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Saturday, March 20, 2010
Vernal Equinox!
Today marks the Vernal Equinox, an important day for QRP radio amateurs. In the Northern Hemisphere, conditions usually start to improve. And this year's equinox is accompanied by higher sunspot numbers. So cheer up guys! Better conditions are on the way.
The equinox comes at 1732 UTC today, 20 March 2010.
Spring seems to be getting off to a good radio start here in Rome. My 20 mW WSPR signal made it across the pond this morning, 8289 kilometers to W3HH (see below). This was the first signal report of the day. I only seem to cross the pond around my local dawn -- never around sunset.
Date/Time TX station SNR PWR RX Station Grid km az
2010-03-20 05:44 I0/N2CQR -7 0.02 PE1DCD JO21fu 1262 334
2010-03-20 05:44 I0/N2CQR -20 0.02 DF6DBF JO31si 1116 342
2010-03-20 05:42 I0/N2CQR -17 0.02 PE1DCD JO21fu 1262 334
2010-03-20 05:40 I0/N2CQR -15 0.02 PE1DCD JO21fu 1262 334
2010-03-20 04:40 I0/N2CQR -29 0.02 W3HH EL89 8289 296
2010-03-19 21:22 I0/N2CQR -28 0.02 LA6TPA JP54rl 2512 359
2010-03-19 21:16 I0/N2CQR -30 0.02 LA6TPA JP54rl 2512 359
2010-03-19 20:54 I0/N2CQR -29 0.02 LA6TPA JP54rl 2512 359
2010-03-19 20:02 I0/N2CQR -29 0.02 G4KFK IO91pk 1457 321
Thursday, March 18, 2010
Look West OM! (For Venus)
Wednesday, March 17, 2010
G.W. Pierce and the AA1TJ GiGi
-------------------------------------------------------
From AA1TJ on March 8, 2010:
It was an exciting QRPp afternoon here on 20m. It started off well
with a ten minute contact with G3MJX. Tony was running 5w to a dipole.
I'm still using the breadboard, two-tube, 250mW (Gigi) station that I
wrote about last week.
KB0PCI in Minneapolis was my next contact. Wayne was using 5w to an
indoor loop. I thought that was pretty cool.
Things seemed to be going so well that I felt the urge to further
reduce my output power. Dropping back to 56mW, I soon snagged Jack,
W7CNL. He's out in Boise with 5w and a five-element Yagi. It was a
great contact with 579/539 reports.
After we signed I resumed calling CQ. Sometime later I heard my call
coming back at me; always a happy moment when you're running QRPp. But
wait...he's signing DH1BBO...Holy Toledo!
With a pounding heart I sent off a 559 report. Olaf came back with a
529 for me, and get this...he says he's running 300mW to a windom! The
first round was an easy copy for both of us, but thing got a little
rougher after that. Still, we were able to hold it together through
the finals for a complete QSO.
Again, my transmitter circuitry is right out of 1928; a
crystal-controlled, push-pull oscillator using a single, 3A5 (a
twin-triode introduced by RCA in 1942). The receiver uses a second
3A5. The first triode forms a crystal-controlled autodyne converter.
The second stage is a standard regenerative detector driving the
headphones directly. My antenna is an end-fed wire at 35'.
Anyway, it was one of those QSO's that I dream about; QRPp on both
ends from start to finish, wire antennas at both stations and an
ultra-simple rig from the days of yore. It was Olaf's first QRPp DX
contact ever, and 57mW now stands as my lowest USA-to-Europe contact
power (230mW was my previous best).
As for working a 300mW German station with a receiver made from a
twin-triode; I think it's a testament to what these little
regenerative detectors are capable of. I was awestruck at the age of
12 or 13; having built my first genny. I love 'em no less some forty
years later as they truly are a beautiful technology.
73/72,
Mike, AA1TJ
From AA1TJ on March 3, 2010:
Bill,
Gigi worked AA7VW (running 5w to a Moxon) in Oregon today with 250mW.
I've been reading a bit of history here in preparation for my
presentation at MassCon next week. For example, I've traced the
crystal-controlled, push-pull transmitter (used in Gigi) as far back
as 1928. Cady and Pierce did their ground-breaking work on quartz
crystal-controlled oscillators in 1923, so it didn't take long for
hams to jump on this one. BTW, Professor George Washington Pierce
("G.W." to his friends) was a real character!
I send my best wishes to you and the family, Bill. The sap has just
started flowing here this week. It's Maple sugaring time in Vermont
again. Spring can't be far away now.
73/72,
Mike, AA1TJ
----------------------------------------------------------
Here is a bio on Pierce: http://profiles.incredible-people.com/george-washington-pierce/
This all makes me want to reconsider my opposition to regens... Maybe they are NOT possessed.
Sunday, March 14, 2010
Online Preview of SolderSmoke -- The Book, SALE!
SolderSmoke Store on Lulu: http://stores.lulu.com/store.php?fAcctID=3999032
Saturday, March 13, 2010
Hamfest tips, 12 Volt Tubes and Cigar Box Radios
Enjoyed very much listening to your adventures in the UK - I very much want to visit Faraday's lab!
When going to the next radio rally/hamfest, can I respectfully suggest the following:
A jacket or waistcoat with lots of pockets, the bigger the better. A backpack with some more bags inside. An idea also would be some kind of lock or restraint so that you could lock a full bag to a post or something out of the way in case you buy something heavy - I usually ask a stall-holder to look after a bag which they are often willing to do after I have made a reasonable purchase from them!
In one of the pockets put a small multimeter with a working ohms range - to test transformers, coils, valve heaters, etc. before purchase.
In another pocket put valve/transistor (or whatever you are interested in) data books or have a handheld thingy (iPhone, etc.) with a working Internet connection where you can look up such things.
In another pocket put a calculator (not needed if you have a handheld thingy) and a small notepad and pen/cil to make notes and work things out and compare prices from competing stalls.
A camera to take pictures of beautiful things you have no money for or intention of buying.
Some personal news:
Currently building a one-valve BC FM receiver - lots of fun. Recently built a MW 2-car-valve superhet which I listen to the World Service on here in Brussels. I build them into Cuban cigar boxes my missus gets free from tobacco shops around the city and in airports.
The fridge broke down and I discovered it was the thermostat and so I decided - foolishly - to spare the money for the replacement part (unemployed) and build one from components I already had in the radio room. Big mistake. I have been fiddling with different resistor values, broken Veroboard tracks and recalcitrant 740 op-amps for weeks now. Managed to freeze an entire bag of perfectly good carrots! I think I am on the tail-end of the prototype development process now and the production model should emerge in a week or so. The missus was initially impressed but now, sadly, not so. C'est la vie.
I experimented with QRSS using a simple PIC-controlled single car-valve crystal-regulated transmitter and a crystal immersed in a large jar of water for temperature stability. I managed to get seen by various grabbers and so am moderately happy. WSPR might be on the boards next, if I can do it with a PIC and a valve...
Good luck with the RC aeroplanes - try and keep the propellor pointed away!
73 cheers
Nick on4Nic / m0NjP
PS Car-valves are designed to operate from 12V only - heater and HT. Great fun for fiddling around with and completely safe - so long as you don't break them or burn yourself on the glass!
Friday, March 12, 2010
Cool Phobos Picture
Windows 2000, SMT, Olive Oil, Difference Engines
Just finished listening to SS 121. Fascinating as usual. In no
particular order:
- Microsoft is ending all support for Windows 2000 effective July
13th of this year. For us little guys there's only one impact, but
it's a doozy: no more security patches. My bench computer is still
Win 2k, so he'll either be losing his connection to the interwebs or
get replaced (don't think his little brain would take the current
Ubuntu release, but perhaps I'll give it a shot.) I'm a pretty tech
savvy guy so I've got no problem moving on, but I hate to toss
perfectly good hardware. Heck, I've got a 1965-vintage USAF surplus
VOM and a Fluke LED readout DVM on my bench (both relatively new to
me!) The scope, power supply and sig gen aren't much newer. I
think the odd duality of hams you pointed out (tech forward and also
sticks-in-the-mud) is another expression of an engineering mindset
that doesn't accept that the new must devalue the old.
http://blogs.technet.com/
- I'm starting to think the Sun has dropped life-cycle support for
HF, effective when I got my HF privileges. I'm following your weak
signal work with a lot of interest.
- I think I mentioned previously that I got to see the Babbage
Difference Engine #2 last fall. After hearing your Dobsonian
maintenance story using "API Grade Extra Virgin" olive oil, I thought
you'd be amused to hear that the BDE is lubricated entirely with corn
oil, which is apparently available in a variety of SAE weights. I
thought they should put a Bunsen burner under the drip pan and make
popcorn in there, but the docents weren't too impressed with my
engineering suggestions.
- SMT: I got my first serious taste of SMT while building, of all
things, a Nixie clock. It had two large quad flat pack (QFP) chips.
They weren't involved in the processing (which was done by a proper
DIP packaged PIC chip) but were the HV drivers (apparently actually
intended for use in a plasma TV). The manual instructed me to tack
down the corners, verify the alignment of all the unsoldered pins,
then just heat 'em and solder 'em down, ignoring pin-to-pin shorts.
After soldering all the pins, it then said to lay a piece of
desoldering braid on top of each run of pins, and heat it until the
excess solder wicked up. I was dubious, to say the least. But to my
complete surprise not only did the clock work on the first try
(meaning all 80 pins had been soldered correctly) but the chips
actually looked pretty good, too. Still a bit nerve wracking!
- In the "keeping old computers working" department I just ordered a
solid state drive to replace the oddball 1.8" drive in the little Dell
I use for travel. It runs Ubuntu pretty well, but I have to have Win
7 on there for work reasons, so I'm hoping the SSD will speed up the
latter (and not blow up the former - Linux and new technology haven't
worked out well for me in the past).
73,
Bob KD4EBM
Thursday, March 11, 2010
Faraday's Transformer Diagram
Wednesday, March 10, 2010
Faraday's Shack and the First Transformer
On display was the very first electrical transformer. And guess what guys: It was a toroid! Here is a picture of it:
I found one of Faraday's drawings of the toroidal transformer and its windings. It looks a lot like the drawings of Doug DeMaw! I'll scan it and post it tomorrow. Off to work now.
Monday, March 8, 2010
Pop Sci! 137 years of Popular Science. Free. Online.
http://www.popsci.com/archives
At the Royal Institution
Billy and I visited the RI a couple of weeks ago and got to sit in the famous theater.
I even got to stand at the famous desk on which so much new science was presented to the world. More on the RI (and Michael Faraday) tomorrow.
Sunday, March 7, 2010
Marconi's House in London
In London, the places where famous people lived are marked with Blue Plaques. I knew that Marconi's name was on the list, but I had never actually seen his plaque. When we were up in London last month we were staying in Marconi's old neighbourhood (Bayswater) so and Billy and I decided to take a look. Video by Billy.
This house is mentioned in the book Thunderstruck by Eric Larson and in Peter Jensen's wonderful Early Radio. Marconi lived here as a young man. His mother took him to London in order to get patent protection for his wireless invention. The way in which Marconi's mom watched out for her son's intellectual property rights reminds me of the way Bill Gates' dad watched out for his.
Marconi's arrival in the UK was a bit difficult. British customs officers were apparently very suspicious of the strange device being brought in by the young Italian. One book hinted that they might have thought that Marconi was involved in some plot to kill Queen Victoria. During the inspection serious damage was done to Marconi's rig.
Saturday, March 6, 2010
Dover update: Falling from tree, B2 inheritance?, HB variometer
Thursday, March 4, 2010
African WSPRs -- Homebrew, QRP, and International Brotherhood
Here is Gernot's creation. Isn't that beautiful? Note the "Homebrewed by OE1IFM" markings on the boards. Truly inspiring stuff!
But there's more: A while back we had a blog entry on Jack Dunigan, 5X7JD. Jack is in Uganda, helping kids who are living with AIDS. Today, one of Gernot's WSPR rigs is scheduled to be delivered to Jack. So soon we should be seeing WSPRs out of Uganda.
You guys should check out Gernot's web pages on this project:
http://www.oe1ifm.at/index.php?option=com_content&view=article&id=52&Itemid=53
His site is filled with really interesting technincal info on this amazing rig.
I found this endeavor to be inspiring at many levels: There is obviously a lot of Knack here, and this is a very good example of what the "International Brotherhood of Electronic Wizards" can do.
Book Review (and a price reduction)
http://stores.lulu.com/store.php?fAcctID=3999032
Dale, G4IPZ wrote this review of the book:
It's not often that I've come across a book that combines the fun of Amateur radio along with understandable explanations of difficult technical concepts as well as being a damn good read.
This book not only achieves this but does it perfectly.
It's described on the back cover as "... the story of a secret, after-hours life in electronics." Why after hours? Well because the author, Bill Meara (N2CQR, M0HBR, CU2JL) is a diplomat, a consul for the United states of America, having been posted to such diverse locations as Rome, London, Panama, El Salvador, the Dominican republic and many other places.
During his career as a diplomat his hobby of ham radio and in particular QRP and home-brewing has followed him around the world.
He admits that he did take time out for a while on meeting his future wife and then marrying her. Then, as so many of us have done before, he began to be drawn back into the hobby; the warmth of the shack, where on a cold night, he could sit clutching a hot coffee, listening to the bands, talking to friends and surrounded by the smell of solder smoke.
During his years as a diplomat-ham he has spent much of his free time trying to understand some of the whys and wherefores of the circuits he was building, attempting to build and attempting to fault find when they didn't work. And so many of us have been right down that road!
And that explains what this book is; it's a form of diary of Bill's Eureka moments combined with an insight into his travels and life as a diplomat.
The technical range covered is quite large and despite all my years in electronics I found many of his eureka moments clarified some of my ingrained foggier thinking.
For example we all know how mixers work. Or do we? How many of us can actually explain what goes on even in the simplest of two diode balanced mixers? Most of us just accept that, by the black necromancy of radio in which we dabble, fearing the release the magical smoke at the wrong moment, it just mixes and that's that.
But Bill took time to ask, query and eventually, by making notes to himself, come to understand what was going on. And his explanations of mixers and other such subjects are indeed highly illuminating. He explains semiconductor principles (Do you really understand hole flow versus electron flow?). And how about resonant circuits for example? Bill explains these and much more in a refreshing new way along with capacitors, crystals, and a host of other often accepted but often not fully understood truths that we, as amateurs just take for granted.
This is an ongoing life's trip through the hobby which we all share with Bill, and remember that he is not a professional electronics engineer; he is a radio ham who wants to be more than an "appliance operator".
He enjoys tinkering and has stuck with some pieces of equipment for more years than I will mention but it hasn't stopped him working through the satellites and bridging the oceans on less watts than a nightlight.
And as well as his obvious love of his hobby, he introduces us to many of the other amateurs he has met on his travels and at his various postings. He paints a wonderful picture of the people that many of us may get to meet on the air but he's been lucky enough to meet face to face.
And as well as doing all this he also ventured into the world of Pod-casting and blogging, the outputs which has reached thousands world-wide on his SolderSmoke website.
I cannot recommend this book too highly and I found that it was one which I couldn't put down until I'd finished.
Dale Haines G4IPZ
Wednesday, March 3, 2010
Black Holes in Workshops?
When I was out in Dover (UK) last week the fellows in the Dover Construction Club alerted me to a problem that has been affecting their workshop, and that may be causing trouble in yours: black holes. Apparently through some strange quirk of quantum physics, small black holes are sometimes generated in electronics workshops. They cause parts and tools to disappear. The quantum element of all this is readily apparent: only those parts and tools that you REALLY need disappear. If you don't need a particular part or tool, it will not be affected. The guys out in Dover recently lost a variometer this way, and while I was there a telegraph key briefly disappeared into the quantum mist. In a variation of this phenomenon, very small black holes sometimes pop out of the quantum vacuum when small parts are dropped to the floor -- that's why you often can't find them! SMT parts are especially susceptible to this (obviously because some of the damn things are getting down to quantum scale) . I don't really know what can be done to counteract this problem -- if you have any suggestions, please post a comment.
On a related subject, Jim Miller sent us this:
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Tuesday, March 2, 2010
Mars Express Phobos Fly-by (Wednesday)
Mars Express carried the Beagle II lander to the red planet. I was in the UK when they made that brave attempt to put the probe on the surface, and shared in the disappointment when no signals came back. Later, I had the privilege of meeting Beagle II's creator, Colin Pillinger. Colin gave me signed copies of his wonderful books on Mars.
Here's some more info on Wednesday's fly-by (from ESA):
1 March 2010
ESA’s Mars Express will skim the surface of Mars’ largest moon Phobos on Wednesday evening. Passing by at an altitude of 67 km, precise radio tracking will allow researchers to peer inside the mysterious moon.
Mars Express is currently engaged in a series of 12 flybys of Phobos. At each close pass, different instruments are trained towards the mysterious space rock, gaining new information. The closest flyby will take place on 3 March at 21:55 CET (20:55 GMT).
From close range, Mars Express will be pulled ‘off-course’ by the gravitational field of Phobos. This will amount to no more than a few millimetres every second and will not affect the mission in any way. However, to the tracking teams on Earth, it will allow a unique look inside the moon to see how its mass is distributed throughout.
How will the ground teams make these tremendously sensitive measurements? Ironically, they will turn off all data signals from the spacecraft. The only thing that the ground stations will listen out for is the ‘carrier signal’ – the pure radio signal that is normally modulated to carry data.
Preparing for closest approach to Phobos |
After the closest flyby, the work is not over. Mars Express will sweep past Phobos a further seven times before the campaign is complete. In addition to the tracking experiment, known as MaRS for Mars Radio Science, the MARSIS radar has already been probing the subsurface of Phobos with radar beams. “We have performed a preliminary processing of the data and the Phobos signature is evident in almost all the data set,” says Andrea Cicchetti, Italian Institute of Physics of Interplanetary Space, Rome, and one of the MARSIS team.
The MARSIS radar is already taking data |
All photos from ESA.
Sunday, February 28, 2010
SolderSmoke Podcast #122
SolderSmoke!
A SHOW FOR ELECTRONICS HOMEBREWERS!
Listen at: http://www.soldersmoke.com
SolderSmoke #122
Feb 28, 2010
Snow in Rome!
In London: A visit to Marconi's house, Maplins, and Faraday's lab
A visit to the Dover Construction Club
Computer problems resolved
A short period of QRSS, then back to WSPR
Putting the Drake 2-B into WSPR mode
The Rome-Norway WSPR pipeline
Increased solar activity
50 years of SETI with Frank Drake
QQ Review
Work Bench Eye Candy
Movie Review: UP! (Five Soldering Irons)
MAILBAG
Thursday, February 25, 2010
KNACK IN THE SHACK: N5ITU
The mug and the bumper sticker are available at the SolderSmoke Cafe Press store: http://www.cafepress.co.uk/SolderSmoke
Jeff is in Texas. We had a feeling that this particular bumper sticker would appeal to those the Lone Star State.
Reverse Polarity Protection -- Words of Wisdom from K7QO
voltage application.
Here is what I do. There is a diode, the 1N5817,
a Schottky Diode. Will take 20V peak reverse voltage,
will handle 1A continuous with 25A surge and has only
a 0.45V forward drop and the reverse current is 500uA.
I put one of this in series with the 12V line input of
every electronic device I build. If the designer used
a 1N4001-7 in series, I replace it.
I am not a fan of the diode across the voltage input
line and having it short out when reverse voltage is
applied. What if the applied voltage is a gel-cell
without a fuse? You blow the diode and you blow the
rig. IMHO is this not an ideal way to do it. Should
be using fuses too, but I don't. Haven't found a way
to use the flat auto fuses with gel-cells in a handy
low-profile way and inexpensive parts. I'd appreciate
the education, if someone has film and photos of great
arrangements.
I buy the diodes from Mouser.Com for about $26 per 250.
For a dime a rig it is a real cheap way to protect your
equipment from yourself and others.
With the limit of 1A at 13.8V, it is well within the
QRP operating limits. And why do you need more than
1A anyway?????? :-) And the low forward voltage
drop means that the finals (which are usually fed
direct from the B+ line anyway) don't lose much
in applied voltage and you get pretty much the
same output as without the diode. And you protect
those expensive parts for a dime. A quarter if you
buy just one diode from Mouser.
Hope this helps. Just the way I do it, and I'm
not always right. But I've only lost a few parts
and that was before I started using 1N5817's on
everything.
The 1N4001 through 1N4007's are fine if you are
feeding 9-12V to a 78L08 regulator.
FYI
chuck
--
chuck adams, k7qo
http://www.k7qo.net/
chuck.adams.k7qo@gmail.com