Ultra Cheap Software Defined Radio!

SDR#

The SDR# front-end

As I’ve said in previous posts, ham radio is an important part of any permaculture design. Not only does it provide for communications resilience in times of emergency, it also makes for a really fun hobby. While the learning curve, licensing requirements and equipment costs can be a hurdle for some, the simple act of listening (AKA ‘monitoring’) is a great way to dip your toes into the world of radio.

Flipping through the January 2013 edition of QST Magazine I read the article ‘Cheap and Easy SDR‘ by Robert Nickels, W9RAN. It describes a very inexpensive way to assemble a 300 KHz to 1700 MHz receiver for your laptop using off-the shelf components that you can buy online. The article is behind a paywall, so I’ll paraphrase the content here and provide added resources and recommendations.

DVB-T & RTL-SDR Receiver

Newsky TV28T v2 USB DVB-T & RTL-SDR Receiver

OK, so here’s the super inexpensive way to get into Amateur Radio (and more!) monitoring. We’ve all heard of scanners — those radio receivers that can pick up public service, weather, police/fire/ambulance, marine, aircraft, commercial mobile, amateur radio, citizen’s band, walkie-talkie and even baby monitor transmissions — but up ’til now, such wideband receivers were quite pricy, costing anywhere north of $400. What is a radio newbie (or even a veteran) on a tight budget to do?

Not too long ago (Q1 2012), Linux kernel developer Antti Palosaari discovered that $20 USB dongles used for DVB-T (Digital Video Broadcast – Terrestrial) reception had a really wide-range radio receiver in them, so he teamed up with developers at Osmocom (Open Source Mobile Communications) to build drivers and utilities to couple these dongles with SDR (Software Defined Radio) software commonly used by licensed amateurs to receive radio transmissions of all kinds. The DVB-T dongles have limited reception in the 64-1700 MHz range (which includes the 2 & 1.25 meter and 70, 33, and 23 cm amateur radio bands as well as many others including FM broadcast, marine, public service/emergency, and commercial 2-way services), but with an inexpensive $40 RF upconverter developed by Opendous, reception could be extended all the way down to 300 KHz, allowing for monitoring of AM & shortwave broadcast, maritime distress, Citizens’ Band and the 160 to 6 meter amateur radio frequencies. Wow… a nearly “DC to daylight” receiver for about $60 plus laptop, free software, antennas, feedline coax and connectors. With this system  you can pretty much monitor anything: all the ham bands, CB radio, AM & FM broadcast channels, public service/police/fire/emergency, commercial 2-way radio, shortwave, marine, air, MURS, FRS, GMRS, intercom systems, older wireless telephone systems and more. This is really quite a breakthrough!

Ham It Up v1.0 - RF Upconverter

Ham It Up v1.0 - RF Upconverter

Here is what you’ll need:

1) Computer with a USB port
2) SDR Software. If you’re using Windows, start here: http://rtlsdr.org/softwarewindows. For those on Linux, see: http://rtlsdr.org/softwarelinux
3) Newsky TV28T DVB-T dongle (w/ R820T tuner): http://www.nooelec.com/store/software-defined-radio/sdr-receivers/tv28tv2.html
5) RF Upconverter board: http://www.nooelec.com/store/software-defined-radio/sdr-accessories/ham-it-up-v1-0-rf-upconverter-for-software-defined-radio.html
6) Antennacraft ST4 ultra-wideband discone antenna for 25-1300 MHz receive: http://is.gd/g5Y2Yo
7) The LNR Precision ‘EF SWL’ antenna for 1-30 MHz receive: http://www.lnrprecision.com/endfedz/
8) Appropriate length of 50-ohm coaxial feedline for antenna connections and any adapters needed to attach the feedline to the antenna jack on the RF upconverter. You’ll also need a jumper to connect the dongle to the upconverter. You can find coax and adapters of all sorts at Ham Radio Outlet, but prices are often cheaper on eBay, so search around.

Antennacraft ST4

Antennacraft ST4 for 25-1300 MHz

I’ll be putting my SDR receiver system together soon and will write a follow-up with my experiences. If you decide to set one up for yourself, please be sure to let me know. It’s really amazing how modern technology is making PC-based wideband radio accessible to nearly everyone now!

And here are some resources that you might like to check out along the way:

SDR#: http://sdrsharp.com
Open source Software Defined Radio project

NooElec: http://www.nooelec.com
SDR dongles, RF Upconverter, and accessories

RTL-SDR: http://sdr.osmocom.org/trac/wiki/rtl-sdr
Info on DVB-T dongles based on the Realtek RTL2832U chip

UniTrunker: http://www.unitrunker.com
Trunk tracking for APCO25, EDACS 4800/9600, Motorola, and MPT1327 protocols

HamRadioScience SDR videos: http://www.youtube.com/user/hamradioscience?feature=watch

HamRadioScience.com: http://www.hamradioscience.com

W9RAN’s SDR Archives: http://tinyurl.com/blsg2or
SDR tutorials, guides and reference material

Monitoring Times magazine: http://www.monitoringtimes.com

Popular communications magazine: http://www.popular-communications.com

ARRL: http://arrl.org
The Amateur Radio Relay League

Ham Universe: http://www.hamuniverse.com
Not just for hams, it includes articles, tip and tricks for CB and shortwave listening too!

Short-Wave.info: http://www.short-wave.info
Shortwave broadcast listening guide, forum and resources

Worldwide Radio Forum: http://www.worldwidedx.com
Discussion forum for all things radio. Have a question? It’s probably already been asked and answered!

Have fun and 73!

Paul

Categories: amateur_radio.

Ham Radio at the 2012 Permaculture Convergence

I’m happy to announce that I’ve been chosen to present a workshop and demonstration on Amateur Radio at the 2012 Northern California Permaculture Convergence in Castro Valley, CA on October 12-14.

My workshop is called ‘Building Communications Resilience with Amateur Radio’ and its focus will be on how and why ham radio should be incorporated into permaculture systems everywhere. During the course of the weekend, I will also be operating my station to demonstrate phone (voice) and digital (data) modes on both VHF (2 meters) and HF (40 meters). The station will give Convergence attendees a hands-on opportunity to work the airwaves for the purposes of demonstrating amateur radio’s diverse capabilities for one-to-one and one-to-many voice and data (including chat and email!) communication. If the propagation characteristics of the site allow it (the M.A. Center is located at the bottom of a canyon), I will be running a VHF packet station on 145.050 FM to show how text-based messages & data can be sent, stored, forwarded and retrieved via Packet Bulletin Board Systems (PBBS) as well as demonstrate the Winlink 2000 system for the delivery & retrieval of email via IP the world over! On HF, I’ll be running 100 watts on the 40 meter band using a horizontal dipole antenna optimized for NVIS (Near Vertical Incidence Skywave) which allows for regional communications within a 30 to 400 mile radius. For updates on my station’s operating times and frequencies, please see my page at HamQTH.com/k6yba

For more information on the 2012 Northern California Permaculture Convergence, please visit their website at http://www.livingmandala.com/Living_Mandala/Northern_California_Permaculture_Convergence_2012.html

Categories: amateur_radio, company, events, news.

Amateur Radio = Communications Resilience

Amateur Radio for communications resilienceOver the dozen or so years that I have been studying and applying sustainable design principles, I have observed that one of the permaculture community’s weakest areas of focus is in the realm of developing resilient communications systems. Here in the relatively affluent western world, we take it for granted that telephone landline, cell phone and internet service is available 24/7/365, all of which is possible due to the readily accessible and affordable energy that is currently at hand. But what is the likelihood that these convenient communications channels will be available in a world of increasing energy access constraints? Will the server farms and cell towers continue to function? Besides the energy issue and fear of a potential ‘Zombie Apocalypse’, how can we stay in touch with our friends and family while also keeping important information flowing when natural disasters such as earthquakes, wildfires and other catastrophies occur at the local and regional level?

Building redundancy into our systems is a key part of permaculture design. When one or two elements fail, fall-back strategies help keep the overall system functioning. This I believe, is why amateur radio is so important and should be adopted as an integral part of everyones’ overall design system, both at the home and community level.

I personally caught the radio bug at a young age. My father, who was an immigrant from Eastern Europe, brought his console radio with him when he moved to the United States. Included in the cabinet was not only a turntable and standard AM/FM broadcast receiver, but also a shortwave receiver with a graphical display of all the frequencies that could be tuned to in order to receive broadcasts from around the world. I was fascinated by the notion that it was possible to hear stations from Mexico, Canada and Europe and I’d listen to them whenever the ionospheric conditions allowed these long-distance transmissions to be heard. In all likelihood, it was this early exposure to radio that motivated me to become a radio broadcaster at KZSC 88.1 FM during my college days. After college, I purchased a shortwave radio of my own and challenged myself to hear DX (long-distance) broadcasts from around the world, I got to guest DJ for a neighbor at Burning Man who was operating a 1-watt FM “pirate” radio station, and later, I toyed around with CB radios, only to find the 40 channels there polluted with cussing loud-mouths using modified rigs and 100 watt linear amplifiers which prevented anyone else from getting a word in edgewise. It was impossible to cut through all the noise and have an intelligent conversation. Then I discovered the amateur radio service!

At first, the notion that I had to take a technically-oriented test in order to get my entry-level ham “ticket” was off-putting, but I eventually put my mental block aside after I realized that hams take the art and science of radio much more seriously than do the jabber jaws of the CB band, and not only that, knowledge of morse code was no longer required! If passing a simple 35 question multiple choice test (the FCC makes the question pool and all the answers available to you in advance) to get a Technician’s license was the only thing getting between me and a free, decentralized, wireless communications system, I eventually had to ask myself, “What the heck am I waiting for?”.

So I ordered a copy of the ARRL’s Ham Radio License Manual and began devouring the info. The great thing about this book is that as you read about licensing regulations, radio theory, safety and good operating practices, you are referred to the relevant test questions that appear in the appendix at the back of the book. To my relief, I discovered that there really isn’t all that much math or knowledge of electronics involved. It took me about one month of on-and-off studying to get through, and at the end, I loaded the book’s software CD onto my laptop so that I could take randomized practice exams. By the 5th or 6th try, I was aceing them and fully confident that I would do just fine on the actual test day. I contacted my local club, the Nevada County Amateur Radio Club, to let them know I planned to attend their next test session and showed up on the day of the test with money, pencil, and photo ID in hand. The club’s Volunteer Examining Committee (VEC) charged me just $15 to protor the test, grade it and submit my test results and license application to the FCC. The license itself doesn’t cost a penny and it lasts for 10 years, at which time you must renew it through the FCC for another decade. The room was quite full, with both aspiring hams going for the entry-level Technician class license, and those who were testing to upgrade to either a General or Amateur Extra License Class which would give them additional operating privileges on the HF (high-frequency) bands. My studying paid off! I scored 35/35 on the Technician exam and was given the option to test for the General license, which I took them up on at no extra charge. Without even studying, I scored 20/35 — not quite enough to qualify, but not too shabby considering that I hadn’t even read up on the General class info. Once all my paperwork was submitted by the VEC, I waited 6 days and my new call sign was posted on the FCC’s amateur radio license database: KJ6UPR. Now I could finally start operating!

So what are you waiting for? Cultivating communications resilience is easy and it doesn’t take a big investment in gear. In my next entry, I’ll detail my particular choice of gear, where I got it, and how I plan to use it for communications beyond voice: file sharing, text messaging, email and even internet access!

73,

Paul

 

For more information on amateur radio please visit:

The Amateur Radio Relay League: The national association for amateur radio

The Federal Communications Commission: Amateur Radio Service

The Nevada County Amateur Radio Club

Amateur Radio at Wikipedia

Categories: amateur_radio.


Sierra Permaculture Design

Permaculture design and consulting services in Auburn, Grass Valley, Nevada City, and North San Juan, California. Also serving Nevada County, Placer County, Sierra County, and Yuba County, California CA.

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