Software Defined Radio: new transceivers from Italy and India

Here are a few more links to SDR for amateur radio. I really gotta start building that SoftRock so that I can then tackle some of the more complex projects…..Dan

Click for full-size image.

Click for full-size image.

Elad FDM Duo SDR transceiver can be used with a computer or stand-alone. This little transceiver was demoed recently at the Ham Radio Fair in Friedricshafen, Germany. The Elad On-Line Shop does not yet list a price for this radio yet.

Apache Labs SDR rigs. These rigs are made in India and are commercial versions of the TAPR HPSDR designs. These radios are getting good reviews on eHam.

A $40 Software-Defined Radio. This article on SDR hacking from IEEE Spectrum mentions amateur radio.

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: meteors, hollow-state, ISS SSTV

Interesting stuff on Twitter this morning…….Dan

RadioGeek's avatarKKØHF @RadioGeek
Everything you need to know: Perseid meteor shower bit.ly/13rxGul #SpaceWeather

 

ke9v's avatarJeff Davis @ke9v
Hollow-State Design blog —> hollowstatedesign.tumblr.com #hamr

 

UB4UAD's avatar

??????? @UB4UAD
ISS Ham Radio Slow Scan TV Active wp.me/p2Mn4x-4zM ? ??????? @AMSAT_UK

Over the weekend at KB6NU/WA2HOM: poor propagation and a jammed copier

Last Saturday was a real bust down at WA2HOM.

First of all, the weather’s been really overcast and rainy around here the past week or so. Saturday was no exception. We didn’t get a lot of rain, but it was overcast and dark all day.

Second, when I got down to the museum, I found that the relatively new keyer wouldn’t key the radio. I tried resetting the keyer, changing the keyer output (the WKUSB keyer has two different outputs), and some other things, all to no avail. Then, it occurred to me to change the batteries. I hadn’t thought about that right off because I could hear the sidetone OK. Anyway, changing the batteries worked like a charm, but I wasted at least 45 minutes goofing around with it.

As it turned out, I needn’t have bothered. The bands were so bad on Saturday, due to some kind of solar disturbance, I guess, that I only managed to eke out one contact.

Then, Tim, KT8K, showed up. No, that wasn’t a bad thing, but the weekend before, I’d been bragging about what a great station we had, with our three-element Yagi and all, and that he should come down and visit sometime. Well, of course, when he does make it down there, that bands were so dead, it wouldn’t have mattered much what kind of antenna we had.

Finally, just to add insult to injury, when I tried making copies of the brochure that I hand out, Getting Into Ham Radio, the copy machine jammed on me! This is only the second time that this has ever happened to me down at the museum.

Sunday, I fared much better. I pointed the beam southwest and made three really nice CW QSOs  with N5KY, KB5GXD, and KB0KIE. All three of them were just a few degrees of the beam heading, and all three had good signals. Morgan, KB0KIE, is just getting back into amateur radio and was a bit apologetic about his fist, but I told him not to worry. We need all the CW ops we can muster.

Sunday night, I got sucked into the RAC Canada Day contest. I got started late, and by that time, many of the contestants already had hundreds of contacts. That didn’t stop me from claiming and running a frequency for a while. I pulled the plug about 0315Z, with just over 1,000 points.

From my Twitter feed: no code test, Contest U, iPhone sig gen

Jeff K1NSSJeff K1NSS @K1NSS
NO CODE TEST! If that don’t grab ‘em, I argue MIGHT AS WELL! Outreach according to http://www.dashtoons.com  #hamr #qrp pic.twitter.com/vAngtDNmmu

Matt MaszczakMatt Maszczak @rocknrollriter
For the new or newer op looking into contesting: http://www.arrl.org/news/view/dayton-contest-university-videos-available-on-youtube?utm_source=twitterfeed&utm_medium=facebook …

Jacob BeningoJacob Beningo @Jacob_Beningo
Turn a Smart Phone into a Signal Generator | EDN http://www.edn.com/electrical-engineer-community/industry-blog/4416138/1/Turn-a-Smart-Phone-into-a-Signal-Generator … via @edncom

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.

From my Twitter feed: FreeDV, W3EDP antenna, IARU on WRC-15

I haven’t been a big advocate of digital voice (DV), but I’m beginning to think it might be fun.

ke9v
Saw a little FreeDV love on Planet Ubuntu in the form of this post. Nice job by 9M2PJU.http://t.co/bdlzFMKVKU #hamr

 

Also, see My Favorite Cheap HF Antenna, The W3EDP on KG4GVL’s blog.

KG4GVL
Latest update on the W3EDP antenna. by: Brandon, the Random Man: More on the W3EDP http://t.co/niN6lzHAUO

 

Are more HF allocations in our future?

amradvictoria
IARU announces WRC-15 positionshttp://t.co/jFofmX02FF #hamradio

 

From my Twitter feed: Whitebox, four-layer PCBs, propagation service

HamBeat1
Combining Software Defined Radios and Smart Phones: http://t.co/reduPzk6Qn#hamradio #hamr

This is a very interesting project, and I hope that it gains some traction.

mikelectricstuf
How 4 layer PCBs are made http://t.co/R4VNy2yloj

DH1TW
Radio Propagation as a service http://t.co/siVQ8tEDsQ #hamr @k6tu

30 bucks seems reasonable for this service.

From the trade magazines: capacitors, inductors, radio architectures

Temperature and voltage variation of ceramic capacitors. Read the data sheet! This tutorial explains how ceramic capacitor type designations, such as X7R and Y5V, imply nothing about voltage coefficients. You must check the data sheet to really know, how a specific capacitor will perform under temperature and voltage.

Circuit measures capacitance or inductance. You don’t need a fancy LC meter to measure capacitance or inductance. This short article show you how to do it with a function generator, multimeter, frequency counter, and an oscilloscope. Hmmmmm. By the time you get that all lashed up, it might have been quicker to just buy one of these LC meters from China.

Understand Radio Architectures. This is the first in a series of excerpts from the book RF Circuit Design, 2e by Christopher Bowick. Even though this appears in an engineering trade magazine, some of this is pretty basic stuff. You even get a schematic for a crystal radio!