Wideband Transmission #10

OpenTechLab

If you've been reading my blog for any amount of time, you've probably observed that I'm a big fan of all things open source, especially on the hardware side of things. One area where OSHW seems to be lagging a bit is in the test & measurement department, so it was a very pleasant surprise for me to stumble upon a fairly new channel on YouTube about a month ago.

As you can see from the first video, the presenter (sorry, I couldn't find the name of the bloke who makes these videos) gives an overview of the cheap logic analyzers on the market that can be loaded with open source firmware and then gives a very detailed demonstration on how to use the devices with the nifty open source Sigrok T&M suite (especially the PulseView GUI tool) and how to use a Linux environment and scripting to take measurements.

If you have any interest in this space, this is definitely a channel to which you should subscribe. There is also a show notes site that has links and other resources for the videos.

Using C++ in Arduino

In another case of me stumbling upon something which takes me down a rabbit hole, last week I was watching coding videos on YouTube when this one was recommended in the comments of another:

It's quite a long video, but if you have any interest in coding and are an old fart who grew up with 8-bit personal computers (or are at least a fan of retrocomputing), then the time will pass quickly on this one. It sounds crazy, but the presenter (Jason Turner) of this talk was able to make a game for the Commodore 64 in modern C++! The way he did it was to create a tool to convert from the 80386 flavor of x86 assembler to 6502 assembler (well really 6510 in this case), which apparently is more feasible than you may think. His development environment is an online tool called Compiler Explorer, which for some reason I only learned about with this video. It automagically spits out assembler from C++ compiled from a variety of different compilers. In this case, the Turner created a custom local version of this tool to do the 6502 conversion.

I was gobsmacked at multiple times in this video. Many of the newest C++ features (from the C++17 standard) were used. With some careful coding, Turner was able to produce code with literally no overhead from all of the C++ features. The compiler was able to optimize many lines of C++ down to a handful of assembler op codes. Just watch it, you'll be amazed as well.

This video, in conjunction with the series of posts that Hackaday has been running about using C++11 in Arduino, has convinced me that it would worth it to investigate the use of C++ in the Arduino coding environment. Arduino library coders already have to use a base level of C++ when they write for the ecosystem, but most people who write sketches do it in vanilla C-style (well, the bastardized Arduino version of it anyway). After seeing that talk, I had a lot of preconceptions of C++ overhead blown away. The ability to use the modern features of C++11 sound tempting indeed, so I plan to do some investigations into the feasibility of incorporating more C++ patterns into Arduino sketches, and I'll be posting my findings here. Stay tuned.

KiCad PCB Rendering Tool

I have a habit of skimming my RSS reader (yes, I'm one of those old fogies who still uses one) in the morning while drinking my coffee, opening tabs of interesting things to examine in further detail later, while simply reviewing the rest of the new posts. Sometimes that means it takes me a bit to get back around to something intriguing among my many browser tabs.

Such is the case with this article from Hackaday. It's just a short blurb about a new open source Python tool for making 2D renderings of KiCad boards. The attached demonstration image certainly looked nice. When I finally got around to downloading the code from GitHub and trying it out on one of my designs, I was pleasantly surprised. The script made a very sharp SVG rendering of my board, but unfortunately, there are only a handful of components in the PcbDraw-Lib library, which meant that most of my stuff didn't get rendered.

Since I've been looking for a way to make nice illustrations of my PCBs for documentation and promotional purposes, I decided that I'd invest some time in adding components to the library, since I think the project has a lot of promise. After about half a day of muddling through making component drawings in Inkscape by studying datasheet engineering drawings, I was able to output a complete render of my Empyrean board, which you can see above. I'm quite happy with the result.

I've got a pull request in for the components that I've created so far, and as I continue to use the tool and fill out more of the library, I will continue to submit them upstream. While it's still pretty rough around the edges, this project gets a strong recommend from me.

Wideband Transmission #9

Arduino in the Cloud

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I saw a recent post on the Make blog about the new cloud ecosystem for Arduino which has been dubbed Arduino Create. Since this will most likely be the future of Arduino, it seemed wise to get an early look at the platform. It includes quite a few features, but the most notable ones in my opinion are the Project Hub, Arduino Cloud (IoT infrastructure), and Web Editor. Arduino Cloud will allow you to connect your network-capable Arduino to the Internet to allow sharing of sensor data, remote control over the net; your typical IoT applications. The Web Editor gives you access to an Arduino IDE over the web. Your code is stored online, and a cloud compiler builds your project, so you don't have to worry about configuring that on your machine. However, you still have to install an OS-specific agent program on your PC in order to get the complied firmware from the Web Editor onto the Arduino's flash memory. The Project Hub is a project-sharing space, similar to hackaday.io, Instructables, etc.

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I don't have much to comment on regarding Arduino Cloud, since I don't have any of the supported devices and cannot try it out at this time. The Web Editor gives me mixed feelings for sure. No doubt that this was created to compete with the mbed platform, which sounds awfully convenient from what I have seen. I like the idea of being able to easily save and share code with others, as well as having a standard set of build tools for everyone. However, the environment is obviously still in early stages, as there is no support for libraries to be added through the official Library Manager JSON list, nor for external hardware definition files to be used. I had some difficulties getting the Arudino Create Agent talking to my web browser in Linux Mint, and once I did, uploading seemed a bit flakier than it does on the desktop IDE. Of course, this is all still in beta, so rough edges are to be expected. Once they get the features of the Web Editor up to parity with the desktop IDE, it should be a very useful tool. Finally, the Project Hub looks nice, but I wonder if we aren't starting to see too much fragmentation in this type of service for it to be useful. Still, the one-stop shopping aspect of it all is very spiffy.

Something to Watch

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Ham radio seems like a natural fit with the citizen scientist movement, so it pleases me to have discovered that some hams have created a platform to advance citizen science in an area where we are well equipped to do so. The new HamSCI website states its mission as:

HamSCI, the Ham Radio Science Citizen Investigation, is a platform for the publicity and promotion of projects that are consistent with the following objectives:

  • Advance scientific research and understanding through amateur radio activities.
  • Encourage the development of new technologies to support this research.
  • Provide educational opportunities for the amateur community and the general public.

HamSCI serves as a means for fostering collaborations between professional researchers and amateur radio operators. It assists in developing and maintaining standards and agreements between all people and organizations involved. HamSCI is not an operations or funding program, nor is it a supervisory organization. HamSCI does not perform research on its own. Rather, it supports other research programs, such as those funded by organizatons[sic] like the United States National Science Foundation.

They already have three listed projects that they are helping with: the 2017 Total Solar Eclipse, ePOP CASSIOPE Experiment, and Ionospheric Response to Solar Flares. The 2017 eclipse is of special interest to me, as totality will be seen at latitude 45°N here in Oregon, which puts it squarely over Salem; a place I will have easy access from which to observe (which also reminds me that I need to build some kind of solar observation device like the Sun Gun before August 2017).

I wish these folks the best and I hope they are able to make a useful contribution to science.

A Challenger Appears

A EEVBlog video popped into my YouTube feed yesterday that was of significant interest to me, and will probably be to you as well. Most of us who are into having a home test & measurement lab are well aware that the Rigol DSA-815 has been the king of spectrum analyzers for the last few years, due to the very reasonable cost paired with the decent amount of bandwidth and load of useful features that are included. Rigol seemed to own this market space since the DSA-815 was released, as the big boys of T&M didn't seem to care too much about serving us little guys with our small budgets. However, those days are probably at an end, as a new SA to rival the DSA-815 is on the cusp of release. Dave Jones gives a cursory review of the new Siglent SSA3021X, which looks like it will cost only a few hundred dollars more than the DSA-815 but may be significantly better in the performance category. I'd recommend watching the video below, but here's a summary of the points that interested me:

  • User interface seems to be heavily "inspired" by the Rigol DSA-815
  • The Siglent has significantly better DANL
  • 10 Hz RBW available on the Siglent vs 100 Hz on the Rigol (I've seen hints that the Rigol was supposed to have a 10 Hz RBW option, but they never released it)
  • Reference clock and PLL in the Siglent look better
  • The Siglent has a waterfall display available, which is missing from the Rigol
  • Dave spotted some potential unwanted spurious signals in the Siglent, but they were low level and his machine wasn't a release version either.

Also, don't miss Dave Jones in typical Dave Jones-style refer to a signal with unwanted sidebands as a "dick and balls".

My impression is that if Siglent can tighten up the fit and finish of this spectrum analyzer, it could give the DSA-815 a real run for its money. This is nothing but good news, as more competition in this space will mean even better products for us in the future. I'll be watching this one.

Fun with Marbles & Magnets

Finally as a palate cleanser, enjoy this clever kinetic artwork contraption built to play with marbles and magnets!

 

Wideband Transmission #8

Another 10 mW WSPR Beacon

I enjoy writing up my projects, but it's much better to get feedback to see that someone was actually able to take my writing and successfully duplicate my project. Via the Etherkit Twitter account, I received this from Tom Hall, AK2B regarding my last posted project:

Awesome work! Tom has been a great supporter of Etherkit from the beginning and I'd like to thank him for sharing his neat creations with the rest of us. It's wonderful to see such a minimalist design perform so well!

More Coding Resources for Fun

I haven't had a ton of free time here, but I do get snippets of time occasionally where I can sit with my notebook PC for a bit and mess around. As mentioned in some recent posts, I've been revisiting coding for fun, and I've stumbled upon quite a bit of new resources that are new to me and that I thought would be good to share.

The first one I'd like to mention is called Scratchapixel. I was curious about the mathematical methods behind 3D rendering, and some searching brought me to this exhaustive tutorial site. It's not 100% complete yet, but most of the fundamentals of 3D graphics are already well-explained there. A fantastic resource if you are curious about the first principles of 3D rendering like me.

A related site is called Shadertoy. Not by the same people, but also related to the topic of learning 3D programming. Shadertoy is a web application that lets you play with shaders in C++ inside a web IDE that can be updated on-the-fly. It takes a bit of CPU and graphics horsepower to run comfortably, but if you've got the capacity, it's worth browsing the demos on the site just to see the cool stuff you can create with it. This tool was created by Íñigo Quílez, who also has a really cool home page with lots of tutorials and whitepapers. If you like demoscene stuff, then definitely check it out.

Another neat find that I only recently discovered goes by the name of Rosetta Code. It bills itself as a programming chrestomathy site, which basically means that it's a way to learn how programming languages are related in a comparative way. There is a large directory of different programming tasks, and each task page lists ways to implement a solution in a wide variety of languages. It's a wiki, so not every page has every language implementation, but there's obviously a ton of work put into the site, and most tasks have implementation in the major languages. Really fascinating and useful at the same time.

Finally, there's The Nature of Code. This site hosts a free e-book download of the content, and provides a link to purchase a dead tree version if you wish. Here's how the website describes the book:

How can we capture the unpredictable evolutionary and emergent properties of nature in software? How can understanding the mathematical principles behind our physical world help us to create digital worlds? This book focuses on the programming strategies and techniques behind computer simulations of natural systems using Processing.

That sounds right up my alley. I haven't read the book yet, but I have skimmed it a bit, and it looks like the kind of things that I love: non-linear systems, physics simulations, fractals, and the like. When things settle down here a bit, I may tackle the book and re-write the sample code into Python. That would give me some more Python practice and force me to really think about the algorithms behind the text, not just blindly copying, pasting, and executing the scripts.

Let me know in the comments if you found any of these links useful or fascinating, or better yet if you know of other links in the same vein.

New Miles-Per-Watt Record Opportunity?

If you regularly follow science news, you may have heard of the Breakthrough Starshot initiative. In short, this is a study to create pathfinding technology that would allow the eventual launch of micro-lightsails with tiny mass to the Alpha Centauri system at a significant velocity (0.2c!) with a ground-based laser array. It's probably a serious effort, as it is being privately funded to the tune of a whopping $100,000,000. No doubt, an extremely audacious undertaking.

Sounds interesting, but what does this have to do with radio? Well, obviously there's the issue of how you can get a usable signal back to Earth across a distance of 4-and-a-half lightyears from a craft that masses in 10s of grams. I was wondering about that exact engineering challenge when I came across this article in my feed reader today. It turns out that someone has studied how one might use the Sun as a gravitational lens for lightwave communication across interstellar distances. Claudio Maccone, an Italian physicist, has run an analysis and has determined that putting a receiver at distance of at least 550 AU from Sol will give the desired lensing effect for optical communications.

Speaking before Maccone at the Breakthrough Discuss meeting, Slava Turyshev (Caltech) pointed out that the gain for optical radiation through a FOCAL mission is 1011, a gain that oscillates but increases as you go further from the lens. This gives us the opportunity to consider multi-pixel imaging of exoplanets before we ever send missions to them.

That's kind of amazing. Maccone calculates that the bit error rate of optical communication from at any significant distance from Sol quickly degrades to around 0.5. However, by using the Sun as a lens, the BER stays at 0 out to a distance of 9 LY. Here is a graph of the effect of standard comms and those enhanced by using the Sun as a gravitational lens, as calculated by Maccone:

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What's really crazy is this next paragraph:

But as Maccone told the crowd at Stanford, we do much better still if we set up a bridge with not one but two FOCAL missions. Put one at the gravitational lens of the Sun, the other at the lens of the other star. At this point, things get wild. The minimum transmitted power drops to less than 10-4 watts. You’re reading that right — one-tenth of a milliwatt is enough to create error-free communications between the Sun and Alpha Centauri through two FOCAL antennas. Maccone’s paper assumes two 12-meter FOCAL antennas. StarShot envisions using its somewhat smaller sail as the antenna, a goal given impetus by these numbers.

So that would have to rate as the ultimate QRP DX, eh? I'm not sure how realistic any of this is, but I'm pretty sure the physics are well-established by now. Kind of makes the Elser-Mathes Cup look like small potatoes.

 

Wideband Transmission #7

More Musings about Etherkit's Future

As I mentioned in my previous post, we are still undergoing a stage of tremendous upheaval in our household. I won't really know how our new life will shake out quite yet, but I am certain that my time will be more restricted. I think I'll have a good grasp on the extent of this within a month or so. In the mean time, I've been thinking about Etherkit. It's a bit weird to air this out on the blog, but I think it would be good for others to hear my thoughts about this and have the chance to offer feedback.

The assumption is that I'm going to have less time to work on Etherkit (the only real question being how much less time), which means that if I do have enough time left to continue with the business I will need help by either outsourcing manufacturing or finding someone to bring on as a partner. If possible, I'd like to go that route, as I'm not really ready to see Etherkit fold up yet. This would also require more funding, so I would probably have to find a way to raise capital via the sale of equity, or perhaps I could crowdfund enough on a future product to keep things afloat.

Right now I have in the product pipeline OpenBeacon 2, which is perhaps 80% finished (most of the remaining work is in firmware), and a handful of small useful RF modules. On the drawing board I have a couple of QRP transceiver designs utilizing the Si5351 that would definitely fall into the category of cheap and cheerful, and would probably be a lot of fun to bring to market. Also, since OpenBeacon 2 is based on the Arduino Zero, I've been discovering the power of the Atmel SAMD series of ARM Cortex-M0+ microcontrollers. I'd love to develop a dev board derivative of the Arduino Zero using some of the SAMD line that have a bit less flash storage and consequently are a bit less expensive. I think hams (and other hackers) would really like such a device.

The other option is that due to time constraints I just cannot realistically continue Etherkit as an active business (at least regarding retail sales of physical stuff). If that happens, then I would still like to stay active in some way, under the restrictions in my available time. Perhaps writing may be a good choice, since that is quite portable and can be picked up and set aside a lot easier than designing electronics. Writing technical books, for a new blog that earns money somehow, or as a contract writer for an existing website are all possibilities. I've thought it might be nice to write about test and measurement for the ham's home lab.

Either way, I'm not done with the ham homebrew community. The open question is merely how much time I can still give. Let me know what you think about the above in the comments.

Back to the Shack

It's been a while since I've transmitted any RF on the amateur bands other than the testing that I've been conducting for OpenBeacon 2. Between how much time I've been putting into OpenBeacon 2 (and refining the Si5351 library), it's been very difficult to find the time to sit down to operate. On top of that, I honestly just haven't felt much of the operating mojo, so unsurprisingly I haven't even tried to make it a priority.

Generally, it's not great to force these things, but I'm getting to the point where I'm feeling a bit disconnected from amateur radio and that I really need to be QRV again in order to rebuild that connection. The ARRL Centennial in 2014 was a great operating year for me because it gave me a concrete and interesting goal to pursue.

W1AW WAS

So I figure that I need something similar to get me motivated again. A good goal perhaps would be to finally finish up basic DXCC from this QTH. As of right now, I stand at 75 confirmed entities in LoTW. It shouldn't be that difficult to get 25 more confirmations in LoTW by the end of the year, especially if I carve out a couple of weekends for contesting. I used to chase a lot of the big DXepditions as well, and that might be another good source to pick up a handful of ATNOs (assuming I pay whatever fee they charge for a prompt LoTW upload). I'd also like to actually get a successful HF SOTA activation or two under my belt, and this would be a good summer to do that.

The League

Speaking of the venerable institution, I let my membership lapse recently. Not really with the mind to do so, but given the rather significant dues increase, it was becoming a bit more difficult to justify the expense. Yeah, they are only asking $10 more per year, but I have to ask myself if I'm getting $50 of value every year.

I was honestly barely reading the QSTs that were arriving in the mail. However, the archives always have been one of the best features of the membership. I'm glad they do work with the FCC to represent our interests. Their lab does a good job of evaluating products. It feels that their organizational structure is a bit too ossified; a bit too hierarchical for my tastes. Getting feedback to the leadership seems difficult if you aren't already connected to leadership.

On the balance, I'm generally pro-ARRL, but I still don't know that I see the value of just forking over $50 annually. I understand why they needed to do a rate increase (although it probably would have been better to phase it in more gradually rather than a 20% hit all at once). I also understand the economics of why it would be difficult to offer a membership without QST, unless a paper QST was scrapped entirely. I would be curious to see how the rate increase ends up affecting their member numbers and their bottom line.

Wideband Transmission #6

Happy New Year 2015!

2014 was a bit of a mixed bag here. It's been a transition year for Etherkit, as I reorganize and reorient the business for a renewed push to get the CC1 and other new products to market. I believe that good things are beginning to happen there.

On a personal level, my two boys have been doing fantastic. Noah started preschool and is really enjoying it. Eli is at a bit of a difficult age (the Terrible Twos) and is between baby and little kid, but he's got an amazing personality and is growing up so quickly. Jennifer and I celebrated five years of marriage and 11 years since our first date! Things haven't been perfect in the extended parts of our families, but at least in our household we've all been pretty healthy and have been able to enjoy many blessings.

Si5351A Breakout Board Campaign

There have been a fair number of neat projects I've seen using the Si5351A Breakout Board that I posted on OSHPark, along with my Si5351 Arduino library, which is absolutely wonderful. However, I realize that it's a pain to order PCBs and all of the parts separately, and that a kit or a finished board would be ideal.

I've decided to try something new in order to bring the Si5351A Breakout Board kit to market: we're going to try crowdfunding the first batch of kits. I'm going to set a modest goal to trigger the funding, but all orders will be welcome over the goal amount. In fact, I intend to set a stretch goal at some higher funding level to devote a certain number of hours to improving the Si5351 Arduino library, including:

  • Add tuning from 8 kHz to 1 MHz
  • Add tuning from 150 MHz to 160 MHz
  • Fix the bug that does not allow output over 125 MHz
  • Implement access to the phase register
  • Implement sub-Hz tuning for modes like WSPR
  • Other bug fixes

I also intend on lowering the BOM cost by removing the broadband output transformers, and offering multiple variants of the kit, including the option to add SMA connectors and a TCXO. I'm composing the campaign on Indiegogo right now, and I'm shooting for a launch in about 10 days. I'm hoping to gain experience with this campaign with the goal of using it to fund CC1 kitting later in the year.

Why am I telling you this now? Because I would like to let those of you are are interested in purchasing one (or otherwise interested in supporing Etherkit) get advance notice so that you can order on the first day that the campaign goes live. This will help to give the campaign more momentum and perhaps help to spread the word further. I will be sure to make a blog post here when the campaign goes live and tweet about it as well, so keep an eye on those channels if this is something that intrigues you.

Simple WSPR Transceiver using Si5351A

I came across this simple WSPR transceiver from KC3XM driven by one of my Si5351A Breakout Boards via @wm6h and Dangerous Prototypes. The WSPR transmitter is simply a BS170 driven by one of the Si5351 outputs, which is buffered by a logic gate and keyed by a standard PNP keying switch. Control of the Si5351 and keying of the transmitter is performed by a plain vanilla Arduino Uno (the code has been posted to GitHub).

This looked so simple to build that I had to give it a try. I quickly built up the transmitter portion, tacked on a 10 meter LPF (the original version is for 30 meters), modified the code for my callsign and grid, and changed the Si5351 output frequency to the 10 meter band. The transmitter put out nearly exactly 1 watt of RF (with only about 1.2 watts of DC input total) into 50 ohms and ran quite cool. Hooked up to my Moxon, it had no problem generating spots when pointed east and started on an even minute so as to properly synchronize. Fun stuff!

Generating PSK with an Arduino

If you haven't been following the blog of KO7M, you should be. Jeff has been doing a lot of experimentation with with NB6M and other home experimenters in Washington state, especially with stuff like the Minima and using microcontrollers in ham radio projects.

Lately, Jeff has been working on getting an Arduino to output PSK audio. He has a series of recent posts about it, but these two are probably the most important. The character timing is not quite right yet, but the basics of how to generate PSK via PWM audio signals are here. Good stuff!

Si5351 and Raspberry Pi

Another really great homebrewer blog is M0XPD's Shack Nasties (oh you Brits and your silly names) blog. Paul has been doing a lot of work with the Si5351 as well, and his latest post about the Si5351 is details of how he interfaced it with the Raspberry Pi. Excellent information to have, as the RPi is of course much more powerful than your garden variety Arduino.

Wideband Transmission #5

Latest CC1 Progress

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As you can see from the above photo, I have finished a significant portion of the digital side of the newest CC1 prototype and now I'm on to the receiver section. This weekend I finished my first pass of the audio chain and characterized the gain and frequency response of the chain. Next up is the design of the IF and front end of the receiver. This time I plan to do a much better job of characterizing the performance of entire radio, designing for specific critical receiver specifications, and iterating the design as necessary instead of holding on to dodgy performance from circuits.

Mixer Investigations and the Search for Better Dynamic Range

Since I decided to ditch the dual-gate MOSFET mixer front end, I've been considering what to replace it with. At first, I was thinking about using the ADE-1 for the mixer and product detector, but I've been intrigued with reading about H-Mode mixers over the last few weeks, which led me to the similar, but simpler KISS mixer by Chris Trask. That seemed like a good candidate for the CC1, with relative simplicity and better-than-average performance. Since good IP3 performance is the main characteristic of this mixer, I wanted to try measuring IIP3 at my own bench to see how it looked in a home made circuit with less than optimal parts and layout.

To get warmed up, I first attempted to measure the IIP3 of a few parts that I had on hand where I already knew IIP3 values to expect: the SBL-1 and the ADE-1. Using a DG1022 as the signal generators, my HFRLB as a hybrid combiner, and the DSA815TG, I was able to measure an IIP3 of +13 dBm for the SBL-1 and +17 dBm for the ADE-1, which is pretty much right on what other people have published.

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Here is my test setup for measuring the KISS mixer performance. I deviated from the circuit described in the KISS mixer white paper in a few ways. First, I used a TI TS5A3157 analog switch, as I didn't have any Fairchild FST3157 on hand. I also used a hand-wound trifilar transformer on a BN2402-43 core instead of a nice transfomer from a company like Mini-Circuits. I drove the KISS mixer with +3 dBm from a Si5351. My measurement of IIP3 for this variant of the KISS mixer came out to +27 dBm, which seems reasonable given the poorer components I was using. Conversion loss was 7 dB. I'm going to try to measure it again with an actual FST3157 and a Mini-Circuits transformer in the near future, so it will be interesting to how much that will improve the IMD performance.

But honestly, I probably won't need better than +27 dBm performance if this mixer is used in the CC1. Since the CC1 is meant to be a trail-friendly radio with modest current consumption, I don't think I want to include the high current amplifier needed after the KISS mixer to get maximum performance out of it. Which is kind of a shame, but I figure that I should be able to keep RX current to around 50 to 60 mA and still have a receiver with better IMD performance than your typical level 7 diode ring mixer receiver. Stay tuned for more details on the CC1 front end as they are worked out in the NT7S shack.

10 Meter Contest!

Yes, it's almost time for my favorite contest of the year: the ARRL 10 Meter Contest. Ever since I moved into the current QTH, it has been a bit of a tradition for me to operate the contest as SSB QRP only. By virtue of entering that least-liked category, it has been no problem to collect some modest wallpaper from this contest. That's fun, but my real goal is to beat my previous score. Last year, I think I did fairly well with 7490 using a stock IC-718 and my ZS6BKW doublet. So this year, I'm going to have to step up my equipment game in order to have a good chance of besting last years score. I'm thinking some kind of gain antenna is going to be a must. If I can get a Moxon or small Yagi up around 20 feet and use an Armstrong rotor, that should help give me a little more oomph than last time. We'll see if I can get something built in the less than 3 weeks before the contest.

Wideband Transmission #4

It's been a while since I've posted one of these. I understand that things have been fairly quiet over here in the last few months, so I wanted to let you all know that I'm not dead yet. I've actually been working on Etherkit a fair amount in the background, and that has been eating up most of my free work time. I know that things have looked stagnant, but please understand that I have been putting in time to revamp the business and bring some exciting new things to Etherkit. I have a few different, parallel projects going on right now. Soon I will commit to one of them and move forward on that, depending on how things pan out. I suspect I'll have more to say on the matter in less than a month on where Etherkit will be going in the future.

In related news, I've had a few people ask about what's going on with the CC1. I apologize for the CC1 being a huge bit of vaporware. To be frank, it has been the most frustrating project I've ever worked on, but I believe in it strongly enough to attempt to finish it. At this point, as much as I have had fun with the BF998, I believe that in order to make the CC1 the radio that I want it to be, I will have to abandon using the BF998 as mixers and switch to a balanced mixer design, most likely the ADE-1. I'm also looking into adding a small OLED display to the radio, which will also necessitate a large redesign to the mechanical layout of the radio (I'll probably end up doing the typical TFR design, such as the KX1, KX3, etc.). I'm also impressed enough with the Si5351A that I'm going to try using that as the new VFO and BFO. A brand new CC1 prototype is just getting started on the bench now, so it should be interesting to see how it works out. I'll post some progress photos and videos to my Twitter feed and the blog, as appropriate.

Thanks for hanging in there with me. It has been a real challenge to try to run a business while also being a full-time caregiver to my two boys. I would say that I haven't been very successful in doing both, so naturally, the business took the backseat. But now that my boys are getting older (Noah is 4 and Eli is 2.5, can you believe it?), I'm able to spend a bit more time during the day handing business. Things will be moving forward.

Wideband Transmission #2

CC1 Beta Kit For Sale

I ended up having one leftover kit from the CC1 beta test and I thought that an experience builder might like to build it. There are a few minor mods to perform to the PCB, so it's best suited for someone who feels comfortable with that. The (hopefully) final PCB spin is coming soon and will be slightly different, but this version works well, as AA7EE can attest to. I can offer the kit for a discount over the final CC1 retail price, and it's currently available for 20 or 40 meters (although the final retail product will be available for more bands). Contact me at milldrum at gmail dot com if you are interested.

SOTA 12 Meter Challenge

I'm not subscribed to the SOTA reflector, but I saw a post on the VK3ZPF blog that there was an announcement on the reflector that there will be a SOTA 12 Meter Challenge. I think this is a great idea and I want to support it if I can. I haven't made too many 12 meter QSOs, but when I have it seems like the DX has been pretty easy picking. When it's open, the band seems quiet and the signals sound great. The plus for SOTA activation is that a resonant antenna is small and easy to pack.

My original plans for the CC1 were to only support up to 15 meters, but I think I may add 12 meters in order to support this initiative. The DDS in the CC1 is clocked at 50 MHz, so technically I should be able to output a 24.9 MHz signal, although I don't know in practice how well this works at a frequency so close 0.5 Fc. If I can get it to work, I will release it as an available band on the CC1.

New PCBs Are Here!

CRX1 Beta
CRX1 Beta

Here is the latest beta PCB from the Etherkit, the CRX1 receiver! It is all-SMT construction, but I spread out the components a bit more than the CC1 and all of the parts are on one side of the PCB only. It's VXO-tuned for the 40 meter band (a few kilohertz around 7.030 MHz) and is based on the Clackamas transceiver which I entered into the 2010 FDIM Challenge (which means it's also a cousin of the CC1). This receiver has only discrete components (size 0805 resistors/caps, SOT-23 transistors), so it should be fairly easy to build. In other words, a good warm-up for the CC1. It also has a port for an external VFO, so it will be a platform for experimentation as well.

I'll build this PCB up today and verify that it works, then get a few beta testers to confirm that all is well. Hopefully I can get this product onto market fairly quickly, with a low price. Stay tuned for more details as work progresses.

More Stuff For Sale!

I've added some new gear to my For Sale page that would be a great addition to the bench of any homebrewer. Please stop by and take a look!

Wideband Transmission #1

This is the first in a series of blog posts covering a wide variety of topics. In the past, I have used Twitter for my microblogging needs. For a variety of reasons, I'm on a Twitter hiatus right now, so I'll be using this series to convey some of the disconnected (and possibly connected) random thoughts that I feel I need to get out there. I don't think I'll be abandoning Twitter completely, but I will be reworking the ways in which I use it once I come back.

I'm also in the process of disconnecting completely from Google, so I wanted to give fair warning to those who correspond with me via my Gmail account that I will be abandoning that service very soon. I've already deleted my Google+ profile, and will be deactivating the rest shortly. I'll probably describe my rationale for this later, but keep in mind that I've been a Google customer data mine for nearly a decade, so this is not something that I undertake lightly. I'll try to get alternate contact information to those of you who regularly correspond with me.

It is an age of new beginnings.

Clackamas 2 Prototype

With the introduction out of the way, let's get down to the good stuff. Above, you can see the latest project on the Etherkit bench. It's a re-work of the receiver from the Clackamas transceiver (the rig that I submitted to the 2010 FDIM 72-part challenge). I've decided to make this receiver into a cheap & cheerful little kit to get people warmed up for building the CC1. It's currently for 40 meters only, is a superhet, and is VXO tuned (covers 7.030 MHz plus a bit more). It is 100% discrete component (you can see a TDA7052 IC above, but I've abandoned it for a different AF amp) and will be SMT construction. The receiver itself is pretty simple, but you can see there's a fair bit of other circuitry on there. That stuff is mute and sidetone circuits. It's easy enough to design a standalone receiver, but most of them will probably just gather dust after being built unless they can interface to a transmitter easily. With this extra circuitry, you can just split off your transmitter's key line and connect it to this receiver to have built-in muting and sidetone. My goal is to make this project cheap and fun to build. I'll be fast-tracking this one so I can get back to the CC1 soon.

Oddly enough, another project from the FDIM Class of 2010 is also coming out soon. As spotted on The QRPer, the Cyclone 40 transceiver is based on the rig that Dave Cripe, NM0S submitted as his 2010 FDIM 72-part challenge entry. I recall that the rig had a very unique design and that the specs were impressive. Dave's a great designer, so be sure to buy one to get a rig unlike anything else you've seen before and to support 4SQRP.

Choking off the Internet firehose that I had previously directed at me has allowed me to devote a bit more time to enjoyable activities that I've neglected, one of those being reading. I'm currently enjoying a book I've had on my shelf for a while now called Seeing in the Dark by Timothy Ferris. It's billed about being about amateur astronomers, but it does get into the professional side quite a bit as well. It's a good read and very entertaining, and I can't help but see a lot of parallels between amateur radio and amateur astronomy.

That's a great segue to the final item, which is a bit of fun from our favorite Canuck astronaut, Cmdr Hadfield. He's leaving ISS in a few days and just released a surprisingly touching (although obviously light-hearted) rendition of Space Oddity by David Bowie (one of my guilty favorites). Cmdr Hadfield may not be on the level of Neil Armstrong or Yuri Gagarin, but he's definitely making a play for Coolest Astronaut Ever.