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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.
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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