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Wednesday, October 29, 2014
"Science Friday" Interviews Author of "The Innovators" (listen)
Michael Rainey alerted me to Ira Flatow's Science Friday interview with author Walter Isaacson. I'm reading Isaacson's new book "The Innovators" (appropriately, on my Iphone 5). The book is very good, with surprisingly frequent references to ham radio. Flatow's interview with Isaacson is also quite good, and will give you a better idea of what the book is about. Here it is. It is worth a listen:
http://www.sciencefriday.com/segment/10/24/2014/meet-the-innovators-who-made-the-digital-revolution.html
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
Labels:
books,
computer history
Tuesday, October 28, 2014
Mailbag: Coils Wound Backwards, Last QSO 1981, Visions of Transistors Keeping Him Awake. Paul has THE KNACK
Hi Bill
I'm just getting back into ham radio after 33 years (last QSO: 1981),
want to do it all through homebrew, seem to have the same mindset as
guys like you and Frank K0IYE, bought your book [love it and Frank's],
and just "discovered" the Soldersmoke podcasts. I've been listening to
them with one ear as I bike to and from work (about 40 minutes each way, so it's almost perfect). I'm employed as a digital geek, but yearn for the days of DeMaw's prime (worked him once when he was W1CER), when the 40673 ruled. I'm very glad that, 40 years later, people like Farhan can weave discrete analog wonders, even if they later choose to use digital *control* (NOT DSP! No!).
I had to start somewhere with your podcasts archive, so I started with
2014 and really enjoyed your struggles with the Herring-Aid 5. My 1st
receiver was the "DC 80-10" by DeMaw from somewhere around 1970 in QST or the Handbook -- used a CA3028 as the product detector -- and I had similar struggles. While listening to it, I immediately thought "you wound the feedback coil backwards, you idiot!"
I got my license back in March 2014 and want very badly to get back on
the air with a homebrewed, or at least minimally-kitted, station. I've
built the receiver: David White's (WN5Y) Beginner's and Experimenters
receiver[1] heavily modified, have a long wire antenna up, a decent RF
ground, and all the parts I need for QRP z-match tuner, swr meter, T/R
switch, sidetone, and IRF510-based transmitter. Target: 40m CW by the middle of December, 30m in the couple of months after that with a
fully-Manhattan-style Barebones Superhet and another IRF510
transmitter. Then one of these BitX things. It's been a couple of
decades since I felt that there weren't enough hours in the day. Some
nights I can't sleep, what with all these transistors and simple analog
ICs whirling around...
Anyway, keep it up, I'll be listening.
-- Paul Lender, AD0HQ
[1] I built an Arduino/AD9850 DDS -- a la AD7C -- and used it to tune a
4-crystal filter (10-cent crystals from Tayda!) for the receiver with
the same Rigol scope that you use. I tried, really tried, to do it with
an analog RF signal generator. Change is good. Change is good.
I'm just getting back into ham radio after 33 years (last QSO: 1981),
want to do it all through homebrew, seem to have the same mindset as
guys like you and Frank K0IYE, bought your book [love it and Frank's],
and just "discovered" the Soldersmoke podcasts. I've been listening to
them with one ear as I bike to and from work (about 40 minutes each way, so it's almost perfect). I'm employed as a digital geek, but yearn for the days of DeMaw's prime (worked him once when he was W1CER), when the 40673 ruled. I'm very glad that, 40 years later, people like Farhan can weave discrete analog wonders, even if they later choose to use digital *control* (NOT DSP! No!).
I had to start somewhere with your podcasts archive, so I started with
2014 and really enjoyed your struggles with the Herring-Aid 5. My 1st
receiver was the "DC 80-10" by DeMaw from somewhere around 1970 in QST or the Handbook -- used a CA3028 as the product detector -- and I had similar struggles. While listening to it, I immediately thought "you wound the feedback coil backwards, you idiot!"
I got my license back in March 2014 and want very badly to get back on
the air with a homebrewed, or at least minimally-kitted, station. I've
built the receiver: David White's (WN5Y) Beginner's and Experimenters
receiver[1] heavily modified, have a long wire antenna up, a decent RF
ground, and all the parts I need for QRP z-match tuner, swr meter, T/R
switch, sidetone, and IRF510-based transmitter. Target: 40m CW by the middle of December, 30m in the couple of months after that with a
fully-Manhattan-style Barebones Superhet and another IRF510
transmitter. Then one of these BitX things. It's been a couple of
decades since I felt that there weren't enough hours in the day. Some
nights I can't sleep, what with all these transistors and simple analog
ICs whirling around...
Anyway, keep it up, I'll be listening.
-- Paul Lender, AD0HQ
[1] I built an Arduino/AD9850 DDS -- a la AD7C -- and used it to tune a
4-crystal filter (10-cent crystals from Tayda!) for the receiver with
the same Rigol scope that you use. I tried, really tried, to do it with
an analog RF signal generator. Change is good. Change is good.
Labels:
DeMaw--Doug,
Farhan,
Knack Stories
Monday, October 27, 2014
Dear Santa: I want a Knack Watch. The one with real tubes...
This is what all the cool homebrewers will be wearing next year. Just be careful at airport security -- they might not understand!
Check it out: http://www.johngineer.com/blog/?p=1595
We received some comments from some noted Thermatron authorities:
Hi Guys,
This will cause all of the bells, whistles and sirens to go off all it once.
Now all that is needed is a logo on the watch that says
EBOLA ( Electronic Bi-state Operational Long Arithmetic) and this will cause you to go to jail without passing Go or collecting $200.
Pete
---------------------
Wow, I love this thing!…even though it uses little black plastic things to work. Have no idea what they are. (johngineer has knack squared)
Reminds me of a project I am trying with fellow ham. We picked up an old HP nixie tube freq counter at junk yard. We were going to strip out the nixie tubes to make a clock, but decided we could make it as clock as is. Want to program an Arduino thing into generating a frequency that is the time and feeding it into the counter.
For example 3:45:25 would be 34,525 Hz.
But my Italian is terrible so haven’t been able to get the Arduino to work. Just learning it. Project a bit over my head. picked up one of those online language courses on Italian. Hard, but not as hard as Turkish!
Grayson
TA2ZGE - Ankara, Turkey
KJ7UM
Follow the Hollow-State Design Blog
-----------------------
I'm wondering if I could do it Manhattan style, with discrete components...
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
Labels:
Tubes
Saturday, October 25, 2014
Spark Forever! Pete's First Transmitter
The SolderSmoke legal team (we too use Dewey, Cheetham & Howe!) has advised us to be very careful about divulging the details on this rig. They are not sure about the statute of limitations. Beyond what he said on the podcast, all Pete will say is that TOOBs were involved: 1S4, 3S4, 3Q4, 3Q5, 3V4s. He says power out was ALWAYS less than 100 mw ERP. That's his story and he's stinking to it.
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
Labels:
Juliano -- Pete,
Knack Stories,
Old radio
Friday, October 24, 2014
Smart-Phone Cosmic Ray Detector
http://hackaday.com/2014/10/17/detect-cosmic-rays-with-your-smartphone-using-crayfis/
I find this cosmic ray project very appealing.
Also, Adam Fabio over on Hackaday recently posted a Hack-let on ham radio:
http://hackaday.com/2014/10/17/hacklet-19-ham-radio/
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
I find this cosmic ray project very appealing.
Also, Adam Fabio over on Hackaday recently posted a Hack-let on ham radio:
http://hackaday.com/2014/10/17/hacklet-19-ham-radio/
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
Wednesday, October 22, 2014
"Two guys and a Minima walk into a bar..."
Thomas, KK6AHT, was in Washington this week. He and I got together for a beer and a look at his Minima.
I'd seen pictures of it, but it was much more impressive in person. Thomas did a great job on this rig. It is a really nice mixture of digital and analog. I liked the fact that he built the analog portion Manhattan style using MePads. He and I agreed that while it would make sense to produce a PC board for the Arduino/Si570/LCD portion of the rig, builders should be encouraged to do the rest Manhattan style.
Showing true homebrew dedication, Thomas was unhappy with the level of audio output when we turned it on. He started to trouble-shoot right there in the Ruby Tuesday bar!
It turns out that we were in a very Knack-ish location. We were on the site where they created ARPANET.
Thomas very kindly left me with a nice package of Minima digi-parts including the Arduino chip loaded with the software and an SI570. So now I have no excuse.
Thanks Thomas!
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
Tuesday, October 21, 2014
Arduino Hell!
Hi Bill,
I am a long time listener of SolderSmoke and a big fan! Since your last podcast was on the use of Arduino’s for ham radio, my Arduino Hellschrieber project may be of interest to you and your listeners. I am using the $15 dollar RadioShack color display they are closing out and a simple circuit with our favorite transistor!
I have a video in my second blogpost and all the details with code below.
Keep up the great work, I have your book both in print and Kindle!
73, Dan WA6PZB
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
Labels:
Arduino,
digital modes
Monday, October 20, 2014
Has AA1TJ Joined the FMLA?
I have learned that esteemed homebrewer Michael Rainey, AA1TJ, recently whipped up a 56 MHz, quarter-wave, helical coaxial resonator (BTW: the spoon is also homebrew). Hmm, 56 Mhz. Or perhaps we should say MegaCYCLES? Michael claims this device is for a low phase- noise VFO, but I find the frequency selection highly suspicious. The last time I heard of that frequency it had to do with an underground group set up by the late (or not so late) Frank Jones.
Here is all the info on Frank's Five Meter Liberation Army.
http://www.sunflower.com/~brainbol/frank/
A man of the '30s awakens one night in the '90s (episode 13) with a new mission: recapture 56-60 mc. He forms a Five Meter Liberation Army from his mobile home in a Barrio trailer park run by Tom Joad of Steinback's Grapes of Wrath (episode 9), and soon draws a decidedly uncolorful bodyguard (episode 7). A six foot tall half Mexican stockbroker named for Ayn Rand makes him rich and a demonic white ferret and a half-siamese cat become his familiars. (episodes 10 and 9). The leader of all this, called only "Frank," settles down in the narrator's basement to be joined by Maj. Armstrong (episode 8), Hiram Maxim (episode 23) and one-time pals Carl and Jerry from the 1950s Popular Electronics (episode 25). His huge 1940s sedan, with contemporary plates, is immune from police (episode 13 et seq) and his breadboarded electronic creations recall those distant days when a ham built his own rig and could "fix a radio." Of course all this is crazy. No one builds anything anymore and the other things Frank stands for, like self- reliance, tolerance and a generally Boy Scout viewpoint are simply out of step. Frank knows that too (episode 20), but he does not care. If you're standing in the middle of the road and see a big brown Frazer coming at you, you better jump - one way or the other.
VIVA EL FMLA! VIVA!
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
Labels:
Jones -- Frank,
Rainey -- Michael
Sunday, October 19, 2014
Tribal Knowledge Video: Putting Screw Threads in Aluminium
http://youtu.be/LuqliWT1k5A
Thank you Giovanni Manzoni, whoever you are!
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
Labels:
Juliano -- Pete,
video,
workbench
Friday, October 17, 2014
Author Walter Isaacson was a Radio Amateur
This is the guy who wrote the biographies of Einstein, Steve Jobs, and Ben Franklin that I've been talking about on the podcast. President of the Aspen Institutes, former Chairman of CNN and editor of Time Magazine. And, as I learned today, a former ham radio operator. In his new book, "The Innovators," he writes:
"My father and uncles were electrical engineers, and like many of the characters in this book, I grew up with a basement workshop that had circuit boards to be soldered, radios to be opened, tubes to be tested, and boxes of transistors and resistors to be sorted and deployed. As an electronics geek who loved Heathkits and ham radios (WA5JTP) I can remember when vacuum tubes gave way to transistors."
When I told Billy about this, he said, "No wonder you like his books so much!" Indeed. Walter has THE KNACK. I'm enjoying his book, "The Innovators."
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
Labels:
books,
Knack Stories
Thursday, October 16, 2014
A Different Kind of Workshop
Sometimes it is good to take a break from the electronics and look at how people are making other things. I've been working on the heat sink for a 140 watt solid state amplifier, so this fellow's comments about working with metal kind of resonated with me.
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
Wednesday, October 15, 2014
SW Echo Theory Confirmed By a BBC Engineer
BBC Relay Station Singapore
Hi Bill,
I heard your description of the echo on your podcast and
before listening I knew the cause - but I think you know that now!
Yes, it's from two separate transmitters, and quite common,
though not usually noticed.
It has nothing to do with path length differences - the
longest round-the-world echo via the ionosphere is only about 0.15 seconds - so
anything more has a different cause.
It's from the audio feed to the transmitter. Your regen
receiver picked up two transmitters on different frequencies. It was very
noticeable before transmitters used digital land-line feeds, just analogue and
satellite.
On a BBC SW frequency (forget the which one now) one tx was
in UK and the other in Singapore, on the same frequency with the same programme
to completely different service areas. When propagation was right and listening
in Europe, the UK signal fed by analogue audio from Bush House came first and
the Singapore tx came with two geostationary satellite delays later, plus the
tiny bit of UK-Singapore ionospheric path difference.
Now it's worse because there are all sorts of digital delays
via land-line and satellite, although using the same frequency for the same
service in not common.
In the UK Absolute Radio on AM medium-wave has multiple
transmitters (mostly 1215 kHz and 1197 kHz) on the same frequency which are
audible at night. If you listen carefully you can often hear multiple (up to
FOUR!) echoes from different transmitters all being fed by different internet
feeds/satellite links with varying delays.
As an ex-BBC engineer, I can tell you that in the old days
not only were these AM medium-wave group stations all synched to within 0.05Hz,
but the phase of the modulation was adjusted so all tramsitters were modulating
in phase! Now the commercial boys have taken over most of these syched groups,
not only are the frequencies all over the place, but the modulation isn't even
time delayed to match, let alone synchronized! Some even put diferent
commercials in the breaks so if you're geographically between stations you get
a complete, unlistenable-to mess. Apparently these days that's ok.
Why did we bother...?
Anyway, I hope this adds to and confirms your findings.
73,
Ian Liston-Smith, G4JQT
(A grumpy old retired BBC Engineer)
Labels:
Short Wave Listening,
Singapore,
UK
Tuesday, October 14, 2014
Swedish Mighty Mite
A thing of beauty! Check out the key!
What a great diagram. Schematic included!
Remnants of mine
Steve "Snort Rosin" Smith's
More on all this:
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
Labels:
minimalist radio,
QRP,
Smith--Steve,
Sweden
Monday, October 13, 2014
Thomas KK6AHT's Pacificon Minima Presentation: Noodling! And Maxima Inspiration!
Thomas has posted his slides and (MOST IMPORTANT) the audio of his presentation. Just click on the BIG ORANGE play arrow below the slides. You folks will love this:
http://www.sarfata.org/2014/10/Minima-Presentation-at-Pacificon/
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
Labels:
Farhan,
Hamfests and Flea Markets,
Minima
Sunday, October 12, 2014
Drake-uino! Arduino DDS puts Drake 2B on 12 meter band!
After using the Arduino DDS as a crystal substitute with my 1982 Barebones Superhet recevier (scroll down), I moved back two more decades and used the DDS as a crystal substitute to put my (early '60s) Drake 2B on the 12 meter band. This was a hack in which I actually used a hack saw -- I used it to cut open the container holding a crystal so that I could make a socket that would carry the signal from the Arduino DDS into the Drake 2B.
This video is a bit repetitive, but it stated out at two different videos. I just put them together. The last part shows the actual crystal socket hack.
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
Arduino DDS meets Barebones Superhet (Video)
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
Labels:
Arduino,
DeMaw--Doug,
Juliano -- Pete
Pete's 17 Meter VXO Transceiver (Video)
Pete:
I like it! You and I may be the only people in the world with that kind of VXO range control switch on the front panel!
I checked my VXO. I run it at around 23 MHz. I use two single crystals, also switched by a relay.
The 23.144 rock tunes from 23.127 to 23.151 24 kHz
The 23.166 rock goes from 23.144 to 23.168 24 kHz
So I could have had 48 kHz were it not for the overlap. As it is, I get 41 kHz. Not bad.
The reason I went with this LO freq was that I had these crystals from the Dale Parfitt/Doug DeMaw Barebones Barbados Receiver. DeMaw had used color burst rocks for a 3.579 MHz IF, but Dale shifted up to 5 MHz. I could occasionally hear WWV! (But with the 3.579 I heard W1AW in the IF!)
73
Bill
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
Labels:
17 meters,
DeMaw--Doug,
Juliano -- Pete
Saturday, October 11, 2014
Homebrew Double Balanced Mixers by Pete Juiano (Part II) Video
Another great video from Pete. I like the unbalancing mod -- I hate having to whistle into the mic!
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
Labels:
Juliano -- Pete,
mixer theory,
video
Friday, October 10, 2014
Hacker with The Knack Does Well, Working for JPL
Wow. This guy has a really inspirational Knack story. He welded (with coat hangers!) a sidecar onto his bike when he was a kid. He majored in Physics and Theater. He did all kinds of hardware and software hacks. He plays a Theravin in a band. He now flies spacecraft for the Jet Propulsion Laboratory.
And Congratulations to Peter Parker, VK3YE, for having one of his ingenious hacks picked up by Hackaday:
http://hackaday.com/2014/10/06/dusty-junk-bin-downconverter-receives-fm-on-an-am-radio/
Thanks Hackaday! And Happy Tenth Birthday to You!
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
Labels:
Knack Stories,
Parker--Peter,
space program
Thursday, October 9, 2014
Edison is Off The Grid (and has been for 24 years!)
I talked to him last night on 17 meters. He's a nice fellow. When your first name is Edison, that's an indication that you might have THE KNACK.
From his QRZ page:
Ready for this?
My wife and I have lived off-the-grid for more than 24 years. Solar and wind are our main power sources on our mountain, although, we did finally add a generator to our available power sources, for those long days of "NO SUN" in Winter. Check out the view from my home at this site: http://mycampage.com/rosevalleycam and also look at the other links on the page. You might find something you like....
I've been a ham since 1967. Started as a Novice near Sacramento, California, where I was born. But WN6FIC soon became WA6FIC, which I remained until the late 90's, when I became N7GCW.
I am a musician. Along with my wife, and Blaine Lindgren, our fiddle player, we comprise the band called "Half-way There". Click on my campage link to see more about me, and you will find all of my other links there too. I am also a photographer. I shoot it all, but REALLY enjoy taking pictures of scenery, and live bands at Concerts we go to. I am also very fond of Sunrises, and Sunsets, and they ARE beautiful here.....
Also, check out his TREK page:
http://n7gcwtrek.weebly.com/index.html
And I liked his description of his county in Washington state:
"...I absolutely LOVE my world, here in our little valley. Our friends are like family here. People smile and wave...and mean it! We heat exclusively with wood we cut from dead trees on our land, use propane for cooking and refrigeration, and we use solar and wind for most of our power needs, only supplemented by a generator in those long days of no-sun in Winter. It's like living in a time warp, here in our neck-of-the-woods.... Do you know that there isn't a traffic signal in the entire county?"
See: http://edisonshomesite.weebly.com/
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
Labels:
Solar power
Wednesday, October 8, 2014
Pete's Homebrew Double Balanced Mixer Video (Part 1)
Another great video from the famed Italian Director Giovanni Manzoni! Bravo Giovanni!
Pete's discussion of double balanced mixers and the associated toroids has made me feel uneasy about my efforts in this area. I wonder if my diodes were completely matched. And I KNOW that my toroids are not as well done as Pete's.
I recently put an SBL-1 into my old, long-evolving 20 meter ceramic resonator DSB rig. Careful with those nice little boxes! A bit too much juice and you can fry the little internal toroids (as I have done!).
A while back I found in an RSGB Handbook a nice diagram showing how the diode ring mixer does its thing:
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
Pete's discussion of double balanced mixers and the associated toroids has made me feel uneasy about my efforts in this area. I wonder if my diodes were completely matched. And I KNOW that my toroids are not as well done as Pete's.
I recently put an SBL-1 into my old, long-evolving 20 meter ceramic resonator DSB rig. Careful with those nice little boxes! A bit too much juice and you can fry the little internal toroids (as I have done!).
A while back I found in an RSGB Handbook a nice diagram showing how the diode ring mixer does its thing:
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
Labels:
Juliano -- Pete,
mixer theory,
video
Saturday, October 4, 2014
SolderSmoke Podcast 166: Getting Started in Homebrew Radio
SolderSmoke Podcast 166 is available for download:
http://soldersmoke.com/soldersmoke166.mp3
Bench Report: Pete working on Direct Conversion Receivers.
Bill on his 2B and on 20DSB rig, and an M0XPD/Kanga DDS kit, and a 140 watt amp.
GETTING STARTED IN HOMEBREW:
Start simple: Build an oscillator. Make it oscillate!
Gather tools, simple test gear, and books.
Try to understand what you build.
Build a direct conversion receiver.
Don't fear the toroids!
Be patient. This is not Plug and Play.
Build a DSB transceiver.
Little tips:
Protect variable caps.
Use heat sinks.
Use reverse polarity protection.
Don't breathe the solder smoke! Ventilate your bench.
China Radio International Mystery Solved.
Book Recommendation: "International QRP Collection" by Dobbs and Telenius-Lowe
MAILBAG
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
http://soldersmoke.com/soldersmoke166.mp3
Bench Report: Pete working on Direct Conversion Receivers.
Bill on his 2B and on 20DSB rig, and an M0XPD/Kanga DDS kit, and a 140 watt amp.
GETTING STARTED IN HOMEBREW:
Start simple: Build an oscillator. Make it oscillate!
Gather tools, simple test gear, and books.
Try to understand what you build.
Build a direct conversion receiver.
Don't fear the toroids!
Be patient. This is not Plug and Play.
Build a DSB transceiver.
Little tips:
Protect variable caps.
Use heat sinks.
Use reverse polarity protection.
Don't breathe the solder smoke! Ventilate your bench.
China Radio International Mystery Solved.
Book Recommendation: "International QRP Collection" by Dobbs and Telenius-Lowe
MAILBAG
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
Labels:
Juliano -- Pete,
SolderSmoke Podcast
Thursday, October 2, 2014
Sines, Squares, Harmonics, 'Scopes, FFTs, and Sounds
Bil Herd of Hackaday did a very nice video on Sine Waves, Square Waves and FFTs. This is, of course, an important part of understanding how mixers mix. I look forward to his upcoming video on Direct Digital Synthesis.
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
Labels:
mixer theory,
video
Wednesday, October 1, 2014
Hunting for Sprites
Don't let the comments about "positive lightning" and "gravity wave" cameras turn you off -- in the world of meteorology, these terms seem to make sense (but I had to do some Googling). The New York Times article on this topic is very interesting:
http://www.nytimes.com/2014/09/30/science/on-the-hunt-for-a-sprite-on-a-midsummers-night.html?_r=0
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
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