India – Page 6 – SolderSmoke Daily News

Re-purposed Computer Power Supply Box Provides a Home for a BITX Transceiver

Jaydip VU3JOJ came up with a really inventive way to box up his new BITX transceiver. Nicely done. I especially like the way he put the speaker in the space intended for the fan. Very nice.

This appears to be one of the new BITX 40 meter “modules” described in yesterday’s blog post. FB! How fortunate the new board fits in the power supply boxes. That’s very lucky.

You know, I had an old computer power supply in my hand just yesterday. I almost threw it out. Obviously that would have been a mistake.

Today was a BITX day. Using my BITX DIGI-TIA on 40 I had a long QSO with Rich N3TDE. Rich has a BIT20 built from a Hendricks kit acquired at Dayton. He takes it with him on the Appalachian Trail.

A Really Nice Project: Farhan’s BITX40 Module

Wow, that board is a thing of beauty. And the story behind it is even more beautiful. Our friend Farhan took his famous BITX circuit, shifted it to 40 meters, and put the whole thing on one small board. It is now a module, but a module that makes up an entire SSB transceiver. The idea is that this module can provide a base for expansion and experimentation. You can add a digital display. Or a (gasp!) digital VFO. Or an RF amplifier. Or more bands. Or all of the above. It is a very cool idea.

Here is the most beautiful part: In an effort to help people who need help, Farhan has arranged for a collective of women to assemble the boards in their homes. They needed work, and Farhan gave it to them on good terms. Bravo Farhan!

In keeping with the earliest purpose of the BITX rigs (simple transceiver for Indian radio amateurs) this board is currently only available in India.

Check out the site:

http://www.hfsigs.com/buy.html

The circuit description is especially good:

http://www.hfsigs.com/circuit.html

Movie Review: “The Man Who Knew Infinity” FIVE SOLDERING IRONS

My wife and I went to see this flick about the mathematician Srinivasa Ramanujan. It was filmed at Trinity College, Cambridge — if you look at the dedication to “SolderSmoke — Global Adventures in Wireless Electronics” you will see a picture of my kids at Cambridge. Alas, that picture was taken at Kings College, not Trinity; nonetheless, the Cambridge connection got us interested. Then there was the Indian aspect of the story, which is very intriguing. There was also the “amateur makes good” angle that all of us should, I think, find very encouraging.

The movie did not disappoint. We really liked it. The presentation of the cultural clash was very well done. Elisa told me that as she watched Ramanujan struggle with England, she found herself wanting to tell him, “You are just going through culture shock. Be patient! I’ve been through this many times!” They included just enough math to give the viewer a sense of what Ramanujan was working on.

I got a real kick out of one scene in which old Professor Hardy, seeking to motivate young Ramanujan, took him into the Wren Library and showed him the manuscript of Newton’s Principia. I had seen the same manuscript in the library of the Royal Society in London — they had take it out on the occasion of the visit to the library of Stephen Hawking and NASA Director Mike Griffin. They also had on the table the reflecting telescope that Newton himself had made. That was quite a day.

Great movie. I give it the coveted rating of five soldering irons.

More about Ramanujan here:
https://en.wikipedia.org/wiki/Srinivasa_Ramanujan

Farhan’s Cool BITX 40 (video)

I especially like the wood base and the transparent front panel. But we have to send Farhan a D-104!

Check out the video of this rig in action:

https://www.facebook.com/ashhar.farhan/videos/10153914094442107/

Farhan posted:

The BITX40 has a redesigned crystal filter at 12 MHz that contributes to a very clear signal. Note the clarity on SSB and the absence of noise due to the three poles of filtering. This was charminar net on May 2, 2016. I couldn’t break-in. Probably because the tiny plug mounted mic was too far away from my mouth.

K.P.S. Kang’s Pixer Superhet

K.P.S. Kang (VU2KR and VU2OWF) has been contributing ideas and circuits for many years from his QTH in Punjab India. He is the source of what became known as the VU Transmitter circuit:
http://www.zerobeat.net/g3ycc/week1.htm

Today I spotted a recent blog post by OM K.P.S. on a simple superhet receiver he is working on. He has a knack for describing the design considerations (needed gain, IF selection, etc.)
Check it out:

http://smallwonderqrp.blogspot.com/2016/04/pixer-empirical-hf-superhet-receiver-i.html

and

https://plus.google.com/111066147552844651495/posts

Possibly the Best Ham Radio Interview Ever: Farhan on “QSO Today”

Stop what you are doing. Run — don’t walk — to the “QSO Today” website of Eric Guth 4Z1UG. There you will find his interview with Ashhar Farhan VU2ESE.

There is so much great information, inspiration and wisdom in this interview. I was so captivated by it that — even with the availability of the pause button — I was unable stop listening even for the time it would take to walk to the kitchen to refill my coffee cup. But at the same time, listening to Farhan describe the joy of bringing a new receiver into operation compelled me to go over to the bench — in mid-podcast — to tweak a receiver that I am working on.

In this podcast you will hear about how Farhan got started in ham radio, about his Elmers about the origins of the BITX, about the Minima and the new HF-1 rig, about Farhan’s spectrum analyzer project and about a new goodwill effort to send BITX circuitry to aspiring hams around the world, especially in developing countries.

Throughout you will hear Farhan speak of the importance of the book, Experimental Methods in RF Design.

I really do think this is the best ham radio interview I have ever heard. Congratulations and thanks to Eric and Farhan.

Here is the link:

http://www.qsotoday.com/podcasts/vu2ese

The Wizard of Warrenton: Jerry KI4IO

That’s Jerry KI4IO of Warrenton Virginia sitting in front of truly impressive collection of homebrew gear. The cream-colored box above the Vibroplex is Jerry’s new 7 MHz phasing transceiver. He has a wonderful write-up of this rig in the qrp-tech group files section:

https://groups.yahoo.com/neo/groups/qrp-tech/files/KI4IO/

You may have to join the yahoo group to access it, but believe me, it is worth it. Jerry took a very eclectic approach to circuit selection and came up with a very cool rig. Lots of soul in that new machine! Here it is in breadboard form:

Jerry worked in U.S. Embassies as a communications officer and is obviously a member of the International Brotherhood of Electronic Wizards. From his QRZ page:

While in India I was licensed at VU2LHO and worked a lot of US hams with a 135′ flat-top and open-wire feed. I had the antenna strung between two bamboo towers atop the embassy housing 2ND-story roof-top. I also put up a 3/8 wave vertical on the roof for 10 meters. That little antenna had 110 radials stapled into the roof scree and worked very well! The rig was a HW-101. I was in Kathmandu, Nepal from early 1980 to late 1982. I could not obtain a license there, but became good friends with Father Moran, 9N1MM, and would often spend time up at his place putting his Drake station on CW. Pretty cool being real DX!

Warrenton, Virginia is not far from my QTH (it is the birthplace of Cappuccio the wonder-dog).

FB Jerry.

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

The Original BITX 20 — Designed at 35,000 Feet in 6 hours, Built in India in 3 Days

I came across what appears to be an early version of Farhan’s description of the design and initial construction of the BITX 20 (see below); this version has some interesting information on the origins of this important rig. The picture below shows the designer himself working on that first BITX20. It is from a CNN video. I know Farhan is sick of seeing this old video, so I present here only the shot of the designer’s hands at work on the original transceiver.

Some thoughts from the designer, Ashhar Farhan, VU2ESE:

This transceiver was designed during a six hour flight from Europe with paper, pencil and the basic calculator built into my cell phone. It was soldered in three sittings over three days. Very little went wrong during the construction. It was one of those easy designs. The only mistake that I made during construction was that I soldered one of transistors in reverse. The design worked as ‘advertised’. I guess that extensively using feed back amplifiers provides designers with greater repeatability. Also, I realized, a little late in life though, that detailed forethought and ‘mental’ home-brewing is important for a clean design.
The linear chain was initially unstable. It tended to oscillate in the 14MHz band as well as around 500 KHz. I traced the 14MHz oscillations to a choke that I was using at the output of the balanced modulator. It has been removed. The 500 KHz oscillations were because of excessive gain in the driver and pre-driver stages. From 5 ohms, the emitter degeneration has been increased to 10 ohms and better bypassing on the power rail has eliminated the oscillations.The receiver is as hot as I need it to be on 20 meters. Signals from USA, Europe, South Africa and of course India were heard with clarity reminiscent of a clean Direct-conversion receiver on the first evening. The transmitter is powerful enough for local rag chew and it is a modest challenge for DX. VU2PEP has an excellent two element beam at 20 meters at about 40 feet height. DX is easy for OM Paddy who uses the rig regularly. We netted LA2FKA within the first 20 minutes of firing up the rig.
No, I don’t offer PCBs. I don’t repair rigs. I don’t offer kits. I might do a PCB for this rig (I hate PCBs, they hamper experimentation).
This transceiver is dedicated to the memory of OM Juggie, SK (VU2JH) who was a great organizer of India hams, he wrote technical articles in Electronics For You magazine about amateur radio, spurring many to take on ham radio as a hobby. He organized the Millennium Ham Meet in the year 2000. He was always searching for a good and simple homebrew SSB transceiver. He died young. He gave me my first morse key.

Jagdish, VU2JH

World Radio Day! Article with Farhan

The Hindu did a nice article on World Radio Day. They wisely featured someone with a true case of The Knack, someone with a strong emotional connection to radio and radios: our friend Farhan.

http://www.thehindu.com/features/metroplus/thank-you-for-the-radio/article6886601.ece

Beautiful Pictures of Mars from India’s Spacecraft

Congratulations to the Indian Space Research Organization. They put a spacecraft into Mars orbit on their first attempt, and they are getting back some spectacular images.

I also like the banner on their web site:

More info here:

http://www.isro.org/pslv-c25/Imagegallery/mom-images.aspx

Confucian Wisdom from VU2BK in Hyderabad

I’m not a big collector of QSL cards, but this one has been kicking around in boxes and on various hamshack walls for more than 20 years. I like the bit of Confucian wisdom that arrived in Santo Domingo all the way from Hyderabad. I was running my trusty HT-37 and Drake 2-B. Anyone know OM Kab, VU2BK?

Parts Cost for BITX in India: $5 US (that’s buying all the parts!)

I knew that in India you could build a BITX for a few bucks, but I thought that this cost estimate assumed a fairly well-stocked junk box. Not true! This morning an e-mail from Farhan points out that even if an Indian ham has to BUY all the parts, he can get all of them for the equivalent of 5 dollars U.S.:

“Less than half a cent per resistor, less than a cent per capacitor, two cents per npn transistor and 50 cents for the IRF510. We use ‘tv baluns’ and tap washers for coils.”

And, from the original BITX design page:

“The purpose is to address the need among Indian hams in particular for an SSB rig that is easily and cheaply built. My original aim was to keep the price under Rs. 1000. The current design brings the cost to well under Rs.300 (less than 7 dollars).”

Now, when you are talking to someone using a new $10,000 Yaesu/Icom/Kenwood rig, it might be a bit unkind to mention that your rig can be had for $5.

VU2JN’s “Transistor Transmitter from India”

VU2JN

VU2INJ’s very interesting blog led me to a wonderful 1967 QST article by VU2JN. Check it out. Necessity truly is the mother of invention and — as is the case with our beloved BITX — we see that in the design of this transmitter. I love how the speaker was left in the cabinet and used as the microphone. Check it out:

http://vu3inj.blogspot.in/2014/01/tribute-to-vu2jn.html

More on VU2JN (who very clearly merits “Homebrew Hero” status):

http://shipwreck1.hopto.org:8080/projects/hamprojects/VU2JNArchive/

Farhan’s New Design: A General Coverage Transceiver: The Minima!

The homebrew phone QRP community has been waiting anxiously for the unveiling of Farhan’s new design: The Minima. It is a general coverage transceiver with many innovative circuit features. It has an Arduino in it and an Si570. Farhan’s write up of the design process and the construction of the prototypes is really interesting.

http://www.phonestack.com/farhan/minima.html

I’ve built FOUR JBOTs and TWO BITXs. I even built Farhan’s Subway Sandwich Straw signal generator. So even though I’ve been trying to keep my rigs all discrete, I know I will build this one too.

Three cheers for Ashhar Farhan! Viva La Minima!

That wonderful first contact, when the new HB rig is still on the workbench…

In this video, YC0AFF in Indonesia seems to be having as much fun with his new BITX as I’ve been having with mine. I think there is something special about those early contacts, when the newly finished (or not quite finished!) rig is still on the workbench. Designed in India and built by radio amateurs all around the world, the BITX has become a global ham radio phenomenon, reminding us that we form an International Brotherhood of Electronic Wizards.

BITX Build: Update #2

Not much progress to report. But I have been thinking about the filter frequency. Here is my latest idea:

Maybe I’ll build the VFO in the 5 MHz range. This would allow me to use the 9 MHz Yaesu filter (and associated crystals) that Steve Smith sent to me (see above). With this I could be on 75 and 20 meters.

I could build another filter at 13 MHz and, using the same VFO in the 5 Mhz range, get on our beloved 17 meter band. I kind of like the idea of plug-in filters.

You can see my ideas for the board layout. I’m thinking of a Doug DeMaw Universal Hartley VFO inside the box shown above. The tuning cap you see is out of an old Heath QF-1 Q Multiplier. It has a very nice reduction drive built into the tuning shaft. It measures 19 to 148 pf.
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Building the BITX! Update #1

There it is guys: A blank canvas of copper-clad board. A clean slate ready to be filled with the components for a BITX transceiver. As you can see, I am fighting my “build first, design/plan later” tendencies. No real design work for me on this one (thanks Farhan!) but I am trying to plan where everything will go on the board. (Thanks to Jim, W8NSA for the board.) I’m going to build it Manhattan style (perhaps with an ugly dead bug or two). I’m starting with a big board because I always seemed to end up with a shortage of space. It looks like I can easily get all of the circuit (minus the PA) on this board. I’ll build the PA on a separate piece of copper-clad.

I’d like to build it for 17 meters, but if I stick with the 10 MHz filter that means I have to build a VFO at around 8.1 MHz. That’s not impossible, but in my experience it is easier to build simple, stable VFOs at lower frequencies.

I notice that there are a lot of cheap crystals available at higher frequencies. So, instead of keeping the filter at 10 MHz and trying to get the VFO stable at 8.1, what do you guys think about keeping the VFO in the 4 MHz range and building the filter with crystals in the 14 MHz range?

Kishan Has the Knack! (video)

Many of us were staring out similar windows, also dreaming of model airplanes, and of transmitter circuits, and telescopes, and rockets… This video runs only 12 minutes. Don’t be deterred if you don’t speak Hindi — the story is easy to follow.

Feynman’s Red Book (on the Sino-Indian Frontier)

Today I bought a copy of “Feynman’s Tips on Physics.” I wasn’t sure about buying it, but this story in Ralph Leighton’s foreword convinced me:

“At a lonely border post high on the Himalayan frontier, Ramaswamy Balasubramanian peered through his binoculars at the People’s Liberation Army soldiers stationed in Tibet ― who were peering through their scopes back at him. Tensions between India and China had been high for several years since 1962, when the two countries traded shots across their disputed border. The PLA soldiers, knowing they were being watched, taunted Balasubramanian and his fellow Indian soldiers by shaking, defiantly, high in the air their pocket-sized, bright-red copies of Quotations from Chairman Mao ― better known in the West as “Mao’s Little Red Book.”

Balasubramanian, then a conscript studying physics in his spare time, soon grew tired of these taunts. So one day, he came to his observation post prepared with a suitable rejoinder. As soon as the PLA soldiers started waving Mao’s Little Red Book in the air again, he and two fellow Indian soldiers picked up and held aloft the three, big, bright-red volumes of The Feynman Lectures on Physics.

One day I received a letter from Mr. Balasubramanian. His was among the hundreds I have received through the years describing the lasting impact Richard Feynman has had on people’s lives. After describing the “red-books” incident on the Sino-Indian Frontier, he wrote, ‘Now, twenty years later, whose red books are still being read?’ ”

Ham Radio, the tsunami, HW-101, Tek 465, BITX-20

I know many of you guys have seen this before. And I know that Farhan is tired of seeing it pop up again and again. But it just appeared on my Facebook page today and I watched the whole thing and saw things I hadn’t noticed before: There’s a Heathkit HW-101 (or maybe its an HW-100). There is a Tech 465 oscilloscope. There is a BTX-20!