DK7IH Improves his Shirt-Pocket Transceiver

More great stuff from Peter DK7IH.   He recently made some improvements to his "Shirt-Pocket SSB Transceiver.  On his blog he explains why he made the changes.  Note the Si5351 that is in there now.  I liked the 1 cm square T/R unit that Peter wrapped in heat shrink tubing. He also provides a really nice description of how to do front panel labeling with a laser printer.

Here it is: https://radiotransmitter.wordpress.com/2020/06/28/re-engineering-my-1st-shirt-pocket-transceiver/

Thanks Peter!

Arduino, Si5351, GPS linked atomic clock, GPS disciplined frequency counter and more...

Wow, it has been a while since I first talked to Rick, N3FJZ.  Above you can see his QSL card.  And here is a link to a SolderSmoke blog post (with videos) that describes our Homebrew to Homebrew contact:

http://soldersmoke.blogspot.com/2015/10/hb2hb-n3fjz-n2cqr-si5351-and-bitx-tias.html

The e-mail below shows that Rick continues to melt solder, bringing into his rigs some very cool technology:  atomic clocks, GPS modules, and color displays.  That's a long way from the original PTO Direct Conversion receiver that he first heard me with.  FB Rick! 

--------------

Leif, 

I've made great progress on my Arduino Mega 2560 based rig controller I call the ZX-Front-Panel. I just finished a feature I always wanted which is a built-in *GPS disciplined frequency counter*. It uses the 1-pulse-per-second timing output from the GPS module to create a frequency counter with atomic-clock accuracy. It's on the solderless breadboard with the rest of the ZX-Front-Panel right now, and even so, it can count up to 30MHz with no trouble! and it should be able to count up to 100MHz or more if built on a ground plane with a little shielding. The best part about it is that it only required one additional chip (a 74LV8154 32-bit counter $1 from Mouser) in addition to the existing parts already on the ZX-Front-Panel; i.e. the Arduino Mega 2560 ($10), the Ublox NEO-6N GPS module ($15), the display ($25), and the Si5351 PLL RF Oscillator ($8). 

Check out my video series covering the ZX-Front-Panel development progress. The first link below will bring up the video page on my website with the latest video at the top, so you'll have to scroll down a bit to get to the earlier development stages. Check out the rest of the website too for the schematics of my Bitx / TIA inspired rig design (which I call the ZX-SSB-II) that I used an early version of to make my first HF HB2HB contact with Bill (N2CQR) back in 2014 or so (Bill and Pete, via the Soldersmoke podcast, were my inspiration to build my first SSB homebrew rig). 

YouTube videos: http://www.remmepark.com/circuit6040/ZX-SSB-II-Front-Panel/ZX-SSB-II-Front-Panel.html#video 

Homepage: http://www.remmepark.com/circuit6040/index.html

Dean AC9JQ and I have been communicating via emailing about his progress in building his own copy of the ZX-Front-Panel, and I'm very excited to learn that he might be thinking about producing a future homebrew rig featuring the ZX-Front-Panel as its controller/VFO. The best thing about the ZX_Front-Panel is that ounce you install the sketch into the Arduino Mega, you don't need to modify the Arduino sketch itself when you build your rig; i.e. the SSB crystal filter's center frequency (the I.F. frequency), the Si5351's clock output drive level, the display brightness and contrast, and the Si5351 crystal correction factor (crystal trim) are all configurable, real-time, right from the ZX-Front-Panel's user interface, and once set, can be saved to the Arduino's non-volatile EEPROM to be automatically loaded on the next power-up. Also, since it has a GPS module, it features a UTC/Local real-time clock with atomic clock accuracy too. 

Anyway that's all for now, take care Leif. 

73 Rick.

Nick M0NTV's Quarantine Rig: The Bread Bin 80

Hi Bill,

Hope you are keeping well and staying safe.

Just thought I’d let you know about a homebrew project I’ve just completed. I call it the Bread Bin 80 - you’ll see why!

It is a single band (80m) SSB transceiver that puts out 25-30W of clean RF. It uses the familiar pairing of Arduino Uno + Si5351 (with 16x2 LCD screen and rotary encoder for tuning). Other than this though it is largely an analogue beast - which I thought you might like!

I made my own double balanced mixers which work really well. But the Si5351 can’t generate the 7 dBm of local oscillator signal to drive them so I then had to build a simple one transistor RF amp for each clock of the Si5351. I even went above and beyond the call of duty and home-brewed my own IF crystal ladder filter (although this was actually a kit).

The rig has a three stage IF cascade amplifier with 2 back to back JFETs in each stage + AGC and analogue S meter. There is something very satisfying about seeing the needle bob about as you are listening. I also put in a switchable analogue audio filter in front of the audio pre-amp which cuts out some of the higher frequency noise on the band.

Overall I’m really pleased with the rig. I’ve been working stations all over the UK and into continental Europe and getting some great reports. Except the one guy (who shall remain nameless) who wasn’t the least impressed that I was working him on a homebrew rig: he was only keen to point out that my antenna must be far too low to give me such an attenuated signal!!! I guess you can’t please everyone.

Anyway, I’ve done a bit of a write up and included some photos (outside and in) on my QRZ page if you are interested:

https://www.qrz.com/db/M0NTV

Thanks for sharing your home brewing story about your short wave receiver on YouTube. I’ve enjoyed following that and seeing it progress. Those little ‘Altoid’ tins are great aren’t they.

Thanks again for all your encouragement through the Soldersmoke podcast. I really enjoy it.

Stay In The Shack!

73 from across the Pond.

Nick

M0NTV

Nick Wood

www.nickthevic.co.uk

N5GTF's FULLY INDOOR Quarantine Receiver and Antenna

Mike N5GTF deserves special recognition for his truly remarkable SITS (Stay In The Shack) quarantine project.  It is not hard to build receivers and transmitters that stay in the shack; Mike went the extra mile by keeping even his antenna inside during lockdown.  Well done Mike!  But that cardboard frame for the antenna seems to be crying out for some sort of inspirational slogan.  Can we get a big "SITS!" in there?    73  Bill 

Hi Bill,

Thought I would share a few photos of what happens when one randomly selects things from the junk box after being inspired by Pete's recent posts about phasing SSB. It starts with a 10.7MHz crystal filter because it was large and shiny. This will prove to be somewhat inauspicious, but I'd had a pair of them for longer than I can remember...  Then there were several ferrite toroids and a handful of swap meet diodes. Instant mixers, (just add enameled wire). A few 2N3904s and an MC1350P, plus a few more toroids (and wire). I'd picked up some TDA1015s awhile back. They have both a power amp and a preamp, so one of those as well. Also, an Arduino and Si5351, because Charlie Morris, ZL2CTM, has been so generous in sharing his knowledge on how to use them. Finally, about 12 feet of 14/2 w/G and a 365pF variable cap for an indoor mag loop. 

Not the best reception though not bad considering the antenna's in the basement with house wiring and metal duct work in the ceiling. The biggest issue is the IF and my choice of LO frequency. I've got the LO below the IF and the LO second harmonic falls inside the 40 meter band. Definitely need to fix that and move on to the transmit side.

Visits to both SolderSmoke and Pete's blog are on my daily agenda. Thanks to you both for the frequent updates of interesting content and for providing a way to get out without going out.

Mike, N5GTF

www.mikesflightdeck.com

An Understandable Chip: The LM386

Over the years I have made my distaste for integrated circuits very clear.  I've presented them as mysterious little black boxes that don't really belong in our homebrew rigs,  rigs that we are building, after all,  because we want to avoid the use of MYSTERIOUS BLACK BOXES.  

So, I don't use voltage regulator chips -- I use Zener diodes.   I prefer analog LC oscillators to AD9850s or Si5351s.  And I have repeatedly built discrete component audio amplifiers when most normal people just put an IC AF amplifier in the circuit. 

When I built the Q-31 Shortwave AM receiver, I kind of ran out of gas at the end.  I wanted to get the receiver going and I didn't want to build yet another discrete AF amp.  So I used an LM386.  

I rationalized this deviation from cherished values by noting that the discrete AF amplifier circuitry that I was using was remarkably similar to what exists inside the LM386.  So that little chip is just as understandable as my discrete component creations.  It wasn't REALLY a mysterious black box... 

Around this time I found a web site that made me feel mush better about all this.  It explains very nicely how the little LM386 does such a great job.  It really packs a lot of amplification into a very small package.   Here is the web site: 

https://www.electrosmash.com/lm386-analysis

Shortly after my transgression,  Jenny List over at Hack-A-Day posted a nice piece looking at the inner workings of Op-Amps.  Who knows, I may seen be using 741 chips too! 

Here is the Hack-A-Day piece: 

https://hackaday.com/2020/05/09/an-op-amp-from-the-ground-up/

Brace Yourselves: DK7IH's New Transceiver -- The Gimme Five

Lock-down is bad enough, but now we will also have to cope with the feelings of homebrew inadequacy that Peter's rigs always cause.  But look on this as an opportunity for inspiration.  Peter once again raises the bar.   

https://radiotransmitter.wordpress.com/2020/04/11/gimme-five-reloaded-a-compact-5-band-qrp-ssb-transceiver-in-smd-technology/

This looks like it is the first in a series of blog posts. Just what we need in quarantine.   Thanks Peter.  

The Si4730 Radio Chip (Luddite Alert!) (video)

I have misgivings about this.  Hack-A-Day presents it as a DIY radio project and wonders if this might be the modern equivalent of the crystal radio projects of days-gone-by.  But notice that the "build" video focuses mostly on building the box.  The electronic "building" of this radio mostly involves plugging in two chips, or two boards with chips. My questions are: 

1) When this project is finished, who REALLY built it? You, or the Si4730 manufacturer?  

2)  After you've "built" this thing, would you have the same sense of accomplishment that you get from an analog, discrete component project?  Or even from that crystal radio?  

Of course, to each his own.   This is all for fun.  Have fun with the Si4730.  But today I'll be working on my Hallicrafters S-38E. 

https://hackaday.com/2020/02/12/all-band-radio-uses-arduino-and-si4730/

VK3HN's Inspirational AM Receiver (video)

I'm always delighted when I check the SolderSmoke blog and YouTube list (right hand column of the blog) and find a new post from Paul VK3HN.  And this morning's post is especially good. 

Paul has built an AM receiver. Above you can see his video.  Here is his blog post with details: 
https://vk3hn.wordpress.com/2019/12/06/8-band-superhet-am-receiver/

This is the kind of blog post that makes you want to heat up the soldering iron and start searching through the junk box.  I'm thinking about putting Paul's 6 kHz filter in my 40 meter HRO-ish receiver.  And I may make use of his AM detector circuit.  And maybe I can put that same receiver on 75 and 160... And then there are the SW broadcast bands... See what I mean?  

Thanks Paul.  73  

SolderSmoke Podcast #210 Boatanchors, Magnetostriction, VFOs, AM, CW, SSB, Mailbag

2 March 2019 

SolderSmoke Podcast #210 is available: 

http://soldersmoke.com/soldersmoke210.mp3

Alexa, Marie Kondo, berets, and ham radio

Bi-Coastal Boatanchors
BATTLE CRY: The Vintage SSB Preamble! "We are NOT ashamed!" 
Bill's HT37 and Drake 2B 
Pete's National National NCX-3  TRGHS
Mechanical Filters
Magnetostriction
Why did Collins go with mechanical vice crystal filters? 
The foam deterioration syndrome in mechanical filters.  Sad. 
Please send any unwanted Mechanical Filters to Bill. 
BONUS QUESTION:   Look at the filter below.  What is different/special about this one?

Pete's antenna trouble
Pete's FB amplifier troubleshooting
Recent improvements in the uBITX finals
Pete's design for a VFO for Bill (and an indoor antenna tuner!)

Bill's VFO for Pete:  HRO dial and gearbox driving a rotary encoder

Guido PE1NNZ puts the QCX on SSB
"The Secret Life of Machines -- Radio"
HB HRO dial from DL6WD
WA1QIX's USB D-104
"The High Frequency Oracle" 
DeMaw's LC filter receiver
Godzilla and Ham Radio
Bill's poor quality SSTV images from space (what happened?) 
Listening to AM on an SSB receiver
Mixed feelings about CW 

MAILBAG
M0KOV's mom took him to the doctor due to THE KNACK. 
M0JGH getting married (ALWAYS LISTEN TO PETE!) 
Jac's FB Receiver

What is different/special about this one?

Jan's Slovakian Si5351 VFO

Jan in Slovakia put together a very comprehensive web page on his Si5351 VFO project.  Check it out: 

https://janoc.rd-h.com/archives/649

Thanks Jans! 

W7RLF Homebrews a Receiver -- FB!

Ryan W7RLF has joined the small and elite group of radio amateurs who have homebrewed a receiver.  And it is a receiver filled with soul, juju and mojo; the project was inspired by Wes Hayward and Farhan, and used components from Hans Summers.   Congratulations Ryan and thanks for all the work you did in documenting your experience. 

Who will be the next intrepid ham to join the homebrew receiver club? 

Hello Sirs!

This month I read Wes Hayward's post on the history and heritage of DC receivers in ham radio and it brought a lingering interest to a head. I had to build one. I run the BITX40 and uBITX group on Facebook, and I posted to the other hams there: Which DC receiver should I build? Farhan recommended his DC40. Mind you, I've never homebrewed a radio before, so this is all new territory for me. 

I did build it, and it does work. It also uses QRP Labs stuff from our friend Hans Summers. This thing has a lot of QRP heritage :) I documented it every step of the way including all of my dumb moves and things I got wrong, and my desire is to inspire others to try homebrewing the way Wes, Farhan, Hans, and you YOU GUYS have inspired me to try it. I am hooked, of course! Here's a link to my blog to Part 1:

https://miscdotgeek.com/building-direct-conversion-receiver-part-1/

It's a four part series (unofficially 5 really) with 8000 words to it, and I hope you guys enjoy it and I'd be ticked pink if was worthy of mention on your show. Here's a video of it too:

https://www.youtube.com/watch?v=ju3kOEyCMYM

73 to you both and I wish you the best!

Ryan Flowers W7RLF

https://miscdotgeek.com

Pete N6QW Rejuvenates the Atlas Twins with an Arduino and an Si5351

Pete Juliano N6QW has turned his attention to the Atlas Twins, a nice single conversion multiband rig. Pete has used an Arduino/Si5351 to replace the analog oscillators in the old Atlas.  This improves stability and allows for USB/LSB operation.  

Pete very graciously kept the old analog circuitry in the rig, allowing the Atlas to be returned to its pristine analog state at some time in the future. Pete also made some very kind comments about the surprising stability of the original  analog oscillator circuitry.  

Check out Pete' site for more details: 

http://n6qw.blogspot.com/2018/11/2018-year-of-ssb-transceivers.html

Pete's New Transceiver with Heathkit Filter and WSPR (Video)

Another beautiful rig from Pete. Inspiration for the winter building season.  More info on his blog:

http://n6qw.blogspot.com/

We hope to discuss this and other projects in the next SolderSmoke podcast, hopefully next Saturday. 

VU3XVR's EMRFD TIA HB TRANSCEIVER

Ram did a beautiful job on this 40 meter rig.    You can read about this project here: 

https://vu3xvr.blogspot.com/2018/10/homebrew-5-watts-cw-transceiver-using.html

VU3XVR's Assembly Language 1K AtTiny-Si5351 VFO

Although Ram VU3XVR's project is in the digital realm, his barebones approach to the bits and bytes is, for me, very appealing. He takes a Si5351 and runs it with ATtiny13 with only 1k of space.  He makes intelligent use of every bit of that space.  He reveals his overall approach to rigs when he states in the video that his VFO will NOT have the traditional glowing numeral frequency readout because those bright lights can be so annoying and distracting.  I'm with your Ram!  Well done OM. Simplicity is a virtue. No more trouble with the Arduino and its fickle IDE.  No more agonizing visits to the Si5351 library.   

I see lots of applications for this little circuit.   Ram mentions beacon transmitters.  

He provides details here: 

https://vu3xvr.blogspot.com/2018/07/si5351-dds-clock-generator-using.html   

Hans Summers and his QCX -- G0UPL Cracks the Code on Si5351A Quadrature

Pete,  Brad WA8WDQ and I were recently e-mailing about our admiration for what Hans G0UPL has achieved with his QCX rig.   I cc'd Hans -- we got this nice and very informative e-mail.  Be sure to click on the link provided by Hans, and from there go to the link to his FDIM proceedings article.  I think that article is a real masterpiece -- there is a lot of very valuable information in there.  For a long time, getting quadrature output from the Si5351 seemed like an impossible dream.  But Hans has obviously figured out how to do this, opening the door to much better and simpler single-signal phasing receivers.   Thanks Hans!  


Hi all

Thanks for the nice feedback on the QCX and the FDIM conference proceedings a article, which I have published on QRP Labs web page along with other Dayton trip miscellany. See

 http://qrp-labs.com/dayton2018.html

My seminar presentation audio was recorded by Ham Radio Workbench podcast and they will be publishing it on 5th June.

The QCX kit has indeed been unbelievably popular, almost 5,000 kits have been sold since the launch on 21st August. It seems to have itched an itch that needed itching, in the QRP world. Sales continue to be strong and I'm currently preparing another batch of 1000 more. 

I'm very proud of my 90-degree quadrature Si5351A and it helped me towards my low cost, high performance target for QCX. Abandoning the 74AC74 saves a part, reduces cost, reduces complexity, reduces board area (and hence more cost) and even seems to provide better performance (higher unwanted sideband rejection when using the Si5351A in quadrature mode). Getting the Si5351A to do this is one of those things which look easy afterwards. But at the time, and faced with SiLabs un-useful documentation, it took an awful lot of headscratching, trial and error!

I'm not sure of the answer to the question about noise figure. Certainly radios such as QCX and the NC2030 which use the QSD architecture seem to have very high sensitivity without an RF amplifier ahead of them. This must indicate a low noise figure. 

73 Hans G0UPL 

http://qrp-labs.com 

Yet Another Household Item Useful to Homebrewers: Toilet Bowl Cleaner for PC Board Fabrication

We have already been using Desitin ointment for heat sink compound, kitchen breadboards for radio breadboards, Scotchbrite pads for polishing, nail polish varnish for toroidal core coating and Olive oil as a field-expedient lubricant. (Am I forgetting anything?)   But I must say I was a bit taken aback by KV4QB's mention of his innovative use of the dilute hydrochloric acid in toilet bowl cleaners in his PC board fabrication process.   Good one DuWayne!   Eric Guth went the extra mile be suggesting a recycling of the liquid. 

This was a really interesting QSO Today interview.  Listen here: 

https://www.qsotoday.com/podcasts/KV4QB

Jeff Damm WA7MLH on QSO Today

Happy New Year!    

There was so much wisdom and tribal knowledge in Eric Guth's interview with Jeff Damm WA7MLH. It was almost overwhelming. 

You should all listen to it.  Twice. At least twice: 

https://www.qsotoday.com/podcasts/WA7MLH
  
My notes:

-- I sympathize with Jeff's decision to go solid state and give up on high voltage after an encounter with an undischarged 600 volt capacitor.  
-- I really like the 1700 kHz IF with a 5 MHz VFO for an 80 and 40 meter receiver. 
-- Interesting that EE degree didn't help much in his efforts to understand ham gear.  Better to read Wes's books and Doug's. 
-- Tek Spectrum Analyzers were specially made to fit down a submarine hatch.  
-- Building and measuring just as important as studying the theory.  Inked-up text books. 
-- Learned ugly from Wes as a teenager. 
--Searched for old commercial gear to gut and use as homes for homebrew solid state gear. The enclosures,  panels and controls are very useful.   Great way to avoid metal work.  These rigs are no longer boatanchors!  Again, I sympathize.  I've sacrificed many Heath Lunchboxes and QF-1s.  
-- Jeff Builds the VFO first.  My preference too. But he understands Pete's AF-first approach. 
-- Finger on the input of the AF amp!  Buzz!  Yea! Step your way back to the front end.
-- ALWAYS one stage at a time.  
-- Osh Park Boards for standard circuit modules.  Like Legos. 
-- Cubic Feet of air variables.   Jeff has a lifetime stash.   
--Thinking about what was and should have been his section of EMRFD. Go for it Jeff. PLEASE! 
-- Hesistant about chips. Analog guy.  Would have been a huge time sink.  Analog guy.  
-- Buying parts on e-bay.  Fewer and fewer RF parts at hamfests. 
-- People reading QST Tech Articles for entertainment. Editor apprach: "Nobody will build it anyway." Handbooks giving priority to entertainment and less to information and education. 

Videos of iPhone Box DC Receiver

These are just a couple of short videos that I made for my nephew before sending him this receiver. 

As you can hear, deafness is not a problem with this design!   I did make some frequency stability improvements after this video was made -- I think you can hear a bit of drift.  Still, not bad for a very simple circuit using a polyvaricon superglued to the back of a cardboard box.  

I'll post more videos of the second version of this receiver.  There are further improvements in frequency stability.  My goal:  "Juliano Si5351" levels of stable-ness.  

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