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Monday, June 24, 2019

Mike KL7R's Web site on Way Back Machine

Thanks to Karl K5KHK for digging this up.  Excellent.  Three cheers for the WayBack Machine.

And thanks again to Walt K3ASW for voicing concern about the disappearance of Mike's site.  Good to know that all is not lost.

Pete N6QW's RADIG SDR On The Air!

Hi Bill: 

So far I have made about two dozen contacts with the new RADIG. Just finished one with a ham I know in New Mexico and he is an RF Engineer –he was a designer at Alpha. I asked that he do a critical review of how I sounded and looked on his SDR –  a good report and his comment was that if I hadn’t told him he would have guessed it was a $4 or $5K box.

So another goal achieved –on my 60th year anniversary and this makes #37.

Saturday, June 22, 2019

SolderSmoke Podcast #212 HDR, Boatanchors, SDR, Antuinos, Spurs, QSX, Mailbag

Dale Parfitt W4OP's  SBE-33 with modern digi freq counter
SolderSmoke Podcast #212 is available:

22 June 2019

CONGRATULATIONS TO PETE:  Licensed 60 years today

Pete Juliano during Field Day, 1959
Sideband Engineers Models 33 and 34 -- Thanks Pete! 
Hans's QSX SDR Rig at Dayton-Xenia and FDIM
W8SX FDIM interviews

Pete's SDR Projects -- Update

The Peregrino SSB transceiver in the summer SPRAT

Why no rare earth cell phone speakers in ham projects? 

My HDR "waterfall" project

Farhan's Antuino
Cubesat origins
RF Lab in an box
Superhet receiver with ADE-1 at front, and log IC at the output
Adapters (SMA to BNC) help
My dirty DIGITIA -- Denial, then acceptance
Useful programs:  SPURTUNE and ELSIE
A better bandpass filter for the DIGITIA 
The importance of a good test set up with Antuino

Manassas Hamfest: WA1UQO, W4WIN, AI4OT

Jeff Tucker -- Who owns Drake 2-B #4215? 

Friday, June 21, 2019

Wall Warts

Thank you to Michael Rainey AA1TJ who posted this cartoon, which I'm sure speaks to us all. 

Wednesday, June 19, 2019

Face the TRUTH! LOOK at Your Signal with an Antuino!

At first, I didn't want to believe it.  I was in denial.  I wanted to shoot the messenger (in this case, the Antuino). How could my beloved HB 40 meter DIGITIA transciever have an output that was so.... so DIRTY!  Everyone tells me it sounds great.  But the little Antuino screen told a different story.  Strong spurs up at 9 MHz and down at around 5.4.  And lots of places in between.  (In these display images, the center frequency is 7.2 MHz and each division to the left or right is 1 MHz.) 

Farhan tried to get me to face the truth: "The frequency domain viewing of RF Signals is the opening of the third eye. Once you start seeing signals as a bunch of simultaneous  sines, you will always be wary of the waveforms on the scope. In fact, time domain readings make little sense."

At first I blamed strong VHF RFI and my somewhat hay-wire test set up.  My homebrew Rube Goldberg 20 db attenuator was probably picking up some of the VHF RF. But as I looked more closely at the output of the transceiver in the frequency domain, I gradually accepted that it was true.  There were a lot of spurs.   I have a general coverage receiver in the shack, and with it I could hear the little devils. And after some adjustment I could see them in the FFT display on my Rigol o'scope.  An exorcism was definitely needed. 

But first came a tightening up of the test setup.  Pete advised me to do this.  I had in the shack some really nice dummy load/attenuators from the HP8640B Signal Generator that Steve Silverman had given me (and that Dave Bamford had hauled across New York City for me).  I ordered the necessary N connectors and adapters and soon my test setup improved a lot. 

All this got me thinking about spurs.  I consulted EMRFD and was reminded of a really great program in the LADPAC software pack that came with the book.  The SPURTUNE program predicts spurs and tells you what to look out for.  It is really illuminating.  Try SPURTUNE. 

Through this, I gained a better appreciation of the importance of the bandpass filter in an SSB transceiver.  I'd always thought of it as something that allowed the other mixing product to be eliminated while passing the one you want.  But I came to realize that it does a lot more than that -- it also helps get rid of spurs.   If it is designed right.  Mine was not.  I had plucked it out of an old QST article and had not paid much attention to it. All it needed to do was knock down the unwanted mixing product, right?  And in my transceiver (9 MHz IF,  VFO running 16.0 - 16.3) MHz that unwanted product would be way up at 25 MHz.  It wouldn't take a lot of selectivity to knock that down.  But I'd forgotten about the closer-in spurs.   Antuino reminded me of them.  And SPURTUNE explained where they came from.  

For the exorcism, I decided to use the bandpass filter design from Farhan's BITX-40 Module.  I had made the BP filter on this rig "plug-in" so it was easy to build a new filter.

I even checked out the filter design in a simulator.  For this I use ELSIE.   Another very useful program.  Here is what ELSIE predicted for Farhan's BITX40 Module filter: 

I plugged the new filter into the DIGITIA and... SUCCESS!  The big spurs that were bothering me were gone and the remaining spurs were all below 50db down from the main signal. Here is what it looks like now:  

The Antuino is a very useful device.  You can learn a lot from it, but you have to realize that this is not plug and play radio.  You have to think about what you are testing, make sure you have the test gear set up properly, think about the circuit you are looking at, and be careful not to put too much RF into the device.  

Three cheers for Farhan and his new Antuino!  More on this soon.  And we will talk about this on the next podcast.  

Sunday, June 9, 2019

First Use of Farhan's Antuino Scalar Network Analyzer

I was learning my way around Farhan's new Antuino this morning.  Very cool.  I decided to start with the Scalar Network Analyzer.   I've spent so much time measuring and plotting filter response curves BY HAND... the Antuino is an opportunity for me to move into the 21st Century.  

In the picture you see the results.  I was using a Heathkit SSB filter with the center frequency at 3.395 Mhz.   The Antuino was set for that freq, with the screen range set at +/- 10.  That means each division on the screen is 1 khz (right?).  The Heath filter is advertised as being 2.1 khz wide at 6 db down.  That pretty much matches what we see here.  

You can see ripple in the filter passband.  This is almost certainly the result of an impedance missmatch.   It looks to me like the Antuino is set up with 50 ohm inputs and outputs.   The Heath filter probably needs higher impedances to have a smooth passband.   I will try later to set it up for a smooth passband. 

It is easy to see how useful this device will be.  Thanks Farhan! 

More on the Antuino here: 

Tuesday, June 4, 2019

Ham Radio in Germany 1955 (video)

Don't be deterred by the lack of English subtitles -- radio amateurs around the world will be able to follow what is going on in this very interesting 1955 film.  It is only about 14 minutes long. 

This video takes us back to a time when hams were hams and rigs were RIGS!

Note the German OM who apparently slept fully dressed (with necktie) in order to be ready to spring into action on the ham bands in the middle of the night.  That's dedication my friends. 

Also note the fellow sending out QSL cards that feature the schematic diagram of his rig.  Lots of solder melted in 1955.  Great stuff. 

Thank God for the Heaviside Schicht!    

Monday, June 3, 2019

FDIM Interview with Farhan VU2ESE

I didn't realize that our correspondent in Dayton/Xenia had interviewed Farhan.  There was a typo in the audio file name and I was wondering who this UV2ESE guy was.  A Ukrainian QRPer?   I was really pleased to find out that it was Farhan.  

In Bob's interview you will hear Farhan discuss the capabilities of his new Antuino (pictured above).  Pete's Antuino is in the mail, going transcontinental.  It should arrive in the Newbury Park Laboratory later this week.  

As for the spectrum analyzer that Farhan got me last year, I am waiting for retirement (soon!) to get that one going.  But there is a danger that the Antuino will leave little room for the older tech... 

In the interview you will hear Farhan talk about the Antuino circuitry, and about the roots of the three main devices in the Antuino box.  Very cool.  

Thanks again Farhan. And thanks Bob. 

Here is the interview: FDIM 2019.m4a

Farhan's Antuino page:

Sunday, June 2, 2019

FDIM Interview -- NM0S on John Reinartz W1QP K6BJ -- Scandal on an Arctic Expedition?

John Reinartz, 1QP, at the operating position of WNP aboard the Bowdoin

Bob Crane W8SX interviewed Dave Cripe NM0S about his FDIM presenation on radio pioneer John Reinartz 1QP and later K6BJ. Listen to the interview here: FDIM 2019.m4a

Here is Reinartz's obit in the New York Times:

Here is some background info on Reinartz:

Dave Cripe's interview left me wondering what the north pole scandal was all about.   I found this passage from a book that seems to partially explain what happened.  Can anyone else shed more light on this unfortunate event?  

Saturday, June 1, 2019

Antuino: Farhan's Compact RF Lab In-a-Box

I now have Farhan's latest invention, the Antuino.  Pete will have his shortly.  Very cool.  SWR meter and antenna analyzer, power meter and scalar network analyzer all in one box. I put an old-school knob on the rotary encoder -- it seemed like the right thing to do.  Soon I will be able to find out if my rigs have spurs or are somehow non-compliant.   I'm sure Farhan's "RF Lab in a box" will be an important addition to my test gear arsenal. We will be talking about this in upcoming podcast episodes. 

Mike N2HTT did a nice write up of the new device:

And here is the info from the page:

Thanks Farhan! 

Friday, May 31, 2019

KG7SSB -- Homebrew SSB in Tuscon -- Learning from the BITX40 Module

On Sun, May 26, 2019 at 1:45 PM William R Meara wrote:

  I was talking to Jim W9UD on 20 SSB today.  When I told him I was running a homebrew transceiver he mentioned that he talked to another guy who is on the air with homebrew SSB gear -- you! 
There are so few of us Dale.  I felt compelled to send you an e-mail.  
What are you running?  
After several years on DSB, I started building separate SSB receivers and transmitters, mostly for 17.  Lately I am running versions of the Indian BITX transceiver. 
Please send info on your homebrew SSB projects. 
Bill N2CQR

Hi Bill, 

I have two radios that are completed to date. I started out building the BITX 40 transceiver from scratch and also a companion 60 watt solid state linear rf amplifier. Then I decided to construct the second transceiver for 20 meter using some of the BITX design concepts and mixed with the UBITX design for additional rf amplification. It too is amplified to about 25 watts output. The 20 meter rig is my favorite radio at this time but I am going to go a different direction on my next build. It's presently just in the design stage but I'm thinking about using the MC1350 integrated circuits for the IF amplification and for the front end I may try using a FET rf amplifier. The beauty of the bitx design is the use of wide band amplifiers that don't have a tendency to oscillate. But, the new design I'm working on will have more shielding between critical circuits and I will use a small amount of negative feedback in the high gain circuits. The reason for changing the radio to a higher impedance design is to simplify the design build. I will basically build a receiver that I can reverse the signal direction over to transmit using the same amplifiers and filters. This will cut in half the amount of circuit building however it will increase the switching circuit complication associated with this new design. 

Today I'm beginning the build of a 100 watt rf linear amplifier design using the kit parts from China (minipa 70) amps. This provides the transformer components and circuit boards. I purchased two kits of parts and I have a large heatsink to build it on. I'm working on a current sensing circuit for protecting the final FETS.  It  will run 4 IRF530's tied together with a splitter and combiner for the input and output matching transformers. It should produce at least 100 watts at 75/80 meters and maybe a little less on 40 meters but 20 meters it will drop off to about 60 or so watts. 

I'm just having as much fun as a guy can have playing around with the homebrew radio's and like you say there's not many doing it these days. I love operating a radio that I built vs. running a factory made radio. I have two commercial rigs on my bench and a couple of Collins radios but the homebrew takes the lead. 

Jim W9UD has become one of my ham friends this year. We end up talking every week or so on the air and keeping touch with local weather conditions.
Side Note:
I wanted to build a SSB radio since I was a young lad with a technician license in the early 60's. SSB came into the picture many years after I was first licensed.  Then move forward to 2015 my ham license had long ago expired during my time in the Vietnam war. I spent several weeks studying the tech, general and finally the extra class exam information and passed on through that adventure. So I decided it's time to build my own radio from scratch. So I started to look online and in books and I still didn't have the confidence to begin building. Then I ran across Farhams BITX 40 and I thought why not buy this radio and just use it as a model of how sideband circuits work. So I did just that and I got it working fine I took the radio and placed it on the test bench and began circuit analysis and signal level evaluation until it all made perfect sense. This is accomplished while transmitting so the levels can be seen on the oscilloscope. Just kill the voltage on the final stage of the bitx. I put a 1khz signal on the mic input. That was just about the only thing I used the bitx 40 rig for and I still keep it handy when I need information. 

Good hearing from you I hope I haven't over done this reply but I really enjoy talking about this subject.
73's Bill.... keep up the building and good luck on your next radio. 



And of course, Pete N6QW knows Dale and has been talking about SSB with him for some time... 

Sunday, May 26, 2019

DIY Waterfall -- A Quick and Easy Panadaptor Using a Sig Gen and O'scope (video)

I've been getting waterfall envy.  The panoramic frequency display is the one thing that could lure me to the dark side (SDR).   Heck, they now have 3D waterfalls!  What next?  Holographic waterfalls? Virtual reality waterfalls?  This is almost too much. 

Anyway, in an effort to counteract all of this waterfall seduction and to show that us analog HDR guys can go panoramic too, I decided to try to create my own panoramic display without resort to SDR.  

Of course, this is a very old technique.  It was invented in the 1930s by Marcel Wallace, F3HM.  He was the inventor of the Panadaptor which was the forerunner of today's waterfall.  Panoramic reception was used by the armed forces during WWII.  In 1946 Hallicrafters marketed a Panadaptor for its ham radio receivers (see below). 

In figuring out how to do this, I thought back to my use of my Feeltech signal generator to scan the response of a crystal filter.  The Feeltech has a very handy sweep feature.  

In this case I set up the Feeltech to sweep from 4.85 MHz to 4.75 MHz in one second.   With the 12 MHz IF of the BITX40 module, this would result in a sweep from 7.150 to 7.250 MHz. 

The sweeping Feeltech just replaced the VFO on my BITX.   I hooked up the Rigol oscilloscope to the audio output of the BITX.  I set the horizontal scan rate at 100 ms per cm.  This would have the trace go across the whole screen in 1.2 seconds. 

After a bit of fiddling, I could see signals on the 40 meter phone band.  But my display would kind of drift along the screen making it hard to know the frequency of the signals I was seeing. 

Alan Wolke W2AEW provided the solution.   He advised me to put a big stable signal at 7.150 MHz near the input of the BITX, then use this strong signal to trigger the 'scope scan.  The HP8640B signal generator that Steve Silverman gave me (and that Dave W2DAB picked up for me in NYC) provided the triggering signal.  

I put a piece of tape across the bottom of the scope display to calibrate the display.  See video above. 

It works!   It is not as cool as the SDR waterfalls, and it does not convey nearly as much information, but it was a fun project. 

Saturday, May 25, 2019

KJ5VW's Cool uBITX Mods (Video)

Beautiful work Gary, and great to see that you are putting ideas from Pete and from Don Cantrell in your rig.  

Gary wrote:
Don and Pete,

I thought you would be interested in the QRP station accessory I added to my version 3 microbitx transceiver.  In addition to using Don's AGC and Reverse/Forward Power and SWR  circuits, I developed another board using a separate Nano and TFT display to show day, date, time, temperature and humidity as well as showing the relative audio strength in three separate bands centered on 400 Hz, 1000 Hz and 2500 Hz.  In addition, when I put the transmitter in a 'tune' mode the power out and SWR will show on the TFT display as well.  The date, time, temperature and humidity information is updated once every minute, the audio is displayed continuously during receive and the power/swr is only displayed when the transmitter is activated.

The audio frequency analyzer is based on the MSGEQ7 microchip and it actually picks up the audio strength in 7 bands covering 63 hz to 16,000 hz.  I just display the three most likely to show up in a SSB transmission.  You can see a 'live' example near the end of the video showing a 20 meter QSO and how the audio strength by audio frequency varies over time.

This project falls into that 'frivolous but fun' category that was a challenge to design but I doubt many other hams would want to replicate it. I learned a lot and wanted to thank both of you for arduino scripts, useful circuits and lots of inspiration for getting started.  I have long admired the work both of you contribute to our hobby.

Here's the link to the YouTube video. 

73,  Gary KJ5VW

Friday, May 24, 2019

Nigerian Knack: Hope Emmanuel Frank

I hope this kid has a lot of success.  He definitely has The Knack. 

Tuesday, May 21, 2019

FDIM Interview with KI4IO -- Homebrew Direct Conversion Transceiver

I've been a big fan of Jerry's for several years.  He is the homebrew wizard of Warrenton, Va.  Warrention is just about 25 miles west of us.  Cappuccio the wonder-dog was born on a farm in Warrenton.  

I'm really glad that our ace correspondent Bob Crane W8SX caught up with Jerry at FDIM.  I liked his description of the joy of using a homebrew rig, and of the advantages of direct conversion.   Inspiring stuff!   Listen to the interview here: FDIM 2019.m4a

Be sure to check out the KI4IO page on

Monday, May 20, 2019

Woz on the air -- Age 11

We discussed Steve Wozniak's early involvment in ham radio here:

Thanks to the K9YA Telegraph for relaying this great picture. 

Sunday, May 19, 2019

FDIM Interview with Hans Summers G0UPL on QSX SDR Rig, Probable Price, Features

Wow, our ace correspondent in Dayton/Xenia Ohio, Bob Crane W8SX, did a great interview with homebrew hero Hans Summers G0UPL.  

Hans discusses the success of the QCX CW phasing rig -- more than 7,300 sold.  That's amazing.  I didn't think there were that many solder melters in the world.  

Even more amazing is his description of his QSX SSB SDR rig, which is currently in development.  Click on the link below to listen to Bob's 6 minute interview.  You will be blown away by the features and the price of the QSX.  Go Hans! FDIM 2019.m4a

Thanks Bob! 

Friday, May 17, 2019

Pete sent me his SBE-34

Pete is such a great guy, and such a great ham.  Earlier this week I came home to find a box in the living room.  In it was the SBE-34 that you see in the video.  Pete had been talking about this rig about 18 months ago.  

So many cool features:  The main tuning dial is dual-speed.  There is the "Geneva" band switching method.  Hybrid, with sweep tubes in the final.  All analog.  A power supply that will take 110V AC or 12V DC (internal inverter).   Collins mechanical filter at 455 kc.   Bilateral amplifier stages.  PNP Germanium transistors. 

Pete suggested that I might want to use this rig for parts.  No way!  There is real radio history and amazing innovation in this rig. Plus, it has been worked on by Pete Juliano, N6QW.  

Here is the write up from Pete's YouTube page. Note the part about how they get the BFO signal. 

Here is an example of what an IC7300 might look like some 50 years ago. It is a hybrid rig using Germanium (mostly PNP) transistors in the low level stages. So OK a couple of NPN (2N706) in several key locations such as the VFO. The driver uses a tube similar to a 12BY7 and the finals are a pair of sweep tubes, the 6GB5's. The rig operated on four bands (mostly the then phone portions) 80, 40, 20 and 15 Meters. The power out on 80-20 was 60 Watts PEP and dropped down to 50 Watts on 15 Meters. That was a real stretch. The AGC sucked as you will see in the movie and the receiver gain was a compromise --too much on the low bands and weak on the higher. This was a bilateral design -- which predates the Bitx series by some 40 years--but not the 1st.The first bilateral design was the Cosmophone - Google that one. The major selling point --a Collins mechanical filter. Also an innovation was how LSB / USB was achieved using a single crystal. It was pure magic and innovation. The basic BFO frequency of 456.38 was doubled and then doubled and tripled again. The first 2X gave you 912.76 KHz and the 2nd 2X gave you1825.52 KHz and a tripling gave you 2738.28 KHz. Mixing that back with 456.38KHz gave you 2281.9 KHz USB or LSB. The VFO operated in the 5.5 MHz range and there were heterodyne crystals to put you on the proper bands. Now that was some clever math! You can download the maintenance manual at BAMA manuals. There were some smart guys leading our ham radio efforts back in the day.

Wednesday, May 15, 2019

Stop what you are doing! Go to the Radio Garden!

This is really fantastic.  The screen display is like Google Earth, but all the green dots are local broadcast radio stations.  Put your cursor on the dot and listen to that radio station live.  And it works very well.  If there are several stations in the same town, just zoom in.  

In the course of a few minutes this morning I was listening to stations in Guatemala, Costa Rica, Getxo Spain, and Bengaluru India.  

Go to the radio garden: 

Sunday, May 12, 2019

Another Amazing SSB Rig: VK3HN's "Summit Prowler 6"

Here is another truly amazing compact SSB rig.   Paul Taylor VK3HN is a true homebrew wizard.  So many great homebrew rigs come out of Australia.   

More details:

Paul's page:

Friday, May 10, 2019

Peter DK7IH's Amazing Rigs and Blog

It has been a few years since we last mentioned Peter DK7IH.  He has continued to melt solder and to document his work on an excellent blog:

I was especially interested in the rig pictured above.  NOTE:  NO GLOWING NUMERALS.  That rig has an analog VFO.  The blog article provides some great pointers on how to achieve thermal stability.  Also, be sure to check out his "Old School" rig.  

I've put Peter's blog in the blog listing on the right side of the SolderSmoke blog.   

Thursday, May 9, 2019

Book Review: "Man of High Fidelity: Edwin Howard Armstrong" (Free Download)

Dave W2DAB sent me this wonderful book.  He picked up a copy at a recent Columbia University lecture on E. Howard Armstrong.  Written by the notable science writer Lawrence Lessing, the book was first published in 1956.  The paperback copy that Dave sent me came out in 1969; while 50 years old, my copy is in remarkably good shape. 

I really liked the book.  The author captures the technical achievements of  Armstrong, while also describing vividly the world in which Armstrong lived.  Being from the area, I especially liked Lessing's description of New York City and the Hudson Valley in the early years of the 20th century. This was the world of my grandparents; Lessing's book helped me understand it better. 

For the radio amateur, I think the most gripping part of the book is the way Lessing describes  the excitement of early radio.  Armstrong was a true enthusiast for the new technology, and he was -- even as a teenager -- at the cutting edge.  He was constantly striving to improve the technology, especially the receivers.  Like us, he often became obsessed with his radio work, often forgoing sleep and missing family meals as he toiled away in his workshop. Lessing tells us of Armstrong's astonishment and joy, when, upon inventing the regenerative receiver, he was suddenly able to clearly receive signals from distant stations that previously had been barely discernible.  Realize that when he was doing that, he was the only person on the planet who was doing it.  He was the inventor. He was the first. 

Lessing gives us a lot of great information about Armstrong's work as an officer in the U.S. Army Signal Corps in Paris during World War I.  We learn more about how his desire to be able to detect noise from the electrical systems of enemy airplanes led him to the invention of our beloved superhet receivers.   But my favorite Armstrong in WWI story involves his visit to the radio shack of the ship that was carrying him to the war.   In the radio shack he found a conventional station.  But he asked the operator if he happened to have one of the then new audion tubes.  On the spot, Armstrong took the tube and rigged up a regenerative receiver.  He and the ship's radioman then delighted in hearing stations that had never before been audible.   Amazing.     

I was less interested in the sad tale of Armstrong's legal patent battles, so I kind of skimmed through that.  I'm also not much of an FM guy, so I'll save those portions of the book for a later date.  

I think this is an important book about a significant part of radio history.  It is well written.  It gets almost all of the technical details right (but sorry Mr. Lessing,  radio waves are not composed of electrons).  The book deserves a place on the shelf of all radio history libraries.   If you can't get a print copy, an online version can be downloaded here:

Thanks again to Dave W2DAB.   

Wednesday, May 8, 2019

"Want one!" F6DMQ's Remote Rig

I talked to Yves F6DMQ last night on 20 meters.  I was on my all-analog BITX20.   Yves was up in Toulouse, operating his station near Cannes via this EXTREMELY COOL remote rig.   He connects to the home station via 4G.   Check out the rest of his station here: 

Tuesday, May 7, 2019

Monday, May 6, 2019

"The Bit Player" A New Movie on Claude Shannon

The Bit Player Trailer from IEEE Information Theory Society on Vimeo.

Thanks to Bob KD4EBM for alerting us to this.  As Bob put it, Shannon definitely had The Knack.  Check out the trailer (above)  for this new movie.   It looks like the IEEE is still working on the release plan for the film.  Does anyone have info on this? 

More info on the film here:

Four years ago we reported on a video about Shannon: 

Thanks Bob! 

Sunday, May 5, 2019

SSB on the QCX? Sounds pretty good here (Video)

In SolderSmoke #211 we reported on recent efforts to generate SSB from the QCX CW phasing rig -- we said that we'd heard that the effort wasn't very successful.  But today we got an e-mail from Jim W4JED pointing us to YouTube video from Guido PE1NNZ.  

I must say the signal sounds pretty good to me, and it looks good in the waterfall.  Listen for yourselves via the video above.  His is the signal on the left. 

Guido has a great write up, along with software here: 

I hope this all works out -- it would be great to get on phone with Hans Summers' amazing phasing rig. Here is a picture that hints at the potential: 

Go Guido! 

Saturday, May 4, 2019

SDR vs. HDR - Is the Superhet Dead?

Pete N6QW had this very interesting video about Software Defined Radio on his blog.  Thanks to G3WGV for putting this presentation together. 

It is very interesting, but -- for me -- it is also troubling.   I think something important is being missed in this discussion. You have to listen carefully, but if you do the thing being missed becomes apparent. 

Like many others, G3WGV asserts that very soon, 100 percent of commercial radios will be SDR.  Traditional superhet radios will be a thing of the past. 

OK, but I will make a parallel assertion:  Looking ahead, I think 100 percent of TRULY homebrewed rigs will be HDR.  

Of course, this really just comes down to how you define "homebrew."  I'm a traditionalist here.  I think of homebrewing as actually building -- from discrete components -- all the stages that send or receive radio signals.  By my definition, I don't think you can really "homebrew" an SDR radio.  Taking an ADC chip and connecting it to a computer running SDR software is not -- by my definition -- homebrew.  Even if you wrote the software yourself, writing code is not the same as wiring up all the stages that go into a superhet-style transceiver.    

There were a few lines in G3WGV's talk that seemed to confirm this difference:  The SDR radio is defined as a "server." Commercial manufacturers like SDR because they can use the same components that go into cell phones (exactly -- and people will soon have the same relationship with these "radios" that we have with their cell phones). 

I kind of grimaced when G3WGV described the two sets of users of SDR technology: the "early adopters" who are "technology enthusiasts",  and the "pragmatists" who don't care what's in the box -- they just want to talk on it.  I think "pragmatist" is a nice way of saying "appliance operator." Even the "early adopters" are pretty far from the world of traditional homebrew.  And for me that gets to the point that is being missed in all this -- this shift away from hardware is also a shift away from homebrew.   

But hey, this is a hobby.  To each is own!  Have it your way.  For myself, I plan to continue with the hardcore, radical fundamentalist, hardware-defined, discrete component, fully analog homebrew radio.  This morning I am attempting to stabilize a cap and coil VFO.  And I'm liking it.  As the world shifts to SDR, I look forward to the appearance on e-Bay of massive quantities of old forsaken HDR rigs.  We will buy them for pennies on the dollar and use the parts for new HDR Superhet rigs.  

Viva  E. Howard Armstrong!   Viva!   

Need Some Trans-Atlantic Support -- "The Impoverished Radio Experimenter"

A friend in the UK writes: 

I'm looking for volumes 2 and 4 of the "The Impoverished Radio Experimenter" pamphlets. I've searched in the UK for them - they are available but at silly money (nigh on £25.00 each). No sign of any pdf downloads, either. pdf downloads (preferred!) or purchasing at £10 and under would do me fine, if you know any sources?

Any ideas?    Thanks,  Bill 

Saturday, April 27, 2019

SolderSmoke Podcast #211 -- Malicious Code! Spaace! Vintage Sideband! MAILBAG

27 April 2019

SolderSmoke Podcast #211 is available

Pete NOT quitting podcast!  Malicious code case RESOLVED! 

Ambiguity and the Digi-Analog Divide

Edwin Howard Armstrong biography 

   Apollo 11 50th Anniversary
   Oscar 100 in Geostationary Orbit.  Why can't we have one too? 
   Farhan puts AISAT in orbit.  FB!  
   Space is difficult
   SSTV from the Space Station

Pete's bench report. 

Vintage Sidebanders
    Recording of Midwest Vintage SSB "tune up session" 
    Vintage rigs that sound bad
    Distorted views on "distortion" 

Bill fixing old Bose Wave Radio

NOT GOING TO DAYTON.  AGAIN!  But SolderSmoke rep will be there

75 meter secrets of success (timing is everything!) 


Steve N8NM sends me FB National Dial
Steve N8NM aspires to complexity -- enough of this simple stuff!
Dave W2DAB goes to Columbia U session on Armstrong, sends FB book. 
Jim W4JED -- reports of QCX sideband a bit exaggerated.  Where is Allison? 
Rob Powell wins beret challenge.  VK2TPM and VK2BLQ also win. CONGRATS!
Colin G3VMU sends nice 1930s radio picture
Alan WA9IRS sends diagram of digi radio signal flow.  CLEAR AS MUD! 
Chris KD4PBJ Grandmother worked at Hammarlund. 
Steve NU0P sends info on Art Collins and the Apollo moonshots. 

Friday, April 26, 2019

BITX on the Beach in East Java (Indonesia)

Nobel Prize winner Joe Taylor, K1JT, Talks to a Radio Club

Really great to see this session with Nobel Prize winner Joe Taylor, K1JT.
I liked his comments on his use of his retirement office at Princeton, University. 
I also liked his slide on how far below the noise level you can go with various modes. 
And then there was his reminder to 1) RTFM and 2) be sure to check the EME delay box so that your software will get the timing right when working earth-moon-earth. 

"Pulsars keep good time." 

Sunday, April 21, 2019

A Beautiful Variable Capacitor (from Pete)

Is this a thing of beauty, or what?   Pete sent this to me back when I was having trouble finding a "smooth running" variable cap for my HRO dial receiver.  It has a standard Jackson Brother's reduction drive attached to the shaft, followed by a really cool gear arrangement.  Note the spring loaded teeth on the big gear -- that is to keep the gears tight when turning in both directions.  

As was the case with the HRO dial that Armand sent me, the beauty of this part will cause me to build something with it, really just for the purpose of putting it to use. We've been talking about double or triple conversion superhets with 100 or 50 kHz final IFs.  At those frequencies you can get good selectivity with LC filters.  As with the Drake 2-B.    Steve N8NM is sending me a dial that will go well with this part.  That will add to the already abundant mojo/juju.  I feel a VFO in the works.    Thanks to Pete for being so supportive of my luddite analogism.  

Saturday, April 20, 2019

Life in Appliance Land

"Sexiest Radio!"   Hmmmm.

"It's the bomb."

The 3D waterfall is kind of cool.    As is the big screen on the wall. 

Friday, April 19, 2019

Homebrew Your Own Remote Head (with a 3D Printer) (Video)

After I issued a luddite complaint lamenting the arrival in ham radio of appliance-like "remote heads", Ed KC8BSV pointed out that at least one guy -- Joe VE1BWV -- is HOMEBREWING his own remote head. (You must admit, this sounds really weird.) I still haven't completely got my head around this, but Joe's video (above) is really impressive.  

We're living in the future my friends!

Remote your heads!  With 3D printers!   

Thursday, April 18, 2019

Our Dismal Digital Future?

I'm sure some would find this device appealing -- to each his own.   But I don't like it.   It seems to mark another step down the path toward the complete appliance-ization of ham radio.  Note how the control head is looking more an more like something for your car audio system, or your cell phone.  
Count me out. 
Just say NO! 
Menus are for RESTAURANTS!  

Wednesday, April 17, 2019

From Cuba: "Technological Disobedience"

Necessity is indeed the mother of invention.  

This video made me think of the Jaguar DSB transceiver made in Cuba from the parts of Soviet-made television sets.  

Somehow I wish we were more technologically disobedient. 

Monday, April 15, 2019

"The Hobby Song" from Saturday Night Live

I kept waiting for OUR hobby to be mentioned....

Sunday, April 14, 2019

Understanding Fourier Transforms

Lots of wisdom and insight here:

Strongly recommended for those trying to understand mixers and harmonics. 

Saturday, April 13, 2019

Digital Engineering vs. Analog Engineering

In  a book review Thompson makes this observation about the digital-analog divide: 

One difference might be that human beings can deal with ambiguity, and computers really can't. If you've done any Python [coding], you make the tiniest mistake, and everything stops immediately. That’s what makes it different even from other forms of engineering. When you are trying to fix a car, if you fail to tighten a bolt on one wheel as tight as it should be, the entire car doesn't stop working. But with code, an entire app, an entire website can go down from the misplacement of a single bracket. I think that's the one thing that sometimes scares writers away, because they are more accustomed to working with ambiguity.

I am definitely more accustomed to working with ambiguity. All of my rigs are filled with ambiguity. 

Friday, April 12, 2019

Understanding Digital Radios

Alan WA9IRS writes: 

Hi Bill,
Thought I would drop you a brief note.  I have been catching up on my listening to past issues of Soldersmoke podcasts and was particularly interested in the discussion between you and Pete concerning the simplicity associated with non-digital, integrated circuits and microprocessors and all of the rest of the very small miniaturized circuit elements.  You rightly pointed out that you desired (along with a lot of the rest of us) to fully understand what was going on in a circuit and for that reason desired to maintain the simplicity of transistor and discrete components in your design and build projects. 
 I agree with you completely but offer the alternative to the simple circuits in the form of the attached simple diagram of the signal flow path in a digital radio. I found this some time ago in a digital electronics magazine and thought you and Pete would find it interesting.  Perhaps this might be something to spring on Pete on 4-1-2018.
Take care and thanks to both of you for many pleasant and thoughtful hours of enjoyment listening to Soldersmoke!
All for now, 73,
Allan,  WA9IRS
My response: 
Thanks Allan, Very illuminating.   It is all clear to me now.   I feel so much better.  FB OM.   73  Bill 

Thursday, April 11, 2019

Circuit for Farhan's Satellite -- Arduino in SPACE

Farhan sent me the schematic of the AISAT amateur digital satellite that went into orbit on April 1, 2019 from India.   He notes that the circuitry is very simple.   Indeed, it reminds me of the very simple but effective circuitry we saw in satellites in the early days of the space age.  Beautiful simplicity, with an Arduino on-board.   And it is great to see that Farhan did not forget the low pass filter.  FB OM.  

Tuesday, April 9, 2019

Packets from Farhan's Space Ship

Farhan's AISAT flew over this morning.   Using HD-SDR software, an RTL-SDR Dongle,  and my Dominican Republic refrig tubing quad I was able to capture some the packets.  Above you can see one of them, floating like a flying saucer in the waterfall.  Pretty amazing that that signal came from a machine put in space by our friend Farhan.  

Monday, April 8, 2019

Congratulations to Farhan on New Amateur Satellite Launched 1 April

This is not an April 1 trick.  Farhan and Exseed Sat have put another bird in orbit.  
Details here:

This site in Argentina gives pass information:

I will be listening tonight! 

Congratulations Farhan! 

More info: 

Monday, April 1, 2019

Malicious Code in the Si5351 -- Pete quitting podcast

Those of you who have been reading Pete N6QW's blog (and all of you should be reading it!) will have seen a recent post about his efforts to modernize (digitize) the VFO in an old tube-type Ten Tec Triton IV model 544.  Pete complained that --oddly -- in spite of replacing the old analog tube-type VFO, the rig with a modern, rock-stable Si5351 VFO, the old rig CONTINUED TO DRIFT.  That had Pete and a number of us scratching our heads.  How could that be?  

Pete then completely removed the Si5351 VFO from the old boatanchor.   Sitting on his bench, all by itself, THE DAMN THING EXHIBITED ALL THE CHARACTERISTICS OF ANALOG VFO THERMAL DRIFT.  Wow!  Why?  Pete was really pulling his hair out on this one. 

We immediately began to see if others were getting the same results.  Nope.  None of our Si5351 VFOs were doing this.   This was REALLY strange.  

At this point we had to turn to a real Arduino expert, a guy who I had met during my time in Italy: Luigi Bugiardo from the Arduino research center in Bocalupo, Calabria.  Pete gave him remote access to his computer and he began to poke around.  

It didn't take long.  Luigi quickly found the problem:  He found several lines of malicious code "embedded in the Si5351.h and si5351.cpp files –sort of lurking out there and not easy to spot." 

Pete then removed this code and -- BINGO -- no more drift.   

Now I know some of you guys are thinking that this was just a bit of harmless fun.   But Pete is really angry about this.  He feels like he has been played for a sucker by some ham who was pretending to collaborate with him.  Pete sees this as yet another violation of the unwritten ham code of conduct.  To him this is another intrusion of computer/hacker noob hazing into the ham radio world.  And worst yet, he thinks this malicious code came to him because of this involvement in the podcast and his blog -- that participation resulted in the widespread exposure that got him into this mess.  

Pete is so upset that he has vowed to drop out of the podcast and shut down his blog. 

So come on fellows.  It is time to 'fess up.  If you did this, or if you think you know who did this, please send an e-mail to me at   I think being able to pinpoint the prankster will help Pete deal with this whole thing, and hopefully get him back into the SolderSmoke...   

Tuesday, March 26, 2019

So Much Cool Stuff on Pete N6QW's Blog

There is so much tribal knowledge, so many good ideas.  Be sure to visit Pete's blog regularly.

He needs the meter from an SBE-33.  Somebody out there must have one.  

Check out his stepper motor antenna tuner video.  

And be sure to leave some comments or to send Pete an e-mail with feedback.  I live in fear that he will think no one is reading and then stop posting.  We can't let that happen!  

Monday, March 25, 2019

Apollo 11 -- The Documentary

My wife is a kind and tolerant person.  Proof of this is that she went with me to see the Apollo 11 documentary that we recently posted about.  

I think you have to be a geek and/or have The Knack to really like a 90 minute documentary with no audio other than Walter Cronkite's reporting and the recorded dialogue among the participants.   But of course, I loved it.  Amazing video, especially of the Saturn V.  

Bob Scott KD4EBM found this great interview with the film maker: 


Audio only (downloadable)

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