KD4PBJ's PTO "Turtle" Receiver

Gents,

Here’s my newest creation. 

It’s a PTO tuned receiver for 40 meters and uses the WA6OTP PTO circuit I built a couple years back. I believe I had sent you a picture of it then. I bought the tuning assembly from him which is the aluminum bracket, acrylic tube fitted with Pem nut, and brass screw.  The circuit uses a J310 as oscillator transistor and several bipolar transistors for amplification and buffering. 

This feeds a ADE-1 mixer, mounted on a little breakout board I bought from RfBay. 

Years ago I had good luck building the Rock Bending Receiver from the ARRL handbook, so I took the audio chain from it and incorporated it. It uses a TL072 and a LM 386. 

As of now I haven’t needed any kind of front end filter, but am working on a 40 meter bandpass filter from Hans Summers that I will put on the input just in case it’s ever needed. 

I had been looking for an easy enclosure and found this in one of the break rooms at work. An empty Christmas nut tin. 

The PTO screw goes in and out like a turtle sticking its head out of the shell, plus my 13 year old son Alex’s favorite animal is a turtle. So it goes. 

Chris 

KD4PBJ

N2CQR Wins a Contest AGAIN!

Pete N6QW suggested I do a blog post on this.  

This past weekend I dusted off my old scratch-built, all-analog, no-chips BITX20. (THREE CHEERS FOR FARHAN AND HIS BITX DESIGN!)   I hooked it up to my trusty CCI .1KW (note decimal point) amplifier and my new 135 foot store-bought doublet.  This all happened just as the Worked All Europe  DX contest was kicking off, with lots of activity on 20.   TRGHS.  I was in.  My contest operating style was in the category of "relaxed-casual-noncompetitive." I took a lot of breaks.  In fact there were more breaks than non-breaks. You have to pace yourself in the contest world.  

My results: 

8 SEPT: DF0HQ, SN7D, GM6X, DP6A, S51A, DL0HN, DB0HX, OZ5E, DJ5MW, HG7T, IK4UPB, VY2ZM, G6XX, EF1A, LZ5R, 9A5W, YP0C, F6HQP, DL7ON, HB9DQL, ON6NL, DA0WRTC,  9 SEPT: EI7M, P3X, RU1A, DP7D, SP2KPD, DL0WW.

P3X might not count because, you see, Cyprus is considered to be in ASIA.  Really? 

Anyway, I 'm assuming that I am the winner in the homebrew, discrete component , all-analog transceiver category.  Woo Hoo!  

The contest rig is pictured above.  Before you point to the glowing numerals and cry foul, realize that the little Altoids box between the two speakers holds a San Jian frequency counter that was deliberately kept OUTSIDE the BITX box.  So it is more of an outboard accessory.  I can run the BITX 20 without the digital assist -- I have an old fashioned non-digital dial pointer to indicate frequency.  The "Low - High" switch you see switches the VFO from the low portion of the 20 meter phone band to the higher part of the band.   The box below the BITX 20 holds the uBITX. 

Seriously though, I was quite pleased with the performance of the doublet.   

EF Johnson's 50th Anniversary Speech. Very nice radio history

Thanks to W0VLZ for this wonderful 13 minute recording of Edgar F Johnson's 50th Anniversary speech.  There is a lot of great radio history in this speech.  Highly recommended. 

Just click here to listen: 

https://www.prismnet.com/~nielw/EFJohnson/EFJ50thTalk.wav

EF Johnson's hometown bio: 

http://www.wasecaalums.com/public/389.cfm

Ralph AB1OP -- A New Receiver (with Mojo) and A New Acronym (with Attitude)

Bill and Pete,

😀 Completed the wiring the LBS Part I (pics attached)

I've said wiring completed but, it's not really done. lt will need some peakin' & tweakin' and I already have made design changes to the power board. 

My Summer Project took ALL Summer, had the usual excuses with Summer activities, family obligations,  interruptions and days of just plain goldbricking. 

At last all the LBS Part I boards were laid out, etched, populated, soldered and installed.  As a novice Toroid winder it took a  while to get the toroids done. (I had to do THREE DBM Transformers to get two  to match.)

Some features of note: 

1. Extensive use of the recycle bin for front / rear panels and feet. (Tin can and bottle caps) Go Green!

2. Extra Mojo was induced with using the 10K pot Farhan supplied with my first Bitx40 Kit that I did not use, (I replaced it because I could not find knobs for 4mm shafts back then)  

3. Junk box speaker (8 Ohm - 0.5 W) from a cheap radio alarm clock my Mom threw away after it stopped working.

4. Use of the RG405 coax for interstage RF connections. (No Murphy's Whiskers)

😞 My tale of woe. Apparently after connecting the LBS Part I stages together I put the AD9850 module back in it's socket upside down --- then applied power,  Awaiting the replacement. HIHI

😜 SITB or Stick-It-To-Bezos.  Again this month my Ham stuff budget was blown on an Amazon order (replacement AD9850 modules being not cheap anymore). I started at the soldersmoke blog web page search bar so there should be a little something heading to your North Virginia QTH from Jeff.

73,

AB1OP_Ralph

SolderSmoke Podcast #206 -- GQRP CONVENTION SPECIAL EDITION

SolderSmoke Podcast #206 is now available: 

http://soldersmoke.com/soldersmoke206.mp3

-- SolderSmoke resumes after a busy summer.

-- We did a portion of #206 via Skype at the GQRP Convention.  Thanks to Steve G0FUW for setting this up.  A portion of our participation appears at the end of the podcast. 

-- Pete's SDR Rig and his new involvement with WSPR and FT-8

-- The allure of SDR and the pitfalls of complexity. 

-- Bill's 135 foot Doublet, 75 AM, 60 USB and 30 Meter CW. 

-- Plans to change the IF of Bill's HRO dial receiver. 

-- Thinking (again) about sold stateing the HW-101. 

--  Hans Summers, QCX and QSX rigs.  

MAILBAG: 

Ralph builds Pete's LBS receiver.  FB!  

Lasers. Big Scary Lasers. And a guy with THE KNACK

Here is another young fellow who shows all the signs of having "The Knack." I think his findings would be very useful for those involved in light beam communication. 

Arduino Gets Command Line Interface

Will this make it easier to put programs into the the Arduino?   Will this resolve the problems we've had when using an updated Arduino IDE with code developed in an earlier version of the IDE?

https://hackaday.com/2018/08/26/arduino-gets-command-line-interface-tools-that-let-you-skip-the-ide/

More Homebrew Wisdom from Frank Harris, K0IYE

In Chapter 13A, Frank Harris writes: 

The Vanishing Art 

The 1986 ARRL Amateur Radio Handbook reported that hardly anyone was building homebrew ham receivers....  Out of hundreds of contacts, so far I’ve worked four guys, George, K7DU, Mike, NØMF, Biz, WDØHCO and Jack, W7QQQ who were using homebrew receivers for the QSO. Three of these receivers were made from vacuum tubes. George's receiver is a beautifully crafted instrument that looks like a commercial design from 50 years ago. All of these receivers had no trouble hearing me on 40 meter CW. I talked to one other fellow, Gil, N1FED who told me he had just finished a vacuum tube receiver. Unfortunately, it was performing so poorly he was still using his modern transceiver on the air. Gil told me he didn’t like transistors. I guess he found printed circuit boards and those pesky oscillations too much trouble. In spite of this pessimism, you CAN build transistorized receivers that work reasonably well. I built mine because I was intrigued by mysterious circuits like “balanced mixers,” “product detectors,” “cascode amplifiers” and “crystal ladder filters.” Before this project, I could recite the purposes of these circuits, but I had no “feel” for how they worked and why receivers are designed the way they are. What better way to learn than to build one? 

Aside from the need to shield circuit blocks from one another, a homebrew receiver with a single big board full of discrete components has another problem. If you build the whole thing at once without buying a kit and pre-cut board, I guarantee it won’t work. To make homebrew stuff that works, you have to develop your own technology based on parts you can get and circuits you understand. Learning to think this way was difficult for me. Rather than “building a receiver,” I had to lower my sights and build one circuit at a time, e.g., “an oscillator,” “a mixer,” “an audio amplifier,” etc. Then I put the blocks together to complete my project. Some of these circuit blocks didn’t work the first time so I had to build a new block. There were various reasons the modules didn’t work. Usually, I wasn’t able to buy the exact parts used in the circuits I was copying. Or my craftsmanship or shielding wasn’t adequate. Sometimes I never did learn why one version of a circuit block was superior to another. By building my receiver using separate little shielded modules for each circuit block, I could replace a circuit block whenever I managed to build an improved version. Otherwise, I would have ruined the entire big board.

On rare occasions my circuits didn’t work because there were errors in circuit diagrams in QST magazine or in the handbooks. I found some serious errors in my 1979 ARRL Handbook and a minor one in my 1998 edition. Perfect editing is not possible, so we shouldn’t expect it.

GET THE WHOLE BOOK HERE (FREE!) 
http://www.qsl.net/k0iye/

Big New Telescopes

https://qz.com/1362650/the-latest-in-a-new-generation-of-giant-telescopes-broke-ground/

W2NBC's AM Boatanchor Video

W2NBC was booming in on 3885 kHz AM this evening.  I took a look at his QRZ.com page and found this video.  Very nice.  

I've been on 75 meter AM with the K2ZA DX-100 and my new 135 foot doublet antenna.  

"From Crystal Sets to Sideband" -- Homebrew Wisdom from Frank, K0IYE (Free Book)

Get Frank's book here (FREE!) http://www.qsl.net/k0iye/

I've had Frank's book on the blog many times over the years, but it is a book that merits repeated mention.   It is filled with great advice and homebrew wisdom.  I found myself looking at it again recently, and at Frank's QRZ.com page.  I came across lots of wisdom that I may have missed in earlier visits.  For example:  

From the QRZ page: 

My version of ham radio is 100% scratch built equipment. I buy nothing manufactured for ham radio except log books...My rig is based mostly on the 1986 ARRL handbook. Modern designs in today's QEX and Handbooks are usually full of mysterious ICs. In my opinion, they don't qualify as homebrewing. 

From his book (Chapter 15): 

I was fascinated by ham radio, but I didn’t learn much about how sideband worked. I had the impression that sideband was MODULATION FOR MILLIONAIRES and too complicated to homebrew. The 1957 ARRL handbook’s opaque descriptions of “phase shifters” and “balanced modulators” only confirmed my opinion.

If you are like me, you will have a devil of a time getting your SSB drivers to produce intelligible speech without hissing and noise problems. All I can tell you is to keep your brain mulling over your difficulties. Shield and filter your prototype until the darn thing works. Keep careful notes so you don't make the same mistakes twice. Persistence will win in the end. 

My sideband transmitters are still in the experimental category. You will find that it takes a great deal of tweaking and fussing to get SSB tuned so it sounds good and doesn’t radiate on unplanned frequencies. You won’t believe how many diseases your SSB transmitter will create for you to conquer! Sideband is not a project for impatient people. 

Foreword: 

We homebrewers are nearly extinct, but there are still hundreds of us scattered around the world, some are even in the USA. Yes, there ARE American homebuilders! We’re rare, but thanks to the QRP hobby, the number is growing. Even if we homebrewers don't change the world, I guarantee you will enjoy learning radio technology and building your own equipment.  

Get Frank's book here (FREE!) http://www.qsl.net/k0iye/
THANKS FRANK!      Send Frank a thank you note:  Frwharris@live.com 

  

QSX! Hans Summer's New SSB Rig Revealed in South Africa

I liked this video.   I liked Hans' description of his mechanical skills, and the way he has at times become a "human CNC machine."  

This seems like a much more sophisticated rig than the QCX.  I may be wrong, but  QCX seemed to be essentially an analog phasing rig with a narrow CW audio filter.  I kind of expected the SSB version to be a QCX with broader filter, but QSX is a different,  more sophisticated, SDR rig. 

Once again, three cheers for Hans Summers.  We should all pay him to go to those summer conventions -- every time he does, something new and important for ham radio comes out of the trip.