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Wednesday, July 9, 2025
Oscillation! Negative Resistance! Barkhausen Explained Very Well!
Saturday, October 28, 2023
Mattia Zamana's Amazing Direct Conversion Receiver
Thanks to Ed KC8SBV for sending me this awesome video. It looks like Mattia built this receiver way back in 1995. The tuning indicator is very cool, and I had not seen a similar indicator before (could this be a way for us to escape the clutches of the San Jian counters or the Arduinos?) The Italian ham magazine articles are great, and you can follow the rig description even if you can't read the Italian. The pictures in in the attached drive are also very good.
WB9ZKY used Google Translate to get English versions of the articles. Thanks Chuck!
https://www.dropbox.com/scl/fi/kil3osilchqlyk8afim2r/part1.pdf?rlkey=9ubgaqb8t4k91d1a10su9mw1p&dl=0
https://www.dropbox.com/scl/fi/t2790qatf5riepyqh5oj1/part2.pdf?rlkey=bhs77gkcchziakh7ngjbpuaz7&dl=0
I have been in touch with Mattia via YouTube: He reports that he has done other electronic projects, but he considers this to be the most interesting. He does not have a ham license -- he has a Shortwave Listener license. His father was a ham: I3ZQG.
This is one of the rare cases in which the builder should -- I think -- be issued his ham licence purely on the basis of this build.
Mattia writes:
Tuesday, November 15, 2022
Dhaka Jack Moves to France
Jack Welch AI4SV has been an important member of the SolderSmoke community for many years. I remember fondly our Straight Key Night CW contact in which he told me that my HT-37 had "presence" even on CW. His thoughtful (!) piece on time crystals was also quite memorable. Jack has finally settled down (a bit) after a string of foreign assignments. He has landed happily in France, in a villa, on a vineyard, surrounded by wild boar and hunters. FB OM.
Hi Bill & Pete,
I've packed up the shack and moved from Cyprus to France, so no more 5B4APL. To obtain a French callsign, you have to submit proof that you've lived in France for three months, so I'm F/AI4SV until December and then we'll see.
I'm not sure how long we will be here, but probably a few years at least. Since we know next to nothing about French real estate, we are renting for the first couple years -- a château on the outskirts of Bordeaux. Before you think that I've come down with delusions of grandeur, I should point out that in that area, château means an old, stone house that is hard to heat in the winter -- and particularly difficult to run wiring around. Antennas and grounding are going to be particularly challenging. The selling point for the house was not so much my hobby as its location in wine country. In fact, there is a Sauterne my house's name on it (although I have nothing to do with production of the wine, that's in professional hands).
Back in the early days of Soldersmoke, Bill used to occasionally mention the dreaded Italian wild boar, the cinghiale. I didn't think that would ever be terribly relevant to me, but it is. A couple days after arriving in the Bordeaux suburbs, a sanglier (French cousin of the cinghiale) strolled across a road as I came around a bend. We almost had a month-long supply of bacon, but I managed to steer around him.
Since it will be a while before all our belongings arrive and even longer to set up a proper station, I have focused on operating QRP in the field and activating SOTA summits. That has gone well, but I aborted my most recent attempt when I ran into a bunch of orange-clad rifle-toting hunters who were combing the mountain in search of sanglier. Apparently it's a big thing here. I decided to survive to activate the peak on another day.
Finally, I have attached a journal article, which at first glance doesn't seem to have a lot to do with radio, but kind of does. It turns out that both the human ear and violins have non-linear characteristics that cause them to function as audio frequency mixers. Looking through the article, you'll find some familiar looking formulas about mixing products, harmonics and resonance. If Bill wants to get away from ICs, perhaps his next rig could include a 17th Century Italian violin as a mixing stage.
Cheers & 73,
Jack
F/AI4SV
Thursday, September 15, 2022
SolderSmoke (Old Smoke) Podcast #103 -- March 15, 2009 -- From Rome -- QRSS, Knights and Wizards, LTSpice, and an Echolink QSO with Jeff KO7M (the guy with the Piper Cub)
15 March 2009
Beware the Ides of March! Ostia Beach and Ostia Antica 248 Knights of QRSS. And Wizards! ET Phones Home (with QRSS?) Possible new grabbers in VK6 and Dubai Telescope, Satellites... REAL QRP QSOs on 80 and 40 Saving an old Toshiba Laptop ECHO-QSO WITH JEFF, KO7M: -- Piper Cubs and MFJ Cubs -- Satellite QSOs -- LT Spice and test gear MAILBAG: Gene W3PM listens from QE2, HB WSPR rig Jim AL7V sending parts for my W3PM rig Jim AB3CV's color burst Gnat Jason NT7S on Tektronix guys and SolderSmoke Kevin ZL3KE on old computers Paul M1CNK's DDS 30-based QRSS beacon Soeren OZ2DAK on exercise bikes to power beacons
Sunday, September 11, 2022
An Especially Good (Old) SolderSmoke Podcast
Wednesday, June 1, 2022
Marconi the Fascist
For obvious reasons Marconi stories pop up in my news feeds. This morning an article from Wales reminded me of a very dark and disheartening aspect of Marconi's life: his fascism and his participation in the persecution of Jews.
There have been at least 14 stories in SolderSmoke extolling the technological virtues of Marconi. I even met his daughter Elettra while in Rome and wrote it up for the blog. But it is just wrong to sing Marconi's praises while ignoring his fascist involvement.
His fascism wasn't even separated from his radio work. He won fascist honors and he won his appointment to Mussolini's Academy of Italy because of his radio work. Take a look at this quote:
The article from Wales:
Saturday, March 26, 2022
Getting More Rigorous About Receiver Design (Video)
The author of the software seems very cool"
My name is Alfredo Accattatis; I love electronics and software, and I have been working for years in commercial companies as software/firmware engineer and software designer. I've been writing programs for embedded systems (with DSP and MICROCONTROLLERS), for PC, for Avionic Computers and even for Mainframes, using C, C++, Pascal, Ada, REXX and assembly. I starting write VA during my free time just for fun and using (also) my DSP experience. The program was and is completely FREE.
More info about Alfredo here:
https://www.sillanumsoft.org/about_the_author.htm
Do you folks think I need to buy the kind of True RMS Audio Voltmeter that is being used at the end of the above video?
Wednesday, January 26, 2022
Image of James Webb Space Telescope In Position at L2
Saturday, February 27, 2021
Update from the Wizard of Wimbledon -- "Always listen to Pete"
In a recent podcast, Pete mentioned that Leo Sampson (the young Brit who is rebuilding the sailing yacht "Tally Ho") should seal the deal with his girlfriend. Well, it seems that "life coach" should be added to Pete's already impressive list of abilities (homebrew hero, pasta chef, guitar player, etc.) A while back Pete gave similar advice to Jonathan, M0JGH. This morning, Jonathan reported in, confirming that Pete's advice was completely correct. A "mixing product" arrived early in the lockdown. Congratulations to Jonathan and his remarkably radio-tolerant wife. It seems Leo should be shopping for a ring.
--------------------------
Dear Bill and Pete
Monday, October 12, 2020
Quino, The Creator of Mafalda ("BASTA!") RIP
Putting "Basta" in the SolderSmoke search box yields many blog posts. The cry of ENOUGH! from six year-old Mafalda has been part of the podcast for many years and is now part of the SolderSmoke lexicon.
https://soldersmoke.blogspot.com/search?q=Basta
We don't do a lot of obits on this blog (we try to keep it all upbeat) but the passing of Mafalda's creator Quino is news that many of you may have missed, and that I think merits mention here. This link has a nice 3 minute report from NPR:
https://www.npr.org/2020/10/04/920038792/mafalda-cartoonist-quino-dies-at-88
Adios Quino. Gracias por todo.
Saturday, September 28, 2019
Radio Art -- Zenith Tube Ad
This ad was recently shown on the K9YA Telegraph. I was wondering about its origins. I asked noted thermatron guru Grayson Evans -- he referred the question to fellow tube guru and author Ludwell Sibley. OM Ludwell gives us the origins:
Ludwell Sibley is the editor of "The Tube Collector." Great stuff. Their web site is here:
She’s in a promo for Zenith, an Italian prewar brand that sold European triodes of types originated by Philips, and a few equivalents of American types. She’s based on classical Italian art. Doing a high-wire act while holding a small early-‘20s European radio! I have an 11 x 17 glossy color print framed on the wail in the display room. I ran her as the cover art in a long-ago issue of “Tube Collector.” “Three cheers for the red, white, and green!"
Sibley's book "Tube Lore" can be purchased here:
https://www.amazon.com/Tube-lore-reference-users-collectors/dp/0965468305/ref=sr_1_1?keywords=Tube+Lore&qid=1569660647&sr=8-1
Thanks Grayson, Ludwell, and to the K9YA Telegraph.
Sunday, February 3, 2019
The Wizard of Wimbledon M0JGH: "Always Listen to Pete!"
Friday, February 1, 2019
UK Wartime Radio -- The Secret Listeners
We had this video on the blog before, but it was seven years ago, so it it time for a re-run.
http://www.eafa.org.uk/catalogue/5108
Thanks to Graham GW8RAK for reminding us of this.
Listening to it again, I was struck by the claim that the nationality of the operator could be discerned purely by his or her CW sending style. Is there really an Italian accent in Morse Code?
Friday, November 23, 2018
The Max Valier Satellite Flies Over, Sending CW
I understand the launch of Farhan's CubeSat has been delayed a few days. That's the way it works in the rocket launch biz --patience is required. In the meantime, I've been practicing with my receive system. Today at 1000 local the Max Valier satellite flew to my west. It rose 78 degrees above my horizon to the W NW. I left my three element quad pointed in that direction and waited for the satellite (which had been launched from India) to fly through its pattern.
The CW beacon was quite strong, very visible and audible through my RTL-SDR dongle and HD-SDR software. You can see it and hear it in the video above. There is something quite charming about this very personal Morse message coming down from orbit and then passing through all that digital technology.
More info on the satellite:
"Max Valier Sat" is an amateur satellite built in cooperation by:
- "Max Valier" High School in Bolzano/Bozen (Italy)
- OHB System AG from Bremen (Germany)
- Max Planck Institute for Extraterrestrial Physics from Garching (Germany)
Beacon by Holger Eckardt DF2FQ:
- Transmit frequency is 145,960 MHz (IARU and ITU coordinated).
- Modulation is CW:
- Duration of one dot is 114 ms.
- Duration of one dash is 342 ms.
- Interval between words is 1881 ms.
- Interval between repetitions of the message is 6000 ms.
- The beacon transmits Max Valier Sat's call sign and a greeting message.
- Transmitting power is 500 mW.
And who was Max Valier? Quite an interesting fellow:
![]() |
Max Valier in his Rocket Car in 1930 |
Saturday, October 7, 2017
IZ7VHF's Video on on Hans Summers' QCX Rig, and a Video from Hans
Thanks to W8SX for alerting me to this.
There is a lot of good stuff on Roberto's site. He obviously has THE KNACK.
http://radio-signals.com/
Hans himself has a less detailed video on the rig:
Tuesday, August 15, 2017
International Brotherhood and the BITX Rigs
![]() |
Bore and Heriberto's uBITX board |
In Italy, Giuseppe is putting a BTX40 on 20 meters and making it a dual bander:
Here the issues registered:
1) the 20 RX sensitivity was a bit weak compared to 40 meters. I need to increase volume. ( To receive the 20 meters the vfo run to 26 MHZ, mybe some stage suffers of poor performance in this High frequency?)
I also tryed to increase the vfo over maximum allowed by raduino, using external buffer, but no results.
Please read the issues as: work but could work better!
The firmware to make the test was a modified version of 1.17.1, few temporary mods to preset the vfo b to 14 MHz USB and correct the freq. Display.
Giuseppe Callipo IK8YFW.

Hi to all.
- Upgraded the operations instructions
- More user friendly version with embedded images.
- Add instructions for the S-meter, AGC and TX-power mods details and tricks.
- Moved all images to its own folder "images".
- Bug removal in the calibrate function.
- Finish the upgrade of the Si5351mcu lib with some improvements.
- Adding CAT support via ft857d lib (https://github.com/pavelmc/ft857d):
- Full compliance needs get rid of all the blocking delay() sentences and that need a structural/paradigm code change and a lot of testing (I have Fldigi/MixW/Hamlib to test, I think if that 3 works the rest will do it)
- Moving to a library (yatuli: https://github.com/pavelmc/yatuli) for the pot usage, that will ease the process of implementing the CAT as almost all delay() calls are related to pot/clicks, so I'm on it.
- Maybe implement a multiclick lib to optimize the code and make it more easy to understand.
I plan to make the CAT operation optional via a #define declaration as not all of us will/want-to use that.
73 Pavel CO7WT
Here we see Bore in Montenegro working on a uBITX designed in Cuba by OM Heriberto
Qrv's
73's Jc
![]() |
Bore and Heriberto's Board |
ja9mat Hidehiko
Look in the lower right, near the LM386 AF amplifier. Click on the schematic to enlarge. 73 Bill N2CQR
Well I added "3-parts"(2N3904+47kohm+100uF) between the D18(1N4148) and the junction of R111(100ohm) and R1113(220ohm). The noise has absolutely gone!
ja9mat Hidehiko.
Wednesday, April 6, 2016
The Wizard of Wimbledon writes of Emperor Hadrian's QTH, HMS Belfast, JFK and QRP
I write this to you from my shack in Wimbledon, south west London, with the crackle of the bands slowly waking up across Europe, having just devoured the final few pages of your excellent Soldersmoke book; an intriguing and entertaining tale to which many of us can relate, a highly-accessible technical primer which certainly helped me to clarify a few niggling “Yes, but why?” questions, and a compendium of handy tricks to try during future projects – thank you for sharing your story.
I was amused to read that GB2RN, on HMS Belfast in London, where I am now one of the “new boy” volunteers, was an inaugural contact for your Azorean 17m DSB rig. As it turns out, 12000 tonnes of British warship seems to play an crucial role in testing QRP radios:
In mid-December 2015 we once again flew out to Rome for our pre-Christmas break. Our first day was spent exploring the stunning Villa D'Este (stunning to behold, an ideal high radio QTH but far too beautiful for my wires to pollute the scenery without getting into trouble...) and Villa Adriana, near Tivoli. It was only right at the end of the afternoon, and annoyingly lower down towards the plains, when I stopped for a few minutes for an attempted sked with GB2RN.
Lesson 1: trees with lots of branches and twigs are a real pain for throwing wires through! I had guessed this already, but it truly is an exponential problem.
After conquering a geometric puzzle, I had my EFHW strung so that the point of maximum radiation was about 4m in the air – not exactly ideal for DX but theoretically reasonable for a nice high angle of radiation, like I needed. The feed point (fortunately a current null) was at roughly half this… time to get on the air!
Lesson 2: when operating outdoors – beware of the locals!
Rather than a comfortable bench I resorted to operating whilst sitting cross-legged on the grass, balancing my ex-German military miniature key on my thigh as I tapped it with my finger and attempted to steady it with my left hand.
The ambient sound of the 40m band seemed very different in I-land – that was the busiest I'd heard it outside of contests, riddled with deafening Eastern-bloc calls but not a single station from any of the British nations, which I presume must have largely been in the shade of the skip; apart from booming GB2RN beaconing to me high on the band :-)
The Villa closes at 1700 and from past experience the wardens come around at 1630 to chase stragglers out from the far corners. Annoyingly one such woman decided that my guy wire and its supporting tent peg looked highly out of place and must be interfered with. My Italian is woefully incompetent at the best of times, so I resorted to gesticulating at her wildly with my left hand as my right attempted to stay faithful to sending clear CW.
Perhaps it was for the best; had she understood that I was “Making a scheduled contact with a British warship via Morse code using home-built equipment which I had smuggled into the country by air last night", the tale might have taken an entirely different twist...
Cold hands, fading light and a dead leg from sitting in an awkward cross-legged position which is frankly impractical for anybody beyond the age of 8, but I was utterly thrilled to have enjoyed my first QSO from overseas, and particularly so since it was with my Elmer on the ship using a station which I had diligently put together myself over a number of months.
The first wisps of solder smoke have already left my iron this morning as I embark on the next stage of my QRP apprenticeship – to make the jump from a kit operator to a scratch-built home brew. All my life I have yearned to understand from first principles, and our remarkable hobby offers us a unique privilege to do so whilst sharing experience along the way.
72/3
Jonathan
M0JGH
PS Should you or any of the Soldersmoke brotherhood ever be in London and wish to operate from GB2RN, please don’t hesitate to contact me.
Tuesday, March 8, 2016
German Mighty Mite works Venice on 40 (video)
Saturday, July 11, 2015
Interview in China with Arduino's Massimo Banzi: "Be nice!"
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20
Thursday, June 25, 2015
A Homebrew Compendium from Hungary
Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20