N3FJZ Builds PTO for High School DC Receiver

Rick N3FJZ has stepped forward and is building the direct conversion receiver that Dean and I have been working on.  This will be big help in our testing of the receiver.  See above for the video report on his build of the PTO stage. 

When I saw this, I found myself thinking two things: 

1) Those really are "rigs." 

and

2) I am not alone! 

Years ago, I was having a tough day on 40 meters.  The Waterfall Policemen were gleefully attacking my admitedly less-than-perfect SSB signal.   Unbeknownst to me, someone out there was listening, and listening with a homebrew receiver.  A receiver with a PTO.  It was Rick N3FJZ.  He made my day when he sent this video: 

https://soldersmoke.blogspot.com/2015/02/parasitic-anguish-on-40-then-homebrew.html

Here are the other blog posts on the amazing rigs of N3FJZ here: 

https://soldersmoke.blogspot.com/search?q=N3FJZ

More to follow, both on Rick's receiver and on the work of other intrepid builders. 

Thanks Rick. 

HB2HB! N3FJZ-N2CQR Si5351 and BITX TIAs on Both Sides, with Some LBS and Peter Parker Circuitry Too!

In those dark days of February 2015, when all the members of the SDR ESSB Panoramic Spectral Police were on my case over some imperfections in my 40 meter homebrew SSB signal, Rick, N3FJZ came to my rescue by sending me a great YouTube video of his reception of my new rig.  Rick was using a wonderful homebrew Direct Conversion receiver with a really cool PTO.   Here is my blog post on Rick and his receiver:

http://soldersmoke.blogspot.com/2015/02/parasitic-anguish-on-40-then-homebrew.html

Then, yesterday, I received this e-mail:

Bill, Pete,

I want to share my excitement with you.

After 32 years as a ham, I finally had my first ever HF QSO on October
16, 2015, and on a homebrew rig no less!  Oh the Joy of Emission!It was on 7.242MHz, 8:00 a.m. eastern on the "Woodpecker net".
- Rig was based on the Bitx, using ZIA bidirectional amps.
- 20 Watts into a 80 meter full-wave loop up at 20 feet.
- 600 ohm homebrew open wire ladder line.
- Balanced antenna coupler inspired by the Annecke and Johnson matchbox
units.
- and most importantly, the Arduino controller software and use of the
Nokia display were derived and inspired from Pete's "Let's Build
Something" code presented on his website, and the carrier
oscillator(BFO) & L.O. are generated by an Adafruit SI5351 clock
generator board.  Thank you Pete.

See my N3FJZ look-up on QRZ.com for photos of my homebrew rig. I have
also put links to the SolderSmoke blog and to Pete's web page and blog.

I just want to tell you both that your podcasts, websites, circuit
diagrams and stories were a huge part of my success.  They were the
inspiration I needed on many dark days when my amplifiers would
oscillate, and my oscillators would simply smoke.  At times I thought I
would never get on the air, but an hour listening to SolderSmoke podcast
would give me the drive venture on.  Thank you!

***VERY IMPORTANT!!!!

Bill, during my first QSO, I was getting 5x8 and 5x9 signal reports
(with 20 watts!)from North Carolina, up-state New York, Michigan, and
Indiana, and I know we are only about 50 miles apart (I'm in north
central Maryland), so I believe we could probably achieve a successful
HB2HB contact if you want to try.

If you want to, and have the time, you could join me on the Woodpecker
net any Friday, Saturday or Sunday on 40 meters 7.242MHz 8:00 a.m.
eastern, or we could set-up a prearranged contact on a General class 40
meter frequency of your choosing.  Let me know - making an HB2HB
contact with you would mean the world to me.

Pete, I also extend this invitation to you as well, but with only 20
watts on my end, it may be a stretch, but we could try.

Thank you both again for the joy you have given me with your pod-casts.
73
Rick - N3FJZ

.................

Rick and I got together on 7.288 MHz yesterday evening.  It was a really amazing QSO.  Rick made a video of it (see above) and I recorded the audio on my side.  My old tape recorder didn't do Rick's signal justice -- it sounded better than this.  But here is the full QSO:

http://soldersmoke.com/N3FJZN2CQR.mp3

Be sure to listen closely at around 21 minutes when Rick describes a software feature that allows him to switch -- with the touch of a button -- from high side VFO to low side VFO.  The BFO frequency also changes to account for the resulting sideband inversion.  Very cool.

Rick's Digital Board

Ricks Rig as it was during our QSO

 

Crystal Filter

Rick's Dual HEXFET Power Amplifier

 

Check out the N3FJZ QRZ.com page for more info. 

 

CONGRATULATIONS TO RICK!  



HB2HB! AC9JQ -- N3FJZ on 40 with Homebrew Rigs

On Saturday October 24,  Dean AC9JQ (Indiana)  and Rick N3FJZ (Maryland) made contact on 40 meter SSB using Si5351/TIA BITX rigs.  FB!:

Bill:

Dean and I made contact.  We both were in and out most of the time, but conditions seemed to improve towards the end where I could understand Dean about 90%.  Using the RST "by the book", I would say he was a 33, 3 =(readable with some difficulty), and signal strength was 3=(weak), and based on what Dean was reporting, my signal back to him was the same - 33.

73 to you both.

Rick - N3FJZ.

WB9IWT's Quarantine Mighty Mite and N3FJZ's "Hiram Percy Maxim Recognition Factor"

Leif WB9IWT has, during the emergency, been working on a Michigan Mighty Mite (See pictures above and below).  FB Leif.  

But also check out the very astute comment from Rick N3FJZ (below) .  I am, of course, all in favor of the HPMR Factor.  Almost all of my rigs would score quite high.    Others, I know, would seek a low score.  To each his own.  This is all for fun.  

Leif,

Great work.  If a ham from the 1920's were to see this rig, they
probably wouldn't recognize the actual components right away (but
knowing hams, they would no doubt figure it out), but the breadboard
layout circuit flow would be immediately recognizable; e.g. the plug-in
crystal, the coil, binding post.  The transistor and variable capacitor
may baffle them at first, but seeing there are three leads on the
transistor would start to give them clues.

That's the cool part about analog discrete component radio, no matter
how many years go by, and the appearance and size of the actual
components change, the physics of what's going on at the electron level
stays the same (SDR not withstanding).

I guess this could be a litmus test for us analog radio builders.  It
could be called the "Hiram Percy Maxim Recognition Factor" or "HPMR
Factor" with a range of 0 to 1.  After you  build your rig, take a look
at it and pretend that you could present it to Mr. Maxim and the more he
could understand the circuits, components and circuit flow on his own,
the closer to a factor of 1 your radio would achieve.  For example, an
SDR might only achieve a factor of .1 or even maybe 0, where as your rig
may achieve a factor of .8, and one of your crystal receivers would
definitely get a 1.

Someone could even workout a check list or formula where you would add
or subtract some fractional numeric values for each component you used;
e.g. you would subtract some value for every IC chip, microprocessor or
LCD display you use, and add some fractional value for each hand wound
coil, vacuum tube/valve or open air variable capacitor, et cetera.

Fun to think about.

Keep building.

Rick - N3FJZ

HB2HB! AC9JQ and N2CQR Make Contact on 40 with Homebrew Rigs on Both Sides (with help from N3FJZ/HB)

This weekend brought another HB2HB (Homebrew to Homebrew) contact.   We have been following with interest the 40 meter transceiver project of Dean, AC9JQ.  Above you can watch a video of Dean's rig in action before it went into the box.  Earlier this month Dean achieved a remarkable "Double First" when he made his very first amateur radio contact.  He was using his homebrew rig to do it.  So his first contact was also his first homebrew contact.   FB. More info on Dean's rig and homebrew exploits can be seen here:
http://soldersmoke.blogspot.com/search?q=ac9jq 

This week Dean got a decent 40 meter dipole up in the air.  We arranged (via e-mail) to meet on 40 on Friday evening.  We made contact, but conditions weren't great.  We tried again several times on Saturday, looking for open spots amidst the madness of the CQ WW DX contest.  Rick N3FJZ joined us and also tried to make contact with Dean, but had no luck either.  Daytime conditions didn't allow for a good contact between Indiana and the Washington/Baltimore area where Rick and I are located. 

Finally, last night after family obligations at both ends settled down, Dean and I found a relatively open frequency on 40 and made a good contact.  A short snippet of it can be heard by clicking on the link below.   Keep in mind that Dean was running about 2 watts to a dipole on 40 at night.   

http://soldersmoke.com/HB2HBAC9JQ.mp3

Thanks Dean!  Thanks Rick!

Rick N3FJZ Completes Build of High-School Direct Conversion Receiver Project -- LISTEN!

Rick N3FJZ has completed his the direct conversion receiver that we will soon be building with students at a local high school.   See video above. 

We are hoping that a number of people will build the receiver as we designed it.  Some folks have sent us versions of the receiver that they have built, but these versions often include significant deviations from our design, rendering them less-than-useful in checking our work.  Rick built it just as we prescribed.  His build is very useful in confirming the validity of our design.  So if you are working on one of these receivers, I would encourage you to -- for the moment -- dispense with innovations and build it the way Rick did:  as per the design we have been using. 

We know that our design is not perfect.  But we have decided to stick with it because it is very simple and very easy to explain.  Examples:  We know there is an impedance mismatch between the mixer and the AF amp.  But fixing this would introduce complexity that we want to avoid.   And the receiver works fine with the imperfection.   We know that a push-pull AF amp would probably work better than the one we have.  But we do not want to have to explain push-pull amps, biasing schemes, and PNP transistors in this short introductory course.  So we stuck with three common-emitter AF amp circuits and an 1K-8ohm transformer. 

Rick did a really excellent job not only in building this receiver, but also in documenting it.   His diagrams and drawings are really superb.  We will probably use these in our presentations to the students: 

http://www.remmepark.com/circuit6040/SolderSmoke-DCR/SolderSmoke-DCR.html#AUDIO_AMP

We will keep all of you informed on the progress of this project.  We will begin this week.  But if you are still working on the receiver, please send us your work,  even if it comes in after we begin the course.  

Thanks Rick! 

N3FJZ's Al Fresco. BITX-inspired, TIA. 50 Watt, SSB Rig (Video)

The last blog postings on Rick N3FJZ were in 2015.  Rick sent me a very uplifting reception report, then we had a pretty amazing Homebrew-to-Homebrew contact.  

Paul Taylor VK3HN yesterday alerted me to a new YouTube video that shows the progress Rick has made with his homebrew SSB rig.   

This is a great example of true amateur SSB construction.  Rick is making use of a combination of digital and analog technology.  He is adapting circuitry developed by others and using it to meet his needs.  During the development stage he is keeping the circuit open (Al Fresco) so that he can easily work on it.  

FB Rick.  

Rick N3FJZ Builds the Mixer for the High School Direct Conversion Receiver

Wonderful progress from Rick N3FJZ.   Having completed the PTO,  Rick went on to build the diode ring mixer and diplexer.  (See video above.)  He then connected these to boards to a band pass filter and an AF amp from previous project.  And wow, the resulting receiver sounds really great!  I think it sounds better than the ones Dean and I have built.  

-- It will be interesting to see how Rick's receiver sounds with the very simple AF amplifier that we are using.  

-- We need to get Rick a coil form for the PTO variable inductor! And getting him the PTO form will allow him to dispense with the varactor circuit (which, I must say, is pretty cool). 

-- In the PTO, for the coupling capacitor (C15) , I now have a 260 pF NP0 cap.  But your .1 uF ceramic disc seems to be doing just fin.  So maybe we don't need the NP0. 

-- I'm glad that Rick grounded the brass screw.  Without that, the hand capacitance effect is bad. 

-- I think results will be much the same with the dual tuned circuit bandpass filter that we use.   But it will be interesting to see if Rick's triple tuned circuit helps with AM breakthrough (I think I heard Radio Marti when Rick tuned to the top of the band). 

-- I haven't had a hum problem and I don't think Dean has either.   Dean is running his on two 9V batteries.  Maybe that would take care of the hum.  Our PTOs are completely Al Fresco! 

-- The Traders Net sounds like fun!  

Thanks Rick!  73 

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.

N3FJZ's New Blog and Impressive Rigs (and a Bandscan!)

Rick N3FJZ and his Lakeside direct conversion receiver bolstered my spirits when I was getting some harshly critical reviews of my signal on 40 meters a while back.  Rick happened to pick me up with his homebrew receiver. The Radio Gods seemed to be trying to balance things out.  There is a LOT of radio mojo in Rick's Lakeside receiver.  Not only does it eschew digital synthesis of the VFO signal, it goes a step further and uses a permeability tuned oscillator -- very cool.  The component and material sourcing adds more luster to the rig.  Rick writes: "A lot of the components used to construct the LS-40 were harvested from discarded consumer electronics I collected back in the 1980's. The base substrate material for the Manhattan style construction, as well as the RF tight enclosure for the PTO, is made from a flattened out tin plated food can. All components are discrete; i.e. no IC's or CPU's."

Rick has launched a blog.  He has some amazing stuff on it.  Be sure to check out his ZX-SSB rig.  Amazingly detailed documentation Rick!  Thanks. 

Find Rick's Blog here:
http://www.remmepark.com/circuit6040/

SolderSmoke Podcast #244 PETE IS BACK! TR-7, CK722, BFR106, HP8640B, High-School Receiver, 10 Min TX, MAILBAG

SolderSmoke Podcast #244 Is available:

http://soldersmoke.com/soldersmoke244.mp3

Video version at:

(118) SolderSmoke - YouTube

HE’S BACK! HOORAY! PETE JULIANO N6QW IS BACK! SOLDERSMOKE COMMUNITY WAS SENT INTO A COLLECTIVE FUNK BY PETE’S ABSENCE. ---------------- Pete’s TR-7 (SEE VIDEO ABOVE) CK722 The BFR106

Pete's new blog: https://hamradiogenius.blogspot.com/ ---- Update on the high school project: Mixers made. Harder than they seemed. First QSO with the DC RX. Allan W4AMV Homebrewer TRGHS Ten Minute Transmitter – Better than the MMM! AF4K (SK) crystals. Other supporting projects: Farhan in Hyderabad. Rick N3FJZ, Walter KA4KXX, Andreas DL1AJG Electronics for Biologists. Peter Marks VK3TPM (fighting the siren call of the Si5351) . Steven VK2BLQ built a beautiful one. Daniel VE5DLD will build three of them with his students. Orlando PY2ANE is building one in Brazil. This week: The Bandpass Filter. (Thank you Hans Summers) --- SHAMELESS COMMERCE DIVISION: BECOME A PATRON VIA PATREON. I am posting some fun stuff for the Patrons. AMAZON SHOPPING ADS Now on both the left and right columns. CHECK OUT Mostly DIY RF in the right hand column. ---- My HP8640B Lives to Fight another day. Two new DMMs A low-end Fluke and a AstroAI 6000 Electrolytic Replacement Controversy Continues

Mailbag: -- Dave AA7EE is blogging again! Yea! -- Mike Rainey AA1TJ back in the Hobbit Hole Building a WWVB receiver. -- Farhan is coming to FDIM. -- Tony G4WIF reminds us that 39 bucks for JUST a 60 MHz counter would be great! -- Dave VE3EAC again helped me fix my HP8640B. -- Dean KK4DAS finalizing 10 meter DSB rig. FB. Upgraded my NanoVNA. -- Mike KD4MM giving me a Nano VNA for the SolderSmoke Shack South. -- Ian VK3LA asked what happened to Chuck Adams content. Good question. -- Don ND6T and I have been discussing envelope detection. -- Nick M0NTV working on AM modulators. He has a new video. -- Ciprian YO6DXE built a Ten Minute Transmitter. -- Steve EI5DD Connacht Regional News: https://www.docdroid.net/YJAV800/crnews0223-pdf

Hyderabad DC RX Workshop

Farhan explaining the receiver in Hyderabad

https://soldersmoke.blogspot.com/2023/03/pictures-from-farhans-hyderabad-high.html

The Secret Life of Machines -- The Radio (Video)

Thanks to Rick N3FJZ for sending this to us.  In 25 minutes these fellows manage to capture and explain much of the "magic" of radio.  Great shots of Marconi, and of Hertz's first rig.  Amazing how they built their own spark transmitter and coherer receiver, launched a kite antenna and sent a signal across the harbor.  Great stuff.  Lots of history.   We've met Mr. Wells before -- he was "jailed for having the Knack!"

SolderSmoke Podcast #250 Dean KK4DAS joins Pete N6QW and Bill N2CQR

SolderSmoke Podcast # 250 is ready for download: 

http://soldersmoke.com/soldersmoke250.mp3

VIDEO VERSION: (1707) SolderSmoke Podcast #250 -- With Pete N6QW, Dean KK4DAS, and Bill N2CQR - YouTube

Intro:   Welcome to Dean KK4DAS.  For 2024 Pete and I hope to jazz things up a bit by bringing in fellow homebrewers to talk about their projects.  Dean is our first victim.  Welcome Dean. 

Some good news:  Several new homebrew receivers are inhaling:  Armand WA1UQO in Richmond has an amazing looking regen.  Scott KQ4AOP in Tennessee got his DC RX working.  Mike AG5VG in Texas has been homebrewing BITX 20s and BITX 40s.  All are on the blog.  

Pete's report: 

-- Recent blog entries on filters,  SSB rig architecture, and of course digital VFOs. 

-- Phasing measurements, quadrature, and the Seeed Xiao RP2040

-- Error in QST article on early SSB transceiver.  ANOTHER ERROR!

--LC VFO on blog!  FB Pete!  

Dean's report:  

-- Tales of woe on the homebrew sBITX

-- Help from Farhan.  

-- Ground Bounce.  FFT Hallucinations.   Wisdom files.

SHAMELESS COMMERCE DIVISION:   

-- Whenever you are tempted to buy something from AMAZON, just start at the Amazon symbol on the right side of the page.  We get a cut from Bezos, and it doesn't cost you anything.  

-- You can try to do the same thing with E-bay.  We are finding a lot of great parts there. 

-- If you see a SolderSmoke post on Facebook,  please Like and forward. 

-- Become a patron!  Go to the Patreon page.  We put the money to good SolderSmoke use. 

-- Visit Mostly DIY RF and buy a PSSST kit!  

Bill's bench:  

-- Building yet another BITX dual bander.  15-10 again. Tried to use a 25 MHz filter left over from the earlier project, but I had to build another.  Built a new VFO using the variable cap and anti-backlash gear recommended by Pete.  Was a bit tough to get the receiver sounding good.   Had a diode ring as the second mixer, but went back to a singly balanced mixer. 

-- 10 meter AM -- Thanks to Jerry Coffman K5JC for mod. 

Other topics: 

--Counterfeit chips.  Why? 

MAILBAG: 

Wes W7ZOI 

Jim Cook W8NSA  Transoceanic BFO

Grayson KJ7UM -- Vintage Computer Museum

Chuck Adams --Glad to hear that Chuck is doing well.  

Frank Harris  K0IYE --  NO CHIPS!!!! 

ED DD5LP  Antenna software

Eldon KC5U  10 AM We  made a contact

Joh DL6ID  10 AM   

Phil   W1PJE of MIT   10AM   Where is L5? 

Bob WP4BQV now in UK 

Dino Papas KL0S in Wilmington   Reverse Polarity protection. 

AA7EE Dave Richards  Liked Armand's receiver

Rogier PA1ZZ  

Jonathan-san W0XO  Listened to my ET-2 CW Whoop,whoop

Nick M0NTV  Great videos from Nick the Vic

Will KI4POV  Working on his own SSB rigs.  

John West -- Who is the South American ham who made his capacitors and heat sinks? 

Ed KC8SBV  Working on DC receiver, experimenting with FETs 

Mike WN2A great contributions.  Si5351 sole source danger! 

Nick N3FJZ -- watch out for dead bands when testing receivers! 

Don KM4UDX encouragement from new Prez of VWS

Dave K8WPE Likes QF1 Cap backlash.  Says I'm getting soft! 

Dave WA1LBP My fellow Hambassador, from Okinawa USMC Sergeant with a workshop. 

SolderSmoke Podcast #243 -- HI7/N2CQR, uBITX mods for 10 meters, High-School Direct Conversion Receiver Project Launched (Success!) Mailbag

 

DC RX and one of the PTO boards we built as demos last night. 

February 10, 2023

SolderSmoke Podcast #224 is available. 

http://soldersmoke.com/soldersmoke243.mp3

Video here: (32) SolderSmoke Podcast 243 (video) Hi7/N2CQR, uBITX, Success with High School Receiver Project - YouTube

Pete N6QW had technical difficulties this morning.  He insisted that the show must go on.  Pete will be back for the next episode. 

 

Travelogue: 

Bill in the Dominican Republic for all of January.  

HI7/N2CQR  Eastern tip of the island. uBITX and dipoles. 

20, 17, 10.  CW and SSB.  SSB was tough and I had reports of RF getting into the signal.

Went to CW. 

Worked VWS Mike KA4CDN, and Walter KA4KXX on 20CW.

Finally moved up to 10 CW.  Lots of contacts. Even though uBITX very QRP on ten.

I am modifying the uBITX now.  

Copper tape shielding to keep RF out.

 Low power out not the fault of the IRF-510s.  The problem is the 2N3904s.

Will replace with 2N2222 in To-18 cans.

Dean KK4DAS putting KD8CEC software into Arduino.  I gave up.

Who sent me this orphan uBITX?

SolderSmoke Shack South in final phase of construction.

 

SHAMELESS COMMERCE DIVISION:

Patreon!

Bezos Shopping!

 

DC Receiver Project

Local High School radio club. 

Simple:  Like Herring Aid 5 and Wes’s original.

Farhan’s four stages:

BP Filter, Diode Ring, PTO, AF amp. 

Simple Colpitts PTO SURPRISINGLY STABLE.

Simple and easy.  No chips.  No complicated circuits.

Guys have helped test out the design:  Rick N3FJZ, Walter KA4KXX,

Daniel VE5DLD, Stephen VK2BLQ and others. 

First session last night:  We demonstrated build of the PTOs.  

They worked (thank God).

 

Open Circuits book.

Envelope Detection Controversy

Save the Antenna – Book “Losing the Nobel Prize” K1JT

 

MAILBAG

--Dean KK4DAS 10 meter DSB!  Tiny SA ULTRA! FB

--John AC2RL on Elmer W3PHL DSB guy

--AC3K reports inventor of Fender Stratocaster guitar was a ham: W6DOE

--AF8E was doing POTA.  I worked him. He said my rig had presence. FB

--Alain F4IET FB DSB rig with mic in Cigar can!

--Daryl N0DP worked him on SSB.  He is homebrewing

--Steve N8NM was in for repairs but is on the mend.

--Rick G6AKG working with sub-harmonic mixers and logic chips

--Paul HS0ZLQ Built DC receiver but looking for something else to build. No DSB!

--Steve AB4I – Coherer, Jagadish Chandra Bose, and Marconi

--Eldon KC5U    Worked VK5QD right after me and mentioned SolderSmoke FB

--Todd K7TFC is building the DC RX.

--Tony G4WIF and Ian G3ROO using automotive relays for antenna switching. FB.

--Dave WA1LBP Great to hear from my fellow Hambassador (Okinawa)

Older post comments:

--Scott VO1DR was also in CF Rockey’s class! (Blog comment)

--Aurora Aug 4, 1972: Twelve people shared memories.  (Blog comment)

--Will WN1SLG Googled novice call and was led to my Novice log.(Blog comment)

A Homebrew QSL Card for a Homebrew to Homebrew Contact

I got a card from Rick N3FJZ today.  FB!   Note the lines for "VFO":  Si5351!   And "Finals": Dual IRF-510s!   Rick wrote that his card is also homebrew!  Thanks Rick.

Parasitic Anguish on 40 then... Homebrew Transceiver Heard by Homebrew Receiver (with a PTO!)

Oh man, I was struggling yesterday. I guess I had been lulled into a false sense of security by the phenomenal ease with which I had put my BITX 17 on the air, then added a 120 watt amplifier, all without any sign of the dreaded feedback and parasitic oscillations that had plagued almost all of my previous projects.  So when I decided to add the low pass filter and the switching/relay arrangements needed to use the amplifier with my BITX 20/40 rig, I kind of expected a similar trouble-free experience.   

WRONG!  And you know what?  I think guys on 40 and 20 are a bit less forgiving and collegial than the folks on 17. As I struggled to exorcise the transceiver, I'd make some changes then hopefully go out onto the airwaves and call CQ, looking for a signal report.  Well, I got them.  Many were not accompanied by call signs.  I'd be in contact with someone who was trying to help, and -- as we were trying to figure out what it might be -- we'd be bombarded with harsh, sometimes angry, anonymous commentary: "YOU'RE 20 kcs WIDE!"  "Are you on AM?"  "You have a CARRIER!"  One fellow scornfully told me "That little QRP rig of yours is not ready for prime time."  Ouch.  (I didn't realize we were on prime time.  Isn't this AMATEUR radio?) 

Others would answer my CQ by announcing that I was "on the wrong frequency."  Others would respond (off frequency) and tell  me I was distorted -- I'd ask them to tune me in, then they would say, "Oh yea, you are OK -- you were just on the wrong frequency." Some of these guys seemed to be under the impression that there are "channels" on 40 meters.   It was a real disheartening mess.

Then came the saving grace.   I got the e-mails that appear below.  WOW! My faith in ham radio was renewed!  In the 18 months that I've been running the BITX rigs, I've never once worked another station using a homebrew rig.  But Rick and I were 3/4 of the way there yesterday.  And he was using a direct conversion receiver of his own design, with a PTO in an enclosure made from "flattened out tin-plated food tins."  Fantastic!  It was as if the radio gods had arranged all this to pull me out of the depths of parasitic despair!  Thanks Rick!    A video of his receiver picking up my BITX 20/40 appears above. 

Pete and I will talk about the actual troubleshooting in the next podcast.  I am HOPING to have it fixed by then.  I may have to sacrifice some chickens to Papa Legba." 

................

Bill,

I'm a long-time SolderSmoke podcast listener, and today one of my ham radio dreams came true.

I was listening to 40 meters today on my homebrew direct conversion receiver, and I heard your call.  At first I didn't believe it was you, but  there you were. 

At first I just sat there dumbfounded, just listening, but soon realized that I should make a video of this "rare DX" (rare DX for me hi hi), and post it on YouTube for you to review.

My apologies for the low audio in the video.  I was using my iPhone and its inboard mic leaves a lot to be desired, but the best audio of you is at 0:13, 0:50, and again at 2:12 into the video.

Heard you on 7.16 MHz, Sunday 2-22-2015 at 10:15 a.m. local east-coast time (15:15 UTC).

I'm located in Manchester Maryland (North - Central Maryland).  My homebrew 40 meter rig is a PTO tuned direct conversion receiver with all discrete components.  My antenna is a simple wire dipole about 6 feet above the ground just outside by workroom window.

Below are links to the YouTube video of your QSO , and the schematic the DSB transceiver that you were received on.  The rig is one that I designed, based on the published works of many home-brewers from the web.  I call it the Lakeside 40 (in homage to Peter Parker's Beach 40 transceiver).

So far I only completed the receiver section, and hope to complete the transmitter sometime this summer so I can use the rig at Lake Marburg (at Codorus State Park in PA), thus the "Lakeside" in the rig's name.

http://youtu.be/emsKg5n5-0c

http://www.remmepark.com/circuit6040/lakeside40.gif


73
Rick - N3FJZ


Bill,

Yes, what a coincidence with the PTO! That's the same WA6OTP PTO design
I based my PTO on.

I created a webpage tonight(very much a work in progress) so you can see
the details of how I constructed my PTO in the Lakeside 40, as well as
my rendition of a BITX 20. Click the [Permeability Tuned Oscillator], or
[My rendition of a Bitx 20] links on the left of the page.

The webpage is here:
[http://www.remmepark.com/circuit6040/index.html]

The ground plane for the Manhattan construction (and RF tight enclosure
for the PTO) are made from flattened out tin plated food cans, and the
coil-form for the PTO is cut from Masonite wall panel material with my
scroll saw.

Don't get discouraged from the less than enthusiastic response from the
others about your signal, pay them no mind; I'm sure they simply didn't
realize the significance of what it represented.  To me, your signal was
the most perfect signal I have ever heard.  It was perfect because I
know (from your pod-casts, and my attempts at homebrew) what it took for
it to be produced.  Its existence, and the fact that I successfully
received it on my little homebrew rig too, represents the fundamental
core foundation of Amateur radio; experimentation, building equipment
with your own hands from scratch, expanding ones knowledge in the radio
art, and most important, having fun and enjoying the excitement that
comes from using gear that *you* built.

I cannot put into words how significant hearing your signal was for me
today - thank you!  My biggest regret is that I didn't have a means of
transmitting yet on 40 meters, and my Bitx 20 is not ready yet, 
perhaps in the future we can have homebrew to homebrew QSO's
where we can fine-tune our designs and tweak things (however we'll have
go above 7.175 MHz, or 14.225 MHz since I only hold a General ticket at
the moment).

Rick
N3FJZ.

Rick's PTO

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Germany: Direct Conversion Receiver Success!

Dear Bill,

Please my apologies for my late update on our DCR project. We started with the course in the semester break and once the semester started only a handful of students were able to finish their receiver. A long shelf of shame .... 

Here is what we've got so far (those were finished at the end of April already). 3 nice DCRs completely sufficient to copy CW indoors without additional antennas starting from late afternoon. Strong stations can be heard all day. I found that coupling some 6m of wire with one or two windings to the ferrite core can boost the signal dramatically but can also increase noise. 

The PTO is based on your design (Bill Meara N26QR &  Dean KK4DAS) which was sparked by Farhan  (VU2ESE) , except that I've swapped the FET for a NPN. The input amplifier and antenna is from the JUMA active ferrite antenna by Matti Hohtola (OH7SV), the band pass filter is from Hans Summers (G0UPL), the mixer and the headphone amplifier is inspired by Pete Juliano (N6QW), you told me that the diplexer (as well as the whole DCR idea) is attributed to Wes Hayward (W7ZOI) and the perfect schematics of Rick Scott (N3FJZ) where crucial to get me started in the first place. I enjoy keeping track of original sources, as I would do in science. This shows that even little achievements are based on the ideas of many other great people -  and this is nothing to be ashamed of. 

This was a lot of fun! Thank You!

Best and yours sincerely,

Andreas

Wow, the direct conversion re-engineering of education continues, this time at graduate-school level with biologists in Munich!  Amazing.  

Andreas points out that his group was also plagued by semester-related problems that caused many additions to the German shelf of shame.  Let's hope that someday soon these builders will come to their senses and join the ranks of those who have finished their homebrew projects.  

Looking at the schematic (below) of Andreas's project, there are a couple of significant differences from ours:   

-- Their AF amp used a transformer-less push-pull design.  We had considered this but abandoned it thinking that it would be too complicated to explain the workings of this circuit to our students.

-- Most significant, is Andreas's use of a ferrite rod antenna and an RF amplifier.   I think a simple 33 foot quarter wave antenna (with a ground or a counterpoise) might work better.  But hey,  to  each his own!   The important thing is that a number of these receivers were successfully built.  They look beautiful.  

Congratulations to Andreas and the successful Munich homebrewers!  

 

SolderSmoke Podcast #183 Pete's B'day, Simple-Ceivers, Binaural Bliss, 160 or Bust, GOOD BEHAVIOR, MAILBAG

Bill's Frankenstein R2 receives 7 MHz signal and generates I and Q outputs

SolderSmoke Podcast #183 is available. And it is GOOD!

http://soldersmoke.com/soldersmoke183.mp3

20 December 2015

-- Foxes in the Backyard
-- Pete completes another orbit
-- Simple-ceiver Success!
-- Frankenstein Receiver: IT IS ALIVE!  AND BINAURAL!!!
-- 160 Meter AM OR BUST!
-- Fun on 40 AM -- Lots of Multi Elmac AF-67s!  Who knew!
-- The Amateur's Code, and violations thereof.
-- Negative Frequencies? I don't think so.
-- Capacitor Offer from our Secret Benefactor: EXPANDED ELIGIBILITY
-- Projects for 2016: Pete goes Raspberry Pi, Bill goes DX-100
Mailbag:
-- Croation Creation
-- Salvadoran 2B
-- N3FJZ's Homebrew QSL
-- WA7HRG's LBS-ZIA-Simple-Ceiver Mashup Rig
-- KC0IZR turning VCRs into Mighty Mites in NOVA
-- AB1YK Starting with DC RX, going BITX
-- G8GNR puts Mighty Mite on AM!
-- G3ZPF Modulates THE SUN (Amazing)
-- VK3YE's Simple Superhet
-- Grayson in Turkey drools over KG7TR's Octalmania
-- N7REP reaches for the Zantac because of Arduinos and Surface Mount