Tag Archives: Cheap Software Defined Radios

The SDRplay RSP1 just turned five years old

Yesterday, @SDRplay noted on Twitter:

It’s 5 years ago today we sold the very first blue and white RSP to someone in Sweden – many thanks to all our customers over the 5 years

Perhaps it’s just because I’m getting older, but it’s hard to believe it’s been five years!

The little RSP1 really disrupted the SDR world. Up to 2014, there were few sub $150 SDRs that included HF reception natively. There were even fewer sub $150 SDRs that I would consider “enthusiast grade”–those that were sensitive, selective, and not prone to overload.

When I initially tested the RSP1 it pretty much blew my mind. I was so impressed by the performance for the price point.

Looking back at my original review, I see that I had a long list of “pros” and only three “cons.” In fact, two of the three “cons” I listed are no longer valid (multi-channel recordings are now an option and SDRplay has their own OEM application, SDRuno).

SDRplay has demonstrated iterative agility with each new product offering and built an impressive community in five years. They have also maintained their position as a price leader even though their products are all designed and manufactured in the UK.

Congratulations, SDRplay! Happy Birthday to the RSP1! Click here to check out SDRplay.

Click here to read my original SRDplay RSP1 review.

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The RTL-SDR V.3 dongle on shortwave: Gary details setup and reviews

Many thanks to SWLing Post contributor, Gary Wise (W4EEY), for the following review of the RTL-SDR dongle:


RTL-SDR-RTL2832U-e1471375714199

Based on your blog post on the Version 3 release of the RTL-SDR dongle I had to buy one. I ordered mine from Amazon for $25, and it came in two days. I have an earlier version of this unit that was VHF and above only. What intrigued me about the V3 was the possibility of HF reception in the Direct Sampling mode (without an up converter). So I had to try it.

I used the RTL-SDR Quick start guide at RTL-SDR.com/qsg. While I did not see any mention of Version 3, I hoped that the software that was linked would be adequate. As I am using a Windows 7 laptop, I downloaded the Zadig driver installer, along with copies of SDR# and HDSDR.

Getting the dongle going was pretty straightforward. And right away I was receiving VHF and above signals. The I/O driver defaults to Quadrature demodulation and this was what is used to receive VHF. But what about HF?

It took me awhile to figure out that you select Direct Sampling in the setup screen for the driver. In SDR# software this is found by clicking on the gear wheel icon.

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Under sampling mode select Direct Sampling (Q branch).

In HDSDR you select the EXTIO icon.

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Here you select the Q Input under Direct Sampling.

Note that with both you must use the Q input.

With the telescoping antennas included with the dongle, I received very few signals (of very poor quality). But I had read that the unit can only receive HF with a substantial antenna, so I moved the laptop to my hamshack.

I use an ELAD antenna distribution amplifier for my HF receive antennas.

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It was easy to use a spare output from the ELAD ASA15 to drive the antenna input of the RTL-SDR V3.

Wow, what a difference!

First up was international shortwave. Here’s a shot from my Alinco General Coverage receiver on 9955 kHz this morning using my 260′ beverage antenna (pointed toward Europe). S9 on the Alinco S Meter.

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And here’s the same signal on SDR#.

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There was a delay in the audio coming from the PC versus from the receiver, but other than that, reception was identical. Audio quality was very good.

I then moved to the 20M Amateur Radio band. USB audio demodulation.

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The little dongle worked! It is not what I would call my first choice in receivers, but it will demodulate AM and SSB just fine.

I did not try it on CW as I ran out of time.

I also tried the HDSDR software, which worked equally as well (but I think I prefer SDR# for ease of use).

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All in all, if you have or can put up a good antenna for HF, the little $25 dongle is in, my opinion, worth trying out.

73,

Gary
W4EEY

Click here to purchase the new RTL-SDR–$24.95 shipped on Amazon.com.


Thank you, Gary, for not only giving a quick evaluation of the RTL-SDR’s HF performance, but for describing how to setup HF reception via SDR# and HDSDR.

Over the years, I’ve gotten probably hundreds of emails from readers who would like to try their hand at SDRs, but were cautious about investing. For many years, a 3rd generation SDR would set you back at least $300-400. At $25 shipped, the RTL-SDR V.3 is an SDR receiver that is accessible to anyone who can afford a fast food meal or a few cups of Starbucks coffee. My how times have changed!

Once I get a few transceiver reviews off of my table, I might do some side-by-side HF comparisons between the RTL-SDR and a few of my other SDRs. 

Thanks again, Gary!

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Ivan’s preliminary review of the new RTL-SDR dongle on shortwave/mediumwave

RTL-SDR-RTL2832U-e1471375714199Many thanks to SWLing Post contributor, Ivan Cholakov (NO2CW), who shares the following video review of the new RTL-SDR dongle on the shortwave and mediumwave bands.

Ivan notes:

This is daytime reception comparison. Nighttime could be a different picture. [The RTL-SDR dongle] tunes and frequency is 100% on spot.

Using SDR Sharp you have several AGC settings to play with and find the best combination. The best setting seems to vary with band and signal strength.

The [SDR receiver] comes with a short (20 cm) and long (120cm) telescopic antennas. Neither one is usable for HF or Medium wave.

When ordering the radio you have to get a USB extension cord for the dongle. When plugged in directly into a laptop and then antenna coax it can become bulky. You also will most likely need an SMA adapter to BNC and SO 238.

I hope this helps.

Click here to view on YouTube.

Many thanks for sharing your video, Ivan! For a $25 SDR, I’m pretty impressed so far! I’m also very curious how it will hold up to stronger nighttime signals and, especially, adjacent signal interference. I imagine it may be prone to overloading as well. Please keep us posted!

Have any other Post readers tested the new RTL-SDR dongle on HF? If so, please comment! 

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New RTL-SDR dongles feature HF reception

RTL-SDR-RTL2832U-e1471375714199

Many thanks to SWLing Post contributor, Aaron Kuhn, who writes:

[T]he newest v3 RTL2832U USB receivers now have HF reception via Direct sampling over the SMA antenna connector directly out of the box with no hardware modding required.

I think this might make it the cheapest, out-of-the-box HF SDR possible at this point.

9:1 balun for longwire puts the whole thing under $50 still

Wow! Now you’re making me wish I would’ve waited a few more months before finally purchasing an RTL-SDR. I like the folks over at the RTL-SDR blog, so I purchased their model.

Amazingly,  the V3 RTL2832U only costs $24.95 on Amazon.com. What a value!  Anyone care to write a review of the HF performance? Please contact us.

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Excellent website dedicated to the RTL-SDR

RTL-SDRSWLing Post reader, Mike, writes:

Check this website – not only does it cover RTL dongles, but others as well as Airspy…

http://www.rtl-sdr.com/

Many thanks, Mike. The depth of RTL-SDR.com is most impressive. They seem to post near daily updates on their blog.

Perhaps it’s time I jump into the RTL-SDR craze and get an upconverter as well to work HF. I’ve hesitated making this modest investment in the past because I have other top-shelf SDRs. A dongle, however, would certainly prove to be ultra-portable; especially for one bag travel.

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

DE_DVB_T_1In 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!

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A very inexpensive Software Defined Radio based on the RTL2832U

DE_DVB_T_1Many 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.

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