Tag Archives: SDR

Looking forward to the 2014 Dayton Hamvention and FDIM

Each year, I attend the Dayton Hamvention and much of the QRP conference, Four Days in May. This year, I’ll be working our Ears To Our World table again, along with other volunteers, at booth 411 in the Ball Arena (BA411). Please stop by and introduce yourself!

What I love about the Hamvention (besides the massive outdoor flea market) is that it is a one-stop-shop for innovations appearing in our radio world.

Here are a few of the companies I’ll be following at the Hamvention this year:

Ten-Tec

Ten-Tec announced yesterday that it will merge with Alpha Amplifiers under the flag of RF Concepts. I plan to stop by Ten-Tec’s booth Friday and learn more about the merger. Personally, I believe the merger with Alpha Amplifiers is a good move. Both of these companies are known for great customer service and quality US-based design and manufacturing.

I know Ten-Tec is introducing a new open-source product to their line, the Patriot, because I’ve been beta testing one (check QRPer.com for details later this week).

Icom

Icom will showcase their new ID-5100 D-star, dual band, mobile with built-in GPS. While I’m more of an HF guy, this radio does intrigue me. You see, for almost one year now, I’ve been very pleased with my Icom ID-51A, dual-band, D-Star handie talkie (HT).

I find D-Star to be a very flexible digital mode and I’m amazed with how many interesting mom-and-pop companies have produced products for the D-Star mode. I’m surprised neither Yaesu nor Kenwood has adopted the D-Star standard (it’s not proprietary to Icom–indeed, read about the CS7000 below).

The new ID-5100 is a mobile version of my ID-51a. What I love about this radio is that it can store repeater frequencies and dynamically load them based on your geographic location. Perhaps my largest gripe with mobile VHF/UHF rigs is their inability to adapt to the repeater “landscape” when you travel. The ID-5100 may change this and push other manufacturers in the same direction.

Connect Systems

In less than a year, Connect Systems has become a household name among ham radio enthusiasts who love VHF/UHF and digital modes.

This Connect Systems is developing an HT–the CS7000–which will be the first non-Icom radio to have the D-Star digital mode. Whatsmore, in addition to D-Star, the CS7000 will also pack DMR.

I don’t think Connect Systems will have a working prototype at the Hamvention (I could be wrong), but there is a possibility that they will be taking early orders.

Elad

I’ve been intrigued by the Elad line of Software Defined Recievers. This year, they will attend the Dayton Hamvention. I look forward to checking out the new FDM-DUO tabletop SDR. I plan to review some of the Elad product line in the near future.

Palstar

Last year, Palstar showcased a prototype QRP transceiver with touch screen interface. To my knowledge, this would be Palstar’s first transceiver (though they’re well known for antenna tuners and their shortwave radio receiver, the R30A).

Last year, I was told that the new Palstar transceiver would be available this year and would retail between $1,600 – 2,000 US (a rather steep price for a transceiver with 20 watts output). One of the transceiver’s designers assured me that the receiver would “be worth the price.”

Bonito

I’ll stop by Bonito’s booth to check out their new AntennaJet ASM300. I’m curious how it works and what the Hamvention price will be.

Though pricing is a little steep, I might bring one home as I often would like to share one antenna with two receivers simultaneously.

Elecraft

The only new product I know of from Elecraft is the PX3 Panadapter for their Kx3 transceiver. Reviews of the larger P3 Panadapter for the Elecraft K3 are excellent, so I imagine this will be a great product. I hope to check out the PX3 at the Elecraft booth–I believe they’ll have a prototype on display.

SDRs

For the past three years, the market for software defined radios has been growing rapidly. I’ll be on the lookout for anything new–especially improvements on current 3rd generation SDRs.

Did I miss something?

Please comment if there’s something you’d like me to check out at the Hamvention–I’ll try to include it!

Again, if you’re attending the Hamvention, please stop by and introduce yourself at our booth: 411 in the Ball Arena (BA411).

Cross Country Wireless introduces an HF Upconverter

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The CCW HF Upconverter (Photo: Cross Country Wireless)

(Source: Southgate ARC)

Cross Country Wireless have just released a HF Upconverter. This will allow HF or VHF SDR receivers such as the RTLSDR dongles, Funcube or our own SDR-4+ receiver to work on HF, LF and VLF.

Unlike other upconverters currently available we have added the RF protection features from our SDR-4+ receiver including an antenna isolation transformer and RF over-power protection. This protects the SDR receiver or dongle and the attached PC from damage caused by static electricity charges on the antenna or nearby high power transmitters.

There are two versions of the Upconverter. One has a 125 MHz local oscillator and the frequency range is 12 kHz to 45 MHz. This is intended for use with the RTLSDR and Funcube dongles.

The other version has a 10 MHz local oscillator and is designed for use with the SDR-4+. This has a frequency range of 12 kHz to 1.6 MHz.

Here are some of the specifications Cross Country Wireless has published for the HF Upconverter:

Technical data – 125 MHz version for RTLSDR and Funcube dongles

Frequency range: 12 kHz to 45 MHz
Input impedance: 50 ohms
IF rejection: > 60 dB
Local oscillator frequency: 125 MHz
Local oscillator level at antenna socket: < -50 dBm
Gain: -6 dB
RF connectors: SMA female
Power connector: USB B

Technical data – 10 MHz version for SDR-4+ receiver

Frequency range: 12 kHz to 1.6 MHz
Input impedance: 50 ohms
IF rejection: >100 dB
Local oscillator frequency: 10 MHz
Local oscillator level at antenna socket: < -60 dBm
>Gain: -6 dB
RF connectors: SMA female
Power connector: USB B

Also, from CCW on YouTube:

“This is a video of a Cross Country Wireless HF Upconverter used with a CCW SDR-4+ receiver to listen to VLF and LF transmissions using a half wave dipole cut for the 80m amateur band.”

(Click here if you are unable to view the video above.)

There are 20 second samples of the following stations:

BBC Radio 5 Live on 693 kHz AM

BBC Radio 4 on 198 kHz AM

GYN2 Skelton on 81 kHz FSK

MSF Anthorn on 60 kHz time signal

GQD Anthorn on 22.1 kHz Anthorn

GQD Anthorn on 19.6 kHz

This version of the Upcoverter uses a 10 MHz local oscillator so the frequency displayed is 10 MHz higher than that received i.e. 10.693 MHz = 0.693 MHz = 693 kHz.

Click here for more information on CCW’s website.

Video: Build your own SDR

Using the RTL2832U $20 SDR for HF & trunk-tracker scanning?

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In response to our post on inexpensive SDRs based on the RTL2832U, Jeff Benedict writes:

Here’s a website that has a lot of info on cheap SDR gear. They have a write-up on an external board which adds HF capabilities. I have one but haven’t done anything with it yet.

http://www.hamradioscience.com

Jeff KB7AIL CN88

Thanks, Jeff! Has anyone tried HF with any success? I’m curious how well this über-cheap receiver will cope with adjacent signals and blowtorch stations within the HF spectrum.

Meanwhile Neil, blogger on Fofio, commented:

I have an RTL-SDR system up and running. I have done 2 demonstrations for my local Ham Radio club. One on the basic setup and use of the dongle, using both SDR# and HDSDR. The other presentation showed the remote receiver capability using a Raspberry Pi as the receiver with the dongle attached and a remote SDR# computer decoding the stream over a network connection. Once I compensate for some minor frequency discrepancies it’s a pretty good receiver. The only issue I have noticed with mine (one of the early E4000-based models) is a tendency to overload in the presence of a strong signal. We have a pretty powerful 2 Meter repeater less than a 1/4 mile from our home, and when it’s active it causes some strange results with the RTL-SDR setup.

I have yet to try one of the HF converters they make for these. I hope to do that soon.

Another project I was reading about today that I may try out is using 2 of the dongles at once to create a trunk-tracker scanner.

Wow! Two $20 USB SDRs and a little PC magic could yield a trunking scanner? I want to hear more about this. Trunking scanners tend to be both expensive and complicated. If a web-updated database could be downloaded and used to control this sort of rig, the possibilities would be most impressive!

Neil, keep us informed!

A very inexpensive Software Defined Radio based on the RTL2832U

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Many thanks to Benn (AK4AV) for passing along this article from the IEEE which describes how a $20 USB digital TV antenna tuner can be transformed into an impressive, flexible software defined radio:

http://spectrum.ieee.org/geek-life/hands-on/a-40-softwaredefined-radio

The article incldes the following embedded video from the IEEE:

Here is another informative video via YouTube:

This year at the SWL Winterfest we had a presentation on the topic of $20 SDRs configured like those above. Some scanner enthusiasts had used them to receive satellite and many other VHF/UHF communications. I’ve heard of some devices being nearly plug-and-play easy to install and configure; others may take some minor tweaking. All of the SDR applications and drivers are either open source or free.

This page contains a wealth of information on the topic of RTL2832U based SDRs–it makes for a great starting point.

If you have experimented with thRTL2832U USB SDR, please comment below.

The 2013 Dayton Hamvention

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WinRadio’s booth in the East Hall.

Whew! Back from the 2013 Dayton Hamvention. You may have noticed the lack of posts over the past week–this is just a hint of how incredibly busy I’ve been following this annual event. Every year that I go to the Dayton Hamvention, I come back exhausted…yet somehow energized about the lasting power and utility of radio.

As I’ve mentioned, one of the main reasons I go to the Hamvention is to build awareness about my non-profit, Ears To Our World (ETOW). The Hamvention donates an inside exhibitor table (worth $550+!) to ETOW each year, and our volunteers (myself among them) man it all day Friday, Saturday, and Sunday at the Hamvention. My voice was nearly gone by Sunday; I’d estimate we spoke with several hundred people. But the great news is, we received a record number of donations this year–and on behalf of ETOW, I just want to say, Thank you! to all who support our mission of providing self-powered world band radios to classrooms and communities throughout the developing world.

I spotted this Hallicrafters Super Skyrider in the flea market. She would look quite good in my radio room!

At the Hamvention, I also get a chance to network with friends, meet fellow radio amateurs/shortwave radio listeners, and check out both vintage radios in the outdoor flea market, and new radio innovations inside. One of the great things about representing ETOW is hearing the stories of others who share our belief that shortwave radio has a place on this planet. It’s very encouraging and cathartic.

Moreover, I’m fortunate that once more this year several SWLing Post readers sought out our booth: it was terrific meeting each and every one of you! This blog provides me with a sense of radio community that lasts throughout the year; I hope it does the same for you.

My Regency MR-10 Monitoradio. (click to enlarge)

Typically, when I go to Dayton, I bring back a few purchases. This year, I did not find a bargain like my BC-348-Q from 2012, but I did come back with much-needed supplies in the form of connectors, adapters, cables, and one $6 Regency MR-10 Monitoradio (see photo).

I was thoroughly impressed by the number of innovations I saw at Dayton this year, especially the Software Defined Radios (SDRs) that are new to the market.

CommRadio’s president, Don Moore, working with a customer at the Universal Radio booth.

One SDR that received a lot of attention, according to Fred Osterman at Universal Radio, was the CommRadio CR-1; it is an SDR in stand-alone tabletop-receiver form (see current sale). Universal sold all of the units they brought to the Hamvention in very short order. We mentioned the CR-1 in an earlier post, and received mixed reactions: many readers noted that it was very robust, but didn’t have the feature set to make it particularly marketable at the price point. This doesn’t seem to have mattered.

Fortunately, at the Hamvention, I met with Don Moore, president and founder of CommRadio, who most kindly gave me a loaner radio for review. He’s well aware that my review will be frank, and I’m grateful to have this little receiver in my possession. I have only had it on the air for perhaps an hour so far. Just long enough to tell that it plays well, has a tidy footprint, is built like a tank and…well, that it’s frankly cute. I will pit it against my WinRadio Excalibur, Alinco DX-R8T, and Elecraft KX3, and include audio samples in a forthcoming review. Stay tuned!

WinRadio also had a booth in the East Hall that seemed to have a constant stream of visitors. I found Dennis Walter with Bonito in Hara Arena showing off the RadioJet receiver we reviewed last year. I also saw many other shortwave receiver manufacturers and retailers including C.Crane, Palstar, TAPR, Ten-Tec and Alinco. Indeed, Alinco hinted that an updated version of the tabletop DX-R8T is on the way, the DX-R9(T). It will have the same form factor of the DX-R8T, but the receiver will be built around Collins mechanical filters, which will be much easier to replace than the current ones in the DX-R8T. I’ll post an announcement when the DX-R9 is in production.

Confessions of an SDRaholic: when 4.5 terabytes is not enough

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Alas, ever since I started using Software Defined Receivers (SDRs) last year, I’ve found that I fill up hard drives faster than I can buy them. As you may have noted, I like to make spectrum recordings–especially during the night-time hours, as I slumber. The following morning, upon waking, I’ll “tune” through, say, the 31 meter band as if it were live. What makes it even more amazing for me, is that I can fast-forward through time and scan for DX stations even more quickly. Great fun–highly addictive. And did I say, space-consuming?

On my WinRadio Excalibur, I find that I use about 4 gigabytes of hard drive space for a one-hour-long spectrum recording, 100 kHz wide. Of course, if I were to record a 2,000 kHz (2 MHz) chunk of spectrum, it would chew through 4 GB in, roughly, 3.5 minutes.

Fortunately, I rarely ever record spectrum that wide. I find that the maximum width I ever record is 1.25 MHz, which I reserve for occasions once in a blue moon. Most of the time, I stick to 100 kHz-160 kHz widths.

After I record a chunk of spectrum, I usually listen to it, create an AF recording of anything of interest, then delete it from my drive. You’d think this would effectively keep my hard drive cleared out, ready to receive the next installment? Not so. Well, at least, not in my undisciplined SDR beginnings.

The flaw in my logic

Quite often, I make spectrum recordings while traveling, and do so remotely (using TeamViewer to control my PC). In the past eight months, I’ve done a lot of traveling. When I return from a trip, I find that I’ve often amassed a sizable collection of spectrum recordings. Upon returning from travel I also find (not surprisingly) that I’m typically busier than normal, catching up with email, phone calls, and delayed appointments. Thus, I never quite get around to reviewing–and therefore deleting–these files. Most of the spectrum recordings taking up space on my internal drives are those I’ve recorded remotely.

Last year, I thought I’d solve the space problem on my ailing laptop by purchasing a dedicated tower PC (Core i5) maxed-out with RAM and with a 1TB internal (7200 RPM) hard drive. This particular Gateway PC also has a bay that accepts cheap internal SATA drives; I simply insert an internal SATA hard drive in the ejectable bay, load the drivers, and it’s good to go. When I purchased an additional 2 TB SATA drive for spectrum recordings, I thought I would be set for years to come…Ah, how the mighty crumble…

As I write this today, I find I only have a total of 350 GB available on my PC. I’ve also filled an entire 1.5 TB external hard drive with recordings I plan to archive and share with a fellow SWLer.

The Tandy Color Computer 2 (or, "CoCo 2") was my first personal computer. (Image: Wikimedia Commons)

The Tandy Color Computer 2 (“CoCo 2”) was my first personal computer. (Image: Wikimedia Commons)

My, how times have changed

Reverse to the 1980s: When I was ten years old, I thought my Tandy Color Computer 2 was the best thing since sliced bread. Its 16 kB was surely plenty of memory for whatever I wanted to do, and the cassette tapes I used as a form of external hard drive gave me the certainty of a virtually limitless supply of memory.

Today, I doubt I could make an intelligible MP3 recording, even with aggressive compression, that would fit a 16 kB file size.

Facing the truth

The frank fact is that I’ve gotten much better at managing hard drive space, now that I’ve been doing spectrum recordings for more than a year. I shouldn’t need to buy additional hard drive space unless it’s specifically for archiving/sharing purposes. I just need to regularly face the music (or static)–dig through spectrum recordings made last year, and delete those I no longer need.

How do I manage space now? Here are my tricks for staying on the wagon, and saving both space and time:

Use the minimum amount of bandwidth possible while making recordings
If possible, have your SDR parse files into 2GB chunks. This makes it easier to delete sections of recording that are no longer needed without having to delete the entire recording. Happily, the WinRadio Excaliber allows for this.
Each time you create a new spectrum recording, have it saved into a specific directory with a label that will help you identify the contents. For example, “Saturday Night Pirates” or “31 M Tues AM.”
Use Notepad or any simple text application and create a log sheet for the spectrum recording; make notes, then save it in the same directory as your spectrum recording.
When saving MP3/WAV files, use a standard file-naming convention to help you quickly ID a recording (you’ll notice all of my recordings do this). Mine follow this pattern: “StationName-Fequency-Date-StartingTimeInUTC.mp3” –e.g., “RadioAustralia-9580kHZ-05Feb13-1000Z.mp3”
Delete unwanted spectrum recordings as soon as you decide they are not worth keeping. If you wait a few days, you may forget that they’re okay to delete.
I also use my Bonito RadioJet for narrow IF recordings (of, say, one station). It allows me to adjust filters and “tune,” but takes very little hard drive space. The same can be achieved by narrowing your SDR spectrum width to 20-48 kHz.