ANOTHER Nobel Prize Winner with THE KNACK

When I heard that the guys who ran the LIGO gravitation wave experiment won this year's Nobel Prize for physics, something told me that at least one of those involved in this historic detection of weak distant signals would have THE KNACK.  It did not take me long to confirm this.  Rainer Weiss (above) definitely has had the THE KNACK all his life. And what an interesting life it is.  Check it out:
http://www.sciencemag.org/news/2016/08/meet-college-dropout-who-invented-gravitational-wave-detector

Knackish excerpts: 

The family soon had to flee again, when U.K. Prime Minister Neville Chamberlain signed an accord ceding parts of Czechoslovakia to Germany. They heard the news on the night of 30 September 1938, while on vacation in the Tatra Mountains in Slovakia. As Chamberlain’s address blared from the hotel’s massive radio, 6-year-old Rainer stared in fascination at the glowing array of vacuum tubes inside the cabinet. The hotel emptied overnight as people fled to Prague.

As a teenager, Weiss developed two passions: classical music and electronics. Snapping up army surplus parts, he repaired radios out of his bedroom. He even made a deal with the local toughs: If they left him alone as he lugged radios to and from the subway, he’d fix theirs for free. “They would steal things and I would have to fix them,” he says. “It wasn’t a good deal.”

Weiss was drawn to tinkering partly as a reaction to his family’s cerebral atmosphere. “This is a German-refugee kid with very self-consciously cultured parents, and he’s rebelling against them by doing things with his hands,” Benjamin says. “But he’s surely not rejecting doing things with his head.”

He applied to MIT to study electrical engineering so that he could solve a problem in hi-fi—how to suppress the hiss made by the shellac records of the day. But electrical engineering courses disappointed him, as they focused more on power plants than on hi-fi. So Weiss switched to physics—the major that had, he says, the fewest requirements.

The Homebrew Receivers of F5LVG

I came across OM F5LVG's work in SPRAT.  He has a wonderful website -- it is in French, but Google Chrome translates is quite nicely.  

http://oernst.f5lvg.free.fr/index.html

From the site's introduction: 

This site is dedicated to the construction and understanding of radio receivers. If you have dreamed of hearing a radio station with a receiver that you have built yourself, this site is for you.  These are essentially direct conversion receivers and modern feedback detectors using only semiconductors, except for retrofitting. The described stations will accommodate amplitude modulation, single sideband (SSB) and telegraphy.

Besides these receivers several articles are devoted to LC oscillators. In particular, an extremely simple original stabilizing device is described.

Similarly, a simple frequency meter is described.

The joy of reception using a homebrew receiver is intense. May this site help you find this joy. Do not hesitate to join the amateur community.

TRGHS: I Can Hear the Roosters of Boa Vista

At the instigation of  Bob N7SUR I've been working on a simple, easy-to-reproduce Direct Conversion receiver for 40 meters. I'm building this for my nephew John Henry,  and I'm hoping this will be a circuit that others can use to break into the ELITE corp of successful ham receiver builders. Coincidentally Joh in Freiburg Germany is working on a very similar project -- we have been comparing notes. 

At first I used an FET detector described by Miguel PY2OHH.  It worked, but at night the AM detection of powerful shortwave broadcast stations drowned out the amateur signals.  So Joh and I started to explore detectors that would eliminate this problem.  I went with a version of one described in SPRAT by F5LVG ( "The RX-20 Receiver"- see below).  Very simple:  A transformer to two back-to-back diodes with a 1K pot to balance the signal from the VFO.  OM Olivier used a very, very cool transformer: he took two small, molded chokes and simply glued them together!  22uH choke as the primary, 100uH choke as the secondary. I went with one of the toroidal transformers that Farhan left me when he visited in May. 

 I'm using a varactor-controlled ceramic resonator VXO  (no Si5351 in this one!) and a non-IC AF amp designed for use with ear buds (the world is awash in ear buds).  It is a "singly balanced" design with the incoming RF signal being the one "balanced out" in the detector.  

Last night the receiver passed the AM breakthrough test.  The SW broadcast monsters were balanced out and kept at bay. 

This morning the receiver passed The Boa Vista Rooster Detection Test.   I fired up the receiver and heard an operator speaking Spanish with a Brazilian accent.   When I heard the rooster crowing in the background I knew it was Helio PV8AL from Boa Vista Brazil.  TRGHS -- this little receiver is a winner.  

I'll try to post a schematic soon.  

And hey -- look at what wonderful IBEW (International Brotherhood of Electronic Wizards) project this is:   Instigation and inspiration from Oregon.  Some design ideas from Brazil.  A French detector circuit described in a British QRP magazine. A transformer from India.   A collaborator in Germany.    And finally, the rooster of Boa Vista.    

Let's not forget Wes Hayward W7ZOI for bringing back (in 1968!) the neglected Direct Conversion idea.

Two new bands for US Amateurs

630 meters 1 October 2017

Steve VE7SL reminded us via his blog that US radio amateurs now have the use of two new radio frequency bands: the 2200 meter band and the 630 meter band.  As always, Pete N6QW was way ahead of the game and is already working on a full-size 6 element quad for 2200.  Good going Pete!  Please send pictures (we may need a satellite photo to get the whole antenna in the shot).  

As Steve points out there is already a lot of activity on the new bands -- the attached pictures are snaps of just ten minutes of WSPR activity this morning.   

I'm especially intrigued by 630 meters -- it is so close to our beloved 455 kc IF frequency.  Will some intrepid ham take advantage of this fact?  Seems like some peaking and tweaking could do the trick...  

Check our Steve's blog post: http://ve7sl.blogspot.com/2017/09/getting-started-on-new-lf-and-mf-bands.html

2200 meters 1 October 2017

NPR: Hams Help in Puerto Rico

I got into my car to drive home yesterday.  As soon as I turned the radio on, I heard this.  TRGHS. FB OM.  Listen.  4 minutes. 

http://www.npr.org/2017/09/29/554600989/amateur-radio-operators-stepped-in-to-help-communications-with-puerto-rico

More on GM3OXX

Sunset at Luce Bay Scotland, 3cm GM3DXJ, GM3OXX and GM8HEY dishes being set up. Photo GM8HEY (GM4JJJ). 322 km QSO to Wales. 10mW GUNNS WBFM.

Bill,

Thanks again.

I recall when George met up with the team from Wales in a car park in the Scottish highlands , they had also built 3cm gear and he found by direct comparison that their 3cm gear was more sensitive than his. He went straight home and redesigned and rebuilt his receiver. That gear then went on to break the World distance record on 3cm on a superrefraction path from Portpatrick to Cornwall with 10 mW WBFM. Smashing a record that the USA had held for 16 years from mountop to mountain top.

George was ambitious, he wanted that UK, EU and World distance record, he wanted to show the RSGB that Scottish hams could get the 3 countries and 20 counties award on 3cm. We  (G8BKE, GM3DXJ, myself and George) did it by travelling round Scotland in my Mini Clubman Estate with dishes and tripods and 3 hams packed in to one car, at the same time fitting in the EU distance record from Luce Bay in Wigtownshire to St David's Head in SW Wales at 322 km just to show them how.

No VHF Talkback, only a phone call from a telephone box earlier in the day to our Welsh counterparts to say we would be there about 6pm and to tune the 3cm band for us. Frequency uncertainty was in the 10's of MHz.  We arrived at the beach, set up 3 dishes, put on our transmitter test tones and then went back to receive, George asked us to make sure we had our test tones -off-  as his receiver was overloaded, it was the Barry Radio Guys he was hearing, they were so strong. Didn't matter where we pointed the dishes, we were in the sea level duct. Open waveguide still full quieting.

George's words audible on the remote tape recording made in Wales, " You can pack up your gear now lads, that's the European Record!"

Happy Days!

-- David GM4JJJ

GM3OXX SK

Bill,

I expect you will have heard via the grapevine, George Burt GM3OXX is silent key. Bad news travels faster than light.

I knew George GM3OXX before I was even licensed in the 70's, as I heard his broad Scottish accent on 2m AM when he was portable on a local hill and was using 2m to set up 3cm contacts with QRPp WBFM. I climbed the hill and introduced myself and he graciously answered my questions. 

George didn't drive but despite that was able to climb all of the Munros (summits over 3000 feet) in Scotland and operated on 2m from all of them. He used hitch hiking and buses or bicycle to get to foot of the mountains. 

Fast forward a few years, I had my first ticket GM8HEY...

I spent a night in my grandfather's ridge tent on top of Snaefell (the highest mountain in the Isle of Man) (GD) with George. We had planned to take my car to the island by ferry, but had not realized that the TT motorcycle races were on and the Ferry was fully booked. We had to go as foot passengers and reduce the amount of gear. George carried his tripod and dish, 3cm and 2m gear and antennas plus rations etc, I carried this huge ancient canvas tent with wooden poles and pegs. We got to a campsite and we were told it was full, when we asked where the next site was the owner asked us where our motorbikes were, we explained we had come by foot, so he let us pitch our tent after all as we weren't bikers.

George originally had planned to climb the mountain by foot, but with this huge tent even though I was fifteen years younger than George I would never have made it, so reluctantly we took the mountain railway which goes nearly to the summit of Snaefell. 

The previous night it had snowed on the mountain, fortunately it was just freezing cold and windy when we camped right on the top. We had to use rocks to try and hold the old ridge tent down, it had no built in ground sheet. George's "rations" seemed to be a bar of chocolate and some tea that he boiled on a tiny stove powered by some little pebble sized block of flammable material. I have never been so cold and hungry after a night in a sleeping bag. We idled some of the time calling stations on 

2m with George's homebrew 2m battery powered transistorised transceiver.

Next morning it was too windy to set up the dish and tripod, so we assembled it -inside- the ridge tent and successfully operated from there on 3cm WBFM across to G, GW and GM. on 10mW QRP of course.

George went on to break UK and EU distance records on 3cm before packing microwaves in and going back to QRP on HF. 

George was as fit as a mountain goat in his youth, tragically he was struck down with a terrible condition in early middle age that robbed him of his strength and ability to even walk, let alone climb mountains, but you wouldn't have known it, he never complained, just the same old George "building wee boxes" as he put it to me on one of the last times I spoke to him. 

If you visited George's shack, you wouldn't find any commercial gear at all, everything he built himself, it was so beautifully made too, I marvelled at how compact and neat it was. 

There won't  be another George Mary Three  O Ocean  X X-Ray  X X-Ray on the bands.

Thanks for all the great times George, I am sure you won't be resting, you are probably designing that next "wee box".

-- David GM4JJJ

Herring Aid Error: C14

Yea, take a look at C14 in the AF amp.   At 1000 Hz 10uF is about 16 ohms.  That would put a serious dent in the AF gain.  And indeed, when I went back to my Herring Aid 5 (38 years from start to finish) and pulled C14 out, there was a dramatic increase in AF gain.  

Mistakes happen, but I wonder if anyone else spotted and reported this one.   Could someone with access to the QST archives check to see if an Erratum was ever published?   The project also appears in the 1977 ARRL book "Understanding Amateur Radio" with the problematic C14.  My guess is that it was just an error in the value of the cap.  

Can You See an Error in the Herring Aid Five Schematics?

Something caught my eye this morning.  Please take a look at the audio amplifier stages (Q3 and Q4) on the Herring Aid Five.  Can you see an error? Above is the original schematic from the 1976 QST.  Below is a 1998 update by VK1GB and KI6DS.  I see the same problem in both schematics.  Please let me know if you see an error. 

Six Stations Worked on BITX Night

I had a a good session with the BITX gang on 7277 kHz starting at  7pm local last night.  Keith N6ORS was on with his MIN-X rig (picture above).  Michael  KN4EAR's signal is much improved (Michael had worked Barcelona with his BITX40 Module earlier in the day). Randy WB5YYM's rig (featured last week on this blog) was booming in from Arkanas.  

LOG: WI1B Ken on BITX, AA4PG Pat, KN4EAR Mike in Falls Church, N6ORS Keith on MIN-X, W1LY Willy,  WB5YYM Randy in Arkansas

Hallicrafters and the Romantic Life of Private Hogarth

The world of the SolderSmoke podcast and blog are -- and will remain -- G rated.   But occassionally our discussion of ham radio technology causes us to bump up against some racy topics.  This happens VERY rarely, and that rarity probably says something about ham radio.   We have noted the alleged attractive power of Pete Juliano's French beret.  There was that April 1 story about the new SolderSmoke cologne ("chicks dig it!").  Jean Shepherd was a man of the world -- our discussions of him sometimes bring us a bit closer to the prurient boundary line.  We occassionally mention the lifestyle of the Dos Equis man.  But mostly, we stick to the circuitry.  

This morning I came across a character that I hadn't been aware of: Private (later Corporal) Hogarth.  He was the theme of a series of ads run by the Hallicrafters Company during World War II.  They were trying to sell their EC-1 broadcast receiver (essentially an All American Five).  Their advertising theme was, essentially, "chicks dig it."      

More of this here: http://www.geojohn.org/Radios/MyRadios/EC1/EC1.html

Don't blame me.  I blame Hallicrafters. 

The Road to QRO Perdition

I want to start out by saying that this is NOT my fault.  I have been TRYING to do QRP things. Remember my recent Tuna Tin 2, Herring Aid 5 rig?    I am aware of the ever-present threat of expulsion from the QRP HoF.   We all remember what happened to poor Pete back on April 1, 2017. 

But sometimes people just deliberately put temptation in your path.   That is what happened this week.  Our old friend Rogier KJ6ETL (formerly known as PA1ZZ) sent me the very LARGE chunk of aluminum that you see in the picture above.  Look at that thing.  It is practically begging to be turned into a very QRO push-pull amplifier.  

At first I told myself that it would be impossible to tap the big heat sinks on the sides.  How would I get the drill in there?  But then I realized that I can just put the threads in from the outside.  I can almost smell the machine oil. And the heat sink compound... 

Thanks lot Rogier. This is all your fault. 

  

More Stations Worked on Sunday Night with the BITXes

I worked AD0RW, AC9PD,  VE3ZBM and WB5YYM on 7277 kHz around 2345 Z Sunday 10 Sept 2017. BITX ops gather on that frequency on Sunday nights at around 7 pm local time. 

The station above is the impressive all HB 40 meter station of WB5YYM.  That's a 49er on the left, and a BITX40 on the right.  The amp in the middle has 2 IRF510s.   HB mic too.   FB

Amazing $49 Rig from QRP Labs

Hans Summers' QRP Labs has an amazing new rig -- The QCX --  that is chock-full of features and FB technology. Hans has long been one of the most innovative guys in ham radio, and this latest rig is one of his most amazing creations.  Like Farhan's BITX40 Module, this new rig is priced in the 50 dollar range. Hams who are paying many thousands of dollars for their "radios" should be asking themselves a question:  Could I be having much more fun for far less money?  This rig is in big demand and there is already a waiting list, so place your order now if you want to work on this during the winter.  Here is the link: 
http://qrp-labs.com/qcx.html

  

QCX Features:

• Easy to build, single-board design, 10 x 8cm, all controls are board-mounted
• Professional quality double-sided, through-hole plated, silk-screen printed PCB
• Choice of single band, 80, 60, 40, 30, 20 or 17m
• Approximately 3-5W CW output (depending on supply voltage)
• 7-16V recommended supply voltage
• Class E power amplifier, transistors run cool… even with no heatsinks
• 7-element Low Pass Filter ensures regulatory compliance
• CW envelope shaping to remove key clicks
• High performance receiver with at least 50dB of unwanted sideband cancellation
• 200Hz CW filter with no ringing
• Si5351A Synthesized VFO with rotary encoder tuning
• 16 x 2 blue backlight LCD screen
• Iambic keyer or straight key option included in the firmware
• Simple Digital Signal Processing assisted CW decoder, displayed real-time on-screen
• On-screen S-meter
• Full or semi QSK operation using fast solid-state transmit/receive switching
• Frequency presets, VFO A/B Split operation, RIT, configurable CW Offset
• Configurable sidetone frequency and volume
• Connectors: Power, 3.5mm keyer jack, 3.5mm stereo earphone jack, BNC RF output
• Onboard microswitch can be used as a simple straight Morse key
• Built-in test signal generator and alignment tools to complete simple set-up adjustments
• Built-in test equipment: voltmeter, RF power meter, frequency counter, signal generator
• Beacon mode, supporting automatic CW or WSPR operation
• GPS interface for reference frequency calibration and time-keeping (for WSPR beacon)

Today: 40th Anniversary of the Launch of Voyager 1

https://voyager.jpl.nasa.gov/          (Thanks Joh!) 

https://www.nytimes.com/2017/09/05/opinion/pondering-voyagers-interstellar-journeys-and-our-own.html?emc=edit_th_20170905&nl=todaysheadlines&nlid=54115026

Nuclear Powered QRPp? Tritium Nuclear Batteries and Plutonium Pacemakers

OK QRPers, it is time to explore another power source.  Enough of the nails in lemons and all that mess.  It is time to go NUCLEAR! Check out the motor in the video above, then look at the video below for more info on how the nuclear battery was made.  Who will be the first to QSO with homebrew nuclear power?  Or has it happened already? 

Mike Rainey -- this seems like the perfect project for you OM.


Oh and by the way, in the course of reading up on this, I learned that we once used PLUTONIUM to power pacemakers.  Check it out:

https://www.mdtmag.com/blog/2016/01/medtech-memoirs-plutonium-powered-pacemaker

And no, today is not April 1. 

SolderSmoke Podcast 199 Eclipse, Regen, BITX, DC RX, 3D OLEDS, Iphone Boxes, Mailbag

SolderSmoke Podcast #199 is available. 

http://soldersmoke.com/soldersmoke199.mp3

2 September 2017

The Eclipse.  The Floods. 

Sawdust Regen gets John Henry off to a good start. 
Voltage regulators as audio amplifiers

The return of the Simple-ceiver (Direct Conversion)

Ceramic Resonators

3D OLEDS

iPhone Boxes as rig enclosures

Electric Radio on Frank Jones

17 Meter Contacts 

MAILBAG

VE1LEB's Ergonomic BITX Enclosure (in Juliano Blue)

Wow, Michael's amazingly cool BITX enclosure looks like you could use it to ask Scottie to beam you up. 
Put an end to those freakish contortions -- 3D print yourself an Ergonomic BITX box! Very FB Michael. Thanks. 

Hi Bill and Pete:

I thought you’d be interested to see my ergonomic enclosure for the BITX40. While operating homebrewed regen radios, I noticed that my hands/arms/shoulders were becoming uncomfortable after a while. After thinking about this for a few days, I realized that the dials on the front of these small radios were forcing my hands into freakish contortions—and having both hands on the dials at all times while tuning made matters worster faster! So I did some homework and determined that our arms and hands most naturally hold things toward each other, as though they are holding a small cylinder by the ends. But the conventional “dials-and-speaker-facing-front” radio case forces us to twist our hands up and outwards from our bodies to twist things. See my blog post http://blog.generaleccentric.net/?p=2009 for illustrations of this problem.

My enclosure design for the BITX40 re-orients the volume and tuning knobs toward the sides of the radio, making their operation much more natural—and pleasant. Although it’s not retro, it does have an unconventional appearance and should fit in quite naturally with all the other homebrewed solutions featured on SolderSmoke. 

You can visit my post at http://blog.generaleccentric.net/?p=2082; the box is available for download and printing at Thingiverse: https://www.thingiverse.com/thing:2508147

By the way, I also have a 3D printable mic for the BITX40: https://www.thingiverse.com/thing:2500483

73, Michael VE1LEB

Something else "Completely Different": Meteor Pings

Very cool.  I want to try this.  I have the RTL-SDR and the software, so all I need is the antenna.  I may try to resurrect the 5 element 2 Meter Quad from my 90's adventures in the Dominican Republic (I still have the copper tube elements!).  I know the Graves radar is out of range, but there must be a suitable North American signal for this kind of thing.  Any ideas? 

For more info:
http://hackaday.com/2017/08/27/sorry-us-europeans-listen-to-space-with-graves/#more-270298

https://dk8ok.org/2017/08/23/graves-reflections-out-of-the-blue/

Knack Victim Makes Good! Alan Yates in Seattle

Jean Shepherd used to say that in life, many of us come to a fork in the road:  down one path lies success.  Down the other, ham radio flea markets.  Alan Yates is proving Shep to be WRONG. 

I have fond memories of Billy and I building many versions of Alan's trivial electric motor.   We look forward to his virtual reality.  

K.P.S. Kang's Speech Processor and Antenna Tuner for the BITX (and other rigs)

Check out the blog of homebrew wizard K.P.S. Kang.   OM has a nice speech processor based on the LM386.   He also has a very simple antenna tuner and SWR bridge.  FB OM.  

http://smallwonderqrp.blogspot.com/2017/08/two-essential-add-ons-for-bitx-and.html

The Return of Pete's Simple-ceiver Plus (and a possible analog option)

Winter is approaching ladies and gentlemen, and it is time to think about radio projects.   Bob N7SUR suggested a direct conversion receiver project.  I think this is a great idea.   As a kid, I had fallen victim to the idea that building receivers was "too hard" for radio amateurs. Not true!  DC receivers to the rescue!  Carry on with the DC revolution first launched by Wes W7ZOI in 1968.

Pete N6QW is providing guidance and tribal knowledge via his blog.  For those of you who want to join the ranks of those who have defied the conventional wisdom and have broken through the "receivers are too hard" barrier.  I say build yourself a DC receiver.  Build it from scratch.  Many of you already got your feet wet in homebrewing with the Michigan Mighty Mite project.  Now it is time to jump into a DC receiver project.  

You folks already know what kind of VFO Pete will prefer:  It will be an Si5351.  That's fine.   But I will try to keep the banner of discrete component analog ludite-ism flying high.  This morning I ordered a batch of 7.37 MHz ceramic resonators.  I hope to pull them down into a significant portion of the 40 meter phone band.  If this works, I will share the batch with anyone who wants to joining my Analog Army (remember the CBLA?).   Note (above) that Pete has magnanimously left open the possibility of using a non-digital VFO. What a guy!    

Check out Pete's project here: 

http://n6qw.blogspot.com/2017/08/a-new-line-of-transceivers-difx_19.html

Pre-eclipse Solar Observation

I'm not sure if I'll be able to get a look at the eclipse tomorrow -- I'll be at work,  and in any case Washington DC will be far from the zone of totality.  But all the eclipse talk made me want to get my old 4 inch reflector telescope out today for at least one solar observation.  And yes, I know not to look through the 'scope. I projected the image onto a piece of white paper.   Notice the three large sunspots at the center of the solar disk.  Pretty cool.  

BTW, it is easy to aim the scope at the sun without endangering your eyesight.  Don't ever put your eye to an eyepiece (even on the spotting or aiming 'scope) when ole' sol is in the sky!  Instead, just look at the shadow that the scope tube is casting on the ground.  Make it circular and you will be very close to having the main tube aimed at the sun. See below.   

 I like to have the eyepiece aimed down at the ground or well above horizontal to avoid the danger of someone accidentally walking through  the powerful sunbeam coming out of the eyepiece.  You do have to be careful, especially if there are kids around. 

Building an Airplane in the Basement with Insulation Foam, Tape, Glue, Poplar...

But this one is not a model RC plane.  This kid intends to pilot this plane while actually sitting in it.  

As a parent, I must say this is really nuts.  Stick to the models Peter!  Or maybe put some goggles on the big dog and let him fly it!  

Nevertheless, this is an inspriational look at what can be built in a basement using stuff from Home Depot or Lowes.    

For more info see:
http://hackaday.com/2017/08/14/building-an-ultralight-out-of-foam-in-a-basement/#more-268614

Here's Peter's earlier Cargo Plane project:

Voltage Regulators as Audio Amplifiers - Who Knew!?

Mike KC7IT pointed out that the AF amplifier chip in my Sawdust regen receiver is actually a TL431 voltage regulator. Mike writes: "It's using the voltage reference input as audio in, and the voltage being regulated as the audio out."  It works great as an audio amplifier, and with just three terminals it is a lot easier to use than our normal LM386 or 741 chips. I'd never seen a regulator used this way.

Here's the data sheet:  http://www.ti.com/lit/gpn/tl431

And here are a couple of sites that discuss this very interesting repurposing:

http://theradioboard.com/rb/viewtopic.php?t=6733

http://techlib.com/electronics/audioamps.html#TL431

A Regen that is NOT Evil

Look at that thing.  It is already painted Juliello -- this is a very good sign.  Steve Silverman sent me one of these Sawdust Regen kits a few years ago.  I put it together this week for my nephew John Henry who is very interested in Morse and ham radio.   

This is a regen that even I can love. It is simple, small and stable.  40 meters comes booming in.

Look at the schematic.  Why haven't we used that simple three-terminal AF amp IC before?   

Get your Sawdust Gear here: https://breadboardradio.com/breadboardradio/Products.html

International Brotherhood and the BITX Rigs

Bore and Heriberto's uBITX board

Nowhere is the International Brotherhood of Electronic Wizards more evident than in the work on the rigs designed by Farhan.  With the BITXs we see rigs designed in India that are now being built and modified all over the planet. Here are just a few examples of the global collaboration currently underway:

In Italy, Giuseppe is putting a BTX40 on 20 meters and making it a dual bander: 

Hi everyone, I just completed some tests on a Bitx40 running in 20 meters band. I addes the 20 as secondary band activate when needed. I apply some mods to switch to secondary QRPLab BPF filter centered to 20 meters and removed the C91 and C92 caps to work in USB. I done some RX tests in the weekend of iaru hf contest to listen some stations Active.
Here the issues registered:
1) the 20 RX sensitivity was a bit weak compared to 40 meters. I need to increase volume. ( To receive the 20 meters the vfo run to 26 MHZ, mybe some stage suffers of poor performance in this High frequency?)
I also tryed to increase the vfo over maximum allowed by raduino, using external buffer, but no results.
Please read the issues as: work but could work better!

2) the RX was not very clean: voice acceptable, but RX of Digital mode not very stable ( probably the cause could be the vfo shift for poor tuning control. I need to add lock function in firmware ...) Or interferences for free wire of connection.

3) Sometimes when switch on or change vfo to other band or mode, the bf amplifier start a self oscillation ...Resulting in my wife's screaming (the tests were also performed during the night!)

No tests was performed at the moment in TX because i need to install the LPF for the new band.
The firmware to make the test was a modified version of 1.17.1, few temporary mods to preset the vfo b to 14 MHz USB and correct the freq. Display.

These my tests.
Giuseppe Callipo IK8YFW.

Pavel is a young fellow in Cuba who is doing great things with the Raduino software: 



Hi to all.

The code was updated, the change log is this:

v1.4Update to catch up with the features added in the Raduino v1.17.1 from Allard's code (CW SPOT and bug fixes)

• Upgraded the operations instructions
  • More user friendly version with embedded images.
  • Add instructions for the S-meter, AGC and TX-power mods details and tricks.
• Moved all images to its own folder "images".

As usual tips/bugs/comments/suggestions are welcomed, you can reach the code here: https://github.com/pavelmc/bitx40/

There is a inoffensive bug in the calibrate process, in which the actual calibrate value is not correctly showed in the LCD until you move the pot to adjust it, I'm working on it.

I'm slowly working in this direction now:

• Bug removal in the calibrate function.
• Finish the upgrade of the Si5351mcu lib with some improvements.
• Adding CAT support via ft857d lib (https://github.com/pavelmc/ft857d):
• Full compliance needs get rid of all the blocking delay() sentences and that need a structural/paradigm code change and a lot of testing (I have Fldigi/MixW/Hamlib to test, I think if that 3 works the rest will do it)
• Moving to a library (yatuli: https://github.com/pavelmc/yatuli) for the pot usage, that will ease the process of implementing the CAT as almost all delay() calls are related to pot/clicks, so I'm on it.
• Maybe implement a multiclick lib to optimize the code and make it more easy to understand.

 Any thoughts or whishes related to that?

I plan to make the CAT operation optional via a #define declaration as not all of us will/want-to use that.
73 Pavel CO7WT

Here we see Bore in Montenegro working on a uBITX designed in Cuba by OM Heriberto

Hi Colleagues

Bore Lezaic from Montenegro is working on the uBitx PCB designed by Heriberto -CM2KMK- from Havana, Cuba

Here some pictures he(Bore Lezaic) have posted in my FB wall.

Any question regarding uBitx PCB please send to Heriberto Gonzalez Mendoza at cl2kmk@frcuba.cu (please take care with the email address it is slight different to his actual call sign).
Qrv's
73's Jc

Bore and Heriberto's Board

Hidehiko in Japan was struggling with some LCD noise in his experimental BITX40.  I passed along the active filter circuit that I'd first seen in Roy Lewallen's Optimized QRP rig. 

To

BITX20@groups.io Jul 29 2017 at 4:22 AM I've finished the Bitx40 experimental project today. I added the AF-AGC and LM386 POP limitter with raduino v1.20.1 (Thanks Allard). And I also added the DuinoVOX for Digital Mode operation. It's a great radio but the problem is only the "LCD noise" when increasing the AF volume. hi... Can I reduce this noise? Or I have to use the analog VFO? Any suggestions welcome.
ja9mat Hidehiko

To Hidehiko JA9MAT: 

Very simple.  Just three parts.   NPN transistor (like a 2N3904) and a 47k resistor (collector to base) 100 uF cap (base to ground).   Vcc the collector. Emitter goes to the DC power input of the AF amplifier.  You can see my use of this circuit in the schematic in this blog post:
Look in the lower right, near the LM386 AF amplifier.  Click on the schematic to enlarge.  73  Bill N2CQR 

My Organic Chip Rig with an LTSpice Schematic

Thanks Bill,
Well I added "3-parts"(2N3904+47kohm+100uF) between the D18(1N4148) and the junction of R111(100ohm) and R1113(220ohm). The noise has absolutely gone!
ja9mat Hidehiko.

_._,_._,_

ZL2CTM's Homebrew Transceiver Project

Wow, Charlie has a lot of very cool ideas in this initial video.   Some suggestions: 

-- With the IRF-510 in the final, beef up the heatsink, and follow Farhan's lead by including an option for 24 volts on the drain.  That would take you  up to 20 watts or so (for those who are so inclined). 

-- Could that Teensy SDR board work at the IF frequency?  If so, consider putting it ahead of the crystal filter.  This would enable us all to join the Waterfall Signal Purity Police Force. 

-- I love the OLEDs too, but I found them to be noisy.  I minimized the noise with shielding around the OLED and active decoupling on the power line to the AF amplifiers.

More of Charlie's work here: 

https://plus.google.com/107506245856154702088

Audio Clips from N2CQR/HI8 Contacts with MIR Space Station (now in mp3)

Back in 1995 I was in the Dominican Republic.  I used an old 2 meter rig and a homebrew 5 element quad (see below) to talk to U.S. Astronaut Norm Thagard on the MIR space station.  (You may have heard me bragging about this before.) I made a bunch of audio clips from the contacts.  They'd been in the now defunct RealAudio format, but I have been able to convert them to mp3.  You can listen here: 

http://www.gadgeteer.us/CLIPS.HTM

Real-Time 3D on an OLED Display

Oh man, I thought I was so cool when I got the OLED to display 7215 kHz and other frequencies.  Then I see this.  What next?  Real-time 3D SDR Waterfalls?  On an OLED?  Holograms?  

From: 
http://hackaday.com/2017/08/08/atmega328-3d/#more-267887

Alaskan Road-Kill Microphone

I got a kick out of Paul's message from Alaska -- on my bench I have an almost identical project, including the sink strainer (see below).  And of course the now-iconic SolderSmoke podcast mic is just an electret element inside what used to be an IKEA floor lamp. 

N2CQR Lamp Mic 

Hi Bill and Pete,

I have been following your and Pete’s adventures on Soldersmoke for a while and want to say that each episode always brings some of my past experiences to the surface.  I have been fiddling with radios and electronics for over 60 years, licensed since 1964.

I needed a mic for Bitx40 build and started thinking about this as I was working on other projects. Every day I walk a mile and a half to my mailbox. Wednesday’s and Friday’s happen to be the days of trash pickup and people put the trash bins out next to the road for pickup.  Last week I spotted a little desk lamp sitting on top of one of the trash bins with the cord cutoff so on my return from the mailbox it was still there and it followed me home.  (fig1)

Removing the shade left a flexible vertical support for a mic, (fig 2).

Your recent podcast you mentioned your D-104 microphone, that was my first mic once I had phone privileges back in ’65.  Scrounging through my treasure box I came across a 1 ¼” to 2” PVC pipe coupling that looked just like the basis for a mic. A few hours of mediation and a couple hours at the lathe and mill produced a mic with stand and a PTT switch (fig 3).

Some scrap bin aluminum and a free lamp from the trash and another hour at the lathe, (fig 4 & fig 5). And yes, it has some heft as the base has a large hunk of cast iron in it. Will admit I spent $1.24 for the sink strainer that sacrificed itself to become the grill ala D-104.

The self-satisfaction of building your own gear and accessories is one of the rewards of this hobby, can’t buy that in a store. And repurposing someone’s trash into something useful is a plus.

Keep the soldering iron hot.

73’s

Paul KL7FLR

Wasilla, Alaska

PS JoAnn’s is one of my favorite places for finding useful materials.

Please Help This Guy

From time to time we use the SolderSmoke blog and podcast to try to help those in need.  We have close ties to the Dominican Republic and often become aware of people who are in real trouble in that country.  Here is case of a man who really needs some assistance.  Please take a look and consider helping him out.
https://www.gofundme.com/ramons-medical-treatment