Farhan's NEW uBITX Multiband Transceiver (video)

It is, truly, a thing of beauty.

Farhan will be posting details on his web site soon. 

Jim WA7HRG's Beautiful Popcorn BITX

From the earliest BITX articles, Farhan has encouraged the use of discarded  cookie or candy boxes.  Jim's popcorn box is clearly in this tradition. There is also, of course, a connection to the idea of using simple "popcorn" transistors.

Popcorn Radio

by Jim Purvis WA7HRG

While celebrating Christmas and a Birthday at Disneyland in Dec., my wife and I enjoyed a box of popcorn during one of the many parades.  It was too nice a box to toss in the trash so I brought it home.  It kicked around the QTH a few weeks until I caught the BitX40 v.3 fever.  Wow, just enough room for the BitX and a few hacks, and the project was on. And a very neat way to remember our good time at Disneyland.

I decided on several hacks and mods and made a list.  In the end I settled for less. Hihi

1.       Switchable 5 or 20 watts out.

2.       Single power supply.  24 volt PA with a 13 volt regulator for the rest of the radio.

3.       Dual band. 40 and 20 meters.

4.       SSB and digital mode operation.  Built in audio interface and sound card.

5.       A tune function for antenna adjustments.

6.       On screen S-Meter.

7.       2.2” color TFT display.  Because I can display more information and it’s just cool. The Radino it came with was set aside for another project.

I had a 24V  5amp laptop power supply as the base supply.  I used two 7812 regulators in parallel and an aluminum plate heatsink and raised the common a little above ground for a 13 volt output.  I could then switch that between 24V for the PA.  Regulators get a bit warm when using them in the 5 watt position so most operation will be at 20 watts.

Dual band operation was soon abandoned simply do to space limitations in the box.  I had no room for additional BPF and LPF.

The audio interface not only provides ground isolation and level control between the PC and the radio it also provides a VOX operation for digital modes.  The digi software can provide the PSK (or other modes) audio on the left audio channel and a continuous tone on the right.  I use this for the VOX operation.  A ‘thumb drive’ size USB sound card provides the connection to the PC with just one cable.

Antenna tune function was provided by a version of Pete’s LBS method and I just used a small relay and a push button to activate PTT and to unbalance the balanced modulator.

The S-Meter proved problematic for me.  I might not have had it if not for help and advice from Pete.  It may not be accurate but provides a good relative signal strength indication.  And looks very cool!

The DDS is a quagmire of several different sketches and some of my own coding.  This was my first adventure into actually coding the sketch from (almost) scratch.  I am sure I am very close to the maximum times you can program an Arduino as my “Guess and Test” method of coding became very arduous. All switching of mode, power and other functions are done at DC allowing me to use that as inputs on the NANO to change DDS function and displays.

All and all I am very pleased with the way it turned out.  Not sure what I’ll do about losing 20 meters.  Hmmm guess I’ll just have to build another radio.  J

Front cover.  Upper Right corner is the Digi/SSB switch.  Tuning and vol are at the bottom. All controls and switches were located, sometimes in odd places, to retain the graphics of the box.

In the lid.  Upper left corner is the digi/SSB switch and across the top is the audio interface ckts.  TFT is in the middle Right.  Below that is the 3.3v level shifter and encoder.  On the heat sink are two 7812 regulators in parallel.  I raised the common a little above ground for 13v out. Far left is the vol control and S-Meter amp and det ckt.

The main chassis. Across the back left to right are power input, spk jack, mic/PTT jack, ant connector, and 5/20 watt switch. Far right is the PA heat sink. A 1x.5x4" aluminum bar.  It's what I had... Lower right corner is the tune push button and if you look close in the upper left corner of the main board is a mini relay glued to the board near the bal modulator. That unbalances the modulator and provides a carrier for antenna tuning. Upper left of the box below the power connector is the USB Sound Card for the PC interface. And a couple extra input wires I ended up not using.  Below that is the standard Nano and si5351.

Last but not least is the 2.2" TFT.  All functions power, mode, etc., are DC switched.  I also use that as inputs to the Nano for display changes. I sense the 12 v relay voltages and through a voltage divider to input pins.

It has been a fun project and I can continue to play with it, but I think its time to button it up and use it a little.

 It's back to my General Coverage Rec that I started but never finished.

 73  Jim WA7HRG

"CQ Transistor" -- The 1958 Mighty Milliwatt

I think it is time that we get back to our QRP roots.  Perhaps under the influence of the wizard of Newbury Park (N6QW), we've all been drifting into the world of high power.  It starts innocently:  you hook up a second gel cell to the IRF-510 and suddenly you are at 20 watts out from the BITX.   Before you know it, you have an uncontrollable urge for 3-500Z's.   Here is a story that will get us back on the QRP track:

It was September 1958.   On the 14th of that month I began my first orbit of the Sun.  Band conditions were VERY good.  OM Don Stoner was on 10 meters with a homebrew solid-state milliwatt rig calling CQ TR, CQ TR (CQ Transistor).  Jarno PA3DMI in Amsterdam sent me the link to a Radio News article by Don Stoner.   The article (and the entire magazine) is a lot of fun.  Check it out.  The QRP fun begins on page  51.    Thanks Jarno!  
http://www.americanradiohistory.com/Archive-Radio-News/50s/Radio-News-1958-09-R.pdf

VE7SL and THE POWER OF THE GREEN GLOW

Steve VE7SL recently discussed Heathkit's wise use of the color green in the VF-1 and DX-100 frequency readouts.   The power of green is visible in the above photo of the N2CQR AM station. (I used this gear to check into the Old Military Radio Net and the Lonely Guys' Net on 75 meters on Saturday).  Note the VF-1 on the shelf in the upper left, and the awesome green oscilloscope trace.  Juliano Blue is all well and good, but let's not deny THE POWER OF GREEN.

Steve's discussion (and cool Knack story):  

http://ve7sl.blogspot.com/2017/01/the-green-glow.html

CONFIRMED: Andy G6LBQ Has The Knack (and OTD)

The early fascination with small light bulbs, switches, and batteries confirms the diagnosis. The Ladybird group seems to have led many a young British person down the path to OTD (see the web site for more info on this malady).

https://g6lbq.blogspot.com/

Andy writes:

Hi Bill

 

I have built a few BitX transceivers and developed a 9 band version which has been built by various hams around the world.

 

Always look forward to the SolderSmoke podcast which I enjoy immensely.

 

For your interest I have attached some pictures to show you some of the modules I have designed/developed and built for my Multi-Band projects. The SMD boards are for my latest project which I call the Irwell Transceiver, my intention is to make it all band HF and multimode.

 

Hopefully my pictures will meet with the SolderSmoke approval and the inauguration can take place for recognition that I officially have The Knack, failing this it will be a Basta moment at the G6LBQ workshop!

 

Keep up the great work you do with SolderSmoke which brings pleasure, fun and inspiration to hams all over the world.

 

Kind Regards

 

Andy de G6LBQ

 

G0ETP's Amazingly Beautiful SDR Rig

This is almost too much for an HDR guy to take. Really impressive. 

Check out his QRZ.com page:

https://qrz.com/db/G0ETP/?mlab= 

More DSB, from Belgium and Spain

Frank ON6UU writes:

Hello Soldermelters,

 

Maybe some interesting news for you as there are some new kits at hand from EA3GCY (http://www.ea3gcy.com)

 

I’ve made the MFT-40 DSB without any problem,  all parts were provided with the kit,  only things to buy were a microphone connector,  a speaker and an antenna plug.   The box was taken from my attic and was a VGA-selector in his previous life.

Kit came together in a few evenings,  I followed the very well written manual,  all was well pointed out,  which resulted in a working kit.  After aligning the kit I could start making qso’s.   The microphone was made from a piece of tube,  a simple switch and a electret microphone,  it doesn’t look pretty but the microphone works.

 

Rx-Tx 7.066 – 7.133  (With DDS the complete 7MHz band)

Pwr :  some 3W peak.

Double Side Band

 

Made some You-tube films about it.  

https://www.youtube.com/watch?v=fPREwd1FowM

https://www.youtube.com/watch?v=3T2dxnTmF7I

https://www.youtube.com/watch?v=eHoPdhmbZz0

 

Easy to make,  no SMD,  easy alignment without necessity of expensive material.   Fine for someone who never made a transceiver,  hence the name...My First Transceiver,  MFT.   As soon as the weather permits I will take the TRX out in the field and activate a SOTA with it.

 

Now working on the MFT-20 DSB.   I’m hoping for an 80mtr version to come available too.  :-)

 

All info is on Javier’s site. (http://www.ea3gcy.com)

 

72, 73

Keep the solder melting !!

 

ON6UU

Walter KA4KXX's "Al Fresco" Oz DSB rig with VFO Mod

A while back we ran a post about the MDT 40 DSB rig out of Australia. Walter KA4KXX liked the design so much that he built his own version and, with it, made his first homebrew phone contacts. I always say that DSB is a great way to break into the world of microphones.  Walter is obviously on the right path -- not only did he come up with a nice Al Fresco DSB rig, but he modified the VFO to get additional coverage and to incorporate a frequency counter.  FB Walter!

Walter KA4KXX writes:

Since I earned my Ham Radio license in about 1979, I have always operated only on CW since I like to build all my own equipment, but recently at the SolderSmoke website I discovered the MDT 40 Meter DSB Transceiver, and decided this was the design I had always been looking for to finally build and operate on phone.

After I made my first phone contact after only 5 minutes of trying, just a few weeks ago, I was so excited I sent an email thanking designer Leon of ozqrp.com.

Then I modified the VFO further to cover the entire 40 meter USA General Class License phone band, which is 7.175 – 7.300, in two overlapping steps.  I also added a 5K fine frequency adjustment, used a more friendly 1SV149 Varactor diode which I purchased on EBay at very low cost, and also added a high impedance buffer (found at the website listed below) to the VFO to drive a frequency counter.
 
http://www.arising.com.au/people/Holland/Ralph/buffer/highimpedanceprobe.htm

I was able to implement these modifications very easily since I always make my own un-crowded state-by-stage Manhattan style circuit boards and build first on a breadboard.
So far I am very pleased with the results.

Walter KA4KXX

HB2HB: Contact on 40 meters with W0PWE

I got on 40SSB this evening and called CQ with my BITX DIGI-Tia.  Hooray!  Jerry W0PWE answered me with HIS 40 Meter DIGI-TIA.  His is still Al Fresco style.  Very nice.  We add this to the homebrew to homebrew scorecard.  Thanks Jerry!

Jerry's rig:

VU2XE's BITX40 (with a cool CAD box)

A year or so ago Pete and I encouraged Kiran VU2XE to try the BITX.  He followed through, on our suggestion and went a step further, using CAD to design a box for the BITX.  I will try to post a link to Kiran's CAD files on the BITXHACKS blog.  

Kiran writes:

Hi Bill and Pete,

It is almost year since you seeded idea about the BITX. I am still a listener of your podcast.

After finishing my RF amplifier project late last year, I was thinking of few projects and BITX was on the top of the list. I ordered and received a very beautiful BITX40 kit with Arduino, I got it recently. I also designed a simple case for it using CAD software. It can be used by anyone -- just go to your local laser/CNC shop to get it cut in Aluminum.  I just thought of sharing the excitement with you.  This rig and it sounds awesomely good :)

Attached are some snaps and design files (I am no expert in CAD etc. it is my first attempt to learn and build)

Happy projects and 73s

Kiran VU2XE 

Peter Parker VK3YE on Vintage Gear (in his new book!)

Homebrew Hero Peter Parker has a new book on the market.   I was really taken by his description of the joys of restoring older gear.  Peter really nails it.   Here is an excerpt:

Vintage Equipment

     The collection, restoration and use of historical equipment is another movement in amateur radio.  The musty smell of warming dust, the heavy clunk of rotary switches and the velvet smoothness of precision tuning drives are joys of every use.
     Such sensuality is absent from modern plastic-fronted, wobbly-knobbed transceivers.  Old rig cabinets felt they had something in them.  A kick would hurt you more than them.  And etched panel markings confirmed they were built to last.
    Unlike today’s dainty push buttons with stunted travel and disembodied beep, toggle switches showed you where they stood.  Weight, life and play made adjusting controls for nulls and peaks (as often required) both a pleasure and occasional frustration.  Even if only as mechanical backlash on a bad tuning dial, it was as if the equipment was telling you something, like a ridden horse does through its reins.  Not like newer gear’s lack of tactility which is like a ‘dead fish’ handshake, all take and no give.
    There are psychic as well as physical joys.  The thrill of bringing neglected or dead equipment to life drives many.  It’s an underestimated skill.  You start with nothing and almost anything done represents progress when building from scratch.  Whereas with a repair it is very easy to render something that’s 80% good completely useless with a careless drop or slip.

More about ‘Getting back into Amateur Radio’ is at
http://home.alphalink.com.au/~parkerp/gettingback.htm 
& the video at https://www.youtube.com/watch?v=g4ktP5K4x-I

Back from the Raspberry Pi SDR Brink

Earlier this week I shocked Pete Juliano by telling him that I was taking a break from my normal analog, discrete component, no-chips mode of construction so that I could put together a Raspberry Pi-based SDR receiver.  Even from 3000 miles away, his astonishment was clearly perceptible. He seemed briefly disoriented by it.  I'm sure some of you may have a similar reaction.  

I'd been lured in by that video of the Raspberry Pi RTL-SDR receiver with the very cool  touch screen display.  It has a waterfall!  And a touch screen! How could I resist?

I went to Amazon, but there I discovered that that attractive display is not exactly cheap. And maybe I'd need a new Raspberry Pi.  At this point, in search of economy and convenience, I began rummaging through my digital junk box.  There I found a Rasp Pi Model B.  And an old computer monitor.  This will be easy, I thought.  Just get some SDR code into that Pi, hook up the RTL-SDR dongle and Bob's my uncle, right? 

Not so fast.  I quickly began to run into daunting digital obstacles. Sure, the Raspberry Pi fired right up and filled the computer display with lines of code.  But it was all Linux.  Yuck.  Sorry Linux fans, but for some of us mere mortals,  Linux is a weird opaque world in which every little thing is somehow a lot harder.

I also began to suspect that my 2013 Model B might be sort of a Model T in the Rasp Pi world.  It might not be up to the computing task.

And finally, as I poked around the internet, I began to conclude that the Raspberry Pi software for SDR is not quite done yet.  All the sites seemed to have the word "experimental" in there.  And lots of "I'm pulling my hair out" comments Maybe I'm wrong, but maybe we just need to give this more time.

Let me ask the distinguished group some questions:

Is my Model B really useless for SDR purposes, even if I don't need all the bells and whistles?

Is there an SDR program that can be easily placed in a Raspberry Pi by someone who has NOT mastered the mysteries of Linux? 

For now, I have cleared the raspberries from the bench and am back to working on HDR stuff.