(Now a bi-weekly program)
Next episode ... May 7
On Component Testing
(See the table below containing the whiteboards and podcast files of all previous episodes.)
Welcome!
Every
other Tuesday evening at 8pm Eastern (0000z), N2APB and N2CX co-host a live audio
conferencing session called “Chat With The Designers". Often joined
by designers of other projects as well,
we gather around this technical watering hole to discuss various topics that are of interest to us
all.
Whether you seek information about your latest project on the bench or just wish to
listen in on the various designers discussing some new chip or product/kit
solution they are currently working on, this is the place to be.
For a little more than an hour, or as long as the discussion is lively, N2APB and N2CX run the session in "net control"-like fashion, guiding the discussion and passing the mic in an orderly way among those wishing to contribute. Augmented by a very useful "text chat window" at the bottom of the screen, everyone is able to post text comments, links and other information when the urge strikes. We record the audio from each session, as well as save the text chat window great reference later on.
We’re using “Teamspeak 3” (TS3), an Internet-based
multi-client audio conferencing system. TS3
is available to run on just about every operating system ... Windows, Mac,
Linux, and even the mobile platforms like Android and iOS 5 (Apple)!
It's free, presents no spam or “friend” sign-ups, and is easily downloadable and
configurable. See our Teamspeak
Instructions page for downloading and installing TS3.
Once you install the client onto your computer, launch the client and connect to
the TS3 server, click on the QRP Homebrewing channel, and you
will see a list of all the people that are signed in, as well as your own name and callsign. A little button lights up when
pressing the “PTT switch” (a key you
set up on your keyboard for when you wish to talk) and you then hear that person
speak. You reply by doing the same when you see that nobody else’s PTT light is
on. Pretty easy and really enjoyable to use.
New! Check out the Tips for listening in on CWTD for each episode.
CWTD
Project Room
Here are the projects we have discussed, designed and
analyzed during one or more of our bi-weekly programs throughout the year. In
some cases, a special offer of a parts kit is made to help you more easily follow along with the principles and replicate the project on
your own. Most of these projects are "limited run" ... but even if you
miss out on getting a parts kit, the project is easily homebrewed from the
information supplied. Have fun!
|
Now available for sale
(quantities are limited)
... |
|||
| 2x16
Character LCD (One per customer)
|
Rookey
(follow link to order) |
Retro SWR
(follow link to order) |
N2CX Choke Balun (follow link to order)
|
|
"In progress", not yet ready ... |
|||
SIC RF Input Carda.JPG) |
CWTD GPS Board |
Signal Quality Metera.jpg) |
Step Attenuator |
Rainbow Tuner |
Electronics
Bench Reference  |
Growler SWR Bridge |
|
.JPG)
Previous Episodes: (RSS feed: https://dl.dropbox.com/u/3549602/cwtd.rss)
| Date | Episode Description | ||
| April 23 | Whiteboard | Podcast |
52a)
Remote 7-segment LED Display for the
Precision Arduino Clock -- This installment of the Clock project combines the XBee RF link topic
from last time with a 4-digit,7-segment multiplexed LED module to provide
remote display of time for the radio shack. |
| April 9 | Whiteboard | Podcast |
51)
XBee RF Data Link for Ham Station Mesh
Networking (Part 1) and
Arduino Clock Synchronization &
7-Segment Display We first start an interesting group project that will lead in several episodes to the creation of a functional, useful and indeed valuable "mesh network" for data and control within our ham stations. We begin by using a couple of XBee modules to set up a remote terminal modem capability. Then we reconfigure the standalone remote node to read a temperature sensor and send data over the RF link to the XBee receiver on the base Arduino for display in the serial console. Our second focus deals with the addition of a 7-segment, 4-digit multiplexed LED module to provide time and temperature readouts (soon) on our Precision Arduino Clock project. |
| Mar 26 | Whiteboard | Podcast |
50)
Two topics this time! ... AM Mode and RTC
Software for the Precision Arduino Clock Project We first consider a venerable operating mode that many of Old Timers grew up using: Amplitude Modulation. We take a brief look at the technology and construct of AM operation, as well as how it is implemented in even one of the most modern SDR rigs today: the SDR Cube Transceiver. Our second focus is on our continuing group project: the Precision Arduino Clock. This time we implement the software for a key element for moving forward: the Real-Time Clock. Surprisingly, the Arduino sketch (software) is vastly simplified and we have the stage set now for making the Arduino and our CWTD shield (hardware) a very useful addition to anyone's shack. |
| Feb 26 | Whiteboard | Podcast |
49) Time & Time Again ... Adding a Real-Time
Clock Chip to the CWTD Precision Arduino Clock Project In this week's episode we take our basic “phase 0” Arduino clock and advance the project to the phase 1 milestone with the addition of a Real Time Clock chip (the DS1307). With this hardware addition, our “CWTD Arduino Clock” can be set with accurate time and retain it when power is removed. Then we take a close, step-by-step look at the initial sketch (software) used on the Arduino last time, and show the construct and way that it works. You won’t need to become an expert on sketch design, but it’s always good for a homebrewer to at least have a feel for what makes this project tick. |
| Feb 5 | Whiteboard | Podcast |
48)
Precision Time Display &
Synchronization with the Arduino Time … you can’t beat it, make it, save it, store it, replay it or out run it. But we amateurs can measure time using a number of techniques for our benefit in the shack, in our rigs, in our QSOs, and more. In this session we overview the sometimes-esoteric world of timekeeping and time synchronization available to us (WWV, CHU, GPS, Rubidium, Cesium, etc.) and then spend a good amount of time on a unique Arduino-based project that can grow and be useful to each of us. |
| Jan 22 | Whiteboard | Podcast |
47)
Arduino Design Tactics Okay, so who hasn't heard of the Arduino in the last couple of years? It's actually been pretty hard to avoid. But have you given it a try yet for a project on the bench? Perhaps a VFO controller, or maybe a dedicated voltmeter, antenna rotor controller, code practice oscillator ... the list goes on! The Arduino is designed for use by non-techie users: artists to add lights and sound to their works, musicians to add new dimensions to their instruments, hobbyists building robots and R/C vehicles, homeowners to make custom home automation, and tinkerers to make unique alarm systems. The functional modules are simple to use and require only basic electronic and software skills. |
| Jan 8 | Whiteboard | Podcast |
46)
Analyze This! Flexible Signal Source A signal source can be extremely helpful on the homebrewer's bench ... and even more so when "flexible", with a Fractional-N Synthesizer/PLL, programmable gain+attenuation stage, and TFT graphic display. |
| Dec 11 | Whiteboard | Podcast |
45)
Decibels and the Hombrewer Decibels (dB, dBm, dBW, dBc, dBu) are useful concepts for homebrewing hams to be comfortable with. When these terms come up in magazines and equipment measurement/evaluation articles, we sometimes have trouble focusing on the real issue if we are busy wondering whether 3 dB means a factor of 2 or 4 (or something else). And when it comes to measuring your homebrew creation on the bench, the dB readings become the universal language describing performance: sensitivity, MDS, IMD, gain, LPF rolloff, and more. |
| Nov 27 | Whiteboard | Podcast |
44)
Emergency Preparedness: Before, During and After In this episode #44 of CWTD, we have noted author and long-time columnist in QRP and ARRL circles: Rich Arland, K7SZ joining with N2APB and N2CX to discuss the equipment, practices and techniques of preparing for emergency communications. Whether your focus is preparing in the calm warmth of your home, or being directly involved in the disaster relief operations with other hams and response organization, this week’s session of CWTD is bound to be of interest to many. |
| Nov 13 | Whiteboard | Podcast |
43) RFI Detective We discuss the topic of finding and eliminating local sources of noise that interfere with signal reception and trying to mitigate them. The basic process is to first try to characterize what the noise characteristics are then to use fairly standard troubleshooting techniques to identify the source(s) and to describe the measures that can be taken to lessen or eliminate the noise. And per usual, we have a great set of references for further study, and a "project" that you can build and use in the shack or around the home to locate troublesome interference. |
| Oct 16 | Whiteboard | Podcast |
42) Homebrewing VHF/UHF Antennas We discuss and illustrate examples of getting on the air with 6m, 2m and 70cm (440 MHz). Most of us know the "mechanics" of HF operation, but VHF and UHF throw some interesting curves at us as far as propagation, feedlines and losses, antenna polarization, power levels, terrestrial impediments, and more. |
| Oct 2 | Whiteboard | Podcast |
41)
Morse Code ... Dying Art or Thriving Specialty? We explore a bit of the background, overview the various equipment out there for CW operation, and then hunker down on what makes a CW operator tick. What his tips and tricks are. If you've never considered using CW mode and Morse code, or if you've let your fist drift away over the years, or even if you are currently active and in the A1 Operator club, we think you'll find the discussion of the "original mode" interesting and eye-opening. |
| Sept 18 | Whiteboard | Podcast |
40) Analyze
This! ... The Desert Ratt Regenerative Radio Receiver One of the easiest and best performing receivers to build, the "regen" offers a unique and incomparable operating experience. Once you hear the characteristics whistles and pops when tuning in a station, you'll think of your grandfather's radio in his den while you lay listening to the 1939 Yanks pounding the Philadelphia Athletics. And you'll also hear dynamic range and crystal clarity that is hard to duplicate with others receivers ... even today!! |
| Sept 11 | Whiteboard | Podcast |
39) Assembling a QRP
Station for Field Operation It's always good to consider what it takes to get a station together for field use. We'll discuss some things that maybe you hadn't yet considered ... or some important aspects that you should be aware of. |
| Sept 4 | Whiteboard | Podcast |
38) Analyze
This!: The PFR-3A This time we study the PFR-3A, the KD1JV-designed QRP CW transceiver |
| Aug 28 | Whiteboard | Podcast |
37) Troubleshooting
Techniques, Part 2 Basic guidance on troubleshooting circuits that should be working ... but are not. |
| Aug 21 | Whiteboard | Podcast |
36) Troubleshooting
Techniques, Part 1 Basic guidance on troubleshooting circuits that should be working ... but are not. |
| Aug 14 | Whiteboard | Podcast |
35) Analyze This!: The 8640-Jr
Signal Source Dissecting and analyzing the 8640-Jr Signal Source |
| Aug 7 | Whiteboard | Podcast |
34) Toroids ... Selection, Construction
and Use |
| Jul 31 | Whiteboard | Podcast |
33) Resistance is Futile Selecting the correct resistor for RF, DC, audio, power, size, SMT or leaded, package, vendors and more. |
| Jul 24 | Whiteboard | Podcast |
32)
Component Selection Tips for selecting the right components when you are trying to adapt or modify a project for your own usage. |
| Jul 17 | Whiteboard | Podcast |
31) Mid-Year Project Recap Review of the 30 technical topics and 15 projects covered during the first half of this year & status of each! |
| Jun 26 | Whiteboard | Podcast |
30) GPS
Applications in QRP Communications Using GPS to enhance our communications: digital modes, frequency standards, stability, and more! |
| Jun 19 | Whiteboard | Podcast |
29) Oscilloscope Applications Building on the o'scope basics covered earlier in our Apr 10th episode, we now delve into the many productive uses of the 'scope with our projects, with guest host and expert lecturer Alan Wolke W2AEW. |
| Jun 12 | Whiteboard | Podcast |
28) QRO Power Supplies Armed with basic principles and components, you can design just the right solution for your needs! |
| Jun 5 | Whiteboard | Podcast |
27) Retro SWR Analysis, design and construction of a simple & useful SWR meter from yesteryear! |
| May 29 | Whiteboard | Podcast | 26) Feedline Frenzy Which feedline should you use? How to measure? Tips & Tricks |
| May 22 | Whiteboard | Podcast | 25) Antenna
Tuners (ATUs) Impedance matching in a world of mis-matches |
| May 15 | Whiteboard | Podcast | 24) Remote Control Techniques
for Hams A review of basic principles and "transports" (RF, IR, wired) and an experimenter's platform |
| May 8 | Whiteboard | Podcast | 23) Homebrewing
Techniques Some ideas for closing the loop on how to get your next new project built up |
| May 1 | Whiteboard | Podcast | 22) Harmonics & Spurs &
Parasitics ("Oh My!") How to see/measure the various spectra that comes with the generation of the fundamental. |
| April 24 | Whiteboard | Podcast | 21) Magnetic Loop Design
Cookbook Design guidelines and critical factors for homebrewing an "STL" mag loop ... and a novel example! |
| Apr 17 | Apr 17 | Podcast | 20) Erecting a Vertical
Antenna Erecting a Vertical Antenna: base, grounding, feedline, tuning, ... |
| Apr 10 | Apr 10 | Podcast | 19) Oscilloscope Basics Wondering about how to use an o'scope for your homebrew project? This session is for you! |
| Apr 3 | Whiteboard | Podcast | 18) Soldering 101 A guide to the science and art of melting solder |
| Mar 20 | Whiteboard | Podcast | 17) Simple & Accurate Power
Measurement Homebrew some simple building blocks to extend the range of accurate lab-grade power meters |
| Mar 13 | Whiteboard | Podcast | 16) Intro to the Digital
Modes Discussion of the many strange-sounding digital mode signals heard on the bands |
| Mar 6 | Whiteboard | Podcast |
15) Return of the Rainbow
Tuner |
| Feb 28 | Whiteboard | Podcast | 14) Anatomy of a PICAXE SWR
Meter How to control things with a simple, inexpensive BASIC controller |
| Feb 21 | Whiteboard | Podcast |
13) Circuit Simulation |
| Feb 14 | Whiteboard | Podcast | 12) Schematic Capture and PCB
Layout Tools and techniques used to get a design from the napkin stage to having a pcb on the bench |
| Jan 31 | Whiteboard | Podcast | 11) Homebrew Battery Chargers Considerations and cautions in buying, building and using the right kind of chargers. |
| Jan 24 | Whiteboard | Podcast |
10) Grounding 101 Different approaches, techniques, tool, products and benefits of doing a good job at grounding. |
| Jan 17 | Whiteboard | Podcast | 9) What is the BEST Antenna? Discussion of the most common antennas, their relative benefits and drawbacks |
| Jan 10 | Whiteboard | Podcast | 8) LPF Design mini-tutorial,
Part 3 Measuring the filter and comparing to expected results |
| Jan 3 | Whiteboard | Podcast | 7) LPF Design mini-tutorial,
Part 2 Designing the filter, selecting components and building the circuit |
| Dec 27 | Whiteboard | Podcast | 6) LPF Design mini-tutorial,
Part 1 Overview of the Low Pass Filter, specifying the important design goals and parameters |
| Dec 20 | Whiteboard | Podcast | 5) Best QRP References The online sites, books, publications, magazines, people, ... |
| Dec 13 | Whiteboard | Podcast | 4) Favorite Parts & Kit
Suppliers Where do you get your parts from? Best deals? Best service? Best kits? |
| Dec 6 | Whiteboard | Podcast | 3)
Best Kits What are the best kits on your bench? Most useful? Best bang for the buck? |
| Nov 29 | Whiteboard | N/A | 2) Technology Round Robin What technology floats your boat? Microcontroller? PMO or DDS? SMT or thru-hole? |
| Nov 22 | Whiteboard | Podcast | 1) RF Power Measurement for
QRPers What techniques, products and parts are around for us homebrewing QRPs to use? |
