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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 
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column