Tag Archives: RTL-SDR Dongle

The New RTL-SDR Dongle Version 4

Many thanks to SWLing Post contributor, Dennis Dura, who notes that the latest version of the RTL-SDR dongle is now in production. Here are details from the RTL-SDR blog:

RTL-SDR BLOG V4 DONGLE INITIAL RELEASE!

We’re happy to announce the first release of our new RTL-SDR Blog V4 dongle which is based on the R828D tuner chip. The pricing is US$39.95 for the V4 dongle with antenna set, and US$29.95 for the dongle only, including free shipping to most countries.

Currently we are only shipping this model from our warehouse in China and the initial production batch is small and so we are limited in stock. However, now that we have confirmed that production of the first small batch of V4 has gone very well, we will be ramping up production, and stocking Amazon USA within 1-2 months as well.

The units are available for purchase on our store page.

The V4 comes with several improvements and changes that are listed below.

- Improved HF Reception. Now uses a built in upconverter instead of using a direct sampling circuit. This means no more Nyquist folding of signals around 14.4 MHz, improved sensitivity, and adjustable gain on HF.
- Improved filtering. The V4 makes use of the R828D tuner chip, which has three inputs. We triplex the SMA input into three bands, HF, VHF and UHF. This provides some isolation between the three bands, meaning out of band interference from strong broadcast stations is less likely to cause desensitization or imaging.
- Improved Filtering x2. In addition to the triplexing, we are also making use of the open drain pin on the R828D, which allows us to add simple notch filters for common interference bands such as broadcast AM, broadcast FM and the DAB bands. These only attenuate by a few dB, but may still help.
- Improved phase noise on strong signals. Due to an improved power supply design, phase noise from power supply noise has been significantly reduced.
- Less heat. Due to the improved power supply design the V4 uses slightly less current and generates slightly less heat compared to the V3.
- Cheaper price! The price of the R860 chip which is used in the V3 and most other RTL-SDR brands increased significantly at the beginning of 2023 which is part of the reason as to why RTL-SDR dongles have been increasing in price recently. For the V4 we are making use of an existing stockpile of R828D chips which are now priced cheaper than new productions of the R860. In a time when high inflation keeps pushing prices up this is incredibly welcome.

There are some other minor changes including a new bias tee LED and a small cutout hole in the enclosure so it’s easy to tell when the bias tee is on.

Of course the same innovations that we brought in with the V3 are still implemented such as the sleek conductive black metal enclosure which works as a shield and doubles as a heatsink, a thermal pad to sink heat away from the PCB, 1PPM TCXO, SMA connector, USB noise choking and improved ESD protection.

The V4 however does come with some disadvantages compared to the V3 that need to be noted [Click here to continue reading…]

Note that the RTL-SDR dongle can be purchased (when it’s stocked) from Amazon via our affiliate link which supports the SWLing Post at no cost to you. Thank you!

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Thomas (N1SPY): How to chase Cubesats with an RTL-SDR dongle and some wire

Buyer Beware: Insane RTL-SDR pricing

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$300 is an absurd price for this RTL-SDR package.

This morning, while browsing eBay, I noticed a high-production retailer selling an RTL-SDR package for $300 US! (To add insult to injury, this isn’t even the latest version of the RTL-SDR dongle!)

I post this warning message to those who are new to the world of the RTL-SDR.

You should never pay more than $30 US shipped for the latest version of the RTL-SDR dongle unless you’re buying custom enclosures, filtering, etc. In fact, the RTL-SDR package above retails for about $25 shipped via Amazon (though currently out of stock). The RTL-SDR stick alone retails for $20.95 shipped. You can find a number of models between $10-20 on Amazon and eBay.

The majority of eBay sellers list the RTL-SDR at the proper market price.

The allure of the RTL-SDR is its affordability–don’t fall for sellers on eBay, Amazon or elsewhere who list these at outrageous prices. They’re simply trying to rip you off.

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

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

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.

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.

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.

And here’s the same signal on SDR#.

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.

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).

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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Creating a global network of inexpensive remote SDRs

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U_Twente_SDR

Many thanks to SWLing Post contributor, Mark Fahey, who replies to Ivan’s preliminary review of the V3 RTL-SDR dongle:

With Shortwave SDRs (the receiver dongle) now costing less than $20, the time has come for us to set up a global group of receivers that we can all log into at will!

Have a look at SDR.hu – here you can put your SDR dongle on line and share it with anyone and they have full control of the receiver just as if it was in their own shack.

Imagine receivers scatted around the world – South America, Tropical Asia, Africa! The cost is now virtually nothing, all that is needed is the dongle, antenna (doesn’t have to be anything special – even a long wire or whip) and a small low cost CPU (Raspberry Pi for example).

Anyone else interested in this dream? Lets get together, get some receivers setup and then talk about our experience in a kick-ass presentation at the 2017 SWL WinterFest in PA!

Also… I am very soon to receive my KiwiSDR matched to a BeagleBone CPU. It will be online at SDR.hu and four remote listeners will be able to tune the full shortwave bands independently, its like my own Twente setup! Heaps of others are getting receivers online in the next few months with KiwiSDRs, this is going to be totally amazing!

I agree, Mark! While there is already quite a network of remote SDRs and receivers in the world, the barrier of entry keeps getting lower and lower. It’s hard to imagine that $25 can buy an SDR that natively covers the shortwave and mediumwave bands!

There’s only one other requirement for an online SDR that Mark didn’t mention: a decent Internet connection. Sadly, this is the only thing keeping me from hosting a remote SDR here at my home. I considered purchasing a KiwiSDR like Mark, but my upload speed (0.2-0.3 mbps) is so terrible and so unreliable that I could only host one listener at a time at best. You can bet that as soon as my ISP upgrades our service, I’ll launch a web SDR as well.

Of course, I’m willing to bet that most SWLing Post readers have more than enough bandwidth to host a $25 remote receiver! Let’s make Mark’s vision a reality!

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

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RTL-SDR-RTL2832U-e1471375714199 Many 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

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

[T]he newest v3 http://RTL-SDR.com 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 http://www.rtl-sdr.com/new-rtl-sdr-blog-units-now-available-in-store-hf-via-direct-sampling-software-switchable-bias-tee-less-noisespurs/ …

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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