Just go to http://soldersmoke.com. On that archive page, just click on the blue hyperlinks and your audio player should play that episode.
http://soldersmoke.com
The presentation starts at about the 4 minute point.
I think if I were only allowed to watch one YouTube video in the next year, I'd make it this one.
In this amazing RSGB video, Ashhar Farhan VU2ESE takes us back to his earliest days as a radio amateur. He tells us about his very early desire to build radios, his early projects, and his personal evolution as a designer and builder, from a simple DC receiver, to the BITX, the Minima, the uBITX and now the hybrid HDR/SDR sBITX.
There is a lot of homebrew wisdom and tribal knowledge in this video. And we learn so many hitherto unknown details about the rigs that have become so important to us:
-- Farhan had the EMRFD book with him on the famous flight from Sweden to India during which the BITX was designed.
-- We learn about the origins of the BITX oscillator circuits, and that the VFO and BFO are essentially the same.
-- I was really pleased that Farhan included a picture of my HB BITX17 rig in his presentation.
-- Farhan discusses the difficulties he faced in obtaining needed parts in India.
-- We actually see the nylon washers that Farhan used in the original BITX.
-- Farhan discusses his early system for measuring coil inductance.
-- In addition the huge contribution of EMRFD, Farhan talks about how he was helped by Pat Hawker G3VA's writing, and the ARRL's SSB Handbook.
-- Farhkan talks about his Tex 465 'scope and his building of a Spectrum Analyzer.
-- We see his evolution to dual conversion. We see the conceptual birth of the Minima and the birth (thanks Wes!) of the TIA amps. I didn't know about the HF-1. Then Farhan designed the uBITX and now the sBITX.
-- Farhan talks about his practice of taking the pictures of new rigs with the new rig sitting atop the book that was most important in its design and construction. FB.
-- I was really blown away by Farhan's presentation of how the uBITX advertisement was inspired by and in many ways based on the Heathkit ad for an HW-101. Amazing.
-- I learned a lot from Farhan's discussion of SDR theory. I pledge to spend more time with this. I really like Farhan's hybrid HDR/SDR approach.
-- But I have a question: Farhan seems to say that we'd need a big expensive GOOGL computer to do the direct sampling HF SDR. But doesn't the little RTL-SDR do just that? Without a GOOGL?
-- Great to see Wes's AFTIA being used in the sBITX.
-- Really cool that Farhan has his mind on VHF transverters when designing the sBITX. I liked use of the TCXO module to free up one of the Si5351 clock outputs. FB. And great to include an idea from Hans in this rig.
Thanks very much to Farhan (who stayed up until 3 am to do this!) and to the RSGB for hosting.
I really hope Ciprian can get a license very soon. His homebrew projects alone should qualify him. Ciprian has The Knack. It would be great if the IBEW (especially the European branch) could help Ciprian get some more parts and test gear.
This guy is quite a character, with a real knack for describing physics. At the start of this video he says that these kinds of adventures are "good for the spirit and the soul." Right you are Professor Miller. I am currently recovering from a minor back injury. It is nothing serious, but it has delayed the production of the SolderSmoke Podcast #230. These videos are, for me, just what the doctor should have ordered.
I liked Miller's references to Michael Faraday.
There are many videos on the Julius Sumner Miller YouTube Channel. They are indeed "good for the spirit and the soul." Thanks to Hack-A-Day for alerting us to this treasure trove.
This has to be one of the most successful of SSB group-build projects. Dean KK4DAS has been leading 20 members of the Vienna Wireless Society in the construction of N6QW's Simple SSB Transceiver, with Dean's "Furlough 40" additions. This is very FB, and very encouraging. Dean clearly has The Knack. Just two winters ago I was smuggling a 3.579 MHz crystal to Dean for use in a Michigan Mighty Mite. He has clearly made a lot of progress.
-------------------------
Dean writes:
It has been just over a year since I completed my initial build of the Furlough 40 with much coaching and assistance from Pete. Mike and Don are two out of 20 members of the Vienna Wireless Society Makers group that is working on a group build the SimpleSSB project as enhanced by me to include features like CAT control for digital modes. Beginning about six weeks ago the group is progressing module by module perSolderSmoke best practice advice. We started with the audio amplifier, followed that with the Arduino/SI-5351 based controller module and the builders are just completing the IF module. This week at our weekly meeting, Mike proudly showed off his success.
-------------------------
Read all about it, and see some really great videos here:
For many reasons, this is a really nice story. It is about a kid with The Knack, a kid who, like young James Clerk Maxwell, wanted to understand how things work. It is also a technology story, the story of the invention of a device very important to us: the electret microphone. (Remember the earlier carbon mics in telephones? I'll bet more than a few of our readers are guilty of stealing a few of those mics from pay phones.) And it is a reminder of the benefits of helping kids who might need a mentor... or and Elmer.
Thanks Hack-A-Day. And three cheers for James West.
This morning I came across his recent article about the workshops he's had over the course of his life. Very nice. Man, I should have held on to that SP-600 I once had. You folks will like this:
Over on Hack-A-Day Jenny List (G7CKF) has a really nice article about ham radio and homebrewing. She truly has The Knack: She got her start in radio electronics at age 9 when her parents gave her George Dobbs's Ladybird book.
One of her paragraphs really seemed to capture the SDR-HDR conflict that we so often joke about:
The age of the homebrew RF tinkerer may be at a close, at least in the manner in which I started it. Nobody at the cutting edge of radio is likely to be messing around with discrete transistor circuits in the 2020s, unless perhaps they are working with extremely exotic devices up in the millimetre wavelengths. It’s all software-defined radios, opaque black plastic boxes that deliver a useful radio experience on a computer but that’s it. No more homebrew, no more tinkering.
Whew, good thing I'm not on the cutting edge. It sounds kind of sad. Oh well, that leaves more discrete transistors for us to tinker with.
Jenny's Profile on Hack-A-Day:
[Jenny List]: Contributing Editor and European Correspondent
Jenny List trained as an electronic engineer but spent twenty years in the publishing industry working on everything from computer games to dictionaries before breaking out and returning to her roots.
She grew up around her parents’ small farm and blacksmith business in rural England, so making (and breaking) things is in her blood. Countless projects have crossed her bench over the years, though these days you’ll find her working with electronics and in particular radio, textiles for clothing and costume, decrepit classic cars, and real cider from first principles.
When she’s not writing for Hackaday she works on language corpus analysis software, designs and sells amateur radio kits, sits on the board of Oxford Hackspace, and is a freelance electronic design engineer and programmer.
Thanks to Grayson Evans for sending us this very encouraging video. It is from Tektronix; I wonder if Alan W2AEW provided some ideas and inspiration? More stories like this: https://www.tek.com/stories
Here is Marc Verdiell, the "Curious Marc" who repaired the Soyuz Clock (shown in yesterday's blog post). Really cool. Many SolderSmoke fans will completely understand Marc and his passion for electronics.
Greetings from a fellow
ham in Northern Virginia. I have enjoyed the
SolderSmoke podcast for a few years now, and I just heard your recent
presentation to the Vienna Wireless Society. We have a lot in common so it is
about time I reach out to make your acquaintance.
I was born in NYC and
grew up in Northern NJ. I was first licensed in 1969 as a high school student
(51 years ago! Goodness!). My novice callsign was WN2JFX, and I progressed from
Novice and then to General and Advanced as WB2JFX, and then eventually to Extra
(in about 1990 -- while the 20 WPM code requirement still existed). At that
point I put in for a 2X1 callsign and received WX2J, which is a nice twist on
my original call.
I was fanatically active
in my early years in ham radio. My Elmer (George, K2VVI, SK) set me up with a
DX-40, and my parents provided a brand new Hallicrafters S-120 (you could copy
the whole 40 meter band without changing the frequency!). I think I Worked all
States as a Novice and learned that the human brain is the most amazing audio
filter on the market. When I made General, George lent me an old Hallicrafters
SX-25, and then I was really in good shape. Besides CW, I was also very
interested in RTTY. I had my own Model 15 leaking oil in the basement and had a
blast watching the magic of that thing printing messages out of thin air. I
have always been a home-brewer, and one of the first serious things I built was
a two- or three-tube RTTY demodulator from the Handbook. Aluminum chassis, chassis
punches, tube sockets -- the whole works. I have no idea what the real
inductance was of the inductors that went into the filters but somehow if the
signals were strong enough, and on 850 Hz shift, it could actually demodulate
signals. I probably still have that thing around here somewhere.
Another local ham
bequeathed me his entire collection of 73 magazines - 10+ years starting with
the first issue (~1960). I read them from cover to cover so many times I
probably have them memorized. I became a real fan of Wayne Green, W2NSD, who
was always ornery and controversial but a very interesting guy. I met him at a
hamfest many years later and we had a great chat.
In any case I wanted to
mention some other things that resonate with me as I listen to your podcast. As
a kid growing up in the shadow of NYC in those years, you can bet that the Jean
Shepherd broadcast was a regular part of our life. My dad used to listen to it
every night -- 10:15 p.m. I believe, on WOR -- and we both used to greatly
enjoy his stories of lighting up the fuse panel and nearly blowing up the house
as he and his old man were playing with radios, etc. It was a common theme in
our house too when my ham radio signal would blast into the TV set or I dangled
new antenna wires off the house and out of the trees -- "You're going to
blow this house up!" I studied electrical engineering in college and was
commissioned in the Air Force upon graduation. I served a 20-year career in the
Air Force and stayed somewhat active in ham radio. I was licensed and operated
out of Okinawa (KA6TF) and England (G5ERE) during tours of duty in the early
1980s. Always an HF guy, in about 1982, in Japan, I bought myself a new Icom
IC-720A, and this is still my primary rig. I was an early adopter of PK-232 and
did some extensive building and experimenting with it. Sadly though, in the
last 25+ years, my ham radio experience has mostly been vicarious as my work
and family obligations have just not left much time for ham radio. I do have a
G5RV wire antenna strung up but very rarely jump on the air -- sometimes during
contests.
In high school we made a
field trip to ARRL HQ in Newington, CT. While there we did all the things
people do on such a visit, but one of the high points for me was meeting Doug
DeMaw. I can just hear how Shepherd would describe it -- "I turned the
corner and there he was! In person! The high priest of homebrewing! Doug DeMaw.
In the flesh!" Cue the kazoo. I actually also met Shepherd at a book
signing (Wanda Hickey's Night of Golden Memories?). I remember presenting him
with a computer-printed banner of his callsign -- K2ORS -- produced by one of
the few functioning computer programs I had written in high school. I also
heard him on the HF bands one night -- I think he was in Florida -- and
actually made contact with him, if barely being able to exchange callsigns can
count as a contact.
Well, more than you
wanted to know. I just wanted to let you know that I enjoy your podcast and can
personally relate to very much of what you say. Although I am steeped in
Hardware Defined Radio, I am also a software guy so I expect that my future
includes SDR. I hope you and Pete are able to continue the podcast for a long
time to come because I need the full HDR-SDR spectrum to be covered -- hi.
As I said a couple of days ago, Farhan has put out a very informative video on amplifier design. During the video we can see him determine bias, feedback and load levels, then select component values. We then see him actually build the amplifier "ugly style" and use his Antuino to test it. Fantastic. Watch Farhan's video here: https://www.vu2ese.com/index.php/2020/06/18/feedback-amplifier/ I sent Farhan some of my reactions to the video. In the hope of stimulating some discussion, I repeat them here: ___________________ Wow Farhan, I really enjoyed your video and learned a lot. You definitely have the Knack for explaining this stuff.
I have been struggling to understand feedback amps for a long time. I took up this topic on pages 187-190 of the "SolderSmoke -- Global Adventures" book. I was more focused on the benefits of FB amps, and on how and why feedback affected input impedance.
I took notes as I watched:
-- I liked the fulcrum analogy.
-- Really wonderful how you describe the selection of components to get desired bias.
-- Even better when you explain tapping down of RF coil to get 50 ohms to look like 200 ohms. Great stuff.
-- Standardized on BNC. FB!
-- .1uF caps. Love them! No argument here!
-- I copied your resistor list. Will use it with Mouser.
-- Saving the pigtails. Indeed!
-- I like your ugly "resistors first" technique. I may have to move away from Manhattan.
-- Wow. Ugly circuits IN SPAAAAACE! FB!
-- 2N3904 I always think it is EBC when looking at the flat end of transistor with leads facing down. Only had reverse pinout with PN2N2222. EBC is my usual assumption.
-- I still have the big box of trifilars you left me. I use them. Thanks!
-- I like that VTVM in your Antuino. Very handy. Want one! Also, We need to get the Antuino to go down to below 455 kHz.
-- I also like your dual Return Loss and SWR display. I think in terms of SWR. Return Loss sometimes messes me up.
-- Didn't know about the Hold and Zoom feature on Antuino. FB.
-- Your measurement of the Q of the crystal was awesome.
-- I checked my soldering iron temp: I'm at 480 C A bit too hot. Will back off.
-- Good description of need for an attenuator at amp output to keep it in Antuino's range.
-- As I watched you tug on the components after the solder cooled, I remember an old and silly admonishment from the ARRL Handbook: NEVER use solder for mechanical connections. Ha! They were WRONG!
-- Demonstration of the flatness of feedback was great.
-- I found your measurement of impedance using the SWR feature of the Antuino to be very useful. Is there a chart relating the SWR/Return Loss to actual impedance values?
-- Loved your description of how output impedance affects input impedance. That is why you advised use of TIA amps in my DIGI-TIA. But now I'm thinking that if I can accurately measure impedances of non-TIA amps, I can design L networks that will keep the crystal filter passbands ripple-free, right?
-- Great explanation of the benefits of the 6 db pads at amp output. Allison often recommends this. Now I know why.
-- Wow! Now I KNOW what that two-tone box you left with me is for! Now I understand how it can be used to measure IMD on FB amps. I pulled mine out just as you began to discuss yours. Really cool.
Thanks a lot Farhan for doing this. These videos will be of long-lasting use to homebrewers around the world. I hope we will see many more VU2ESE videos like this one.
Ben Krasnow has a KNACK for explaining technical things. I liked his videos on impedance. At the end of the second video, he said he'd do a third one that would focus on impedance in coaxial cables. But I couldn't find it on his channel. I hope it was made -- this is very interesting and useful. Ben's YouTube channel is here: https://www.youtube.com/user/bkraz333
This guy has some amazing tools, and even more amazing skills. I find it inspirational to occasionally take a look at other kinds of workshops. Check it out. Video above. Along similar lines, the young Englishman Leo was in Washington state with his girlfriend when the lock-down and travel bans kicked in, so his work on Tally Ho (and his videos) continue. See: https://youtu.be/zXV0ywqj7zY SITS! or Stay in the wood-shop!
https://www.youtube.com/channel/UCg-_lYeV8hBnDSay7nmphUA I present this as part of our occasional series on people with other kinds of Knack. The young Englishman in this series of videos is definitely in this category. Watch him acquire the 1910 yacht "Tally Ho" for 1 pound sterling, transport it to Washington state, SINGLE HANDEDLY build a boat shed around the huge vessel, and carry out the restoration. Oh yea, all the while shooting videos of his work. Great stuff. I advise you to watch the series from the beginning. The next video in the series will load automatically. Be sure to subscribe the channel. Thanks to Ryan Flowers of https://miscdotgeek.com/ for alerting us to this.
Flying drones with Billy. Amazing tech out there. In the 50 buck range with video cameras and facial recognition and tracking. Check out Air Pix.
Bill's Bench:
Active CW filter in uBITX.
Hi-Per-Mite from 4 State QRP. Easy to do. Works well.
uBITX to 5 W level.
S-38E adventure.
Replaced antenna input coil BUT -- it came from an earlier S-38 and doesn't resonate.
So I bought a junker on e-bay and will take the E model coil out of that one.
Had to re-string the dial! And add rosin to it from Maria's old violin.
BFO was not working. Bad buzz sound.
So: Re-cap, Re-tube, Re-string, Re-align, Re-build power supply.
Shortwave sounds good. Nice to hear music coming from our machines.
SHAMELESS COMMERCE DIVISION: Please use the Amazon Search Box in the upper right hand portion of the blog.
Pete's Bench
A teensy-weensie explosion and fire
Mint! Kl7FLR
60 Meters
Cheese Microscopes
Peaberry
Radig
California hams using online SDR receivers for local nets.
News You Can Use!
J-310s in LTSpice
MAILBAG
K5HCT August via Regen and YouTube
Doug WB5TKI and his wife read "Us and Them."
Rich K7SZ finally following SolderSmoke Podcast. Welcome aboard Rich.
Rick KD4KRA His son was one of the kids in the MIR-Classroom contact that I monitored around 1993...
David AD8Y Read SolderSmoke Book. Similar Knack story. Shared 1978 story: Homework net on 75 meters.
Paul KL7FLR Tapping and other tribal knowledge.
Dave K8WPE Says I'm fortunate to have a supportive wife. So true.
SPECIAL REQUEST: IT IS VERY DIFFICULT FOR US TO KNOW HOW MANY PEOPLE ARE LISTENING TO THIS. SO PLEASE, SEND AN E-MAIL TO SOLDERSMOKE@YAHOO.COM JUST SAY THAT YOU LISTENED TO PODCAST #218 AND TELL US HOW YOU LISTENED TO IT (ITUNES, DOWNLAD FROM BLOG, STITCHER, PODBEAN, WHATEVER... THANKS
I really like the way Lex PH2LB measures and demonstrates the effectiveness of the Hi-Per-Mite CW filter designed by David Cripes NM0S. Watch the short video above. The blue trace is the audio input to the filter, the orange trace is the output. Watch the output change as Lex sweeps the audio frequency range. He wrote: After studying the schematic I shifting through my spare parts stock to collected the components and build one according there design on a breadboard (I changed the center frequency from 700 to 600Hz). I hooked up my signal generator with a amplitude of 2v max and sweeped it from 250Hz to 2KHz looking at the output on my rigol osciloscoop. On 2khz VMAX=0.04V, 885Hz=0.2V, 700Hz=1.5V, 662-585Hz=2V, 400Hz=0.2V, 500Hz=0.9V, 250Hz=0.04V. So a nice flat top between 585Hz to 662Hz. A full description of Lex's project (with more videos) is here: https://www.ph2lb.nl/blog/index.php?page=ubitx-mods3#ubitx-mod14 Lex's Knack Story and the intro to his blog is here: https://www.ph2lb.nl/blog/index.php?page=history
The AM Rally this past weekend was a lot of fun. I was reminded of how the guys that you talk to on AM are just so much more likely to be running interesting homebrew or vintage gear. First contact was with Howard VE2AED who has one of the most amazing antenna farms I have ever seen. Take a look: https://www.qrz.com/db/VE2AED He also has an R-390 and a KWM2 in his shack. Next I spoke to Robert W0VMC (Voice Modulated Carrier) out in Wisconsin. Robert is a homebrewer of AM gear with a Knack story that is very familiar: http://w0vmc.com/ Next up was W4GON. Joel was on the homebrew AM transmitter that we reported on back in 2017: https://soldersmoke.blogspot.com/2017/08/thermatrons-al-fresco-w4gons-fb-hb-am.html
Joel has completed his rig, adding a FB front panel. Here it is:
Then came the W1AW contact. See the video above.
Finally, I talked to Jack W9GT who was running a rig that must be unique on the amateur bands: A Federal 167 B Maritime transmitter. You can see this magnificent transmitter here:
I found this site through Paul VK3HN. He took the AM detector circuit for his AM receiver from one these Lebanese homebrew radios. There is some really great information on this wonderful website. It has been online for some 20 years -- I wish I had found it earlier. The author shares his Knack story -- this is a wonderful example of the International Brotherhood of Electronic Wizards (IBEW).
"SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
http://www.amazon.com/dp/B004V9FIVW
Around the world, around the world
-
FastRadioBurst 23 here letting you know of our shortwave outings this week.
On Sunday 18th May 2024 at 0900/1300 hrs UTC on 6160 kHz and then at 2000
UTC o...
Moorabbin Radiofest
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The Moorabbin RadioFest was a terrific show this year. The turnout looked
good to me although I'm told it was down on past years.It was great to see
a vend...
Broadcast Band AM Radio
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See the YouTube series for more information:
http://www.youtube.com/c/CharlieMorrisZL2CTM
Buffer Amplifier
Low Pass Filter
IF Ampli...
An Inline RF Step Attenuator for QRPp Work
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I don’t need to explain the attraction of low power operation; if you’re
reading this, the chances are that you are already a convert. I’ve been
operating ...
A 51S-1 Restoration Story
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I came across my Collins 51S-1 in a big junkyard in Ankara, Turkey around
2012. It was in a pile with a lot of other electronic scrap, probably from
one o...
New QRP Cluster Online From OM0ET and OM6APN
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By DX EXPLORER
DX EXPLORER
Paul OM0ET and Peter OM6APN recently launched a new cluster dedicated to
QRP operations. Have a look and I hope you will enjoy...
3D Printing The Hadley 114mm Newtonian Telescope
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Yes, we’re building a 3D Printed Newtonian Telescope called Hadley. It’s
being printed in PETG and in the video below, I give a quick tour. My build
isn’...
3D printed project boxes
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I have been busy with some other things that have kept me away from
electronics projects for quite a while. Now I can get back to them, but
realize I n...
Daylight Again – An all Analog Radio
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What’s all this? In 10 seconds, A high performance, 7MHz, 5 watt SSB rig
Draws just 24 mA of current 90 dB dynamic range, 80 dB close-in dynamic
range 3D ...
Adding Enclosure to your sBitx Boards Order
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The early buyers of the sBitx board set who bought it for $270 USD might
want to also add the enclosure (box) for in the kit. What you will now get
is a f...
Digi-chirp! Digital synthesis of ‘nostalgic’ CW
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The bottom ends of 80, 40 and 20m are not what they used to be. For
starters, the busiest part is the digital segment where computers talk to
computers – l...
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A Simple Speech Processor
(For QRP/SSB Homebrew Transceivers )
Over the last few weeks I had been thinking to build a small AF speech
processor to add to...
A New Look for your uBitx!
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Adding a "Cool Blue" Display to your uBitx!
The standard "green background" with black lettering frequently reminds me
that I suffer from Chronic seasickn...
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