SSB transceiver. Well actually I built two of them and the second was a diminutive 2" X 4" X 2". Both used through hole components...Tags: Si5351, transceiver
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Friday, December 23rd, 2016
m0xpd writes: I've been tinkering with a quick lash-up of Wayne Burdick, n6kr's famous 'Forty-9er' receiver, implemented on an Arduino shield and tuned by one of my DDS systems. Regular readers will remember how I tried running my Kanga / m0xpd Sudden-inspired receiver shield under the control of the new...Tags: Forty-9er, receiver
Posted in digital radio data, RF | No Comments »
Friday, December 9th, 2016
Oona Räisänen from Absorptions wrote an article about experimenting with CTCSS fingerprinting: Identifying unknown radio transmitters by their signals is called radio fingerprinting. It is usually based on rise-time signatures, i.e. characteristic differences in how the transmitter frequency fluctuates at carrier power-up. Here, instead, I investigate the fingerprintability of another...Tags: CTCSS, radio fingerprinting
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Tuesday, December 6th, 2016
M0xpd documented his experience building DuWayne's Scalar Network Analyzer Jr: DuWayne's baby uses an AD9850 in one of our familiar modules to generate RF, under the control of an Arduino NANO. You can read on DuWayne's blog how the SNA Jr is the descendant of earlier experiments in which an Si5351...Tags: scalar network analyser
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Tuesday, October 18th, 2016
Vasily Ivanenko blogged about his input and RF preamplifier build: Above — Build of the input and RF preamplifier stage. I put in a 0 or 6 dB attenuator right at the input. That's double-sided Cu+ board with copper vias joining the 2 surfaces intermittently and also at crucial ground points....Tags: DIY
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Tuesday, October 11th, 2016
A Raspberry PI RF frequency counter project from Scott Harden, that is available on GitHub: Raspberry PI RF Frequency Counter with Python Interface. The RF signal clocks a 32-bit counter (SN74LV8154) connected to a 16-bit IO expander (MCP23017) accessable to the Raspberry Pi (via I²C) to provide real-time frequency measurements from...Tags: Raspberry Pi, RF Frequency Counter
Posted in R-Pi, RF | 3 Comments »
Wednesday, September 7th, 2016
Scott has published a new build: This is the general idea behind how this frequency counter works. It’s so simple! It’s entirely digital, and needs very few passive components. sn74lv8154 is configured in 32-bit mode (by chaining together its two 16-bit counters, see the datasheet for details) and acts as...Tags: Microcontrollers, python, radio frequency
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Tuesday, August 23rd, 2016
Scott from SWHarden has published a new build: Line driver chips are one of my go-tos for quickly amplifying digital signals because they’re so fast to drop in a breadboard and they provide a strong output with very high impedance inputs and need no external components. Individual buffer of the...Tags: radio frequency
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Friday, July 29th, 2016
A business card size homebrew 40 meter XCVR project from Ray Ring: I tweaked my previous XCVR design to use push button tuning and made the board layout extremely compact. I improved the side tone injection to be absolutely perfect – not too loud, full break in and no clicks. I went...Tags: DIY, XCVR
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Friday, July 29th, 2016
An update on Pete's (N6QW) LDMOS amplifier project we covered previously: The real value of the breadboard test system is that it enables you to find/discover things that were not so obvious. Currently I have the Start & Stop buttons wired to the Arduino. I also have all six of...Tags: LDMOS amplifier
Posted in DIY, RF | 1 Comment »
Tuesday, July 19th, 2016
m0xpd writes: I've been playing with a new RF generator for the IoT beacon... Actually, I do myself a disservice, because I've done rather more than just play with the RF generator. First, I've replaced the little USB to serial dongle which I used to program the original system and built...Tags: AD9834, IoT, RF generator
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Tuesday, July 5th, 2016
Dave Richards AA7EE has published an article about Georges F6DFZ’s homebrew regen receiver: Several months ago, Georges F6DFZ sent me pictures of a Manhattan project he had just completed, using Rex’s MeSQUARES, and I have waited far too long to share it with you. It began life as a copy of the...Tags: homebrew, regen receiver
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Friday, June 24th, 2016
Pete (N6QW) writes: This project encompasses proving an Arduino Control of a hi Power Linear Amplifier. It is a new departure for N6QW as it has extensive I/O requirements which required moving to the Mega 2560 a Arduino variant that has 56 Digital I/O and 16 Analog Inputs. The on...Tags: amplifier, Arduino
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Friday, June 3rd, 2016
Tony G from Weird-Lab writes, "The idea of this project was to build a trackuino board with small gps module, low power arduino pro mini (3.3v @8mhz), a VHF transceiver DRA818V, and power management integrated." Project info at Weird-Lab site.Tags: APRS, DRA818V, tracker
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Thursday, May 19th, 2016
[embed]http://www.youtube.com/watch?v=y-rCgumTn4Q[/embed] Craig writes: Ever tried searching through your datasheets for the motional parameters of that quartz crystal you just bought? Good luck! Vendors simply don’t specify these parameters to general end users, and for most applications that’s OK. But for high Q oscillator and filter design, measuring and matching crystals...Tags: motional parameters, quartz crystals, Saunders 150B
Posted in how-to, RF | No Comments »
