Mike’s overview and review of the $40 Soft66RTL3 SDR by Kazunori Miura (JA7TDO)

RTL3

Many thanks to SWLing Post contributor, Mike Ladd, for the following guest post and overview of setting up and using the Soft66RTL3 SDR:


Soft66RTL3 SDR: A low cost…Good performer direct from Japan

by Mike Ladd

Much has changed in the last 8 years in the world of SDR radios. Fast forward to 2016 and just about everyone in the hobby has heard the buzz word “SDR radio”. When SDRs first came out to the market they were all aimed at HF listening and you had two types to pick from. The first being soundcard based and the second being direct sampling. The price gap between the two were several hundred dollars. The more expensive being direct sampling. As the hobby progressed, so did the technology and the prices started to shift dramatically.

You can now purchase a TV dongle for $10.00 and turn it into a SDR. The Soft66RTL3 is basically a TV dongle but with a lot more features.

The Soft66RTL3 comes from an engineer who is no stranger to the world of SDRS. Kazunori Miura (JA7TDO) has been designing and selling many models of SDRS over the internet and shipping them direct from Japan for about 7 years. The Soft66RTL3 is his latest of model hot off his bench. This SDR is a dual input RTL-SDR with a built in 50 MHz upconverter along with 4 user selectable band pass filters that greatly increase your signal to noise ratio in the HF bands.

Soft66RTL3-board-001 Soft66RTL3-Board 2 Soft66RTL3-board

The frequency range of the RTL3 is from DC to Daylight (0.4 kHz to 1.7 GHz). Miura also addressed a heat issue with the previous version (RTL2) by adding a thermal pad and heatsink. RTL dongles are notoriously unstable due to overheating. In theory, the thermal pad should add frequency stability and keep drift to a minimal.

RTL3-TrimmerPot

The last feature of the RTL3 is the input gain trimmer pot (see image above). The trimmer pot is for the HF side of the SDR and is already set before it’s shipped from Japan. If you would like to reduce or increase it the trimmer pot is easily accessible. I would suggest leaving it as is.

The RTL3 is broken down into two sections: the HF input side and the VHF/UHF input side.

Soft66RTL3-encoder

The HF side of the SDR (above) has a red rotary encoder and trimmer pot port. The VHF/UHF side (below) has the USB Mini-B connection.

Soft66RTL3-back

Both sides of the RTL3 terminate to a SMA-Male connection and Power comes from a single USB Mini-B cable.

Soft66RTL3-BandPassFilter

Band pass filter selection

If you look at the rotary encoder (red cap cover) you will see a small notch window. The 12 o’clock position is #5 on the encoder dial. One click clockwise will take you to switch position #6 and one click counterclockwise will take you to #4. You should pull the red cap cover off to have a look and get your bearings.

The band pass filter selection is as follows:

  • #4 enables BPF 0.4 to 1.2MHz
  • #5 enables BPF 1.2MHz to 5MHz
  • #6 enables BPF 5MHz to 15MHz
  • #7 enables BPF 15MHz to 30MHz
  • #8 or #9 enables the VHF UHF side of the SDR

All other positions will bypass the filtering section on the HF side of the SDR.

Installation

If you already have a RTL-SDR on your system then all you need to do is swap it out with the RTL3 and change the offset of -50,000,000 in HDSDR or SDR# to listen to the HF side of the RTL3–but if this is your first SDR we will need to install 2 items: the front end app and the driver.

I will assume your system is Win-7 or better and we will be using SDR# as our program of choice to drive the RTL3. The RTL3 runs just fine in HDSDR and SDR-Console, but by choosing SDR# it will reduce our setup time considerably.

ScreenShot-SDR

  1. Plug in the RTL3
  2. Make a folder on your desktop and name it SDR#
  3. Download the latest version SDR# from www.airspy.com and copy the contents of the zip file to your newly created SDR# folder
  4. Inside of your SDR# folder, double click on install-rtlsdr
  5. After the batch completes, double click on the “zadig.exe” inside your SDR# folder

screengrab

When you run the “zadig.exe” make sure you select “list all devices” as shown above.

ScreenGrab-Window

The next 3 steps are:

  1. Select “Bulk-In Interface” (Interface 0)
  2. Make sure the proper USB device is selected (2838)
  3. Click “install driver”

The RTL3 is now ready to be used and no further setup is required.

For a more detailed installation I would visit RTL-SDR.COM for a complete setup instructions: http://www.rtl-sdr.com/rtl-sdr-quick-start-guide

I will assume you did not have any issues setting up the ZADIG driver and now move on to using the RTL3 inside of SDR#. I will show you real world conditions that are not from any scientific standpoint.

Antenna wise, for the HF side I will be using a G5RV mini and for the VHF/UHF side I will be using a Scanntenna ST-2.

You can now launch SDR# and check the following settings (see image below).

SDRSharp-Settings

For the VHF/UHF side of the RTL3 you will want the rotary encoder on position #9. You want the cutout in the encoder cap showing the 5 o’clock position.

Summary

I have been using this SDR for a little over 3 months. Out of all the low cost SDR’S on the market, this one gives you the most bang-for-your-buck and it is a great entry level SDR with some “Pro” features.

Pros:

  • Low Price
  • HF VHF/UHF in one package
  • Works with any app that supports the RTL-SDR front end
  • 4 user selectable band pass filters for HF
  • Highly sensitive user controlled input RF amp
  • Small & very compact metal case
  • Dual input SMA jacks
  • ESD protection diode

Cons

  • Some intermod in the 460-470 MHz range
  • Inputs are on opposite sides of the SDR body

The Soft66RTL3 price is $40.00 US shipped–click here to order.


Mike, thank you so much for this excellent overview of the Soft66RTL3!  I’m especially appreciative of the time you’ve taken to explain the installation process–for many, this is one of the more difficult RTL-SDR learning curves.

I’m very tempted to check this out for myself–I love the fact that this little SDR has bandpass filters.

Post Readers: I suspect Mike will monitor the comments in this post, so feel free to ask questions. Make sure to check out Mike’s website, where you’ll find more articles about software defined radios.

A.P. Richards’ 1939 thesis on the Crosley WLW Model Super-Power Radio Receiver

Crosley

In response to our recent post about the Crosley WLW Super-Power receiver, SWLing Post contributor, Larry Hagood, writes:

A photo of Dr Richards from the class of 1927.

A photo of Dr Richards from the class of 1927.

I am an EE student at Oklahoma State (Formerly Oklahoma A&M)–the school where the designer of the WLW [Super Power receiver], Amyle Richards, got his BSEE in 1927.

[Richards] wrote and submitted a masters thesis on the design of this radio, which earned him a PhD!).

I found a picture of him in the Engineering South building and found him in the 1927 yearbook in the library.

Anyway, the archive department located his paper on the WLW and is scanning it for me.

Many thanks to Larry for doing the research and sharing a scanned copy of Dr. Richards’ thesis about this Crosley benchmark receiver!

Click here to download A.P. Richards’ thesis as a PDF.

The Crosley Radio Corporation’s 1936 “WLW Model Super-Power Radio Receiver”

Crosley

(Image: AntiqueRadios.com)

(Source: Nuts and Volts)

In 1935, the Zenith Radio Corporation produced a stunning radio receiver called the Stratosphere model 1000Z. The set used 25 tubes and three loudspeakers — more than any other radio to date. An amazing (for the time) 50 watts drove its three speakers — one 6 inch dynamic high-frequency and two 12 inch dynamic low-frequency speakers.

Standing 50-1/2 inches tall, the Stratosphere sold for $750.00 — more than many automobiles; in comparison, a new Ford cost $652.00. At that price, it’s no wonder that only about 350 sets were produced during the four years that the Stratosphere was offered.

This achievement impressed Powel Crosley, Jr. — the President of the Crosley Radio Corporation — who praised it as a fine example of quality in radio construction, but it used “only” 25 tubes and three speakers! Crosley — who also owned the 500,000 watt powerhouse radio station, WLW — was inspired to surpass Zenith by bringing the world the largest and most powerful radio receiver yet known.

[…]Out of the numerous [engineering conferences were held throughout the winter months] and Crosley’s imagination came the basic specifications: the radio would be a superheterodyne receiver with no fewer than 30 tubes, six loudspeakers, four chassis; a suitably impressive cabinet would house it. More intricate than any set ever built, it would naturally have the highest possible quality and richness of tone.

[…]In its completed form, the WLW Model Super-Power Radio Receiver indeed surpassed the Zenith Stratosphere model. It had 37 tubes, six speakers, and 75 watts of power. The cabinet stood 58 inches tall, 42 inches wide, and 22 inches deep. Everything inside the cabinet that could be was chromium-plated. The transformer coils, tubes, and speaker frames were finished in black and each chassis had its own serial number plate.

Continue reading the full article at Nuts and Volts…

Regular SWLing Post readers know that I’m a bit of a vintage radio nut, so I thought I’d do a little digging to see if any WLW Model Super-Power Radio Receivers had been sold or auctioned recently.  I was curious what sort of price they’d fetch.

Let’s just say, some owners demand a high price…Crosley-WLW-Receiver-eBay

This unit was put up for sale on eBay for $160,000 US last year! While I know the Crosley WLW receiver is rare, that price was obviously over the top as is wasn’t sold. Still, the seller included some great photos of this near-mint model:

Crosley-WLW-RX

WLW Model Super-Power Radio Receiver-1 WLW Model Super-Power Radio Receiver-2 WLW Model Super-Power Radio Receiver-3 WLW Model Super-Power Radio Receiver-4

Around the time of the Zenith Stratosphere and the Crosley WLW–the mid to late 30s–radio manufacturers must have either believed there was a market for these high-end, high-fidelity receivers, or they simply enjoyed designing and manufacturing them as a company benchmark or showpiece.

While not as feature-packed as the Crosley WLW receiver, at the National Capital Radio and Television museum last year, I was completely enamored with this gorgeous powerhouse console: the E.H. Scott All-Wave 23 console.

Scott-ConsoleRadio

The docent told me that the E.H. Scott All-Wave 23 console could easily fill a banquet hall with hi-fi audio. It sported 23 tubes and a very large speaker. If memory serves, it originally sold for $750–easily three or four times the price of most console radios.Scott-Console-Radio-Dial

Post readers: Do you know of any other benchmark console radios?  Do you own one of these amazing receivers?  Please comment!

The KRC-2 shortwave regenerative receiver kit

KRC-2 shortwave regenerative receiver kit1

Tony Westbrook recently contacted me about a regenerative receiver kit he has designed and produced in the UK.  It’s called the KRC-2.  Here’s the product description:

1 – 30 MHz with band spread tuning.

Regeneration with a difference. The regeneration setting on the KRC-2 is unaffected by the receiver tuning or the antenna coupling. How do we achieve this? The regenerative stage is fixed at 10.7MHz and used as an IF amplifier. The main receiver board is extremely simple to construct using only one FET and an audio IC. Like all the KRC kits it comes with a comprehensive construction manual which brings this project well within the grasp of the keen constructor. It was referred to as “a very sensitive little receiver” by Rob Mannion of Practical Wireless. Its unconventional design and simplicity should amaze even the experienced constructor. Case size 7 x 4 x 3 inches. 6 x AA batteries supplied.

According to Tony, the kit comes with everything; UK orders are even supplied with batteries. Tony stated, “the only thing the customer needs is a soldering iron, solder cutters, etc.”

By request, Tony sent a few construction photos and three videos of the radio in operation:

Photos

KRC-2 shortwave regenerative receiver kit4KRC-2 shortwave regenerative receiver kit11 KRC-2 shortwave regenerative receiver kit10 KRC-2 shortwave regenerative receiver kit8 KRC-2 shortwave regenerative receiver kit7 KRC-2 shortwave regenerative receiver kit3 KRC-2 shortwave regenerative receiver kit2 KRC-2 shortwave regenerative receiver kit9 KRC-2 shortwave regenerative receiver kit6 KRC-2 shortwave regenerative receiver kit5

Videos

Video 1

5.505mHz Shannon Volmet

Video 2

17.650mHz CRI

Video 3

21.505mHz Radio Saudi

Click here to view the KRC-2 and Tony’s other kits. 

GODAR antennas

GodarAntennasMany thanks to SWLing Post contributor, Mario Filippi (N2HUN), who writes:

[Check out] this site I came by accidentally, small company, USA made antennas, most are OTA TV but he has a few shortwave antennas, quite reasonable. […] Also has old vintage pics. A little of this and that on the website, quite interesting company. He sells on Ebay too.

GODAR USA

Thanks for the tip, Mario. I love supporting mom-and-pop manufacturers like Godar. It appears–based on his eBay rating–that Michael Godar has very satisfied customers and produces quality antennas.

Thanks for the tip!

Stuart Sizer: Heathkit designer, dad, and “bon vivant”

Heathkit-Drawings-2Two weeks ago, through a radio preservation group, I met the son of Heathkit product designer of the 1950s-70s, Stu Sizer––”stylist, artist, maker of models, bon vivant.” His son described the discovery of a few vintage Heathkit brochures, photos, and illustrations his father kept in his family’s basement shop, many of which had been scanned at some point.

Stu Sizer––”stylist, artist, maker of models, bon vivant”––was tasked with crafting Heathkit’s user-friendly and attractive exterior designs. For many years Sizer was Heathkit’s only product designer, and was therefore often busy. “He was a great dad,” his son told me, “but he spent a lot of time in the basement proof-building kits.”  He adds wryly, “Let that be a lesson to the hams of this world.”

Sizer’s son kindly shared with us the following scans and photos of his dad’s work, many of which are original drawings; the series concludes with some clippings featuring Sizer.

PC241116 PC241108 PC241107 PC241106 PC241099 Heathkit-Drawings-16 Heathkit-Drawings-15 Heathkit-Drawings-13 Heathkit-Drawings-12 Heathkit-Drawings-11 Heathkit-Drawings-10 Heathkit-Drawings-9 Heathkit-Drawings-8 Heathkit-Drawings-7 Heathkit-Drawings-6 Heathkit-Drawings-5 Heathkit-Drawings-4 Heathkit-Drawings-3 Heathkit-Drawings Heathkit-Advertisement

On Stuart Sizer

Heathkit-Stu Walter SizerHeathkit-Stu Walter Sizer-3Heathkit-Stu Walter Sizer-2

SDRplay shipping the RSP in quantities of 1,000 a month

SDPlay-RSPThis article from Electronics Weekly just popped up in my news feed:

SDRplay of Wakefield, the 18-month-old software defined radio specialist, is now shipping its $149 software defined radio (SDR) receiver in quantities of 1,000 a month

Inspired by the SDR capabilities that even a simple 8-bit TV dongle can perform, SDRplay had the idea of partnering with Mirics to take their 12-bit wideband broadcast chipset and to re-purpose it for the hobbyist market.

At the moment, the hobbyist market for SDR radios tends to be dominated by radio amateurs and ‘short-wave listeners’ and SDRplay’s initial product, the ‘Radio Spectrum Processor’ (RSP) has been well received – winning Ham Radio Science’s RSP ‘Best Bang for the Buck’ rating.

Continue reading at Electronics Weely’s website…

I’m quite proud of the folks at SDRplay as their RSP is truly one of the best receiver values on the market right now.

After (apprehensively) agreeing to review the SDRplay RSP last year, I was simply blown away by this little $149 receiver’s performance. Click here to read the review. Later, I couldn’t bring myself to return the RSP on loan for the review–so I purchased it instead.

I’m glad I bit the bullet!

In fact, last year, at the SWLing Post DXpedition, my buddy, Mark Fahey–who traveled all the way from Australia–forgot to bring the appropriate power adapter for his WinRadio Excalibur, so I let him use mine. I had planned to run the WinRadio Excalibur and Elad FDM-S2 simultaneously on my PC so that I could record spectrum in two different parts of the band at the same time.

Fortunately, I brought the SDRplay RSP, so it took the Excalibur’s place and ran alongside the FDM-S2. It worked amazingly well!

(I should note here that I also believe the FDM-S2 is a great value–at $519 US, it holds its own against receivers that cost upwards of $1,000.)

Shortly after I published my RSP review, I invited SDRplay to become a sponsor of the SWLing Post. I’m happy they accepted. Sponsorship on the SWLing Post is only open to retailers and manufacturers who produce quality goods; those who are well-known in the industry and, often, ones with which I have direct experience. I think SDRplay is a great fit.

So, Kudos to Jon Hudson and his team at SDRplay! I’m very happy to hear how popular the RSP has become.

If you’re an RSP owner, or plan to be soon, make sure you check out the official SDRplay forum and the SDRplay Facebook group: both excellent resources backed by active SDR enthusiasts!