Homebrew SSB in Germany: DK7IH

Pete WB9FLW alerted us to the work of Peter DK7IH, a very talented homebrewer who recently followed the lead of Pete N6QW in building some really small SSB transceivers.  Here is his Micro QRP SSB rig:

You can see more of his fine work here:

https://radiotransmitter.wordpress.com/

https://www.qrz.com/db/DK7IH

Have you guys noticed how many Peters there are among homebrewers, especially among SSB homebrewers?  Just from recent mentions on this blog:

Pete Juliano N6QW
Pete WB9FLW
Peter Parker VK3YE 
Peter DL3PB
Peter W1UO
Peter GW4ZUA
Peter G6GNR
Peter VK2EMU
Peter VK2TPM
Peter HA5RXZ
Peter DL3JIN

Amateur Nuclear Fusion in Your Garage

We had some posts about this kid a few years ago.   He is 21 now and was recently interviewed on the TED Radio Hour -- the nine minute interview (above) is worth listening to.  Just click on the arrow.

Philo Farnsworth would be pleased.  An amateur creates a star in a jar.

From Mountaineer to the KX1 -- N6KR on Trail-Friendly Rigs

This is from 2014, but I stumbled upon Wayne Burdick's article just this morning.  Great stuff.  That picture of Wes had a big impact on many of us. 

Wayne's article:

http://www.elecraft.com/KX1/N6KR_KX1_History.html

Christmas Present! 4Z1UG's Interview with Han Summers G0UPL

I found myself almost cheering out loud as I listened to this wonderful interview, especially at the point where Hans lets it be known that he has NO COMMERCIAL HAM GEAR in his shack!  Yes!  That's the ticket!   You can also hear the story of Hans and Farhan meeting up in Mumbai for dinner. The interview includes discussion of  WSPR and QRSS and BITX and crystal ovens and, at the end, a special QSO TODAY overtime session in which Hans describes the little WSPR rigs that fly around the world, carried aloft by half-filled birthday party balloons. 

Thanks to Eric 4Z1UG and Hans G0UPL for this very nice Christmas present.

Listen here:

http://www.qsotoday.com/podcasts/g0upl

A Nice History of BITX 40 Module: Production and Finance

Some fellow jumped into the BITX20 yahoo group this morning, casting aspersions on our friend Farhan.  The fellow alleged that a lot of money was being made on the BITX 40.  He seemed deeply unhappy about the shipping materials and found fault with the documentation that came with the boards. 

Farhan came back with a very gentlemanly and detailed response.  He was a lot more patient and temperate than I would have been.  And when I think about how Pete would have responded, well, it would likely have involved -- at the very least -- a lot of colorful words from Southern Italy.   

Anyway,  below (unedited) is Farhan's response.  I think it provides a lot of very interesting background info on our beloved BITX 40 Module and on the place that these boards come from.

thanks for writing in, I couldn't get your handle from the mail, so do excuse me for improper address! I think you have raised from valid points. I think it is important that everybody understands what tried to do, what we did and where we are now.

this is going to be a long and full of personal details that i didn't consider to be of any interest to the group and hence it was kept out. but i guess, i need to let a few cats out of the bag.

i am retired, early. i had a modestly successful run in a few businesses but i had promised myself to retire from active work, which i did around five years ago. i no longer run any for-profit businesses. most of my investment goes into 'stuff that matters'. i founded a libera cultural space in hyderabad, i am a partner in a strategic venture fund that promotes technologies that are important rather than profitable. neither ehsan nor i are any longer running anything full time. i do mentor some startups now and then but never as an investor.

i would be only too glad if someone else takes over the entire hfsigs approach. the design has been out in the open for more than a decade. apparently, it doesn't make economic sense to make them at $45 dollars a pop. so, there is nothing preventing others 'creaming the market' if they want to. surely, the turnover is modest but it is not profitable.

it is fallacy that India is cheap. In Hyderabad, a modest apartment will cost you over 250K USD.  An independent house in a reasonable area goes for a million USD. A gallon of gas will costs you more than 5 dollars. smart people are hired by facebook, google and microsoft. they have a big a presence here as in the valley and seattle. there is no healthcare, all education is privatized and has to be paid. there is no social welfare. the multinationals they pay top dollar and that drives the living index up, not down. a quick indicator is that only 7% of the population of Hyderabad moves in cars and taxis and they account for 85% of the traffic congestion. our purpose is not provide the women who work low wages, but respectable wages. but i am getting ahead of myself...

Two years ago, our local club conducted India's annual hamfest. As a part of the delegates kit, Ehsan and I decided to put free BITX PCBs in the kit. These were done without any commercial interest. At this time, the hamfest was still short of money, so we decided to buy the back page ad of the souvenier to help them with the money. I had to put in something in as text, I decided to put a message in the name of HF signals (which was the name of the wiki that is still up at www.hfsignals.org). We distributed a 1000 PCBs for free. Only a few turned up on Air. It was time to do something.

Later, in 2015, I decided to conduct a workshop to help those interested in assembling the PCBs. asked them to get the components off the local shops and we settled down to do it. i discovered that a seemingly simply job of scrapping the enamel off a copper wire would take them hours and often they'd end up doing it the wrong way. the PCBs were badly designed too. we aborted the attempt. i had learnt something : homebrewing cant be taught in a day. first fail.

i also figured that it might be easier to begin with something that is already working and then start modifying it. something that happens in open source all the time. so,i sat down and designed a new single side pcb .. with through-holes, on Express Pcb. we turned up 100 boards, found a group of five young girls who were laid off after the unit where they worked to assemble TVs had closed down. showed them how to assemble the boards. they made quite a few mistakes. the transformer windings got mixed up, resistors got swapped, the transistors were inverted, etc. each board was an adventure. you can probably see some pictures of these boards floating around. they were cheap to produce. the actual component cost of the bitx is ridiculously low. it cost us about 1000 rupees in components, another two hundred for the assembly and testing and a hundred bucks to ship it. we rounded it off to Rs.1500. About 100 of them were sold. it gave me nightmares. each board took an hour or more to fix. i decided not to do it at all. we rolled up the operations after a while. second time, fail.

by now, i had given up on doing anything with bitx boards. but a conversation with convinced me that SMD might be the way to go. we looked around and found a local SMD shop that agreed to do small runs for us. the smd components are much more expensive in india. we decided to keep the more expensive components like crystals, electrolytics in through hole format. i had to learn kicad. the women were now retrained to do the windings, insertion of through hole components and two rounds of testing. the component cost was at Rs.1500, another Rs.200 to the SMD insertion machine, Rs.200 for through hole insertion, testing. add another Rs.100 for packing and Rs.100 for local posting. we were selling these for Rs.2400 inside india and 45 dollars (a few hundred more to cover the additional expense of international postage) outside.

now, we come to the packing and shipping saga. the DHL/Speed Post quoted above Rs.1500 for shipping it internationally. that would be nearly 60% of the board's sale price. instead, we looked at the ordinary postal service. so, we bought some amazon shipping cartons, assuming that these must be good enough for us as well and shipped some boards to friends around the world. we shipped five of them with the boards in bubble wrap. all fo them arrived in good shape. we rolled with this. WE USED BUBBLE WRAP. When we started actual shipping, we realized that the bubble wrap wouldn't prevent the carton from collapsing. the coils were getting damaged. we needed some kind of a stiff roof over the board so the box's sides wouldn't collapse down. That's when we started using the foam plate over the board. The foam provides a physical shield for the coils. The foam + the amazon cartons worked for a while. Then, we ran out of cartons. 

Diwali is the christmas equivalent in India, the packing materials just disappeared from the market. we looked around and bought some other cardboard gift box. we sent them out as gifts to another set of people, they reported no problems, so we continued with those. after a while, we started getting complains about those boxes as well. then, we started looking around for something else.

we found these plastic boxes to be sturdy. we tossed them around, shipped them to a few volunteers around the globe and finally agreed that these were holding up. so we continued with these boxes. these boxes are costly. they are not 'cheap'. i am personally averse to using plastic, but we thought that these were the best for the purpose. if anyone has a better idea, do test it out and let us know. we are always glad to accept anything better.

2.) Secondly, components and PCBs in the Indian market are generally available at a lower cost, sometimes much lower, than components purchased from prime US suppliers such as Mouser, Newark, etc. The US is one market, India is another. That's the way it works. Components even cheaper than these: http://www.ebay.com/itm/Reel-O f-3000-MuRata-0-1uF-Multi-Laye r-Ceramic-Surface-Mount-Capaci tors-25V-X7R-/161765931843

we buy our toroids from w8diz. these are genuine micrometal parts. the pcb is of high quality made to ISO-9000 standards. we import components from mouser. the only thing that we do on the 'cheap' is that we use microprocessor grade crystals that we sort out manually.

 

What's the current serial numbering up to as of December. Anyone know? It was #465 in early December. 465 units multiplied by $45 USD is about $21,000 USD. That converted to INR has the purchasing power in India of $70,000 USD here in the US. That's a lot of bread.

we have shipped 1000 boards. we got 45,000 dollars in revenue and we have not yet recovered our expenses. i have provided you with the figures. add them up.  as i said above there are far easier ways to follow to make money than bother with these boards. that's why no one else is doing it. the design is in open source anyway. 

 

What's my point?

Seems like with that kind of wealth in play:

1.) The product could be double-boxed and well bubble-wrapped so it arrives undamaged after it's 12,500+ km trip from Hyderabad. Old candy boxes or scraps of waste paper taped together just isn't doing the job. Broken product means unhappy customers and a bad reputation.

as i said, bubble wrap didn't work. there will be enough people here to vouch for that. we did try it.

 

2.) The single schematic that represents the functionality of the product could be up-to-date and error-free.

this is the schematic that was used to produce the PCB. where are the errors?

 

And for totally optional bonus points: A section by section Theory of Operation write-up that explains exactly how all the sections operate and how to troubleshoot. If a template is needed, look at vintage HP test instrument manuals or Heathkit ham radio transceiver manuals. Hint: Saying that, "It's all been explained many times before on many forums, Google it." does not get any points. 

surely, it could be done. probably it is already done. bitx happens to be most well documented radio now. it is a community effort. look at http://golddredgervideo.com/kc0wox/ and soldersmoke and arv's work and the large amount of stuff in the file section of the bitx group and you will realize that more people know, understand and write about bitx than a proprietory manual might contain. if you think it is lacking, go ahead and write some more documentation.

oh, btw, Ehsan is not an Ayn Rand supporter. He is a radically liberal guy who is more at home with the socialists at lamakaan than the suits of the software gang.

 

- f

Big News! BITX 40 Module Gets Digi Side Car! Raduino!

A very nice Christmas present from Farhan in Hyderabad!   An Si5351/Arduino Nano VFO for the ALREADY AWESOME BITX 40 Module.   I'm really glad Farhan kept the digital stuff on a separate board -- it just seems like the right way to do it. 

Details on http://hfsigs.com

Armstrong, obsessed

Jerry AA6KI sent me a nice website about radio hero E. Howard Armstrong. It contained an image that seemed to cry out for a meme.  I couldn't resist.

India's Successful Mission to Mars (Video)

NPR's "Science Friday" produced this very nice video on India's successful mission to Mars. Really nice.

SolderSmoke Podcast #192 FPM Rig, BITX Module Madness, HRO Al Fresco, Boatanchor Day, Mailbag

SolderSmoke Podcast #192 is available:

http://soldersmoke.com/soldersmoke192.mp3

N6QW COMPLETING AN ORBIT TOMORROW!!!! Happy Birthday Pete!

Shortwave Woes:   Deception and Disappointment!

Voice of Vietnam!  But it is from Cyprus Creek S.C.

Radio Athmeeya Yatra in Punjabi!  but it is in Nauen Germany.   Yuck! 

Sort of like these 9 cents per minute on-line relay ham stations.  Yuck I say!

You know you are a hardcore homebrewer when a near empty can of Deoxit makes you nervous, so you order more, just in case.

Bench Reports: 

Pete:

FPM  FPM    FPM!!!  Tell us about it!

BITX 40 Module in Juliano Blue

Explaining the BITX 40 to the local club.  

CULTURE SHOCK!  Plug and play vs. Hardcore Homebrew.

Bill: 

An EXTROVERTED BITX 40 Module

QRO with 24 volts on the Drain:  20 watts out. Heatsink upgrade,  Chris KB4PBJ Thanks.

Analog Readout -- Dymo tape and a Sharpie arrow

REVERSE POLARITY PROTECTION     Where the perfect is the enemy of the good enough.

HRO no longer AL FRESCO  Boxed up. Thanks Armand.  Thanks Tim Sutton.  Still working on AM receiver.  Not inhaling very well. 

Boatanchor Day:  Fixed HT37 and hurt my back.  Really. Got 160 meter station going. Changed ball bearings on CW key. 

Next project.  Another BITX 40, but perhaps for 160, 75 and 60 with Si5351 and plug-in filters.

Sideband History:  THE SIDEBAND SUZY AWARD.   Pete deserves this.  I say we revive it.

LEX:  Al Fresco.      And Tim Walford calls them "Blackbox rigs" not "rice boxes" 

HB2HB contacts.   Often with guys who built their linear.  I say that counts Too!   

MAILBAG

The Nauen Transmitter Station (Germany)

There is a lot of radio history in this shortwave transmitting station.  I came across it tonight with my BITX DIGI-TIA rig.  It was on 7.215 MHz transmitting in Indian (South Asian) languages.  But alas, the signals were not from distant India (home of the BITX!). Instead -- as often happens these days -- the signals were from a relay station.  In this case they came from  relatively nearby Germany, from the Nauen transmitter site.

Check out the Wikipedia page:

https://en.wikipedia.org/wiki/Nauen_Transmitter_Station

NO3M's Amazing Homebrew 1934 Single Signal Superhet

Jim AB3CV reminded me this morning about the work of Eric NO3M.  Jim was pointing out that breadboard construction need not be ugly and that Eric's work is the proof of that.  Indeed.

Almost one year ago, I worked Eric on 160 meters.  He was using one of his beautiful breadboard rigs:

http://soldersmoke.blogspot.com/2016/01/happy-new-year-straignt-key-night-on.html

Jim's reminder sent me once again to Eric's site.  I see he has been melting a lot of solder, and to very good effect.  In just three weeks he built the magnificent 1934 QST "Single Signal Superhet" pictured here.

Eric has a great series of articles on this project, with excellent pictures and videos:  

http://no3m.net/category/projects/

Bravo Eric!

Beauty and the Beast: Pete's Beautiful BITX 40 Module and My Ugly Version

As the proud owner of what has to be one of the world's UGLIEST BITX 40 Modules. I feel somehow qualified to declare Pete's version of this rig to be one of the world's most beautiful.  His is resplendent in Juliano Blue -- mine has no paint at all.  His features glowing numerals -- mine has nothing but Dymo stickers and an arrow drawn with a Sharpie marker.  Bravo Pete! 

The Revenge of Analog

Keep it Real!

http://www.nytimes.com/2016/12/05/books/revenge-of-analog-david-sax.html?_r=0

Great Homebrew Interview on "QSO Today"

This week Eric 4Z1UG has a really nice interview with Jim Veatch WA2EUJ.  Jim is the three time winner of the ARRL Homebrew Challenge.  There is a very interesting discussion of Arduinos, SDR, the technology behind automatic antenna tuners, and even some Raspberry Pi.   Jim's first receiver was a Halli S38 and his first rig was a Heath HW-7. 

Listen here:

http://www.qsotoday.com/podcasts/WA2EUJ

Thanks Jim.  Thanks Eric.

Great Hackaday Article on the Venerable LM386

I'm not crazy about chips, but I've come to like the LM386.  It is not really a little black mystery box -- as the article points out, the internal circuitry is simple and completely understandable.  So you shouldn't feel any appliance-op angst when you use one of these. 

http://hackaday.com/2016/12/07/you-can-have-my-lm386s-when-you-pry-them-from-my-cold-dead-hands/

A Charming Detail About the BITX40 Module

In the BITX20 yahoo group, Farhan responded to a question about the BFO and the crystal filter in the BITX 40 Modules.  In his response we learn more about the work of the members of the women's collective.  Uma is the name of the lady who has the job of sorting the crystals. She sorts 1000 a day:

Farhan writes:

There is a longer explanation to this. The crystals we use in the BITX are microprocessor grade. This means that they are not very precise. Uma is the crystal sorter. She takes a bunch of 1000 crystals a day and sorts them by their frequency into different bags. Each board takes its five crystals from any one bag. Hence, the central frequency of each board will be slightly different from another board.

The central frequency of the ladder filter moves down from the oscillating frequency of the same crystal. That is why, in a set of matched crystals, one can be directly used as the carrier/beat frequency oscillator without needing any trimmer : it directly sits on the higher side skirt of the filter.

The BITX40 board's BFO usually ranges from 11.990.0 to 11.997.0, though in almost all cases it is very close to 11.998.0. The best way to determine the BFO frequency is to take it another ham's shack, tune in the BFO to zero beat on USB or LSB and note the frequency. I use the Rigol scope's built-in frequency counter to measure it off the modulator transformer's primary.

So, the IF offset should ideally set to the measured BFO's frequency. These are however, very subjective choices. Given that 2.2 KHz is not an ideal passband, 3 KHz is more like it, setting the BFO will determine how you would like to hear the receiver. Setting it close to the passband will make it bassy, setting it away will make it tinny. Setting it a few hundred hertz away will make it hollow. You get to choose which way you want to make your radio sound bad (harr! harr!)

- f

Boxed-up and Looking Good: An End to "HRO Al Fresco"

The "al fresco" phase has ended for my HRO receiver project.  As has happened with homebrew projects around the world, this rig was literally pushed aside on the workbench to make room for BITX-40 Module Mania.  I began to worry that the circuitry of the HRO receiver might suffer damage from the various kinds of electronic construction mayhem that take place on our workbenches.  Also, I wanted to see what it would look like in the nice big metal box that Tim Sutton had sent me (thanks again Tim.)  And I was hoping that the box would help with the AM broadcast breakthrough that I sometimes hear with this receiver.  So, as you can see, I have good excuses for declaring Basta! on the HRO Al Fresco. 

I think it looks great.  Black on silver is very cool.  It sounds great.  I'm listening to 40 right now. Thanks to Armand WA1UQO  for the very cool HRO dial that got this all started.   

TRGHS! HB2HB! Homebrew Extravaganza on 40 Meters!

AC7M HB Amp and HB Power Supply

I was flying solo last night.  Everyone else in the house was out.  So I turned to ham radio for some company.  And I was rewarded.    

I called CQ with my BITX DIGI-TIA rig and was immediately answered by Doc AC7M in far-off Twin Peaks, Idaho.   Doc was running a K3 to a homebrew solid state full gallon amp.  And get this -- Doc had also homebrewed the 3 kw switching power supply.  I looked at my store-bought supply and felt like an appliance operator.  I hang my head in shame.

As we discussed solid state amplifiers, we were joined by another builder of silicon after-burners: Don K9AQ, who called in from a beautiful cabin in rural Wisconsin. Don's amp is based on the venerable EB-104 design.   

Both Don and Doc talked about the work of W6PQL.   He has a really amazing site devoted to homebrew solid stat amps, and he is selling lots of great boards and parts for this kind of project:
http://www.w6pql.com/  

As I finishing up with Don and Doc, I got a very welcome call from an old friend from the SolderSmoke community: Dino KL0S.  He as booming in from Williamsburg, Va.  Dino has an amazing workshop.  He is building a serious vertical antenna for 160 meters.  Dino is going for the DX.

Dino's Bench

At this point Mike WA3O in Pittsburgh called in.  And get this:  Mike heard me on his new BITX 40 Module.  The Radio Gods Have Spoken! (TRGHS!).  We switched up to 7.285 MHz where I fired up my BITX 40 Module for a BITX40-BITX40 QSO (albeit not at QRP levels).
We should definitely make more use of 7.285 for BITX40 and other HB QRP SSB QSOs.  1930 EST (0030 Z) seems like a good time.

Finally, just when I was thinking that things couldn't get any better, they did:  Armand WA1UQO called in from Richmond.  Armand and I collaborate on parts acquisition at Virginia hamfests.  We specialize in the contents of the musty cardboard boxes found under the tables.  We discussed the DISRUPTIVE influence of Farhan's BITX 40: All around the world, other homebrew projects are being literally pushed aside on workbenches to make room for that fantastic little module from Hyderabad. 

I was very pleased to hear that Armand is building an analog VFO for his module, using a coil in the 4 uH range, wound on a piece of cardboard tube from a coathanger.  The inspiration for this kind of coil (which I now have in THREE rigs) came from Farhan, who used sipping straws from fast-food restaurants as coil forms in a sig generator that he built years ago.  This week, seeing a Facebook picture of my daughter and me in a restaurant with drinking glasses in front of us, Farhan asked if I had brought home the straws. 

Pete Juliano Adds Yet Another Great Word to the Homebrew Lexicon

We've talked many times about the pleasures associated with a rig that is still just a collection of parts and boards, all still spread out on the workbench, unboxed, perhaps held together by clip leads and bits of duct tape.  They seem to sound better this way.   This is the condition under which we experience that magical moment of "First Signals"  (similar to First Light with a new telescope).

We haven't had a concise way of describing this (note my long-winded description above).  Well, this morning the Sage of Newbury Park has, on his amazing blog, provided us with the words that we have so long needed: 

Al Fresco! 

That's it!  Perfect.  When a new rig is put into operation in this way, we will henceforth say that it is being run "al fresco."  Thanks Pete!

Check out the blog post that gave us this wonderful phrase:

http://n6qw.blogspot.com/2016/11/a-little-arduino-magic-for-fpm5.html