Podcasting since 2005! Listen to Latest SolderSmoke

Showing posts with label Rainey -- Michael. Show all posts
Showing posts with label Rainey -- Michael. Show all posts

Thursday, November 30, 2023

AA9IL's Sputnik Tube, Altoids Tin Transmitter

November 24, 2023
Hello Bill
I have just built an tested a 20 meter “Sputnik” transmitter. It uses two Soviet era “rod” tubes and is fixed tuned to 14.060 MHz.  I was able to compress the design to fit in an Altoids tin. The plate tuning capacitor was replaced with a fixed capacitor value closest to the variable for peak power out. Plate voltage is 90 volts and I key both the oscillator and PA via the B+ line. Power output is around 200mW and my first test transmission from the Chicago area was picked up 864 miles away on the east coast via the Reverse Beacon Network. It was definitely Joy of Oscillation and Joy of Transmission!

73, Mike
AA9IL
EN52
----------------

Mike's rig has been heard by many Reverse Beacon Network stations: 


------------------
November 29, 2023
Bill: 
I started a QSO with AC2C in Ellicott, MD who responded to my CQ but the band dropped (20m)
But that’s a good start and I’ll keep at it!  So, yay!
73 Mike
-------------------

Here are some earlier blog post on rigs using Soviet rod tubes: 

Sunday, July 30, 2023

Understanding Maxwell's Equations (video)


And you should also look at the accompanying web site: 

Writing about the equations, the author notes, "They are formidable to look at - so complicated that most electrical engineers and physicists don't even really know what they mean.  This leads to the reason for this website - an intuitive tutorial of Maxwell's Equations. I will avoid if at all possible the mathematical difficulties that arise, and instead describe what the equations mean. And don't be afraid - the math is so complicated that those who do understand complex vector calculus still cannot apply Maxwell's Equations in anything but the simplest scenarios. For this reason, intuitive knowledge of Maxwell's Equations is far superior than mathematical manipulation-based knowledge. To understand the world, you must understand what equations mean, and not just know mathematical constructs. I believe the accepted methods of teaching electromagnetics and Maxwell's Equations do not produce understanding. And with that, let's say something about these equations.

Thanks to Armand WA1UQO for sending me the wonderful book about Faraday and Maxwell that put me -- once again -- on the path toward a deeper understanding of their work.  

Sunday, July 16, 2023

The Super Islander Mark IV -- A Cuban DSB Transceiver Made From CFL Lightbulb Parts


Trevor Woods also sent us this report from Arnie Coro.  It is not clear to me what difference (if any) there is between the Super Islander Mark IV and the Jaguey Five (described yesterday).  But the bit about using parts from old CFL bulbs is interesting.  This was something championed by Michael Rainey AA1TJ several years ago.  See: https://soldersmoke.blogspot.com/2009/01/soldersmoke-98.html  
and:
https://www.qsotoday.com/transcripts/aa1tj

April 2010:

Today, I will be answering a question sent by listener Bruno from Croatia... Bruno picks up our English language programs via Internet, but he is now also listening on short wave too. He sent a nice e-mail message asking me about the latest version of the Super Islander amateur radio transceiver, because he wants to build one.

Well amigo Bruno, the Super Islander Mark IV is now on the air, and results are very encouraging considering that it is a 40 meters band transceiver built using recycled electronic components.

The Mark IV uses a totally different approach to the receiver design, and it adds two solid state audio filters.

Amazing as this may sound, some of the electronic components used to make the Super Islander Mark IV transceiver came from the circuit boards of broken or damaged Compact Fluorescent Light Bulbs... and that means that there is virtually an endless supply of those parts.

Here is now amigo Bruno, and amigos listening to the program at this moment, a brief description of the Super Islander's Mark IV receiver module.

It starts with a simple resistive signal attenuator that feeds a dual tuned bandpass input filter.

The filter has a limited bandwidth , chosen so as to limit response to out of band signals... The filter is followed by a cascode transistor radio frequency amplifier stage, that feeds a broadband four diodes product detector.

Low level audio from the product detector goes to the audio filtering and amplifying module, made with discrete transistors, of which several of them are also recycled from the Compact Fluorescent Light Bulbs circuit boards...

This version of the Super Islander, the Mark IV , is radically different from any previous ones, as we have now switched over to a totally low cost solid state design , that can be easily reproduced because it uses very common electronic components and straightforward , easy to adjust circuits.

In our upcoming mid week edition I will describe the VFO, or variable frequency oscillator and the transmitter module of this unique low cost amateur radio transceiver, the Super Islander Mark IV... about the lowest possible cost transceiver that will make possible regular two way ham radio contacts on the 40 meters band using either voice or radiotelegraphy modes.

Wednesday, September 7, 2022

Building a Workshop (or a Shack) in a Crawl Space


At first, this video made me think of Michael AA1TJ and his underground Hobbit Hole workshop.  Then I started thinking about my own crawlspace -- it looks remarkably similar to the one in this video.  Hmmm...  But no, I think I will stay above ground. 

One thing that would DEFINITLY not work for us would be the flooring that kind of eats small parts that get dropped.  I would all soon have large numbers of small parts under those mats.  This would drive me nuts.  

But lots of good ideas from Australia in this video.  

Monday, December 27, 2021

A Christmas Story: Mike AA1TJ Builds Receiver for 486 kHz, Listens to Fessenden Commemoration (Audio)

Mike's 486 kHz receiver

As if being able to get home on Christmas Eve 2021 and then catching the Webb Telescope launch was not enough, Santa had another gift for us:  Michael Rainey, AA1TJ, the Homebrew Hero of the Hobbit Hole, was back at it, melting solder. Mike threw together a regen receiver that allowed him to receive a transmission commemorating Reginald Fessenden's historic first transmission of phone signals.  I was really pleased to once again be able to read about an AA1TJ radio adventure.  Thanks Mike!  Here is what Mike heard: http://soldersmoke.com/AA1TJ 920km.mp3

Mike wrote: 

My chum, Peter/DL3PB, recently told me that Brian/WA1ZMS would broadcast a commemoration of Reginald Fessenden's mythical (operative word) 1906 Christmas Eve AM transmission. Doesn't that sound like fun?

True to form, I began scratch-assembling my receiver yesterday afternoon just as Brian went on the air. Then again, a two-transistor regenerative radio for 486kHz isn't exactly rocket science. In any case, I was up and listening inside of a half hour.
 
What did I hear? Static. Just static. As a sanity test I quickly tuned down to 371KHz to find my favorite non-directional beacon, "GW," beaming in loud and clear from Kuujjuarakip.
 
Kuujjuarakip?

Kuujjuarakip is a tiny settlement of mostly Inuit and Cree inhabitants located up on Hudson Bay. The villages are primarily accessible by air and water so a robust radio beacon is an obvious necessity.
 
Satisfied that my receiver was working properly, I re-tuned to 486kHz. Back to static. On the bright side, at least there were no commercials. I continued listening intently until Vic called me to dinner. After the dishes were done I slipped back down to my underground radio shack for one last try.

I heard it right away. Beneath the static I heard a weak, out-of-tune, solo violin playing, "Oh, Holy Night." The signal strength varied wildly with ionospheric propagation. When the signal finally climbed high enough above the noise I ripped out the bipolar transistor audio amplifier stage, connecting my headphones directly to the junction field effect transistor detector output terminals. Of course the audio was far weaker now, yet I could easily follow the tune until it eventually faded away. Not bad for an estimated 15 watt ERP AM signal from a distance of 920km. And on 486kHz, no less, just a hop-skip-and a jump from the old 500kHz Maritime CW band; where countless ship radio operators went to send their last SOS.
 
Returning to the house, I emailed my reception report and included a short recording that I had made of it. Brian replied just after midnight; apparently, equally as stoked

"Yours’ is the best DX ever given your regen RX! Way to go! I just love it."

He went on to tell me that he was born and raised in Vermont, but he'd been working as a radio scientist down in Virginia since 1990. Told me his heart was still here in the Green Mountains and he was touched to learn his meager signal had found its way back there on Christmas Eve. All in all, a night to remember.
 
If you're still with me I hope you'll listen to the short NPR story in the provided link. It originally aired on the supposed 100th anniversary of this event. It's not just about radio history. It's about belief, memory and the myths we lug around in our heads. I thought it was well done.
 
Cheers,
Mike

Listen to what Mike heard. He says he "merely connected the mic input line of my computer across the headphone terminals. Some of the noise in the recording, - certainly the higher frequency stuff - is a byproduct of the computer. The headphone audio with the computer switched off was much more pleasant."  Here it is: http://soldersmoke.com/AA1TJ 920km.mp3

NPR story (audio and text)

Monday, November 25, 2019

SolderSmoke Podcast #215 Regen Madness, KWM-4, Paesano, Mailbag

Latest N2CQR version of N0WVA's Regen
SolderSmoke Podcast #215 is available. 

25 November 2019

http://soldersmoke.com/soldersmoke215.mp3

Happy Thanksgiving! 
Transit of Mercury
Book Reviews 

Bill's Minimalist Adventures:
-- 15 Contacts with the ET-2 
-- Ethical issues:  Is spotting yourself OK?  OK to use TWO FETs? 
-- Using Reverse Beacon Network
-- How to keep receiver on the right frequency
-- N0WVA's receiver sounded better, so I built a second N0WVA receiver
-- Regens reach back to Edwin Howard Armstrong's 1912-1923 breakthrough
-- Regens are fun, but they are not good projects for new builders. 

-- Pull out those Michigan Mighty Mites and listen for yourself via on-line SDR receivers.

Pete's Projects: 
"WHEN YOU KNOW STUFF YOU CAN DO STUFF!"
-- Left Coast SSB -- "The Paesano" -- To be featured in December 2019 SPRAT. 
-- Pete's KWM-4 on The Collins Collectors Net
-- Pete builds an N0WVA regen -- just in time for Sweepstakes CW Saturday! 
-- Arduino IDE Library trouble
-- uBITX 6.0? Fake News? 

No more BITX40 Modules.  Long Live BITX40 HOMEBREW! 

BITX-101.   Intriguing but on second thought, no.   

MAILBAG

Steve Silverman:  Lexicon:  "Audible Modes." 
Felipe CU2BD   Old buddy from the Azores
Michael Rainey AA1TJ:  Come back Mike!  The ionosphere needs you! 
Jack Welch  AI4SV is in 5G land  (Cyprus, not the cell phone thing). 
Walter AC4IM is at the San Vito Solar Observatory in Italy.  DO SOMETHING WALTER! 
Kostas SV3ORA has an amazing homebrew web site.  Thanks Kostas! 
Mike KC6SAX -- How to deal with the frustration of HB projects that don't work. 
Paul KL7FLR -- Pete is 7 Hz high. 
Keith W3ISZ  sent his photo of the Transit of Mercury.  

PLEASE USE THE AMAZON SEARCH BOX ON THE SOLDERSMOKE BLOG PAGE WHEN DOING YOUR CHRISTMAS SHOPPING. 

PLEASE SUBSCRIBE TO THE SOLDERSMOKE CHANNEL ON YOUTUBE. 


N2CQR's ET-2 with callsign Tattoos 

Saturday, October 19, 2019

QSO #3 with the ET-2 Minimalist Transceiver

The Radio Gods were clearly supporting me on 16 October 2019.  I had sent out a plea for people to listen for the 80 mW CQ from my ET-2 rig.   I had specified 0930 Eastern as the time.  Little did I know that there would be a contest at that hour (on a Wednesday morning!) on 40 meter CW.  There was no chance of my signals getting through.  I leaned that the contest would be over at 1000 hours, so I waited and called CQ again at that hour.  Jim W1PID had guessed that I would do that.  I immediately recognized his call -- he was often at the other end of Michael Rainey's most daring low-power adventures.  He was a participant in the famous Rexpeditions, including a coastal effort to send Michael's voice-powered CW signal across the Atlantic.  His normal operating habitat is in the field.  We had a wonderful QSO.  He told me I peaked at S-6.  

I have worked W1PID on at least two Straight Key Nights and this blog has had many postings about his long-standing involvement in QRP. 

Thanks a lot Jim! 
 


Friday, June 21, 2019

Wall Warts

Thank you to Michael Rainey AA1TJ who posted this cartoon, which I'm sure speaks to us all. 

Saturday, March 24, 2018

SolderSmoke Podcast #203 Winter, Transceivers, Antennas, DC RX, uBITX, Mixers, 'fests, MAILBAG

N6QW in 1959. Building an SSB transceiver
SolderSmoke Pocast #203 is (FINALLY!) available: 

http://soldersmoke.com/soldersmoke203.mp3


24 March 2018

--The reasons for our delay. 
Winter, Computers, College, Family Trees, Lawyers....

-- Winterfest 2018 
-- Pete launches 2018    THE YEAR OF THE TRANSCEIVER
    http://n6qw.blogspot.com/
-- SDR -  Satan's Digital Radio?  
-- Direct Conversion Receiver Projects
-- Mixer Musings 
-- A Thailand Troubleshoot 
-- Nor'Easter knocks out Bill's Moxon -- An appliance replacement? 
-- Homebrew Electret Mics.  Seriously.  
-- uBITX Build with Rogier
-- Civilized Crystal Testing
-- Baofeng! 
-- DRAGNET

-- MAILBAG
KD4PBJ's REGEN 
N6ORS's SDR rig
Mike Rainey's DX-100

Sunday, January 21, 2018

Mike Rainey and Heavy Metal AM Phone

Michael Rainey AA1TJ wrote:  
I can tell you exactly what's going on here. I'd just received a license upgrade from "Novice" to "General." My new license granted radiotelephone privileges and I was eager to try them out.

In the early 1970's no self-respecting amateur radio operator would dream of using amplitude modulation (AM) on wavelengths above 10m. It wasn't illegal, rather, it was frowned upon due to bandwidth issues, among other things.
But in my excitement - and in the time-honored spirit of, "don't ask permission, ask forgiveness" - I tuned my clunky, Heathkit DX-100 to the 40m radiotelephone band and began calling CQ on AM. Everyone that I contacted was very polite, but to the man they all mentioned how "odd" it was to hear an AM signal on 40m. I eventually took the hint, but not before I'd figured out that yakking on a microphone wasn't my thing after all. Morse telegraphy was my first and enduring love.
-------------------------------------
I think Michael's next phone transmitter was that voice-powered rig that he used in an attempt to cross the Atlantic with the only power source being his vocal cords. But even there, he was using his voice to send Morse.  


C'mon back to radiotelephone Mike.  There is more to life than dots and dashes!

Saturday, January 6, 2018

Straight Key Night at N2CQR



I did my part for the retro-Luddite-CW-Straight Key cause.   My HT-37 was kind of wheezing.  I may have to go in there to striaghten it out.  At times I had it cranked back to less than 5W (to maintain some semblence of QRP street cred). 

A highlight was the QSO with Jim W1PID.  Jim is a well-known QRPer and a friend of QRP Hero Mike Rainey.  Jim and I talked last year -- same date, same event, same rig. Jim has a really nice web site: http://www.w1pid.com/

My nephew Jeffrey joined me for the last two contacts.   He got a real kick out of it, both the CW and the SSB. 

31 December 2017
17S  P49MR   Martin – Back in the islands!  Like an annual QSO.
40CW  Pre SKN   W1PID on 40 with my HT-37. An annual event!  Jim running 75 watts
40CW SKN KF5RBR Dan in AR.
1 January 2018
40CW SKN W8HOG SKCC 87750 Perry in Ohio
40CW SKN N1CGP Dave in Maine using J37 key
40CW SKN WB4JJJ Al in Fairfax
40CW SKN K8SRB  Stan  in Ohio (with nephew Jeffrey with me)


17SSB WJ2N Andy in Florida (with Jeffrey in the QSO)

Sunday, September 3, 2017

Nuclear Powered QRPp? Tritium Nuclear Batteries and Plutonium Pacemakers


OK QRPers, it is time to explore another power source.  Enough of the nails in lemons and all that mess.  It is time to go NUCLEAR! Check out the motor in the video above, then look at the video below for more info on how the nuclear battery was made.  Who will be the first to QSO with homebrew nuclear power?  Or has it happened already? 

Mike Rainey -- this seems like the perfect project for you OM.


Oh and by the way, in the course of reading up on this, I learned that we once used PLUTONIUM to power pacemakers.  Check it out:

https://www.mdtmag.com/blog/2016/01/medtech-memoirs-plutonium-powered-pacemaker

And no, today is not April 1. 

Monday, January 2, 2017

Straight Key Night -- Bandscan from WA6ARA (audio)

WA6ARA SKN Station
Mike Herr WA6ARA was on 40 meters with old gear this Straight Key Night.   Mike was receiving with a venerable Heath HR10B.  One of his favorite QSOs was with Keith W6SIY; Keith was running Conar twins that had the kind of "swing" that stirs up the kind of memories that SKN is all about.  FB.  Mike made a bandscan recording of what 40 sounded like, and he made another of W6SIY's beautiful signal.

You can listen by clicking on these links:  

http://soldersmoke.com/SKNBANSCAN.mp3

http://soldersmoke.com/SKNQSO.mp3

My own SKN effort was cut short this year by technical difficulties.  The HT-37's relays stopped doing their thing.  Probably the relay drive tube going soft.  But I did manage to make two great contacts on 40:

WA6URY is in Los Angeles.  This was a very timely contact -- my wife and I went to see the movie "La La Land" on New Year's eve -- the film features a lot of beautiful LA scenery.  Dan was running a kilowatt to a 2 element Yagi on 40.  He too owns an HT-37 and a Drake 2B.  He was on a straight key "with dirty contacts."  FB Dan, thanks.

And then I worked W1PID!  Wow! Jim is well known for his operations from field locations and for his intrepid participation in many of the radio adventures of Michael Rainey AA1TJ.  Jim was on the Maine sea coast expedition when Michael was attempting to cross the pond with his voice-powered radio.  On SKN Jim was in New Hampshire running 35 watts to a Windom off-center fed dipole.  His Morse key is a Kent.    TRGHS.   Thanks Jim.

Happy New Year!

W1PID Maritime Mobile

Sunday, November 6, 2016

SolderSmoke Podcast #191 RIGS! REAL RIGS!, BITX40 Module, EMRFD, MAILBAG


SolderSmoke Podcast #191 is available:

http://soldersmoke.com/soldersmoke191.mp3

TRAVELOGUE AND FAMILY DOINGS:   Pete son's wedding, Billy's Birthday, Gonzalo safely home in the Dominican Republic, MORE BEARS IN THE SHENANDOAH WOODS

BIG NEWS:  EMRFD LIVES ON!   Three cheers for Wes and for Tom Gallagher of the ARRL.

BENCH REPORTS:

PETE:   FPM Rig.  Some Halli history.  A TRUE RIG!  Working Japan. 
             WITH 600 WATT LINEAR AMPLIFIER!!!!!!!!!!!!!!!!!!!!!!
               New FEELTECH  Sig Gen.  

BILL: Farhan's BITX Module
           Built to Mod, built to get you started in homebrew
           Very impressive.  BITX in miniature.  But completely recognizable.
           REMARKABLY stable.
           Farhan personally checking each one.
           Ladies collective doing toroids.  DONATION money bought them some Diwali candies!
           VFO Drift:  Will NP0 SMD caps and lower current help enough?
           My Analog VFO -- BANDSWEEP

QRPppppppppppp  with REX's Hamfest Buddy.   Thanks Rex and Bob Crane.

HB2HB with KW4KD

MAILBAG
Jan's Netherland Mate Mighty Midget
Charlie's Kiwi DSB
Steve, Donald Fagan, and Jean Shepherd
Rob VK5RC repairs Tek Tube 'scopes
Colin M1BUU Si5351 superhet
Denis Klipa and NRL 3538
Jonathan M0JGH Wizard of Wimbledon Matchbox rig
JH8SST Simpleceiver
Peter Parker Vk3YE Reviews Book
Peter GW4ZUA Welsh LBS
Michael Rainey helping hobbyist in Germany with tuning forks.





Sunday, September 4, 2016

First Signals from the "Armand HROish" Receiver


I've been kind of busy lately with other things, but I have managed to squeeze in a few minutes most days to work on my latest receiver project.  I call it the Armand HROish receiver.  Armand WA1UQO sent me the big National HRO-style dial and gear box, and he was there at the Manassas hamfest when I bought the dual variable cap that now serves in the front end pre-selector.

I went with a 455 kHz IF.   The idea is to have a receiver that tunes from around 6.5 MHz to around 8 MHz so I can do some shortwave listening AND listen to 40 meters.

So far the filter consists of three IF cans (one small transistor can and two larger tube-type cans).  The small transistor can was given to me by Michael Rainey AA1TJ - thanks Mike. Doug DeMaw suggested this use of IF transformers in his "Design Notebook."

At the front end I have a tunable dual tuned circuit filter followed by a 40673 amp. 

The mixer is an SBL-1.

1st and 2nd IF amps are a 23 db 50 ohm termination insensitive amplifiers.

I have a second SBL-1 that will be the product detector, but I haven't built the BFO yet.  So today I hooked up two 1N34A diodes in voltage double config and -- with a bit of AF amplification, got the receiver inhaling with a diode detector.   I could pick up Radio Canada.  Then I heard SSB sigs on 40.  With no BFO, I decided to put my sig gen on 455 kHz and just wrap the lead around the IF cans.  It worked -- I could listen to SSB and CW sigs.  Very satisfying. 

Still to do:
-- BFO and product detector.
-- Work on AF amp.
-- Get my CM-455 crystal mechanical amp in there with some relays around it so I can switch from narrow to broad via the front panel.

Lots of soul in this receiver:  All parts either 1) came out of the junkbox, 2) were gifts from friends, or 3) were recent hamfest purchases.  The HRO dial from Armand and the IF can from AA1TJ.  The 455 kHz filter idea came from Doug DeMaw, the VFO circuit from SSDRA.  The VFO base is from Whole Foods and the whole thing is built on a kitchen cutting board. It includes a 40673 and germanium diodes. The VFO amps are in Altoid tins.  It will, when finished, go into a big metal box given  to me by Tim KI6BGE and shipped east by Pete Juliano.  And when I was working on the 1st mixer, I accidentally pricked my finger and a drop of N2CQR blood went onto the breadboard.  Of course, I left it there.   SOUL!

The Radio Gods are apparently pleased:  In the first hour or so of listening, I was rewarded for my efforts when I managed to hear Tim WA1HLR on 40 AM describe his troubleshooting of an old piece of gear.  TRGHS.  


Saturday, July 16, 2016

Preserving Vanguard 1


Ira Flatow of "Science Friday" was recently talking about how best to preserve important bits of the history of mankind's exploration of space.  Our old friend Vanguard 1 was mentioned several times.  It is now the oldest satellite still in space.

You can listen to the Science Friday show here:

http://www.sciencefriday.com/segments/protecting-the-historic-human-record-in-space/

They also have a transcript of the show on the same page.

SolderSmoke fans will remember the Vanguard adventures of Mike Rainey AA1TJ:

http://soldersmoke.blogspot.com/search?q=Vanguard

This seems to be the month for Vanguard:  just a couple of weeks ago, on 40 meters I spoke to Dale Parfitt W4OP. Dale was one of the first people to pick up Mike Rainey's Vanguard replica signals (see link above).

AND...

The Vanguard reproduction project came up during Eric Guth 4Z1UG's "QSO Today" interview with Graham Firth G3MFJ of the G-QRP Club:

http://www.qsotoday.com/podcasts/g3mfj

(Graham has such a great voice.  He definitely SHOULD build a phone rig!)

VIVA VANGUARD!  
  

Saturday, March 5, 2016

AA1TJ -- On the Air with a Tuning Fork Transmitter using the 2,212th Harmonic and Olive Oil Cooling

The saturable magnetic frequency septupler. The tiny computer memory core is submerged in olive oil (Italian...naturalmente).


Not a very good picture, but here's the 1600Hz tuning-fork, fork oscillator, SRD pulse generator, PLL S/H phase-detector (diode gate), differential amplifier D.C. amplifier, and part of the 500kHz VCO.


The Wizard (AA1TJ) reports from the Hobbit Hole:

I was pleased to have made the first contact with my tuning-fork transmitter this evening. My contact, N1QLL, runs a pretty B&B on the Maine seacoast, midway between Bar Harbor and Cutler. Jerry was operating a solar-powered QRP station.  I found a follow-up email from him when I came up to the house for dinner. He's asking for a better explanation of my set-up. I can't wait to tell him about the passive frequency septupler made from an East German computer memory core, heat-sinked in a thimble of olive oil. 

My signal was also logged by a number of automated "Reverse Beacon Network" receivers (image attached) located in Ohio, North and South Carolina, Virginia and Pennsylvania...not bad for 90mW on 80m. Please note that my operating frequencies, 3,528.0 and 3,539.2kHz, are the 2,205 and 2,212th harmonics, respectively, of my 1,600Hz tuning-fork frequency reference.
FYI: the third attached image illustrates the block-diagram and tuning-fork reference oscillator circuitry for three common-wavelength AM broadcast transmitters operating in Berlin, Stettin and Magdeburg, Germany from 1928 through the mid 30's. A central 2,000Hz tuning-fork generated reference carrier was transmitted by landline to transmitters in the aforementioned cities whereupon the 529th harmonic was generated, amplified and broadcast at 1,058kHz. The equipment was designed by the Berlin-based firm, C. Lorenz A.G.. The fourth image details Lorenz' technique of frequency multiplication via saturable magnetic iron-core inductors. My septupler operates in an identical fashion.
A very pleasant day...





Mike points out that this is a work in progress.  He hopes to cross the pond (the Atlantic!) soon. Here is a update from Mike:

A nasty cold has delayed work on the 20 meter implementation, although some of the time I've spent crashed on the sofa was put to use redesigning the loop filter network. I think yesterday might have been my "hump" day so I'm looking forward to getting in some quality bench-time over the weekend. 

By the way, my PLL-based transmitter frequency stabilizing circuit has much in common with a garden-variety frequency-synthesizer. Obviously, the tuning-fork frequency reference is the main point of departure. My sampling phase detector, for example, was old hat by the mid-1960's. Nevertheless, this has been a fun project.

Saturday, February 27, 2016

Sputnik Replica Transmitter, an "Error" in the Sputnik Schematic, and Why 20.005 MHz?


Mark K6HX pointed me to very interesting Hackaday article on Frank PA3CNO's Sputnik transmitter replica.  As blog readers will recall, we went through a period of Sputnik-mania a few years ago:  http://soldersmoke.blogspot.com/search?q=sputnik  Chief Designer Comrade Mikhail Rainey AA1TJ sent me some of the Russian tubes (like those pictured above). 

The Hackaday article pointed to our post reporting that Oleg RV3GM had found the schematic:
http://soldersmoke.blogspot.com/2013/04/sputnik-schematic-found.html   Stefan reports that PA3CNO found "an error" in the original Soviet schematic:
http://www.radio.cc/post/Franks-power-supply-for-sputnik    A mistake you say?   HAH, I say!  Hah!  This must have been part of a sinister commie plot to prevent the capitalist imperialists from ever being able to reproduce the glorious transmitter of the Soviet people.  They almost succeeded. 

Just kidding.  

In the course of looking through our old Sputnik posts, I came across a question I posted:

I have a question: OK so the crafty Soviets picked 20.005 MHz for some good reasons: Being so close to the WWV freq, it would be easy for hams and SWLs to find it with precision. In the November/December 2007 issue of "Break In" (from NZ -- thanks Jonathan-san!) ZL3DW notes that this frequency selection would allow a receiver set to exactly 20 MHz to "produce an audio tone plus or minus the Doppler shift without ever going through zero beat." But zero beat with what? Most of the receivers out there would not have had BFOs, right? So the Soviets wouldn't have been using ordinary CW, right? Were they using AM, with the beeps produced by an audio oscillator modulating the carrier? 

Was their diabolical plan to use WWV as the BFO for those using ordinary AM SW receivers?   If so, a 5 kHz separation from WWV seems to be too much right?  Especially when the Doppler shift on approach would push the frequency up a bit. Maybe they just chose this freq to make it easy for listeners to find -- just a bit above WWV.  Comrade Rainey surmised that they were keying the PA stage -- the oscillator "backwave" was at times audible on the ground.

What do you think Comrades?
DSW and 73.

Sunday, February 14, 2016

"QSO Today" Podcast Interview with Michael Rainey AA1TJ

Picture

Eric 4Z1UG has a really great interview with Michael AA1TJ:


I listened to it as I aligned my HQ-100 receiver and worked on a digital frequency readout for the old receiver.   The interview was the perfect accompaniment for such a project.  Inspirational stuff.  Lots of great info on QRPp and homebrewing.  Mike talks about some of his more famous rigs including the voice-powered New England Code Talker (pictured above).  

I loved the story of Michael carting his DX-100 home in a wagon.  And I really sympathized when he described the harsh reaction of the phone operator to his early efforts at voice modulation.

Strongly recommended!   You won't be disappointed.  Great interview.  Thanks to Eric and Mike.


Saturday, February 6, 2016

Michael's Log: AA1TJ Has FIVE Contacts with the Unijunction Transistor at 1-2 milliwatts

Michael writes:

Dear Friends, The UJT transmitter circuit was improved considerably today. The power output has increased to 1.48mW and the start-up "whoosh" is now far less objectionable. It's currently running in beacon-mode at 3687.8kHz. I'll resume "CQing" as soon as I've returned from an hour's walk in the woods. I hoping to work K1QO among others. 73, Mike

Added five QSOs today. Seabury/AA1MY is in Maine...exactly 100 miles from my doorstep. It's wild to think that we made a one-hundred mile radio contact on a unijunction.
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column