SDR ~ The Wave of the Future

Where can I get a Cheap SDR RADIG?

5/26/2019 ~ Memorial Day Weekend

I observed Memorial Day weekend in 1965, at our base at Chu Lai South Vietnam. We had made the first across the beach amphibious landing since the Korean War just a few weeks earlier. It was no holiday, as we were working 7 days a week on two 12 hour shifts building a temporary airfield.

One thought that went through my mind that weekend --would I make it home to see another Memorial Day. I was one of the fortunate ones who did. But it is with sadness, that I reflect on those who didn't and who made the ultimate sacrifice. 

Regrettably many of those running (or is it ruining) our government never served and thus will never know what it is to serve. Hopefully before they "pull any trigger" they give deliberative thought to the human scarifies that will result. I truly worry when someone has the audacity to call themselves a stable genius. Really?

I will never forget standing at a helicopter landing pad one day awaiting transport to Danang, and near the pad was a group of fallen comrades neatly covered with ponchos and an American flag.  With great reverence, I salute all of those who served.

Pete, N6QW

5/25/2019 ~ Some Reflections on SDR

Soon it will be 60 years since I sent my very 1st CQ on a five watt output 6V6 oscillator (a vacuum tube for those born after 1990) which was affixed to a wooden board and the RX was a converted 80 Meter ARC-5. What a hoot? Today it is the SDR RADIG I built/fabricated/assembled/loaded software on etc. What a hoot?

There are many in our expansive  ham community who have a different opinion about moving to SDR. There is a feeling of a disconnect with the hardware (no more 6V6's) as the real hardware is minimal --and soon it will be less. The power is not in the 6V6 but the smaller form factor computers and the software.

Recently I received some comments from a ham about the MB1 transceiver from Europe. The comment was that it had a Windows 10 computer embedded internally in the box and once that died you had a dead radio. 

A point to be made; but not all RADIGS have such a computer --mine has either a $35 Raspberry Pi2 or 3 and now a $64 ASUS Tinker Board.* The Quisk SDR Software does not limit you to a single SDR board and in fact as it now stands will work with either the DDC SDR's or the ancient I & Q sound card SDR's. [Fry's Electronics in Oxnard, CA have them for an instore pickup for $64 as of today] 

So I must refute  the comment about a dead radio. I have many options and the bonus is the open source nature of the software only makes our rigs capable of doing more things.

Here is a good example with the ASUS Tinker Board. I bought mine about a year ago and the then available OS v1.8 did not work very well with the Quisk software. Today with OS V2.0.8 you can experience the results first hand in the video below. Like night and day. 

There has to be some reasons behind the "foot dragging" to even try SDR. I like to think of it as an "is it analysis"

  • Is it because there is always a resistance to change?
  • Is it because now you have to know a bit more than Bad Boys Rape Our Young Girls But Violet Gives Willingly? When I was studying EE in college our instructor used that phrase and we were all offended, until he said the first letter of each word is the resistor color code. Black Brown Red Orange Yellow Blue Violet Grey White. See Mr. Jones I still remember the color code --some 60 years later! I doubt I could remember the colors individually; but sure remember the phrase. But knowing the color code is not enough as you had to know Ohms law, how to calculate power and tolerance values. You had to know more than just reading resistor values! Oh he also said Gold is always better than Silver --5% versus 10% on the last band!
  • Is it the cost? I now find that the hardware cost are approaching a 0 sum game. Individual through hole parts now cost more than Surface Mount . The $35 computer is a trip to McDonald's for a family of four (maybe that cheap, probably more). Soon that argument like an old capacitor will not hold a charge.
  • Is it the fear of not being successful with an SDR RADIG build, by claiming with a hardware build one knows what each part does and how it works in the circuit? At this stage I personally really no longer care about individual components. My bent is performance! I have many scratch built homebrew radios, some even being quite sophisticated; BUT none comes close to what I hear and see with the Omnia and the ASUS Tinker Board. All this with free software!
  • Is it a fear that having roots in the old school and moving to SDR will put you in a somewhat novice position with the younger software nerds who eat, drink and sleep 1's and 0's ? Get over it --you have a smart phone, right --ask yourself did you even know how to unlock the phone on day one? Now you do snapchat, instagram, facebook, video streaming -- it is no different with SDR.
  • Is it the fear of being called an appliance operator? Well you have me there.. But that depends on whether you put together an SDR station like I did or just buy a box and connect power and hopefully a resonant antenna and yak away? There is a difference! I do understand that there is a ton of math and physics in those little computer chips. The Fast Fourier Transforms and D to A conversions are all math guys, so it is very technical.
I am done. But it appears that the next phase will be with the giants like Hans Summers who is soon to release a SDR rig for production as will Farhan who announced some work in the SDR direction at FDIM. With former HDR advocates such as these two making the "U Turn" there will be more soul searching about reasons not to make the move to SDR.

Pete N6QW

5/23/2019 ~ ASUS TinkerBoard SDR

View the ASUS TinkerBoard Driving the Omnia SDR Transceiver using the latest Quisk [4.1.39] Awesome!!!

Pete, N6QW

5/22/2019 ~ Some Sage Advice...

BREAKING NEWS … The RADIG is now working off of an ASUS Tinkerboard!

About a year ago I purchased and installed the ASUS Tinkerboard on one of my SDR RADIGS. It was awful. Lots of audio distortion. 

Now with the latest OS V2.0.8. It works amazingly well. The ASUS is a faster machine 1.8 GHz and has 2GB of on board RAM. I am using a 64 GB SD Card. The cost is about 2X a RPI3B+ but the performance appears to be better. Here is a sneak peek. It is the same size as the RPi.

This offers more opportunities for advancement. The NanoPi M4 looks like another great candidate.

Read on below about the sage advice... 

Xenia not the Warrior Princess; but the former Dayton Hamvention clearly laid down a marker with all of the crop of new SDR RADIGS. Yaesu and Elecraft had some very exciting SDR du jour and the predictions of John Linford are now a reality and not just some very reasoned guess work.

But as typically happens -- there is an impulse to jump on the bandwagon and make "noise like you know what the difference is between French Fries and Twice Baked". In a majority of cases there is a learning curve and perhaps for 1% that curve is merely a bump; but for others it is a steep incline. The simple answer for the 99% of us is to get smart and research the hell out of the subject. I had to and now things are not so dim. 

Start with the webSDR radios and do as I suggested --tune in your station radio and tune in the same station on the webSDR --listen to the signal quality and observe the various manipulations you can make to the received signal using the webSDR. True it is not a FLEX6700, FTdx101MP or a new K4; but you will get a sense that you actually have more control over the received signal --well beyond the capabilities of that scratch built, four pole filter, Analog VFO radio you fabricated. But you also get a lot of clout with that $35 computer board.

Yes you will have to learn some software stuff and you will have to dip your toe in a different pond --but that is what happened in 1960 when SSB became available for the masses. The die hard AM crowd of those times, sound a lot like those who will only stick with the non-SDR technologies today. 

I speak with real experience as I soon will observe my 60th year of continuously being licensed. In 1959 I had several AM rigs including a screen grid modulated Johnson Adventurer and a DX-100B. It took me until 1963 to get my 1st SSB radio -- a National NCX-3 (what a piece of crap). 

Moving to SDR is more of an investment of time and with a few bucks spent on hardware --the rewards very much outweigh the actual dollar costs.

Pete N6QW

5/21/2019 ~ Some home movies...

5/20/19 ~ A really good question.

Check the comments section where I was asked about a configuration of hardware that would get you up and running?

I think once you try SDR you will move over to the "dark side". In fact I often hear nets on 40M where the stations use the free webSDR receivers located in Utah or the several in California and then transmit using their non-SDR transmitters in their station transceivers. That would be a good place to start --have both your station receiver on and the webSDR and listen. That would be a really cheap way of evaluating whether you want to spend anything more than just some time.

Assuming that moves you, here is a starting list.

  • The Raspberry Pi3B is a great processor for $35 and you will need a 5 volt, 4amp Walwart (about $10) to run that jewel
  • You will need an SD Card --get a minimum of 16GB and I just bought one for $10.
  • You will need an external sound card such as the StarTech 7.1 to process the I & Q signals. About $35.
  • To provide an audio output and microphone input get a Sabrent plug in USB sound dongle --about $8.
  • HDMI Monitor. I discovered recently that an old LED TV set we replaced with a larger unit has an HDMI port. So scrounge for one of those
  • Logitech wireless keyboard and mouse  about $20.
  • The SoftRock Ensemble (from Five Dash) was still available as of this morning  as a kit for $90.

You are right at about $200 and add some $$$ for cables and wiring. Of course you will need a computer to flash the SD card with NOOBS 3.0 but that should not be an obstacle.

The Ensemble is built in ranges so it is not a 5 Band rig -- probably a good choice would be the 40-30-20 Meter Model. At times built units of the Ensemble are offered for sale and this adds almost $50 to the mix.

Since I have all of these pieces I hope to set up this exact configuration and make a video of it running. 

NOW --ways to save some $$$$$. The RPi2 can run NOOBS 3.0 and maybe a friend has moved up to an RPI3B+ -- offer him or her $5 and you are in the running -- it might even have an SD card in it.

A Good Question.

Pete N6QW

5/20/2019 Win 10 Still Problematic!!!

I spent several hours yesterday and am sad to report no working Windows 10 with quisk. When you go into the config panel several of the entries cause that error message and you must start over. You go to the Jetson file [ .JSON file] (how appropriately named ) and remove it and then you can once again start over. There are some other cute files names like "curses" -- that one in the past, must have been a problem too

The one action that is most critical is the selection of which rig for USB (Peaberry, Softrock, Ensemble). There just doesn't seem to be the flexibility to "fix" things as you do with the Linux operated rigs. I will keep working at it but soon I will just swear off Windows 10. I am beginning to understand the comment by many hams who have migrated to Linux for many of their computer applications.

Another note --Python 2.7 will cease to be supported in about 7 months -- N2ADR is working on a Python3.0 version so it is time to burn a couple of extra python 2.7 SD cards to have for future SDR projects.

BTW last night using the Linux version I worked the east coast (Boston) on 40M using the SB200. The station picked me up out of the large group calling him because as he said --your signal stood tall amongst the many calling! He had an Apache Anon and Big Amp. His final comment --you really sounded good! There you go. 

I also find that there is a discernable difference in the sound quality coming from an SDR RADIG versus an old school filter rig. Must be the audio bandwidth. The record feature on the Quisk lets you replay what you hear … thus you can really make comparisons. All that with free software and about $250 in hardware. My filter rigs must feel neglected.

Pete, N6QW

5/19/2019 ~Windows 10 now Working!

See the comments --Nigel, that did the trick. It now displays and I will pursue doing the rest of the set up!

But why????

Pete N6QW

5/18/2019 ~ Not Good Success with Windows 10.

Based on the success I had with the RPi3, I decided to test drive a small form factor Windows 10 Computer that is only slightly bigger than the RPi3. But faster and more compute power.

Loading the software was pretty easy once I decoded that you had to call up the Command Prompt after downloading Python 2.7.16

In order to enter data you had to enter ...
C:\python2.7\scripts\pip.exe install --upgrade pip

and so on

The final launch is C:\python27\scripts\quisk.exe

Now the 1st time through I got all to load OK and then when I entered the last command I got the quisk window. Wow I was excited. Then I named the RADIG and made the sound card changes and then did the Restart Quisk. Now the quisk screen never launches. There is a brief microsecond error message which I am never able to read. Something went wrong!

So then I uninstalled everything and I mean everything and reloaded all. Same problem: failure to launch and no quisk screen. I simply do not know what to do at this point.

If this was the LInux/RPi install then I would just burn a new SD card and problem solved. Something is corrupted.

Any suggestions. BTW kiddies I am using the RPI3 to update this blog --just like a regular computer.

Pete N6QW

5/17/2019 ~ Loaded another SD Card

Today I loaded another SD Card only this time it was a 32GB. The method to my madness was to follow the procedure I wrote up yesterday to "fit check" that it was good. It is GOOD! 

This streamlined install from N2ADR sure makes it a breeze to get up and running. There is much fun to be had on the bands as later in the evenings it seems like 60M and 20M are loaded with signals. 

I did get one ham who told me I sounded really good; but that my $250 SDR was nowhere near his FLEX6700 --hmmm must be a bit of envy here. Mine is not DDC and only has one receiver and only looks at 200 kHz of spectrum; but I am OK with that.

C'mon guys jump on the SDR wagon you won't regret it.

Pete N6QW

5/16/2019 ~ You Ask and You Receive!

[ I just loaded Quisk 4.1.39 onto a formatted 16 GB SD Card fitted with NOOBS 3.0. The process specified by N2ADR is much easier than what I came up with when I wrote the document that is on my website. Here is a brief capsule of what to do. 

[There is an app called SD Formatter that I use to format SD cards. You cannot load any software on the SD Cards unless it is formatted. I mention this because I got a blistering email yesterday from someone I will call a pre-newbie telling me he can't load the software. I do not do this very often, but suggested he take up Golf]

  1. First load a minimum of 16GB SD card with NOOBS 3.0 (or the latest version available form the Raspberry Pi Foundation). Get that installed on your Pi3. If at the time of install you are hooked up and connected to a WiFi, then when you initially boot up you will automatically get all of the updates.
  2. Next go to the File Manger and right click on an open space and create a new folder call quisk and a new empty file called (don't forget the dot in front the For now leave it blank but later you can add all kind of stuff to customize your set up. If you do not have this empty file (even though empty) quisk will not run! On boot up quisk looks for this file.
  3. Next go to and download the latest version. This will end up in your "Download Folder" in the main Pi Directory. Once the download is done go to the folder and right click on the new download and select "extract to" and that selection is the quisk folder. Once it is extracted open it > select all of the files > copy those and then put them in the quisk folder. The quisk folder will now contain the source folder PLUS all of the files. Close that out.
  4. Open up the LX terminal and install all of the files shown in the Linux setup on the Quisk website. 

  • sudo apt-get install python-wxgtk3.0 
  • sudo apt-get install libfftW3-dev
  • sudo apt-get install libasound2-dev
  • sudo apt-get install portaudio19-dev
  • sudo apt-get install libpulse-dev
  • sudo apt-get install libpython2.7-dev
  • sudo apt-get install python-usb
  • sudo apt-get install python-setuptools
  • sudo apt-get install python-pip

PLUS one more sudo apt-get install pavucontrol. The libpulse-dev installs pulse audio but the pavucontrol gives you the control panel to make various audio adjustments.

Now that these files are installed, the next steps get the Pi3 ready for Quisk

  1.  Now we have to set up the software so it can find the hardware. On the LX terminal type in the following sudo nano /etc/udev/rules.d/local rules This will bring up a new screen where you type exactly SUBSYTEM=="usb",ATTR{idVendor}=="16c0",ATTR{idProduct}==05dc",MODE="0666",GROUP="dialout" Next Click Control X, Shift Y and enter. reboot the Pi3. This lets the Quisk find the 570 frequency control on your RADIG
  2.  sudo -H pip install -upgrade quisk this installs quisk
  3. Next navigate to the quisk directory cd /home/pi/quisk
  4. When you are in the quisk directory type in make -j4 this is to match the hardware to the software. The -j4 is to designate you have a quad processor. You must have your sound cards and softrock or omnia connected and powered on at this time so all hardware is recognized.
  5. You should see a flurry of files and activity once done and in the quisk directory type in python build
  6. Again a flurry of activity and once done type in the following sudo python install
  7. Again a flurry of activity and no error messages. Again in the quisk directory (not the main home)  you now will type in the following for the launch python

This will launch quisk but now you have to name your RADIG and set up the sound cards. These were taken with another RADIG and at the top you see Quisk 4.1.15 --it now shows Quisk 4.1.39 in a later photo in this series. This is a nice feature. Later on the command sudo -H pip install -upgrade quisk will install the latest quisk right over what you have already installed. This means you can always be up to date. I don't notice too many differences with 4.1.15 but I am sure they are all behind the scenes. One notable -- you can enter a frequency and the software will take you there. Formerly that number was kept there until changed -- now it is one and done and the block goes blank after the change is executed.

There is an anomaly with the Quisk setup and that is the default for the Tx level is 70%. A long time ago I was aghast that I was only getting 700 MW out of my SoftRock when it would easily do 1000 MW. Look at the slider below that shows 100% -- it will not stay at 100% so each time you boot up you need to move the slider to 100%. I wondered why my amp was only doing about 400 watts when it could do 500 watts. That 30% makes a big difference. Who runs these SDR rigs QRP????

This is what 200 kHz of spectrum looks like with Quisk 4.1.39

Firstly, thanks to the several hams who responded to my posting of 5/15 regarding other options for SDR RADIG's.

But hold on --we need to take a bit of a detour before sharing the additional information. In the old days there were many ways of generating SSB signals. One involved the use of filters such as LC Filters or Crystal Filters and the other broad category involved what is called the phasing technique. This phasing technique relied on complex mathematical functions to add and subtract signals thus producing upper and lower sideband signals. If you are bored and want to read up a bit on some of the old technology do an internet search on the fourth method for generating SSB from Messrs. Weaver and Brown. We need to thank them for their work many years ago.

Early SDR RADIG's used that phasing technique in the form of direct conversion receivers and the mathematical manipulations involved summing or subtracting components. A really good example is the work of Charlie ZL2CTM where you have two detectors (SBL-1's or ADE-1's) and the LO is fed to them out of phase --the two outputs of these DBM's are either In Phase (I channel) or Out of Phase known as Quadrature (Q Channel). The clever approach to the processing was the use of a stereo sound card to further process (mathematically manipulate) the two channels. Much credit goes to hams like Dan Tayloe and the Tayloe Detector and of course Gerald Youngblood the founder of Flex Radio.

Thus the Soft Rocks and the Omnia use this older sound card processing. But just as the mousetrap has always been the subject of redesign and the new approach to RADIG's is the DDC (Direct Digital Conversion) using fairly sophisticated Digital to Analog Convertors and computers with a bit more muscle. The current crop of FLEX Radios and the Apache ANON use the DDC. The advantages of DDC over the DCR approach is like driving a Maserati over a lawn mower powered Trike. Built in are capabilities like looking at MHz of Spectrum versus maybe 100 kHz and of course multiple receivers. I think some of the FLEX radios can look at up to essentially 8 independent receivers. Wow. The other factor (Big Time) is that you do not have to go nuts getting sound cards to work with your RADIG!

Thus we have the DCR (all of the stuff I have is this) and now the DDC. There are groups working on the DDC as something you can buy and build yourself.


Out of the box -- Quisk will work with this DDC RADIG. This is a kit offering at this point not by a commercial company but a group. So a group of firm orders is aggregated (like maybe 100) and then the order is released to a manufacturer who runs the boards. So in Italian we have a word which translated means "Patience and don't get your underwear in a knot". It may take a while to get one -- but if I thought my DCR RADIG was cool --this is like 10X better/


(The last link is very useful.)

I understand the Heremes-Lite (This almost sounds like a special Micro Brew from Portland Oregon)   is open source so you can take the available info and have your own boards made in China if you don't want to wait.


This is a DDC but takes a bit more to get working as it is more of here is the info and you are on your own from there. I may be mis-stating this but I think that is the deal




This I think is more of the DCR approach and you  will need a sound card



Thus fellow RADIG followers we have many more assets available to us and I suspect there will be more to come. That also suggests perhaps less cost as more product hits the market, a greater vertical integration of those little chips into unitized assembles. 

You will not be able to tell what is inside the box; but like the LaPlace transforms of old -- the black box is doing all of the work. Personally I only care what comes out of the box and as long as I have a transform road map --that is all I need for me to understand how it works.

I personally am intrigued by the DDC BUT and a Big BUT, I need to get smarter on this approach and hope to share some of the things I will learn on this blog.

Thanks again to the several hams who contacted me with this additional information and as the Star Wars guys would say may the SDR be with you.

Pete N6QW


I was asked that question yesterday and you know that is a really good question. As John Linford pointed out in his RSGB 2017 Presentation, I am an early adopter and thus have some gear in the bins that was acquired inexpensively. Today may present some obstacles to repeating my earlier good fortune.

Soft Rock Transceivers.

Tony Parks KB9IYG started this movement and his current company Five Dash Sells the Ensemble Kits (unassembled) for about $90. The earlier V6.3 had plug in coil sets so you could work all of the ham bands. The Ensemble are sold by range segment like 80/40 etc. and do not have plug in coils. The Ensemble can also be purchased as an assembled kit for more $$$. You best check with them on future availability. You will need an external sound card (s) to make this play such as the StarTech 7.1. I have both the V6.3ng (a surface mount clone of the V6.3 made in Canada) and the Ensemble.

Omnia SDR Transceivers

AE9RB took the SoftRock architecture and added an on board CODEC so no external sound card was needed. He called his creation the Peaberry and two models emerged the V1 and the V2. Like the Ensemble it was sold in band ranges. Later the Peaberry was acquired by another group and called the Omnia. Like the Ensemble it is sold in band ranges. Mine is a four bander 60-40-30-20 Meters. I paid around $170 for the kit as I got some options.

The Omnia design has now been altered to cover all ham bands and boasts a 5 watt output. Its new name is the Multus SDR. Its price is around $250 for the bare bones kit. You best contact Multus SDR LLC for more details as I have scant knowledge about their current product.

The SDR software of choice for the Omnia is the HDSDR which I frankly did not like. Ever the fool, I migrated my Omnia to the Quisk and boom it works and I am a happy camper.

Other Choices ...

Moving up the price spectrum we have many self contained SDR transceivers such as the mcHF from the UK  and a host of boxes from China. You have now moved beyond $300 and some are in the 10 to 15 watt power output range.

There is also some offerings from Australia like the Genesis that use an external computer. I have heard some really good things about the KIWI SDR but believe it is a receiver only.

The unveiling at Dayton of new gear, soon to happen, will undoubtedly add to this list. 

If any of the few readers of this blog have other suggested units please email me at and I will update the blog.

Pete N6QW

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