Podcasting since 2005! Listen to Latest SolderSmoke
Wednesday, January 1, 2025
Happy New Year from the Dominican Republic! SKN from HI7/N2CQR
Tuesday, December 24, 2024
So Many Great Pictures, So Much Radio History
Thursday, November 14, 2024
FDIM 2024 Interview with Farhan VU2ESE
Thanks to Bob Crane W8SX we have some great interviews with those who made presentations at the Four Days in May event (FDIM 2024). Sorry for the long delay -- it is all my fault, but I have excuses. Our thanks to Bob W8SX, our correspondent at the FDIM event.
Here is the interview with our friend Farhan, VU2ESE, the ham who has brought so much homebrew goodness to the hobby, starting years ago with the BITX 20 schematic.
http://soldersmoke.com/FarhanVU2ESE.mp3
Thanks Bob! Thanks Farhan!
Friday, November 8, 2024
Video Update on the Mythbuster II 20 meter SSB Transceiver
We will discuss this further in an upcoming Ham Radio Workbench Podcast, and in SolderSmoke Podcast #254 (mid-November 2024)
Wednesday, October 30, 2024
Bill N2CQR Builds Yet Another Mythbuster Transceiver
This one is for 20 meters (no need for 75) and will go to the Dominican Republic.
6 crystal filter at 5.2 MHz. VFO from old Yaesu FT-101 Termination Insensitive IF amplifiers using boards from Mostly DIY RF No RF amp ahead of the mixer. First mixer is homebrew diode ring. Bandpass filter has 4 LC circuits. Steep skirts. Low insertion loss. Bal Mod/Product detector has two diodes (singly balanced) Carrier osc is crystal controlled and homebrew. Audio amp starts with a 2N3904 amplifier followed by an LM386 board. Transmitter portion will be done next.Monday, October 14, 2024
Monitoring Maritime Radio Messages with YADD
Monday, September 30, 2024
Homebrew Receiver -- AG5VG's 20 Meter "Mythbuster" Receiver
Thursday, September 26, 2024
AI Podcast #2: Here is Another Short Podcast ABOUT SolderSmoke.
Click here for the second "About SolderSmoke" podcast.
http://www.soldersmoke.com/About SolderSmoke 2.mp3
This one looks not at the SolderSmoke Daily News blog, but instead at the SolderSmoke podcast itself.
I was delighted to see the inclusion of Pete, Dean, Farhan and Mike Rainey! This was really great.
Look, it is not perfect. There are errors. But probably about the same number of errors that you would get from real, human hosts, right? Voltaire told us not to let the perfect be the enemy of the good. And I find this to be amazingly good. Look, it is so good that it is kind of scary, right?
Before you get too critical realize how this has been done: I did nothing more than load the SolderSmoke Podcast Archive website into GPT-like model. Then I asked it to produce a deep dive podcast. That's it. About 5 clicks. It developed the podcast in about 3 minutes. I did the same thing yesterday but with the SolderSmoke blog. And this is only the beginning.
Wednesday, July 10, 2024
A Paraset and the Heathkit SG-6 Signal Generator (Video)
Mike WU2D put out this nice video (above) about whether or not he should part out his Heath SG-6 signal generator, using the parts in a Paraset construction project. I faced a similar question years ago:
https://soldersmoke.blogspot.com/search?q=SG-6
I just solid stated the SG-6. I was influenced by Farhan and the drinking straws that he picked up with his kids at a McDonalds in Hyderabad.
As with the QF-1, I say to Mike: GO FOR IT OM! You need those parts for other projects. Don't feel bad about the SG-6. But keep that switched coil assembly -- it is quite useful.
Tuesday, June 25, 2024
Field Day with Farhan, his Family and an sBITX Near Hyderabad, India
Farhan and his son Rayyan with an sBITX
The SolderSmoke crew thought it had a tough time this Field Day: Pete N6QW had hoped to do something, but was stymied by hot California weather. Dean KK4DAS had even worse weather. Bill HI7/N2CQR was at a remote QTH with an HW-8 and a wire antenna -- he managed just ONE contact (W7RN in Nevada on 15 CW). But none of us had as much trouble as our friend Farhan had. In his account of Field Day in Hyderabad, we see an intrepid ham standing up against the slings and arrows of outrageous fortune that Field Day often throws at true radio amateurs. Here is Farhan's Field Day story:
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You asked for it, so here it goes...
Saturday, June 1, 2024
Farhan Talks Radio Tech at SolderSmoke HQ (EAST) (TWO VIDEOS!)
Monday, April 29, 2024
Old Tricks, Lore, and Art -- Freezing and Baking our LC VFOs -- An Example from Cuba
Pavel CO7WT explained why Cuban hams used a process of thermal endurance to improved the frequency stability of their homebrew rigs:
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I'm CO7WT from Cuba, I started my endeavor in ham radio with a islander board.
They (FRC, like ARRL but in Cuba) made a print of a PCB to build the Islander, with component numbers and values, making construction fool proof, I think it was on the 90 or end of the 80...
Mine was built with scraps from an old KRIM 218 Russian B&W TV as Coro's explain, later on I get the 6bz6 and 6be6 tubes for the receiver (this worked better than the Russian parts) the VFO was transistorized, made with Russian components. A friend CO7CO Amaury, explain me a trick: thermal endurance:
For a week put a crust of ice on the VFO board by placing it in a frosty fridge during the night. Put them in the sun by day. This indeed improved stability, this was an old trick.
By thermal endurance I
mean improving thermal resistance vs tolerance, meaning that tolerance doesn't
vary as much with temperature changes.
I remember that my vfo was on 7 MHz, with Russian kt315 as normal Russian transistors and capacitors, nothing 1-5%, 20% at most, it ran several khz in 5-10 min, mounted on a Russian "Formica" board (no PCB) and wired underneath.
After that treatment to the complete board with components and everything, including the variable capacitor; I managed to get it to "only" noticeably in the ear after 30-40 minutes.
To me it was magic!!
Basically, what I'm describing is just "thermal annealing", but Cuban-style and with more extreme limits.
In a refrigerator you could easily reach -10 c and in the sun for a day in Cuba 60-80 celsius at least.
In Cuba in the 1990s-2010s many designs of DSB radios proliferated, both direct conversion and super heterodine (using an intermediate frequency)
At first tubes and then transistors, mostly using salvaged parts, so it was common to find 465/500 kHz (if common Russian) 455 khz and 10.7 Mhz with or without "wide" filters since narrow filters for SSBs were not scarce: they were almost impossible to get.
Not only that, crystals, ifs, PCBs, transistors, etc.
Then, around the 2000s, Russian 500 khz USB filters began to appear (from Polosa, Karat, etc. equipment from companies that deregistered and switched to amateur radio) and that contributed to improving... Even though at 7 MHz 500kc if is very close.
I made many modifications with the years mostly from 1998 to 2004 ish... better filters in front of the first RX stage (same IF described between stages) improved selectivity and out of band rejection, remember we had on that days broadcast as low as 7100 khz
Tx part was a pair of russian 6P7 (eq. RCA 807) in paralell, etc.
The Jagüey and others is one of those evolutions...
73 CO7WT
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This is not as crazy as it sounds. We can find versions of the same technique in the writings of Roy Lewellan W7EL, Doug DeMaw W1FB, and Wes Hayward W7ZOI. I found this 2007 message from our friend Farhan VU2ESE:
I think the word 'annealing' is a bit of a misnomer. the idea is to thermally expand and contract the wiring a few times to relieve any mechanical stresses in the coil. after an extreme swing of tempuratures, the winding will be more settled.
this techniques owes itself to w7EL. I first read about it in his article on the 'Optimized transceiver' pulished in 1992 or so.
but all said and done, it is part of the lore. it needs a rigorous proof.
- farhan
And here is another example of coil boiling:
https://www.qsl.net/kd7rem/vfo.htm
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I can almost hear it, all the way from across the continent: Pete N6QW should, please, stop chuckling. Obviously these stabilization techniques are not necessary with his beloved Si5351. Some will see all this as evidence of the barbarity and backwardness of LC VFOs. But I see it as another example of lore, of art in the science of radio. (Even the FCC regs talk about "Advancing the radio art." ) This is sort of like the rules we follow for LC VFO stability: keep the frequency low, use NP0 or silver mica caps, use air core inductors, keep lead length short, and pay attention to mechanical stability. Sure, you don't have to do any of this with an Si5351. Then again, you don't have to do any of this to achieve stability in an Iphone. But there is NO SOUL in an Iphone, nor in an Si5351. Give me a Harley, a Colpitts, or a Pierce any day. But as I try to remember, this is a hobby. Some people like digital VFOs. "To each, his own."
Thanks Pavel.
Tuesday, March 5, 2024
A Contact with my Old Azorean DSB Transceiver
"Looking inside and seeing the o-scope probe in place while the radio was on the air reminded me of neurosurgery where the patient is awake and talking while the surgeon probes different brain regions soliciting feedback. Sure, ham radio isn't neurosurgery, but it's not too far at times. Also, you already have rocket science covered."
Sunday, February 25, 2024
Innovation and a Dual Band Sweep with Version 2 of the 15-10 Transceiver
The video below shows the receiver in action this morning on 15 and 10 meter SSB. I think it sounds pretty good.
Monday, February 12, 2024
Dean's Amazing Homebrew sBITX
Tuesday, February 6, 2024
Pine Boards, Analog VFOs, and Homebrew BITX Transceivers -- AG5VG's Magnificent Creations
This is amazingly cool. WE ARE NOT ALONE! There are others out there breaking the tyranny of the Si5351, building BITXs with analog LC VFOs. And using copper clad boards affixed to pine boards. Plywood cabinetry! And medicine bottle coil forms. Really great. And what a wonderful workshop. Thanks Michael.
Good Afternoon Bill,
Sunday, February 4, 2024
Scott KQ4AOP Successfully BUILDS a Receiver (Video) -- This is the Homebrew Spirit at its Maximum
This is just so cool. Scott KQ4AOP has successfully homebrewed a ham radio receiver. He used the circuit Dean and I developed (with a lot of input from Farhan and others) for the High School receiver project. But Scott has had more success than any of our students. And I think he has had -- in a certain sense -- more success than any of us. After all, how many of us can say -- as Scott can -- that he used a homebrew receiver that he made to listen -- for the very first time -- to amateur radio signals? Scott writes: "Those first sounds were my first time ever hearing any Amateur Radio first hand!"
In the video above you can watch Scott tune the entire 40 meter band and a bit beyond. You hear CW at the low end. Then FT-8. Then SSB. Up just above the top of the band I think you can hear our old nemesis Radio Marti. And this powerful broadcaster is NOT breaking through on the rest of the band. FB Scott. Congratulations.
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Bill,
Bill and Dean - Thank you for sharing and documenting this receiver. I greatly appreciate you publishing the circuit, class notes, and build videos. That got me 75% to completion.
I feel blessed that both of you chipped in and encouraged me through the troubleshooting to finally getting the receiver to start “breathing RF”.
Those first sounds were my first time ever hearing any Amateur Radio first hand!
Friday, February 2, 2024
First Light! First Signals received on Version II of Homebrew 15-10 Transceiver
Ianis S51DX in Slovenia was the first call sign heard. Some peaking and tweaking remains to be done, but the receiver is working.
Congratulations to Scott KQ4AOP who got his Direct Conversion receiver working yesterday, And congratulations to Armand WA1UQO who got his regen receiver working. I think all of us are following Farhan's advice and are taking some time to just listen to the receivers we have built ourselves.