A Major Change For SolderSmoke: Introducing the WireWrapRap Podcast!

A New Direction for SolderSmoke

Introducing Our New Podcast:  “WireWrapRap”

Attentive listeners have probably noticed that for some time now the podcast has been drifting in a new direction.  Some have been concerned by this change.  I myself, as you know, have shared in many of these misgivings.   But I have become convinced that it is time for a major change in direction.  We've been doing this for more than ten years -- we are one of the oldest ham radio podcasts.  It is time for a change.

A number of people have encouraged me to make to this change.   My co-host Pete Juliano N6QW is clearly the main influence.  Pete has made me see the errors of my Ludite ways.  He taught me that it is time to put away the Dymo tape and get with it with glowing numerals.  Whenever I started getting enthused about VXOs or about Permeability Tuned Oscillators using brass screws moving through hand-wound coils, Pete was there to remind me of the beauty, simplicity, and efficiency of Arduino Microcontrollers and Si5351 chips.   Paul Darlington M0XPD contributed an element of old world legitimacy to this push for modernity. Tom Hall AK2B was another influence -- whenever I was on the verge of quitting, he’d Skype in from the Big Apple and get me back on the digital track.  And we can’t forget Farhan over in India – as soon as he started putting Arduinos and Si570s in his Minima, I knew this was really, as the kids say, “a thing.”

So anyway, it is time for a change.    I know many of you may find this shocking, so it is probably best for me to just go ahead and say it:  We are changing the name of the podcast and we are changing its focus.

n  Instead of SolderSmoke, the new name will be “WireWrapRap.”   Wire wrap is the solder-less wiring technique often used in computer circuitry.  We hope that the “Rap” thing will be especially helpful in attracting young people – especially those Maker Millennials -- to the show.  And, you know, soldering just seems so 20^th century.     

n  Instead of traditional homebrew radio, the show will be focused on Mini Computers (especially the Raspberry Pi), Software Defined Radio, Digital Signal Processing, Microcontrollers (especially the Arduino), and the use of smart phones in ham radio

n  Obviously this implies a move away from minimalist radio and QRP.  So yes, we are going maximalist and we are going QRO. And we are getting more involved in contesting (see below).  

Now I know what some of you are thinking – that this must be part of our long-standing quest for sponsorship and that this is all about money.  But that’s only part of it.  Yes, we have secured a lucrative sponsorship arrangement with a company involved in microcontrollers, small computers and smart phones that is focused on the millennial market.  But we’re really doing this for the good of our listeners. 

Don’t worry, you will find many of your favorite parts of SolderSmoke in the new show.  They will be the same, only different.   For example, instead of the “Bandsweep” segments that we used to do, now we are going to have “Codesweep”  (and it’s not about Morse).  Where we used to have SolderSmoke Mailbag, well, don’t worry -- we are going to continue to have a segment that will allow for listener input.  We going to call it “Pi Hole.”  We’ll only be accepting listener input via TEXT messages or Tweets – we are, after all, trying to be modern.  Along the same lines, we will be distributing the podcast exclusively via Soundcloud.  So get with it gentlemen! Get into the cloud!

In the new and improved podcast we want to explore the new and exciting digital modes.  We plan segments on all the new ones: PSK-99, Opera, WSPR, SNICKR, Throb, Thor, Piccolo, Oreo, Oregano,  you know, all those weird sounds you’ve been hearing near what used to be considered the CW portion of the band.  It will be such fun!  I can’t wait to decode some Oregano!

Smart phones, are, of course, the future of ham radio, and we intend to be fully into those little magic boxes.  I don’t know if you guys realize it, but all of that ugly dusty junk in your shack can be replaced by a few lines of code from the App Store.  That room you used to call “the shack” can be converted into the Yoga studio or knitting room that your wife has been longing for!  Now you can carry your station with you wherever you go and autonomously participate in contests from stations around the world.  Imagine the thrill of learning that while you were playing golf or bowling, you were also WINNING a major DX contest from a “station” in Ulan Bator. And that ALL of your reports were 59!   It’s like owning your own ham radio drone!  Congrats old man.  YOU WON! Welcome to the 21^st century! That’s the kind of operation we are going to explore on WireWrapRap!

For those of you who are worrying that we might be abandoning our microphones, have no fear my friends, Pete and I remain committed phone operators. Only now, it will be DIGITAL VOICE.   We’ll be squeezing our dulcet tones into a mere 800 Hz of bandwidth.  This way we both sound exactly the same.  Heck with this new technology everybody will sounds the same.  How cool is that!   We’ll all sound like a mix of Stephen Hawking’s synthesizer, Apple’s Siri, and MTV's Max Headroom.   The AM guys and the Enhanced SSB crew may need some time to get used to this, but c’mon fellas, it is time to get with it!  There will be no more need to tweak all those menus for “presence” and “brightness” and “mid-range.”   Heck no, we’ll all sound the same!  Progress my friends, PROGRESS!

As I said, I had my doubts about this.  But over the weekend I walked into the TV room and Elisa happened to be watching one of those “inspirational self-help” speakers on Direct TV, and you know what?  He made a lot of sense. Change IS good!  We have to EMBRACE the future!  Impossible = “I’m possible!”  Yea!  So thank you Deepak Chopra!  Thank you Pete Juliano!  And welcome --  all of you -- to the WireWrapRap!

From Wayne and Garth in San Diego: EMRFD Joy of Oscillation Part 2

Oh great and mighty masters of the SolderSmoke:

We've continued on with this project and it has been a lot of fun.

Sure, there's

THE JOY OF OSCILLATION

but we've progressed to

THE JOY OF MODULATION (added a keyed buffer)

THE JOY OF AMPLIFICATION (added driver and PA, not threatening QRO, yet)

THE JOY OF RADIATION (perhaps my favorite)
THE JOY OF RECEPTION (picked up by RBN, yeah!)
last on the list is to experience
THE JOY OF COMMUNICATION

for that, we'll try out a number of different receivers.  Cheap SW
portable.  Softrock Lite.  websdr.org.

Does one try to count all the joys?  :-)

Here's a few snaps:

0.jpg - RBN evidence
1.jpg - lashup on the lid of a tupperware container
This worked great for throwing the work in progress in a backback for
our build session meetups.
2.jpg - Fig 1.34 less output LPF.
3.jpg - The missing LPF.  THE JOY OF FILTRATION  (OK, that's taking it too far.)


4.jpg - Fig 1.35 amp with BD139 transistor.
5.jpg - "breadboard" and a front panel to hold the T/R switch.  Key
and cheap SW portable for RX.  Waiting for DX contest to end, so I
have a chance.  :-)

6.jpg - simple breadboard chassis

Our fun has certainly been cheap.  The parts cost, including PCB and 1
BNC jack, was about $13 in low quantity from Mouser (and Diz) for all
but the amp.  The amp portion was $4 in low quantity from Mouser (and
Diz), and most of that was the expensive heatsink.  The "chassis" was
just a piece of cheap 3/4" hardwood and lexan from home depot.  I
drilled and tapped the holes in the wood for the #4 screws.  (Seems to
hold quite nicely.  I thought I might have to harden the threads with
CA adhesive as is done sometimes with balsa.)

If there are any of those air variable caps left that you are meting
out to the worthy, well, like Wayne and Garth, "we are not worthy."
If you do have between 1 and 4 and find it in your heart, we'd be very
grateful.

Best regards,

Drew
kb9fko
San Diego

Renewed Hope for Divide by 2 I and Q

An anonymous reader posted this interesting message in the comments section yesterday.  Very interesting.   A potentially important tip that may help in the quest for 90 degree phase shift with divide by 2 Flip Flop circuits.  What do you guys think?   And who is that masked man?

I wanted to make a comment regarding your Frankenstein R2 Clock divider, but did not come around to do it until now and fear if I were to put it below the appropriate post, it would be so many pages away nobody sees it. Please forgive me for posting this here if my assumption is wrong. I had a play with two edge-triggered JK - Flip Flops (74HC109 & HC107) and tied the J and K to the appropriate rails to use them as T- Flip Flops. Because of one being positive, the other one being negative edge triggered, this behaves as a divide by 2 IQ clock generator. The HC107 has an inverting clock input, so as with the other design, some kind of inverter is involved. And as Bill has reported, I initially measured the Phase shift on the scope to be off. But while playing around, I realized this was a function of the signal level. I could tune the phase shift by adjusting the signal level of the driving clock! When the clock and power supply levels were almost equal, the phase shift was very close to 90° and pretty stable with frequency (tested with 1-10Mhz). Later I thought about it some more and suspect it might have to do with the exact time the inverter "flips" on different signal levels in relation to supply voltage level. Aside from the exact cause, I believe one could vary the supply voltage of the gates with the same effect on the phase shift as with varying the signal level. I hope my observation helps to somewhat make the advantages of divide by 2 IQ clock generators more accessible.  

Grayson Evans TA2ZGE on "QSO Today"

Eric 4Z1UG has a really great interview with Grayson Evans TA2ZGE.  I'm writing this as I listen.

My reactions:

I sympathized completely with his reaction to EE professors who insisted that current flows from positive to negative.  Indeed.  Let's turn those arrows in the diode and transistor symbols around!

I too stripped down a Heathkit VFO and rebuilt it from scratch.

I share Grayson's aversion to metal work.  Viva Manhattan!  

Here is the interview:

http://www.qsotoday.com/podcasts/ta2zge

Switching to a Resistive Splitter on the Frankenstein R2

I did a little work on the Frankenstein R2 phasing receiver.  I noticed that I had a lot more noise and hum on 30 meters and above than I did on 40 and below.  I don't think it was common mode hum -- switching to a battery supply didn't help much.  But when I took a look at what happened to RF signals between the antenna connector and the input to the DC receiver mixers,  I noticed that the signal level seemed to vary quite a bit with frequency. 

There were only two circuits in there:  a 1.7 MHz high pass filter (to knock down AM broadcast interference) followed by a simple bifilar toroidal transformer signal splitter.   My guess is that the 1.7 MHz high pass filter's response was being messed up by the bifilar toroid transformer that I was using as a signal splitter. There might have been some unplanned-for resonances between them. This might have had the effect of knocking down the higher freq signals, making any noise in the receiver (probably from the digital VFO) more apparent.  Also, I noticed that I had this toroid too close to the digital VFO box and to the DC power plug for the Arduino/Si5351 combo -- that might have been sending some noise into the DC receiver input. 

To make a long story short, I took out the toroidal signal splitter and went with a resistive splitter like the one above.  This seems to have helped quite a bit.   I know it adds some additional loss -- about 3 db over the toroidal transformer, right? 

Another possibility:  While rummaging around I found a little 3-terminal TV signal splitter.  It is marked "5-900 MHz" but I'm guessing it would be fine down to 1.8 MHz.  Any thoughts on trying that?  

KK7B's Thoughts on Notebooks, Experiments, and Building

From the r2pro yahoo mailing list:

Hi All,

Some interesting posts lately, with notes or links on "to build or not to build," new H-Mode mixers for HF, and front-end filter intermod.  A recurring thought is that I do lots of projects and each of my projects is a separate design, starting with a bunch of sketches.  I didn't invent this approach--think of DaVinci, for example.  I don't count my sketches, but probably make ten or twenty for every one that progresses to a design of something that would actually work, and maybe only one in ten of those makes it to prototype hardware.  I do a lot of sketches--hundreds for every working radio, and maybe finish a dozen working radios for every one that I write up, either as a good or bad example.

But my sketches all seem to have something in common--they are sketched to do one particular thing well.  They tend to be for one band, one mode, and are designed with particular power supply limitations and the antenna I'm going to use known ahead of time.  They often include at least one but no more than two experiments--something new and risky enough that it might not work.  More than two experiments almost always end up interacting in some unpredicted and dysfunctional way, so I try to limit risky new brilliant ideas to no more than one or two per project.  The key is to do lots of projects, and lots and lots of sketches.

I don't normally operate in brutally strong signal environments, so my dynamic range/IIP requirement is already satisfied with techniques that have been standard since all the excellent work by Wes Hayward, Ulrich Rohde et al. in the 1970s and 80s.  The problem has been solved, like the appropriate number of wheels on a bicycle.  Sure, there are extreme enthusiasts who limit themselves to one wheel and play the bagpipes while riding...  My risky new front-end sketches are often aimed at meeting those acceptable prior benchmarks in some clever and different way, rather than adding a few dB on top of already good dynamic range.  ...Yes, that works well, but I think I'll try doing it this way instead...

Similarly, my input filters aren't the limitation on my intermod performance.  PIM is a big deal in some contexts, and the latest research is fascinating.  Do a google search on Passive Intermodulation PIM to get started on some interesting reading on that topic.

Regarding the question "to build or not to build," I believe that comes down to something very basic: are you a builder?  If yes, then you have no choice.  I can look around my radio room and see a hundred different radios that I've designed and built, and a few more in progress.  If you do the math in my first paragraph above, that's around ten thousand sketches.  My lab notebooks have 200 pages, and I've filled up 140 notebooks since 1975, so that figure is reasonable.  It's just something I do, like some guys go fishing.  Sketches don't take long.  I can do two or three on a half-hour train ride on the way to work.  A complete design to where I start cutting metal and gathering parts might be a few hours a day for a week.  Then another month, maybe a few hours at a time on weekends to finish up a nice project.  There have been more than 2000 weekends since 1975, so even 100 completed radios has left most of my time for other things.

I am very close to folks who are the same way writing code.  They've been filling notebooks with it since grade school, and doing Software Defined Radio since long before they ever encountered the abbreviation "SDR."

If your personal sketches are full of code or CMOS logic, I expect your radios to look and work differently from mine.  If you operate 6m weak signal modes a half mile from a hilltop kilowatt contest station, you have a fascinating set of dynamic range problems to solve.  Years ago, my 11 year old daughter and her best friend thought the absolute best radio ever was the morse code transmitter that Wes Hayward and Bob Culter worked across town using a couple pieces of metal stuck in a lemon for power.  Neither Wes nor Bob would embrace the limitations of that rig for all their amateur radio contacts, but at the time it was a really cool project.

These are just some rambling, Saturday night thoughts, but if you read between the lines you can maybe understand a bit more of why I tend to do things some interesting way that might not apply to your particular application.  One time I accidentally left one of my notebooks at a close friend's house, and he took the liberty of making copies of a bunch of the pages.  I'm not sure it did him any good, but he sure found it entertaining.  There is great freedom in sketching things that have a small probability of actually having to work well in practice.

Enjoy the experiments, and if you have self-identified as a builder, as have many of the denizens of this site, then enjoy making sketches, developing designs, and taking risks that either pay off or end up as learning experiences.

Best Regards,

Rick

Be afraid! Be VERY afraid! Digital Audio on 20 Meters (video)

Here is a very interesting comparison between digital audio, and plain old SSB audio (from a Collins rig!).

I don't know.  I may be prejudiced here, but that digi audio just doesn't sound too good to me.  And I ask myself: "How could it?"  They are restricting the transmit bandwidth to 1.2 kHz.  Can the error correcting elements of the software help them get around the bandwidth limits of Shannon's communications theory?  

The digi audio sounds quite robotic to me. Even Siri sounds better.  Is this because -- as the receiving station noted -- they were only getting "80 percent decode"?   Would the digi audio have sounded better if signal strength had been better? 

Again, I don't know.  But remember. I am a Ludite (with a single d -- the ORIGINAL spelling!).

W6JL's Amazing Phasing Station

Eric 4Z1UG interviewed Don Huff W6JL a few months back.   I really like Don's approach to homebrewing.   I recently came across his QRZ.com page -- I was lured in by the phasing receiver with the Tayloe detector.  And of course I like the modules spread out in the desk.  FB Don.  

Here are the details on Don's rig:

https://drive.google.com/file/d/0B7YOOrbLoXkvbHkwWDRnV1JFVHc/view

Here is Eric's interview on QSO Today:

http://www.qsotoday.com/podcasts/w6jl

Could Grayson's Arduino Thermatron Shield Protect Us From Digi Domination?

Something old, something new, eh Grayson?   The author of "Hollow State Design" is engaged in an (I suppose) admirable effort to bridge the gap between our beloved Thermatrons and those new-fangled Arduinos.  Here Grayson tries to explain and justify his flirtation with the dark side:

I want to do some experimenting with Thermatrons and Arduino.  Sound weird?  Maybe not.

I really like playing around with the Arduino even though it violates my ban on digital technology in my shop. (My excuse is I am trying to use it teach my son something he can use to get a job someday.)

Sure Grayson.  That's what they all say.  "I was doing it for the kid..." 

Kidding aside, that tube shield looks pretty cool.  And I like the MeTubes base for the Thermatron.

Winterfest Hamfest with Armand WA1UQO

 I had a great time at the Vienna Wireless Society's  Winterfest Hamfest.  As I have done for several years now, I joined forces with Armand, WA1UQO. A prediction of cold rain caused many of the tailgaters to stay home, but there was still a lot of good stuff to be found at the 'fest.  I came home with a large stock of potentiometers, a 130 foot doublet with open wire line, TWO copies of SSDRA (one given to me by Armand) and various other bits and bobs (including some Cadmium Sulphide light sensitive resistors....)   I successfully resisted the siren calls of several old Hallicrafters receivers.  After the 'fest Armand came with me for a visit to SolderSmoke HQ.   Armand always brings along some part to be used to help members of the International Brotherhood in their radio endeavors.  This year, that included several 80 meter crystals suitable for Michigan Mighty Mites and the ColorBurst Liberation Army.  Thanks Armand!  And thanks to the Vienna Wireless Society.