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Tuesday, December 22, 2009

A Report from South Africa

Hi Bill

Africa "field QRP station"
Thanks for another great episode of your experiences - I'm tuning in from Africa while on my vacation Each December I make the trek from San Diego to Cape Town.
Then, my Dad (zs1xd) and I take the family out to a remote
location - and setup a field station. Around the camp-fire, under the Milky Way and no rf-pollution is a great way to hunt some dx and spend vacation time. This year
we selected a cabin located in a beautiful mountainous region about 100 miles north of Cape Town. 2 wheel vehicle will get you there and "just in case" , we
also took a capable 4x4 with.
I posted some pics and QRP HF operating notes here: http://k6wh.blogspot.com/

"SMT"
I'm following your Softrock SMT construction comments with keen interest and am glad you're finding the challenge - well - "not so much of a challenge"
I think it's so great that you're encouraging hams to jump into SMT.
I chuckled at your comment about "desoldering smt's" - Try de-soldering the Si570 SMT chip. I had the good fortune of measuring messing up the
"measure 10 x then cut once" when soldering this IC on the rxtx kit. Well - we know a mistake will happen, and when it happens, murphy's law will ensure
that it involves the most sensitive and tricky smt component on the board - hi.

It's a real trick, due to the contacts being under the chip (no pins like the other smts)
Well - try de-soldering that piece. And of course one realizes the mistake, only once the last solder joint has dried. Determined to correct the mistake there and then,
at 9pm while busy with the kit, I rushed off to the nearest radio shack to get some de-solder wick. Took me about 1 hr of patience, and careful "wicking" to suck
up all the solder underneath the chip - one contact at a time, (each desolder attempt, hoping the chip pops loose) - no easy task. I don't know of another easy way
than lots of patience, and a good magnifying glass.

I agree there is no greater reward than "homebrew" and with the advances in SDR tech, we're surely living in a wonderful age.

Once you get the SDR on-air, I'm sure you'll be blown away by the reception quality - sensitivity and especially the almost non-existent noise-floor.
(I'm not sure which model you're building, but I think all of Tony's designs are utilize the same Tayloe detector design which is very quiet)

I still can't believe the performance I get with the Softrock's kit - It's now become an antenna measuring instrument - While having fun with PSK QSO's and WSPR.
Of course, with the SDR one can adjust the output (via soundcard drive) to basically uW levels.

As we know, at these levels, each little bit of antenna optimization helps, and SDR+WSPR/PSK has become my "far field antenna measurement tool" of choice.

WSPR from Africa
Not too many stations active on WSPR on the African continent - Now that I've setup my Dad on DSL, I assisted him in activating his WSPR station in
Cape Town (ZS1XD). His antenna is a 20m homebrew 2 el yagi. I'm pointing it north during the evenings to see if n2cqr pops up in the log. Nothing yet, but I'm sure
one of these days, you may just be surprised. Keep watching for the Africa report :)

thank you again for such a great entertaining and educational program ...
73 - best wishes to you and the family from the tip of Africa.
de deon (k6wh)/zs

Monday, December 21, 2009

Technical woes: Linux, WSPR, SSSSS

Help me, help me! I want to get WSPR running on Billy's Asus eeePC. I have Ubuntu Easy Peasy running off a thumb drive. And I have the WSPR sofware package in in the machine. But I can't get WSPR to run. I click on it, and the machine asks me if I want to run the program. Indeed I do! But nothing. Help me Linux heads! What am I doing wrong? I've tried running it from the terminal using the instructions in K1JT's excellent manual (see, I have read the manual!) but the computer informs me that I need superuser privileges. Now what?

Also looking for feedback on the SSSSSSS problem. Was it better in SolderSmoke 119?

Thanks!

Sunday, December 13, 2009

Crossing the Pond to KZ1H

We were out the Sabine Hills this weekend and on Sunday afternoon I go on 20 CW with my trusty HW8. I made just one contact, but it was a GOOD one. KZ1H pulled me out of the noise and we had a very nice chat. My fist was not at its best, because it was COLD in those hills -- I'm arranging now to move the shack off the front porch and into the heated (I hope!) library.
Anyway, from the courteous way in which he persisted in copying my QRP signal, I knew that OM George, KZ1H, was a FB ham. Sure enough, when I plugged his call into Google this morning, I was taken to a site with the above picture of George in his younger days. Note the bug and the mill, and the homebrew transmitter. Here is George's story:

I grew up in Corona, Queens, NYC. I became interested in radio at the age of ten or so. My father bought an "Eilen" and I was introduced to Morse code. I met many hams around town (W2HDK, W2KAP, W2APT, W2KCD, W2JGV?). They were all very cordial and happy to show off their rigs.

In April of 1939 (age 14), I took my test at the FCC office at 641 Washington St, Downtown NYC and became W2MDE. My father bought me a Hammarlund Comet Pro (plug-in coils with shield cans). I built an oscillator/ transmitter using a type 59 tube.

I was invited to join the W2USA radio club at the 1939 NY World's Fair. W2KU was the Chief Op and my boss. We handled a lot of traffic for the fair visitors and kept the station on the air during the winter when the fair closed between summer sessions.

At 16, I graduated from high school and went to work for a large patent law office as a clerk. From there I went to work for Hazeltine in Little Neck, NY. I thought I might faint when I saw that my first check at Hazeltine was signed by Jack Binns, the radio operator who was the subject of the book "SOS to the Rescue".

At 17, I was made chief inspector of Hazeltine's first war-time production line and worked along side of Frank Hinners.

When I turned 18, Mr. Bailey of the ARRL became head of the Bureau of Scientific Research and Development in Washington, DC. He invited me to become a member of the Army Intelligence Service when I was drafted, which I accepted.

After the war, I attended the Cooper Union School of Art in NYC. I worked for PAA, Grace Lines, Andrea, Sperry Gyroscope, Varian Corp, and Global Systems. Much of my career has been in microwaves. I have been retired for 20 years and am still active on the bands. My present call is KZ1H.

I have been married to my wife Mildred for 53 years. We have three daughters, Jean, Janet and Diane.

Saturday, December 12, 2009

Dale Parfitt, W4OP, Homebrew Hero

Yesterday, in my search for pictures of the Drake 2B, I came across VE3MPG's excellent interview with Dale Parfitt, W4OP. Dale and I crossed paths years ago: After I built my first version of Doug DeMaw's Barebones Superhet, I went out on the net and found a couple of kit versions of this receiver for sale. A few years later, I was working on one of them, and turned (as you do) to QRP-L for some advice. Dale came to the rescue and we started exchanging e-mails. After a while he told me that the version I was working on sounded familiar. Sure enough, he was the original builder! The story appears in SolderSmoke -- The Book.

Here is further evidence that Dale and I have similar tastes in receivers: Pictured above is his solid state version of the Drake 2-B. FB! I note that the dial scales are the same as the hollow-state version.

Here is the VE3MPG interview:
http://ve3mpg.blogspot.com/2008/10/interview-with-dale-parfitt-par.html

Friday, December 11, 2009

Mechanical Resonators

Mike, KC7IT, sent along this interesting article on the use of mechanical resonators in cell phones.
http://spectrum.ieee.org/telecom/wireless/radios-with-micromachined-resonators

Somehow, this made me think of my beloved Drake 2B. The 2B uses an L-C filter at 50 kHz, but -- sure enough -- a quick visit to the e-ham review section showed that Henry Radio had a vailable a mechanical filter kit -- some of the 2Bs out there are apparently fitted with this device.
Check out the e-ham Drake 2B love-fest: http://www.eham.net/reviews/detail/3868 All of it true!

And of course, this all provides an excuse to put up a picture of the Drake 2B.

Thursday, December 10, 2009

A Fondness for Phasing


As the proud owner of a Hallicrafters HT-37, I have long had a fondness for phasing rigs. It took me a long time to figure out exactly how they manage to drop the carrier and one of the sidebands without the use of crystal filters. This was one of the technical understanding battles of my radio youth, and is detailed in SolderSmoke -- The Book. (See the upper part of the right column of this blog for details on how to get the book.)

I was reminded of all this by a link sent in by Jim, AB3CV. It is an EDN design note, and describes a simple modern SSB generator using two phasing networks, three IC's, and a handful of discrete components:
http://www.edn.com/contents/images/93099di.pdf
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column