From the trade magazines: satellite tracking, online circuit design, open-source test board

More cool stuff from the electronics engineering trade magazines….Dan

LEO satellite tracking in your backyard. Learn how one guy built his own satellite tracking system in his backyard.

The rise of the online circuit-design collective. Though still in the infancy stage, design and simulation tools that run entirely in the browser are pushing their way onto the EDA landscape. The ultimate goal is that they become essential players within the realm of professional design.

Test and measurement  turns to open source, Kickstarter. The field of test and measurement is set to benefit from open-source software applications if a Kickstarter fundraising project is successful. The Red Pitaya is a credit card-sized, reconfigurable measurement board with 60MHz of input bandwidth and an onboard Xilinx Zinq FPGA to perform signal processing.

Are you isolated?

There are many times in amateur radio where you want to “isolate” two pieces of equipment or avoid “ground loops.” For example, when connecting a computer to a rig to do digital modes, you should isolate the signals so that there’s no direct connection between the rig and the radio.

What does it really mean to be isolated, though? And, for that matter, what is “ground”?

You can learn what these  terms actually mean and when and why you need isolation if you view the webinar Fundamentals of Signal and Power Isolation. Here’s how they describe the webinar:

This Fundamentals course will briefly look at power isolation (often required in conjunction with signal isolation) and then focus on signal isolation techniques. It will look why it is needed, where it is needed, the relative attributes of techniques for implementing it, and other considerations.

From my Twitter feed: SDR rx, cool projects, JT-65

sparky73dx's avatar

roteno's avatar
Victor Laynez @roteno

July Call for Projects! Send links/pictures of your cool projects. One of mine: @eevblog uCurrent for my bench


w0sun's avatar
Bill WØSUN ? @w0sun

“JT65 – Easy as Pie!” #hamr #Hamradio

How to build a WWVB receiver?

A recent news story about the 50th anniversary of WWVB got me to thinking about building my own WWVB receiver. I Googled “wwvb kits” and came up with the following:

Unfortunately, all of these kits use a little PC board made by a company called C-MAX, and the company has either discontinued making the IC that powers this module or simply quit selling this module in the U.S. As recently as a couple of years ago, Digikey actually sold this module for about seven bucks.

There are several Web pages that show how to interface the CMMR-6 module to an Arduino or a PIC processor. Here are two:

A couple of companies in the UK seem to still have the modules in stock. The price from a company called Earthshine is only six pounds, but that doesn’t include shipping, of course.

There are some plans that don’t  use the C-MAX chip, but, of course, they’re much more complex. One guy designed his own receiver, but it’s quite a bit more complex than simply using a single chip. There are also several commercial receivers available, but the cheapest one I found is $220.

There are several Web pages that describe how to use the WWVB receiver modules from “atomic clocks.” One of the projects scavenges the WWVB module from a Sony clock. The second uses the module from an Atomix 13131. The Atomix 13131 costs as little as $13.

So, I’m still unsure which way I’m going to go here, but it looks as though hacking an existing clock might be the way to go, especially if I can find one at a thrift shop or garage sale.

From the trade magazines: litz wire, vector network analyzers, SDR

Another selection of amateur radio related items appearing recently in the electronic engineering trade publications.

Litz wire and other component cleverness
If you’re not familiar with it, litz wire is not named after a person or a place. It’s short for Litzendraht, the German term for braided, stranded, or woven wire. It’s a very clever solution to the problems and inefficiencies caused by the skin effect — as the frequency of the current that a wire carries increases, the current tends to go to the outside of the wire.

Vector network analyzers support versatile testing
Among the most valuable of RF/microwave test tools is the vector network analyzer (VNA), which can measure amplitude and phase with frequency. VNAs have long become associated with the measurements of complex impedance parameters—such as scattering (S) parameters—using the test data to design efficient impedance matching networks for the optimum transmission of high-frequency signals through active and passive devices and networks. At present, VNAs are available from both well-known and not-so-well-known instrument manufacturers, in both bench top and portable configurations for making measurements on high-frequency (HF) through millimeter-wave-frequency signals.

Integrated RF analog, multi-standard, software-defined radio receivers
The scaling of CMOS technologies typically has a great impact on analog design. The most severe consequence is the reduction of the voltage supply. Imec and Renesas have managed to put a complete, high-performance SDR (Software Defined Radio) receiver into a 28nm CMOS process with a 0.9V power supply. The IC has everything except a PLL on a single monolithic chip. (See Figure 1.) This is an impressive integration of analog functionality.

From my Twitter feed: lighting safety, 40m Moxon, diy lead bender

KI4OZG's avatarTracy A Stephens@KI4OZG
Lightning Safety Week: June 23-29, 2013 “When Thunder Roars, Go Indoors!” #hamradio #fieldday

This is a little late, but better late than never…….Dan


stahlbrandt's avatarBo G. Stahlbrandt @stahlbrandt
This looks interesting, a 40m Mini-MOXON Beam Antenna by W7XA via @dxzone #hamr #hamradio


DIYEngineering's avatarDIY Engineering @DIYEngineering<
Electronic Component Lead Bending Tool – When assembling a circuit it is pretty common to hook up a resistor or ot…

I still have a lead bender I got from making a Heathkit many moons ago…..Dan

More on the new Heathkit

Heathkit_TM-logo_smallThere’s now a FAQ page on the new Heathkit site. Whoever they are, the new owners sure know how to build up the hype.

Here are a few interesting excerpts:

Big changes, big plans

Q. Is Heathkit back?
A. Yes. We’re back.
Q. So are you really going to make Heathkit® kits?
A. Yes.
Q. Wow! That simple? “Yes?”
A. Yes.
Q. Will Heathkit products include entirely new designs?
A. Yes.
Q. Will you revive any old kit designs?
A. Very likely. Tell us what you’d like – take our survey.
Q. When can I start ordering Heathkit® kits?
A. They’re coming. But it’s a long road, and we need every product we offer to be Heathkit® quality. We will communicate with you, here and elsewhere, as we make progress. Thanks for being patient while we rebuild this great company.
Q. I have great ideas—about products I wish you’d make, and past kits I’d buy if Heathkit brings them back. What should I do?
A. You are our favorite customer. We want to hear from you. Of course, don’t tell us anything proprietary unless you have a non-disclosure agreement signed with us. But if you want to tell us about yourself, your favorite past or future Heathkit product, and what you most hope to see and buy from us: Please—take our survey.


Questions about the company

Q. So who are you guys?

A. More on this later. Notwithstanding this FAQ, we’re presently in stealth. But here’s what we want you to know right now: We have enormous respect for the Heathkit® name, and we know you do too. We consider ourselves this decade’s caretakers of the most respected name in do-it-yourself and educational electronics and related products over the past century. It’s a terrific opportunity and a historical responsibility we take seriously, and we want to preserve and grow this opportunity, together with you. We know we need to earn and keep your trust every day. Meanwhile, to whet your appetite: Our new CEO/President, and every member of Heath Company’s Board of Directors, are avid kit-builders and DIYers.  We own and use Heathkit® products ourselves. For those with this interest, it happens we all are licensed amateur radio operators. (Also happy with our team will be: car buffs, pilots, musicians & artists, sports/outdoors enthusiasts, parents, educators, and people who value community service.) Our management team have substantial experience as high-tech executives, in startups and public companies, and in technology and finance. We are carefully growing a team of highly experienced industry advisors. Most importantly, we want you to help and advise us too. Ultimately, it is you, with your excitement and enthusiasm and interest in doing great things with great products, who will make Heathkit a success.

From the trade magazines: spectrum sharing, active filters, real capacitors

Passive components aren’t really so passive (Part 1): Capacitors. Transistors and ICs are considered active components because they change signals using energy from the power supply. Capacitors, resistors, inductors, connectors, and even the printed-circuit board (PCB) are called passive because they don’t seem to consume power. But these apparently passive components can, and do, change the signal in unexpected ways because they all contain parasitic portions. So, many supposedly passive components, like the capacitor shown below, aren’t so passive.

The model above shows that a capacitor adds more than just capacitance when you use it in a circuit.

Peaceful coexistence on the radio spectrum. How two engineers (shown at right) tried to get the military to share some spectrum with their small company.

Signal-chain basics #43: Active filters. While low-frequency filters can be designed with inductors and capacitors, they often require physically large and often expensive inductors. This is where active filters, which combine an operational amplifier (op amp) with some resistors and capacitors, become attractive. Active filters can provide an LCR-like performance at low frequencies

From my inbox: interplanetary communication, emcomm router, 3.3V logic

From ACM Tech News 5/8/13. Now all we need are sub-space transceivers….Dan
Google’s Chief Internet Evangelist on Creating the Interplanetary Internet
Wired News (05/06/13) Adam Mann
Google chief Internet evangelist and ACM president Vint Cerf has been working for years on an interplanetary Internet with protocols capable of handling a space environment. Together with the U.S. National Aeronautics and Space Administration (NASA) and the Jet Propulsion Laboratory, Cerf has created an early-stage space-based network with a few nodes that he says are “the front end of what could be an evolving and expanding interplanetary backbone.” The project began in 1997 when Cerf considered what the Internet might need in 25 years, and concluded that NASA and other space-faring agencies would need greater networking capabilities. The interplanetary protocol has the capacity to store a large amount of data for a long time prior to transmission. If the protocol is adopted by the Consultative Committee on Space Data Systems, which standardizes space communication protocols, then all robotic and manned space missions will have the option of using these protocols. View Full Article

Also from ACM Tech News 5/8/13. Sound like something useful for emcomm….Dan
This Box Keeps Information Flowing During a Crisis

Technology Review (05/05/13) David Talbot
The creators of Ushahidi, a software platform for communicating information during a crisis, have developed BRCK, a Wi-Fi router that can connect with any network in the world, can provide eight hours of wireless connectivity, and can be programmed for new applications. The BRCK device can serve up to 20 devices when there is an Internet connection and connects to a cloud-based server that enables any BRCK user to monitor its performance remotely and manage alerts. The device also is programmable, apps can be written for it, and it comes with up to 16 GB of storage. “Once you understand what the product does–provides a reliable connectivity backup in places where power and connectivity are spotty–it’s hard to understand why no one has built the tool before,” says Massachusetts Institute of Technology’s Ethan Zuckerman, who serves on the board of Ushahidi. The nonprofit company says the purpose behind BRCK was to build the world’s most simple, reliable, and rugged Internet connection device, but with sophisticated cloud-based features. “No other single device does these off-grid communications, software cloud access, and remote management of sensors connected to it,” says Ushahidi co-founder Erik Hersman. View Full Article

From André N4ICK via the Tacos mailing list…..Dan
This could be useful (see table of contents): 3V (Logic) Tips ‘n Tricks.

What to do about SDR?

For quite a while now, I’ve been thinking about what I should do about software-defined radio (SDR). For one thing, I’d like to write about it here on KB6NU.Com. For another, I’d like to learn more about it – how it works, what’s available, etc.

I”ve decided that short of writing a book about the topic, I’m not going to try to write something comprehensive, but instead just little bits about SDR as I come across them. So, with that in mind, here’s some SDR stuff that I’ve come across recently.

  • DVB-T Mini DongleDVB-T Mini Digital TV USB Stick Dongle. Based on an exchange of e-mails on the AMRAD mailing list, I recently purchased one of these little dongles. Apparently, a bunch of AMRAD members purchased this unit at a recent hamfest, and they’ve all been having fun with them.Unfortunately, it looks like I purchased the wrong one. This design is not supported by the commonly available SDR software. The dongles that are supported use the Realtek RTL2832U chip, so look for that before purchasing.

    Coincidentally, one of the guys here in Ann Arbor, purchased a FunCube Pro dongle at Dayton and brought it down to the museum Saturday. It costs significantly more ($150), but it will tune 150 kHz to 1.9 GHz. It will be fun to compare the two.

  • SoftRock, Peaberry. A couple of months ago, I purchased a SoftRock Lite II kit from someone who hadn’t gotten around to building it and decided that he was probably never going to get around to it. Well, of course, I haven’t gotten around to building it yet, either, but I do hope to get to it sooner rather than later.I have since come across the Peaberry line of kits. The Peaberry SDR V2 kit looks interesting. For $150, you get a multi-band SDR transceiver.
  • RTL-SDR.Com. This blog covers a wide range of topics including how to receive all kinds of different transmissions with DVB-T dongles that use the RTL chips. One recent article compares SDR using the RTL dongles and the FunCube Pro dongle.