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Wednesday, February 10, 2010

KPH: Maritime Radio History

That's OM Dick Dillman at the controls of maritime radio station KPH in Bolinas, California. Bob, W8SX, sent me an mp3 recording of a show that Dick did for public radio station KWMR. It is about the magic of radio, and about the efforts of Dick and his friends to preserve an important element of radio history. You will also hear about spy stations, the Linconshire poacher, SKY KING and much more. You guys will like this program. It will fit nicely in those iPods and mp3 players:

http://www.g4aqg.sussex.ac.uk/IRT.mp3

More info on station KPH can be found here:

http://radiosquirrels.net/gallery/show?keyword=kphhistory

Sunday, February 7, 2010

Drake 2-B Goes Digital with WSPR

7 spots:
TimestampCallMHzSNRDriftGridPwrReporterRGridkmaz
 2010-02-06 16:04  DK9MS  10.140210  -11  -1  JO40tm  2  I0/N2CQR  JN61fv  983  166 
 2010-02-06 16:04  PA3BTI  10.140271  -8  0  JO22og  5  I0/N2CQR  JN61fv  1276  152 
 2010-02-06 16:04  DL9DAC  10.140246  -4  0  JO31qi  20  I0/N2CQR  JN61fv  1120  158 
 2010-02-06 16:02  DL6NL  10.140262  -20  2  JO50cb  0.1  I0/N2CQR  JN61fv  924  168 
 2010-02-06 16:00  DF6DBF  10.140279  +1  -1  JO31si  10  I0/N2CQR  JN61fv  1116  159 
 2010-02-06 16:00  M5LMY  10.140248  -14  1  IO91oi  5  I0/N2CQR  JN61fv  1455  131 
 2010-02-06 16:00  DL1EEZ  10.140201  0  0  JO31qi  20  I0/N2CQR  JN61fv  1120  158 
Query time: 0.002 sec

 Until this weekend  have been "transmit only" on the WSPR system, running the world's only homebrew double sideband WSPR rig (please correct me if I'm wrong).  I'm also running one of the most low-powered of WSPR stations (20 mW). 

I've been feeling a bit guilty about my "transmit only" status.  I felt like I wasn't doing my fair share in the WSPR effort.  I was sort of a digital free-loader. 

So Saturday I decided to do some receiving.  I fired up the old Drake 2-B.  I ran a lead from the headphone jack of the receiver into the audio in of my old Tecra 8100 (running Linux Ubuntu Jaunty Jackalope). Antenna was a pathetic little end-fed wire.  The only tricky part was getting the Drake on the precise freq.  I just put my WSPR transmitter on 10140200 Hz and then put the bandpass in USB 2.1 kHz.  I found the computer clock was off a bit (I had neglected to run the ntp program), but once that was taken care of signals started pouring in.  And reports were automatically uploaded to WSPR HQ, and appeared on-line (see above).
I was very pleased to receive DL6NL's 100 milliwatt signal.  OM NL is well known in the QRSS/WSPR world.  A picture of one of his more QRO rigs appears above.  A shot of his balcony Microvert antenna (the white thing at the end of the dark indicator line) appears below.  

Haiti: Dominican Hams Help



The video (from a phone patch the day after the quake) gives you a real sense of how bad it is. It was good to see that hams from the Dominican Republic were going over to help out. See below.

From: http://spectrum.ieee.org/telecom/wireless/hams-in-haiti/1
BY Anne-Marie Corley // January 2010

... Which leads to the other difference in Haiti: The country is home to very few amateur operators in the first place. Though there are around 100 to 120 ham licenses active for Haiti, according to Pitts, only about seven or eight operators were actually in Haiti as far as the ARRL can determine. According to Bill Pasternak, the president and cofounder of the Amateur Radio Newsline, which broadcast audio from one ham operator outside Port-au-Prince soon after the earthquake hit, most of the operators who have Haitian licenses aren’t even Haitian but rather missionaries and aid workers who travel in and out of the country.
Pitts says that the ARRL has heard from only a few operators, most from outside Port-au-Prince, though one operator did radio in from the city just to let the organization know he was alive. ”The ones that were there did all they could,” Pitts says, ”but we haven’t heard from all of them.” It is likely that some were killed, Pitts speculates. Others may have been concerned with safety, McPherson suggests, so hams in Haiti have been ”on and off the air,” he says.
To help out, hams from the neighboring Dominican Republic have traveled into Haiti several times to set up equipment, despite being attacked by looters last week. They set up a 2-meter analog repeater high on a mountain close to the Haiti–Dominican Republic border. The repeater takes in weak signals—even one from a clip-on radio putting out just 5 watts—and rebroadcasts those signals on a different frequency and at a higher power.
Dominican operators installed a second repeater near the airport in Port-au-Prince and were expecting a third to arrive from ARRL Tuesday, which they will likely put in the region southeast of the capital.

”They’re doing really good work,” Pitts says of the Dominican helpers, ”getting things where they need to be and coordinating with other teams.”
Pitts adds that the international nature of ham radio is well suited to emergency missions like this one. Hams in Argentina, Brazil, Cuba, Florida, and Puerto Rico, among others, were on the air and listening for any signals soon after the earthquake. ”Nobody was going to hiccup without being noticed,” Pitts says. And because they talk in radio code, language barriers don’t matter as much. ”We all have the same language,” Pitts says. ”We’re used to talking with each other.”
The embedded hams in Salvation Army recovery teams work, too, McPherson says, because they can tap into the entire amateur radio community. Nonofficial operators, for example, who may hear an embed trying to reach Haiti or to call out, may help relay a signal. ”It’s like [all the] amateur community is listening, standing by to help,” McPherson says.
The lesson to be learned, according to Pitts, is that ”in a situation or population where amateur radio is encouraged and present,” hams can provide better and faster information during a major disaster, which allows a faster response. ”That golden 48 hours is where the hams really can shine, if they’re there.”
So while cellular and Internet communication return ever so slowly to normal (or better than normal), what Haiti might also want to invest in is a few more homegrown radio operators.

Friday, February 5, 2010

SolderSmoke Podcast 121

 http://www.soldersmoke.com
5 February 2010
Into the Apennine snow! 
Technical troubles 
Roadkill computers
Luddite Curmudgeonism
Mars and Andromeda from Sabina
Telescopes and Olive Oil
Math and Electronics
Crashing R/C planes
5X5JD and the Uganda Tuna Tin
AA1TJ's diode amplifiers
Rotating parts boxes
MOVIE REVIEW: Avatar (2.5 Soldering Irons)
MAILBAG  

Thursday, February 4, 2010

PA1ZZ Gets Ticket in Southern California


A while back we reported on the Californian travails of long-time listener Rogier, PA1ZZ.   We are happy to report that OM Rogier has joined the ranks or U.S.-licensed radio amateurs and is preparing to wiggle the ether with the FB rig pictured above. 



Hey Bill,
Since the FCC doesn’t like it if you use the foreign license as a Permanent resident. I took the plunge and passed the technician and general exams in one day.
So here I am KJ6ETL QRV from San Mateo, CA.
One day I will do the Extra class but that's for later. First I have to study for my career, hobby comes 2nd…

I still had my DSW-II build from a kit when I was living on Bonaire. But never managed to get in the air due to the lack of a dummy load to tune the final stage and a very strong HF signal from a local US religious broadcast station (50KW) aiming at South America and the Radio Netherlands relay station. Both put so much HF in the air that my SWR meter needle was pushed in the corner without my transmitter hooked up…

Now, years later, I polished the March R3A paddle and finally tuned the DSW-II. Next step will be to hang an invisible 20mtr band dipole on our balcony (hoa’s….) and see what happens.
Since my morse skills are very rusty and antenna and power are rather limited I might want to jump ahead and start with the digital modes...


Smiles across the wires,

Rogier

Wednesday, February 3, 2010

15% off on SolderSmoke -- The Book

Lulu is running a sale today.  You can get SolderSmoke at 15 percent off by using the coupon code SHADOW when you check out of the Lulu site.   It is better for me if you get to Lulu via Amazon.  Here is the link:

Saturday, January 30, 2010

H1N1? No. 72N73!

Wow, Jeff REALLY has a bad case of 72N73 (aka "The KNACK").  He's actually piping the SolderSmoke podcast into one earphone of his cockpit headset.  (I hope the gong doesn't cause any problems!)  Maybe the lady next store will start to like that strange voice from Rome coming in on 88.3 FM...
 
Bill: 
I have been a devoted Soldersmoke fan since I found it about a year ago on a new HamInfoBar application that I installed on my Internet Explorer (yes, the Dark Side!). I have started back at SS #1 and working my way up…wonderful podcasts, Bill!
Waiting to get Ubuntu installed on my shack PC so I can gleefully delete Internet Explorer!
Have been a ham for 35 years now, operating all modes from HF, digital HF (including WSPR on 30 meters) through AMSAT satellites and of course VHF and UHF. I recently retired as a sales executive from IBM after 27 years, so have more time to follow my life-long passions.
Shortly after listening to Soldersmoke for the first time, I noticed a strange feeling after sitting by my PC for a few hours. Thought it was just neck strain from peering at the PC and your Blogspot, but after a few days it remained. My medical background (Ph.D. in Neuroscience) led me to the conclusion that a nervous system virus I had contracted when I was 13 had been dormant in my nervous system peripheral ganglia for these many years, but has re-emerged and re-infected me. That virus is the 72N73 virus, or more commonly known at THE KNACK! Yes, Soldersmoke has activated that bad boy virus once again and I am on the hunt for projects to complement my Old Spice after shave with that 'other' cologne, Eau de Soldersmoke!
Since I like to listen to Soldersmoke as I walk around the house, decided to get the Weller soldering station out and I 'protoboarded' and then built a small two transistor 20 mW FM transmitter on 88.3 MHz (unused channel in Dallas) to transmit Soldersmoke through my whole house stereo system. Works great. However, my neighbor next door (12 feet away) who has a small yagi antenna for her stereo system asked my why every Friday evening the jazz station on 88.5 MHz she loves to listen to has some guy rambling on for hours about some electronics projects in Rome??? Did that jazz station change formats on Friday evenings? (Woops...............better get my frequency counter out once again!).
You will be glad to know that I listen to SS on my IPOD as I fly (on longer trips) on WWII vintage aircraft to air shows around the country. I volunteer at the Cavanaugh Flight Museum in Dallas (www.cavanaughflightmuseum.com) and usually fly right seat or rear seat depending on the plane.  I modified my communications headset to listen to Air Traffic Control on one earpiece and SS on the other earpiece. So, yes Bill, you do get interrupted by Air Traffic Control advising us of new radar vectors! You can view additional pictures of me flying with Cavanaugh at my www.qrz.com pages.
Just purchased SS, The Book and having a ball reading your antics of years past. BTW, I just joined GQRP and got a nice note from Tony Fishpool. I had mentioned that it was due to SS that I found GQRP and joined up. Tony sent me a nice note and indicated "Yes, Bill is worth every penny that we don't pay him for GQRP advertising!!
Other interests include flying large radio controlled aircraft, astronomy (purchasing an Orion 10" Dobsonian next week to supplement my 10x50 binoculars), satellite tracking, and weather satellite imaging directly from American, Chinese, and Soviet polar orbiting satellites. High Power Rocketry (average flights to 10,000 feet) round out my technical interests.
Bill, don't want to make this email too long, so let me say 73's, and will plan on future correspondence as I release more Soldersmoke around my shack.
Send me best to Billy (Soldersmoke Mailbag, It's Awesome...Indeed!!).
Eagerly awaiting Soldersmoke, The MOVIE!!!!!


By the way, no Chingales (sp?) in Dallas, but we do have our share of Armadillos laying dead by the roadside.


73s,
Jeff
N5ITU
In Dallas, TX.

Friday, January 29, 2010

Quiz Question for Knack Victims

Hey Bill,

I know you have the knack . . . so I'm coming to you.
I've got 31 years of ham radio experience, on top of 16 years experience in the Wireless Telecom industry, that said I have a tech question that has really got me stumped. Maybe the answer is just too obvious.

Here it is: About 2 years ago an electrical engineer/ham radio operator/nuclear engineer threw the following question by me (I've yet to get back to him with my answer). Maybe you, or some of your listeners know the answer.

Knack Question: For yagi antennas only one (yes, sometimes two) element is electrically driven/xmit. Instead, why aren't all of the elements (simultaneously) electrically driven/xmit (vs parasitically driven)? Now the stumper - according to the engineer supposedly the answer excludes the following as the answer(s):

  • Impact to antenna gain,
  • The need to have any type of phasing harness
  • Impact to transmit horizontal beam width (directivity).
Any idea what the answer might be? What am I missing?

Thursday, January 28, 2010

QRSSing again, AA1TJ's new page



As I mentioned earlier, computer problems have delayed the SolderSmoke podcast (don't worry, parts are on the way).  They have also knocked me off the WSPR system.  So I switched over to QRSS mode and am now pumping out about 20 milliwatts of upside down sloooooooooow FSK on about 10140050 Hz.  (Don't you like how in QRSS you find yourself giving the frequency not in kilos or megas, but in just plain Hertz?   If I get into a retro mode I may start giving them in cycles.) During daylight hours in Europe you should be able to watch my little signal arriving at ON5EX's station in Belgium.  Just look down on the right on this page for a live view of Johan's receive screen.


VA3STL has some good QRSS stuff on his blog:  http://va3stl.wordpress.com/



I noticed this morning that Mike, AA1TJ has moved and updated his very fine site.  Check it out: 
http://www.aa1tj.com/radio.html
Be sure to click on the link that lead to info about Mike mountain-top work site.  Like I said, truly the kind of job that Knack victims dream about.

Rumor has it that Dan's Small Parts is back in operation after a winter break.

Monday, January 25, 2010

More Mars (with olive oil)

No podcast this week. I have two excuses: 1) Computer problems (a long, sad story), and 2) we were once again out in the Sabine Hills. Above is another look at the olive grove QTH. That solar panel thing on the right is an automatic weather reporting station installed by the Region of Lazio. Those trees behind the weather station are olive trees.

We had clear skies this past weekend, and with Mars approaching full opposition, I had the telescope out. We got some better views of Mars than we had last week. When the atmosphere (ours!) would settle down a bit I could make out some of the dark "canali." The Northen polar cap was very visible. The moon was bright (first quarter I think) and so I was wondering if we'd be able to see the M31 galaxy in Andromeda. Even with the moon close in the sky, I had no trouble finding the galaxy using my old Soviet-made 7X50 binoculars. We also looked at the North America nebula in Orion's sword (very appropriate as we had Canadian friends with us).

My telescope (above) has a simple but effective Dobsonian mount. (This system is named for the amateur astronomy guru John Dobson -- interesting guy.) The 'scope basically slide on teflon pads. These pads need a bit of lubrication from time to time. Mine were getting a bit sticky, so I started to look around for something to to grease the teflon. The solution was literally all around me:

Worked like a charm!

Also got on the air with the HW-8 and worked stations on 80, 40, and 20, including two QRP stations.

Friday, January 22, 2010

Does Math Lead to Understanding?

In "SolderSmoke -- The Book" I describe the quest for deep understanding of the circuits that we build and use. There is some discussion in the book of the role of mathematics in this quest. A while back a reader e-mailed me on this subject. In the hope of stimulating a discussion, I'll present the key paragraph from that e-mail here (the author will, for now, remain anonymous):

I appreciate your quotes from Feynman, Asimov, etc. about not
really being able
to fully understand everything. As a math teacher
I can say that one of the
biggest misunderstandings about math
is that it "explains" the phenomena of
physics and engineering.
(Science and
math teachers are notorious for saying to a student
who has just asked a "why" question things like, "well the
math is
a little bit more complicated than what you can handle right now.
Wait until
you have had a year or so of calculus.") In reality it's
the exact opposite!
The math equations actually hide the answers.
They are very good at accurately
describing phenomena, or at
predicting what will happen next, but they can never
answer the
question of why one equation works and another does not. We
get very
comfortable with allowing the familiar math equations
to hide our inability to
really answer the "whys."

This really resonated with me. In my effort to get a better grasp of mixer theoy a lot of people seemed to be simply pointing me to the trig equations, and equating a knowledge of those equations with an understanding of how the mixer circuits really work.

Of course, I don't mean to be anti-math here, but I thought the e-mail on the limits of mathematics was very interesting.
In "Empire of the Air" Tom Lewis wrote, "At Columbia, Edwin Howard Armstrong developed another trait that displeased some of the staff and would annoy others later in life: his distrust of mathematical explanations for phenomena of the physical world. All too often he found his professors taking refuge in such abstractions when faced with a difficult and seemingly intractable conundrum... Time and again as an undergraduate at Columbia, Armstrong had refused to seek in mathematics a refuge from physical realities."

My QSO with K4TWJ

Like everyone else I was saddened to hear of the passing of Dave Ingram. We've all been inspired by Dave's magazine articles, columns, and by his books. I'll always remember his QRP transmitter in a pen!
It was my privilege to talk to Dave once, on the air. I was on 30 meter CW with a brand new,scratch-built, HB QRP transceiver. I was in Virginia. I recognized Dave's call, and was thrilled when he came back to mine. I told him I was running homebrew QRP, and that I'd found inspiration in his articles. I know he was happy to hear that.
73 OM!
Dave's wife Sandy put a nice message on his blog: http://k4twj.blogspot.com

Thursday, January 21, 2010

Some Real DX: Andromeda Galaxy, M31

I mentioned that Billy and I had spotted the Andromeda galaxy. The photo above (not by us) is sort of close to what we saw. The astronomy books usually show these spectacular images of Andromeda in all its glory. But those pictures come from long exposures through big telescopes. Through our little six inch reflector, Andromeda looks like a cloud, not quite as defined as the one in this picture. This picture is a 4 minute exposure through an ordinary digital camera using a 300mm telephoto lens.
(From: http://www.prairiehillfarmiowa.com/prairiehill/Home.html)

It is a real thrill to look at Andromeda. That little cloud represents 300 billion stars, and they are around 2.5 million light years away. So when you look, you know the photons hitting your retina started their trip LONG before there were homo sapiens. Icing on the cake: A satellite went through the telescope's field of view just as was looking at M31.

Another nice thing about Andromeda galaxy is that you can see it with the naked eye (you have to know where to look!). Because of this, people have been observing it for quite some time. Here is the first known drawing of M31. This is the work of the Persian astronomer Al-Sufi, and was done in year 964. The Persians imagined a constellation in the form of a fish in that part of the sky. Note the little cloud near the mouth of the fish -- that's M31.

Until 1923 astronomers thought M31 and other "nebula" were just clouds within our galaxy. The thought was that the Milky Way was the only galaxy. But then Edwin Hubble got some distance readings (using variable stars) on Andromeda and realized that he was looking at an entirely separate galaxy. That was a BIG discovery.

Wednesday, January 20, 2010

Homebrew transistors, QRSS Blog, Shep Show, Nose as toubleshooting tool

Some odds and ends today:

Ed, KC2TYP alerted me to this one: Jeff, K7JPD, has a very intriguing blog post about homebrew transistors. I suspect AA1TJ will have a rig made of these things on the air within a week. Check it out:
http://jeff-duntemann.livejournal.com/227856.html

There is a new blog for the Knights of the QRSS:
http://knightsqrss.blogspot.com/

Dave in Ireland sent me a link to the Jean Shepherd show in which he discusses his first soldering iron: http://www.archive.org/download/JeanShepherd1975/1975_07_30_Soldering_Iron_full_show.mp3

Alan, WA9IRS, alerted us to a nice EDN article on using your nose as a trouble-shooting tool:
http://www.edn.com/article/CA6713738.html

Monday, January 18, 2010

The Sabine Shack

How's that for a shack! Elisa rescued me from the frigid front porch and got the owner to agree to let me use this little building. You can see the VW solar panel in the window.

Here's the view:

Here's a little silent video we shot of the Sabine Shack:



The HW-8 runs of a 7AH Gell Cell that is charged by my Volkswagen panel. Antenna is a doublet fed by TV twin lead. The Blackberry provides internet access, and I can send in blog articles from it by e-mail.

Springtime on Mars (as seen from the Sabine hills)

Ian Sharp in Britain took this image at 0:54 UT January 4, 2010. The North Polar Cap is huge and obvious. The slightly bright region on the southern limb (top) is the dusty Hellas basin.
---
After months of looking at Jupiter, we now have a good view of Mars. On Saturday night we had a "Mars-rise" over Monte Calvo shortly after sunset. Mars is really bright now (explained below) and the distinctive red color really jumps out.

I didn't take the picture, but the shot above gives you a good idea of what I was looking at on Saturday night. The Northern polar cap was very apparent in my six inch Newtonian Dobsonian. It looked like it had a dark border around it. Martian North is at the bottom in this shot. It is Spring in the Northern hemisphere of Mars now.

Mars is now in a very good position for observation from Earth. On January 27, it will be in full opposition:

So hey, this is the time for those of you who are hoping to win the Elser-Mathes Trophy! Aim those Yagis and be sure to tune UP!

Sunday, January 17, 2010

No smoke but Mars, Andromeda, and QRP

No podcast today because we are out in the Sabine hills.But here is a
report on activities here; RC plane was a flop. Advice from WA6ARA and
others helped, but wings are now really messed up. Big success in
astronomy: clear skies and no moon on Saturday. We had a really
beautiful "Mars rise" and were able to see the polar ice cap. Then we
spotted Andromeda galaxy naked eye, and then viewed it in the scope.
Awesome. I'm on the HW8 now. There is a contest but I've managed a few
real QSOs. Back to Rome tonight.

Friday, January 15, 2010

5X7JD: Tuna-Tin To... Uganda

SolderSmoke listeners might recall that Jack Dunigan e-mailed me prior to his move to Uganda. Jack had been listening to our stories about QRSS and WSPR and was thinking about setting up an East African beacon. Jack in now in Uganda and on the air as 5X7JD. He has a beautiful and very interesting blog. Check it out:

http://hamradiosafari.com/

(Jack: Maybe run WSPR using your computer and the Icom at low power, and then use the Tuna-Tin-Two for a separate QRSS beacon. You need an SSB rig for WSPR, but a simple K1EL keyer hooked up to the Tuna-Tin is all you would need for visual QRSS. The TT may need some modification to put it on 30 meters. Let us know if you need help, parts, crystals, etc. It would be a real hoot to have a Tuna Tin beacon from Uganda!)

Jack's blog is filled not only with tales of ham radio in Africa and Jack's personal radio roots (in his Dad's TV repair shop), but there is also information about the work that took Jack and his wife to Africa. Here is his description of it:

Aidchild, the organization for whom I work here in Uganda, cares for orphans living with Aids. There are two homes filled with kids for whom we care completely. This means we provide complete care because they are in every respect our own children. We also provide clinical and laboratory services for about 3000 more children. All of this costs money, lots of it. You can check us out at www.aidchild.org

We raise money through donations, but we also have started businesses here in Uganda to provide funds. We have an art gallery and shop at the Sheraton Hotel in Kampala, a gallery and cafe on the Equator, and a restaurant here in Masaka called Ten Tables (any guess as to how many tables there are?). But caring for Aids children is not inexpensive. So we can always use more funds.

From Jack's postings you also get a sense of the personal sacrifices and hardships that come with his kind of work: scroll down to his posting about malaria and you will see what I mean. As we all watch the suffering in Haiti, it is a good time to think about the many good people like Jack and his wife who are working hard to help our fellow human beings in difficult third-world areas.

Speaking of Haiti, of course the situation is unspeakably bad. We feel real connections to it: My wife is from the same island (from the Dominican Republic). When I was stationed in Santo Domingo, I traveled to Port-au-Prince, and went to many of the places that you now see (crumbled) on TV. Here in Rome, the principal at our kids' school is Haitian. And I have friends in our embassy there. As a kid, one of my first DX contacts was with HH2JT -- Jules Tomar (I still remember getting his QSL). I see that the good fellows at G-QRP have made a contribution to the relief efforts. We should all follow their lead. Graham, G3MFJ, reports that the club made their donation to :
http://www.dec.org.uk/donate_now/

VK6ADF: Echolink, WSPR, 6 Meter Yagi



From London I used to talk to Phil, VK6ADF, on Echolink. We have a lot of interests in common. This may be due to the fact that we were both born in the International Geophysical Year. Phil is now reading "SolderSmoke -- The Book," so we will probably discover other areas in which we have crossed paths. This week, I decided to get back onto Echolink, and in my first session I was looking for OM Phil. He wasn't on, but, IN A VERY MYSTERIOUS TWIST, that morning he sent me an e-mail. Spooky, eh? Anyway, yesterday we got on Echolink and covered our usual wide-range of tech topics. Phil alerted me to a web site called Real Flight that provides an on-line simulator for Radio Controlled airplane pilots. Obviously Billy and I could use some time in the simulator!
Phil is also into WSPR and as we spoke I fired up my 20 mW DSB WSPR rig. I was immediately heard by an Irish station, and Phil almost instantly saw the report on the WSPR database. I noticed that the EI station was reporting that I was on 40 meters, when in fact I was rock-bound on 30. Again, as Phil and I talked, I went to the WSPR chat section and asked about the freq discrepancy. Another VK6 (a friend of Phil's!) answered my question (a simple set-up problem). Small world.
Phil and I have similar curmudgeon-like thoughts on Surface Mount Soldering, and he seemed sympathetic when I said that I think I am more of a "Hardware Defined Radio" guy. Again, this may be an IGY thing. Oh yea, almost forgot: We're not crazy about LINUX either. We are only a few short steps away from the "SPARK FOREVER" mentality and full-fledged Luddite status.
One interest that Phil and I DO NOT share is Six Meters. Phil is now addicted to the Magic Band (which I still consider to be a white noise generator). Check out his video on his six meter yagi.

Tuesday, January 12, 2010

AA1TJ: Reggies Rule! Diode Amps! QRP to the Max!



Whenever I find myself in need of some radio-inspiration, an e-mail from Mike, AA1TJ, seems to pop up in my inbox. This morning's message and the associated video (above) were especially inspirational. Mike was e-mailing Steve, WA1HFF.

Hi Steve,
Thanks for the message and the great QSO! I was running my one transistor transceiver that I call the Reggie. You can read about it on my webpage at

http://mjrainey.googlepages.com/reggie

My antenna is nothing to write home about; just an end-fed half-wave wire bent into an "EL" at 35 feet.

I've made just over 240 contacts with my Reggie in a little more than a year's time; working 19 states. My best (and only) real DX was the Bahamas. All of these contacts were made with no receiver gain on this end; just a pair of diodes fed by a one-transistor BFO, and onto the headphones.

A couple of fellows have built their own Reggies, so you might run into one on 80m now and then. I've made three Reggie to Reggie QSOs thus far.

Steve, last night I was trying something new; I ran a loudspeaker from an audio amplifer connected to my Reggie. What's unusual is that my audio amplifer was made from three, common power supply rectifiers (1N5401's). I'm not kidding! It's a nearly forgotten circuit from 1954 that I (re)stumbled upon a couple of weeks ago. It uses the phenomenon of PN junction charge-storage to produce amplification.

Last week I used two diode gain stages for a total power gain of 48dB to drive my headphones. Yesterday, I added a third diode gain-stage and connected it to a loudspeaker for shack-filling audio volume.

I made a video of last night's setup (the same setup I worked you with). You can see it at

http://www.youtube.com/watch?v=3DA07A6BLDg

Thanks again for the nice contact last night, Steve. You were armchair copy here! :o)

Best wishes,
Mike, AA1TJ

Here's a question for Mike: Can you build that kind of amplifier with homebrew point-contact diodes? If so, you'd be opening up the possibility of a homebrew solid state receiver with homebrew solid state devices. Oh man, this stuff makes me feel like such an APPLIANCE OPERATOR.
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column