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Wednesday, March 17, 2010

G.W. Pierce and the AA1TJ GiGi

Mike, AA1TJ, continues to provide the global solder-melting fraternity with large doses of QRP/homebrew inspiration. And, as usual, his latest series of messages to QRP-L contain interesting references to the radio pioneers who laid the ground work for his low power exploits. This time, it was G.W. Pierce.
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From AA1TJ on March 8, 2010:
Fellers,

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

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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!

I was working on the websites for SolderSmoke -- The Book, and I managed to set it us so that you can get a preview of the first part of the book. Just click on one of the links on the upper right hand side of this blog page, and look for the preview link (under the picture of the front cover). Lulu is running a 10% off sale this month. Use the coupon code "IDES" when you check out. (Very approriate - tomorrow marks the Ides of March.)
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

Bill,

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

This one is not from the recent fly-by. This one was taken by ESA's Mars Explorer in January 2007. I thought it was a very nice picture. There should be new close-ups of Phobos coming out this week.

Windows 2000, SMT, Olive Oil, Difference Engines

Hi Bill:

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/lifecycle/archive/2010/02/25/end-of-support-for-windows-2000-and-extended-support-phase-transition-for-windows-server-2003.aspx

- 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

Looks familiar, doesn't it? Reminds me a lot of the toroidal transformer diagrams that you see in the Doug DeMaw books. This is from an 1831 lab notebook of Michael Faraday.

Wednesday, March 10, 2010

Faraday's Shack and the First Transformer

In London, Billy and I visited Faraday's workshop in the Royal Institution. Poor Michael set up shop in the servants' quarters in the basement. The shop is still down there (behind glass and well-preserved now). The painting above depicts Faraday at work in his shack.

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.

I know I promised more about Faraday today, but I think Michael would agree that this story should take precedence. Niels, PA1DSP, reports that ALL 137 YEARS of Popular Science issues have been made available FREE ON-LINE. This is Billy's favorite magazine. Amazing. We're all going to have to quit hour jobs to have more time for this kind of thing! Three cheers for the publisher and for the boys at Google for making this possible. Here it is:
http://www.popsci.com/archives

At the Royal Institution

The Royal Institution in London is one of the world's most important scientific organizations. In the picture above, Michael Faraday delivers one of the famous "Christmas Lectures."

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

That's me (the new boy in the workshop) at the key of Ian G3ROO's B2 spy set. Beautiful rig. You will all, I'm sure, understand Nigel M0NDE's question to Ian (see below). The Dover variometer project is very interesting (picture at the bottom). Thanks Nigel! (Try to keep Ian at ground level, OK?)

Hi Bill, a Dover construction club update:
Ian was cutting down some trees in the garden this weekend, and took a tumble. As he fell I asked him if I could be left the B2, I can't tell you exactly what he said but you can imagine. Fortunately he was not injured as the ground was soft with all the rain we have had. The B2 remains in the museum for now.
The black hole has taken the variometer from us forever so a new one was made Thursday night at club. You got the blame tonight for anything that was not in its proper place when sought, the new boy in the workshop always takes the blame!
A length of plastic drain pipe was selected. A coil of about ten turns was wound around a large capacitor as a former and tied off with beeswaxed rafia then mounted onto a plastic rod. The plastic rod had a hacksaw slot put in it lengthwise to facilitate the copper wire exiting the plastic pipe. The plastic pipe was drilled and squeezed and the coil inserted into the pipe. The rod was held in place by friction fit brass washers. Two coils were wound around the plastic pipe,in similar directions. The wire is just tensioned by being passed though holes and threaded in and out of the pipe at each end. A plastic screw allows the inner coil to move through just 180 degrees. The first test showed two inductance ranges were possible 6-12 micro Henries and 12 to 21 mH. We will add additional coils up the pipe to give 21 to 30, 30 to 40 etc. A ten meter fishing rod will form the vertical element, with this variometer and switched coils providing the tuning. The experiment continues next Thursday night.
73 de Nigel Evans M0NDE QTH Dover

Thursday, March 4, 2010

African WSPRs -- Homebrew, QRP, and International Brotherhood

Jeff, K07M, and others have noticed that the WSPR system's maps show very few stations in Africa. Gernot, OE1IFM, has launched a fascinating project to help fill this WSPR-gap. He has designed and built a stand-alone WSPR transmitter. No computer is required. It is all in two little boxes. It pumps out 1 watt of WSPR signal. And -- get this -- it jumps around from band to band, transmitting a sequence of WSPR signals on all of the HF ham bands. WSPR requires good synchronization. How, you might ask, does Gernot keep these rigs in synch without a computer and without the internet? No problem: He uses time signals from GPS satellites! Bravo Gernot! One of these rigs is currently on the air from Namibia (V53ARC). You can see it in the screen shot above (taken this morning).
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.
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column