Channelized! BITX 60 with the Five Channels (with video)

Here's an update on my BITX 60 project.  The modified module is in the lower box.  An Arduino Uno and an Si5351 (this one with unreleased smoke) is in the Heath QF-1 box on the top.  I am using an Arduino sketch written by Don ND6T. It spits out the needed 17 MHz LO freq needed for each of the five 60 meter channels. You can scroll through the channels by just holding down the rotary switch interrupt button.

There is a move afoot to liberate from channelization about 15 kHz of the 60 meter band. When that happens, I'm ready to go -- I'll just reconnect the rotary encoder for the Si5351 and load some new code.  I suspect that by the time that happens, Don will have modified his code so that the 15kHz "tunable" segment will be integrated into the current program and will appear as one of the options as you scroll through the choices. 

For reasons that most readers will understand, I have resisted channelization for many years.  But here I am, channelized on 60.  It is not so bad.  I'm having fun listening to a new band, using a modified BITX, an Arduino, a bit of Heathkit and code from a fellow ham.   

BITX 60 (with three short videos)

Inspired by Don ND6T, I decided to put a BITX40 Module on the 60 Meter band.  All you really have to do is modify the bandpass filter.  Don showed us how to do this by simply adding three 100pf caps.  I was going to order SMD caps, but this just didn't seem right -- I found three of the old "with wires" kind and easily soldered them into position.  The bandpass shifted as Don had promised.

You also have to change the VFO freq.  You need it to be in the 17.3 MHz range. Don has a nifty program for the Raduino that also works with the Si5351/Ardunio Uno combo that I use.  It keeps you on the five channels currently authorized on 60. Unfortunately I managed to let the smoke out of yet another innocent Si5351 breakout board.  Amazon and Lady Ada are sending me another one, but in the meantime I pressed into service an old AD9850 DDS. I had a little trouble getting the 17MHz signal through the BITX's VFO 4 MHz VFO system, but I eventually figured it out. (More on this later.)  

The receiver is working nicely.  I like the relaxed 60 meter conversations. 

For Pi Day (3.14) - Looking Back on 5 years of Raspberry Pi Tinkering

Not by me, thank God! No, the five years of Rasp Pi maso-tinkering were done by Thorin Klowsowski.  His report appears here:

http://lifehacker.com/what-i-ve-learned-from-tinkering-with-the-raspberry-pi-1793236686

In the second and third paragraph, he confirmed all my suspicions:

The Raspberry Pi is far, far away from being as user friendly as a PC or Mac. That’s a feature, not a bug... Before hobbyists latched onto the Raspberry Pi, it was a computer for learning how to code targeted mainly at kids. Since then, the appeal has broadened, but it’s still impossible for a project to “just work” out of the box. You will have to tweak something, dig into the command line, or spend a few hours buried in an obscure internet forum to find solutions to problems that only you seem to be having. You will slam your head against the wall, yell a little, and throw your Raspberry Pi at least once for every project you attempt to make.

I told you so. 

KC1FSZ's Peppermint Bark BITX: Aeronautical Mobile for his FIRST QSO. TRGHS.

Bill and Pete:

Can’t say enough good things about your podcast - thanks for all that you do.  I’m a fairly new ham and have been trying to go the home-brew route as much as possible.  

I bought a BITX40 module (pre Raduino vintage) and added my own VFO board using the usual parts.  Actually, I’m using a Teensy 3.2 instead of an Arduino because it is a faster part and has a lot of DSP functions built into it that I’m using for digital mode stuff.   But it’s the same basic idea.  

My BITX40 is not as photogenic as some of the others, but I sent a picture below. This is the “biscuit tin” variety.  It’s was funny actually: a co-worker of mine stopped by my office around Christmas to give me a gift and pulled out of his bag a very nice box of “peppermint bark” candies with a ribbon around it.  The VERY FIRST thing that crossed my mind the instant I saw the gift was …. BITX40 ENCLOSURE!  He must have been pleased to see the huge smile that came across my face. :-)   I’ve been bitten by the bug for sure.  

My first three HF QSOs (ever) where on the BITX and were all very interesting:

• First real QSO of my life was with KE4TJB “air-born mobile” off Delaware.  He is a commercial pilot flying for JetBlue and apparently has time to work QRP stations during flights??  I wonder who was flying the plane?
• Then I was scanning around this morning and caught K4HW making last calls for check-ins on a net running on 7242 out of North Carolina.  I decided to give it a shot, having never joined an HF net and I was recognized!  As the first round got going I realized I had joined a Jehovah’s Witnesses net.  They were very friendly and the net control stopped to help my get my frequency calibrated before they continued with the scripture passage for the week.
• Later this morning I reached K3KLC in Maryland who had the high-end SDR rig with the waterfall/panadaptor/etc.  Remembering comments that you guys have made about these types of folks on 40m, I was very concerned.  But this guy turned out to be very helpful and sent me some screen shots showing what my signal looks like.  

Thanks again, and 73s,

Bruce MacKinnon

KC1FSZ

Wellesley, MA

https://www.qrz.com/db/KC1FSZ

WA8WDQ Builds OZ1JHM's Arduino CW Decoder (Video)

Bill, Pete:
I wanted to update you on my DC receiver progress.  While I'm still operationally proficient in CW, many of my friends are not.  So I thought it would be fun to add a CW decoder to my DC receiver. 

In my research for a solution, I ran across a sweet decoder I thought might be of interest to the SolderSmoke listeners.  OZ1JHM developed a totally software based decoder for Arduino that uses the Goertzel Algorithm.  This algorithm performs similarly to a Fast Fourier Transform but only for tone decoding at specific frequencies.  This limitation keeps the code small and fast making it perfect for microcontrollers like the Arduino. 

I was able to hack Hjalmar's code into mine and the result is CW decoder functionality in the receiver with no additional hardware!  But, the Arduino Uno's performance is limited so I need to dynamically switch between receiver VFO/control code and the CW decoder in order to preserve real-time performance.  This is only my first pass so perhaps I will find a way to optimize the code to more fully integrate the two.  I currently switch back and forth based on whether the VFO knob has been rotated or is idle.  This at least gives the illusion of real-time integration but makes it harder to tune in a signal for the decoder. 

Now that the Arduino Zero is available, I've been considering moving that direction to dramatically improve available horsepower.  This isn't the first time I've run out of gas with the Uno.  Now it's time to start working on a transmitter module for the radio :).  You know, even though I have an operational K3, I find myself reaching for this radio first.  Something magical about using something you've created :).  But hey, preaching to the choir!

Be sure to check out Hjalmar's site (http://www.skovholm.com   and 

http://skovholm.com/cwdecoder) for details on his design and a video demo.

Brad  WA8WDQ

WU2D's Wonderful Video on Retro-QRP

(Link to video appears below.)

Stephen G7VFY sent me the link to Mike WU2D's Retro-QRP video.  In the last month spoken to Mike at least twice on 40 and 75 meter AM.  Stephen was responding to a post I did about a 1958 18 milliwatt solid state QRP rig.

Mike's video is really wonderful.  I've never been into military surplus, but this video made me think I might want an ARC-5. The rig Mike builds and tests is very similar to our beloved Michigan Mighty Mite. His description of the build and the testing procedures he used will be of great interest to those who've built the MMM rigs.  And he made some contacts.  Finally, there is a cameo appearance by Paris Hilton.  And she is holding a HOT transistor!  Wow!  

Mike has a real talent for making these kinds of videos. Thanks a lot Mike -- see you on 40.  And thanks Stephen (Stephen has sent us so much great stuff over the years, including a fantastic box of British valves.)   Pete:  See how nice it is to get back to QRP?

Here's Mike's YouTube Channel. I love the intro:
https://www.youtube.com/channel/UCN7RQv_qmzhzuJV1HhJ4OEA

Beyond Al Fresco: Boxed Up In Style with AB1YK's Very Cool BITX Box

Mike AB1YK is doing some excellent work boxing up the BITX. 
Check out his article on the Nashua Area Radio Club Blog:
http://n1fd.org/2017/02/28/my-ssb-bitx-40-build-from-vu2ese/

Here is a picture of Mike's case:

These enclosures might become available for purchase soon...

SolderSmoke Podcast 194 - Approaching the Digital-Analog Singularity

SolderSmoke 194 is available (scroll down for link)
March 4, 2017

BIG NEWS:   uBITX from Farhan

BENCH REPORTS
Pete: Recycling Old Boards
Working on Arduinos and advanced displays

Bill: SDR Adventures and Misadventures.
RTL-SDR is fun.  Built HB front end.  
HDSDR under Windows is fun and easy.
Thought about Raspi3, 7 inch touch screen, Linux, software YUCK.  
Followed advice of Ken G4IIB and got a 50 buck tablet with Google Play. 

Who needs tiny OLEDs?  Use a 7 inch tablet as your display!

Building a Ceramic Resonator for the HRO  455 kc filter
The value of doing something different. 
Boxed up my NE602 OLED rig. 
OLED noise and ACTIVE decoupling.
NE602 and MOSFET tips

LEXICON:  
OTD   Obsessive Tinkering Disorder  G6LBQ
"A Thing of Beauty"  
Source of Tombstoning term:  Don ND6T.
Ken G4IIB’s extremely smooth audio.

ON THE AIR:
On AM on 75 and 40.  Fun.  Old Military Radio Net and "The Lonely Guy Net" on 75 Saturday morning.
Good old 17 meters. Open at mid-day
HB2HB on 40 with W0PWE.
Listening on 60

Hambrew magazines disappeared, but are back now.
EMRFD Classic Edition available
New Posts to BITX HACKS

MAILBAG:
Gloves follow-up. Not a good idea.
VK3YE’s QRP by the Bay event  and a new book!
Colin M1BUU achieves Mountaingoat status
Martin A65DC JoO MMM in the UAE
Tom NY2RF Editorial with mention of JoO!
Lots of Al Fresco rigs: W8LM BITX on a board, Brad WA8WDQ DC RX, KA4KXX Al Fresco OZ DSB
ON6UU DSB from Spain via Belguim
Hugh ZL1UEM SMALL Si5351 OLED
Cookie Tin rigs VK2EMU’s Biscuit Tin DC RX,  WA7HRG’s Popcorn rig
VK4FFAB FB LTSPICE intro
Ken G4IIB’s BITX adventure (with VERY smooth audio.  How smooth? We can’t say.)
VU2XE’s BITX with a CAD box
G0ETP’s shockingly beautiful SDR receiver
Alan W2AEW on the mend with broken ankle.  His videos are a treasure trove of tribal knowledge.

http://soldersmoke.com/soldersmoke194.mp3

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