-- The Franklin oscillator is an interesting, but complicated circuit. The gimmick is, well, gimmicky. Here is the thing: You can achieve similar levels of stability using simple conventional, single transistor oscillators. We dispensed with the variable capacitors, and used PTO--style variable inductors. They worked fine. This Franklin oscillator still does seem to drift a bit, right? I would ground the board to the inside of the metal box.
Podcasting since 2005! Listen to Latest SolderSmoke
Sunday, December 1, 2024
A 40 Meter Direct Conversion Receiver from M0NTV -- With some SolderSmoke Comments
-- The Franklin oscillator is an interesting, but complicated circuit. The gimmick is, well, gimmicky. Here is the thing: You can achieve similar levels of stability using simple conventional, single transistor oscillators. We dispensed with the variable capacitors, and used PTO--style variable inductors. They worked fine. This Franklin oscillator still does seem to drift a bit, right? I would ground the board to the inside of the metal box.
Thursday, September 5, 2024
Excellent New Video from Grayson KJ7UM on his Thermatron version of the Michigan Mighty Mite
Friday, November 10, 2023
SolderSmoke Podcast #249 -- Travel, Pete's 6BA6 rig, Books!, VFOs, SDR, Computers, Spectrum Analysers, Transistor Man! MAILBAG
Bill's DXCC-100. DONE.
Tribal Wisdom: W1REX on HRWB https://soldersmoke.blogspot.com/2023/11/listen-to-rex-w1rex-lots-of-tribal.html
Pete's Bench:
Pete's 6BA6 rig
Pete Re-invents the Shirt-pocket SSB Rig
BEZOS BUCKS ARE BACK! PLEASE BUY THERE! >>>>>>>>>>>>>>>>>>>>>>>
Mostly DIY RF: Work proceeds in the Oregon Silicon Forest on P3ST kit development. Todd is confident the P3ST will be released on December 18th.Many other kits available now: https://mostlydiyrf.com/
Sign up for the newsletter: https://mostlydiyrf.com/subscribe/
Rebuild of the 15-10 VFO (for improved Dial Spread) (with yet another QF-1 capacitor) https://soldersmoke.blogspot.com/2023/10/dial-scale-linearity-spreading-out.html
Why Building for 10 meters is harder: https://soldersmoke.blogspot.com/2023/09/why-building-for-10-meters-is-harder.html
Copper Tape shielding of 15-10 rig.
Crushing Spurs with Better Bandpass Filters (see blog post) https://soldersmoke.blogspot.com/2023/09/crushing-17-and-12-meter-spurs-with.html
Another 15-10 rig in the works... for SSSS. Boards are accumulating...
More problems discovered with the Herring Aid 5 Receiver . Lots of SS blog posts Comment from Rick WD5L. ) https://soldersmoke.blogspot.com/2023/10/a-big-error-discovered-in-1976-qst.html Did you try to build one? Did you succeed or did you fail? Please let us know.
The Basil Mahon books (blog posts) https://soldersmoke.blogspot.com/2023/11/basil-mahon-is-author-for-us-he.html
The Sunburst and Luminary book of Don Eyles (blog posts)
The Art of Electronics by Horowitz and Hill (blog posts)
Spectrum Analysers: Tiny SA Ultra https://soldersmoke.blogspot.com/2023/09/the-tinysa-ultra-spectrum-analyser-video.html and Polarad 632C-1; George WB5OYP gave me one of these spectrum analysers (I NEED a manual! Does anyone have a manual or a schematic? ) :
Stabilizing the EB63A (with Pete recommended LP filters from e-Bay.
MAILBAG:
TRANSISTOR MAN T-SHIRTS! Thanks to Roy WN3F!
Todd VE7BPO on AF amplifiers. Thanks Todd.
Wes W7ZOI -- Always a privilege to exchange e-mail with Wes.
E-mail from Jay Rusgrove W1VD. About the Herring Aid 5.
E-mail from Eamon Skelton EI9GQ! Amazing!
HB2HB with Denny VU2DGR https://soldersmoke.blogspot.com/2023/09/hb2hb-contact-with-denny-vu2dgr.html
Nick M0NTV on diode matching for ring mixers: https://soldersmoke.blogspot.com/2023/10/does-matching-matter-diode-matching-for.html
Paul Taylor VK3HN on the new Elecraft CW rig.
Dean KK4DAS fixed the noise in his Hallicrafters SW receiver. A long battle, finally won.
Dean also in contact with G3UUR.
Ramakrishnan VU2JXN helping me set up a backup of blog on WordPress.
Mark KA9OOI noticed that SS podcast archive appears gone. In fact just temporarily relocated to http://soldersmoke.com/
(SS PODCAST Archive temporarily relocated to http://soldersmoke.com/
Andreas DL1AJG - Crystal radio video. https://soldersmoke.blogspot.com/2023/10/building-crystal-set-videos.html
George N2APB on the Herring Aid 5
Grayson KJ7UM experimenting with Varactors and Thermatrons!
Thomas K4SWL on Mattia's DC receiver. https://soldersmoke.blogspot.com/2023/10/mattia-zamanas-amazing-direct.html
Bob Weaver of Dial Bandspread Linearity fame. Electron Bunker
Mike Bryce WB8VGE QRP Hall of famer -- he too couldn't get the Herring Aid 5 working.
Kirk NT0Z wrote about the Wayback machine. But this former ARRL staffer he also tried and failed to get the Herring Aid 5 going. Way back when... https://soldersmoke.blogspot.com/2015/03/kirks-herring-aid-tuna-tin-and-regen.html
Thursday, November 2, 2023
Listen to Rex. W1REX. Lots of Tribal Wisdom in this Ham Radio Workbench Interview
Saturday, March 25, 2023
Update on the High-School Direct Conversion Receiver Project: Board #4 Completed
This week we had two sessions of about two hours each. We introduced the final board: the audio amplifier. Many of the students began work on this amplifier; others were catching up with work on boards presented earlier.
The AF amp is their most challenging board: It used 14 Manhattan pads and about 26 components. We warned the students that amplifiers often aspire to be oscillators. We told them to pay attention to layout, and to keep their leads short.
At first, the students just built the first stage on the AF amp board. They tested this, then moved on to build the other two stages.
By the end of Friday, two groups had completed the build of the AF amplifier board.
We think there are about 13 receivers in production. Some are near completion, others will need more work.
On Thursday of next week those teams that have completed all four boards will put the circuits together and will test the entire system. They will then add all needed front and back panels and socketry.
We really want the students to complete as many of these receivers as possible. Exam season and the end of the school year is approaching, so we have to get this done. We will remind students that they don't want to that person who ALMOST finished a project! We will urge them to GET IT DONE! They can tweak it and mod it later. This kind of tweaking and modification is part of the homebrew experience.
We have been presenting awards to the students who are first to complete each stage: The winners of the PTO board competition got a copy of SolderSmoke: Global Adventures in Wireless Electronics. Those who won the mixer competition got a W1REX Hamfest Buddy transmitter. Thanks Rex! And this week we presented an award to the students who were the first to complete their bandpass filter. You've heard of the Tony, the Emmy and the Grammy? Well, we presented "The Torry" (from Toroidal). The trophy was made from a toroidal winding tool made in Alaska by KL7FLR. I explained to the students who had made it. Thanks Paul!
Wednesday, March 3, 2021
The SolderSmoke Team Talks to the River City Amateur Radio Communication Society (Video)
Sunday, November 6, 2016
SolderSmoke Podcast #191 RIGS! REAL RIGS!, BITX40 Module, EMRFD, MAILBAG
SolderSmoke Podcast #191 is available:
http://soldersmoke.com/soldersmoke191.mp3
TRAVELOGUE AND FAMILY DOINGS: Pete son's wedding, Billy's Birthday, Gonzalo safely home in the Dominican Republic, MORE BEARS IN THE SHENANDOAH WOODS
Thursday, October 13, 2016
Smoke-Free! On the Air with the W1REX Dayton Hamfest Buddy
Thursday, June 2, 2016
Manhattan-style Vacuum Tubes: "An Evolution of Thermatron Homebrew Techniques" by Grayson Evans
Grayson Evans was at Dayton. Scheduling problems prevented him from being interviewed by ace correspondent Bob Crane, but Grayson was kind enough to e-mail us the essence of his presentation. And it is really wonderful. He brings the advantages of the Manhattan construction technique (fast prototyping, all components on the same side of the board, easy modification) to the world of tubes (aka valves or, as Grayson prefers, thermatrons). We also see in Grayson's work an admirable willingness to bridge the digital-analog design, to bring into his rigs the best of the old and the new. Thanks Grayson!
I pre-mount a dozen or so of the 7-pin and 9-pin sockets on MeTube pads so I have them ready to go when prototyping. The “crude” example below shows and 7 and 9-pin socket on one of my prototypes. I think this was a microphone amp for my AM transmitter. Pardon the mess.
The nice thing about the pads is that they provide plenty of room to tac solder lots of parts to a single pin–easy to add or remove parts. This is a lot easier than using the traditional tube socket pin.
This is another example of “right side up” thermatron mounting on a prototype test board for crystal filters. I mounted a small “plug board” (not sure what you call these things) in the center to allow me to easily swap filter components. Notice the acorn thermatron soldered direct to the pad. The board works great, the filter design sucked. I gave up. Maybe too much distributed C.
Saturday, May 28, 2016
HOMEBREW HERO: REX HARPER W1REX AND THE WORLD'S BIGGEST BUILD-A-THON
Rex, shortly before questioning by authorities |
Just as impressive as the results were the ways in which Rex overcame the technical and organizational hurdles prior to the event. You can read all about this in Rex's excellent write up:
http://www.qrpme.com/docs/FDIM%202016%20Report.pdf
The OFFICIAL SolderSmoke Correspondent at Dayton was once again our friend Bob Crane, W8SX. Bob caught up with Rex and somehow managed to get him to stand still long enough to do this interview:
http://soldersmoke.com/W1REXDaytonInterview.mp3
And it was very nice that Rex did this as a tribute to Dave Ingram K4WTJ whose magazine articles about simple QRP rigs inspired many of us. Years ago, right after completing a homebrew QRP transceiver, I talked to Dave on 30 meter CW and told him that his articles had helped motivate me to build.
Finally, no SolderSmoke post about Rex would be complete without a repetition of the video showing him transferring the prodigious mojo of the original Tuna Tin Two into my BITX-17 transceiver.
Friday, July 17, 2015
Colin's Tuna Tin Mighty Mite (Video)
You will remember Colin as the builder of that beautiful BITX20 that he first used from his backyard and later used with great success from a hilltop in Northern England. In this video we see Colin demonstrating his Michigan Mighty Mite. Lots of soul in that little machine! Colin notes that this rig worked well from the start. The Radio Gods were obviously pleased by his use of a tuna tin as the chassis. I think they also liked the MePads from W1REX and the Tek 465 'scope. And of course the T-shirt was obviously a key element in Colin's success.
Here is that beautiful BITX, now equipped with an internal speaker:
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
Thursday, November 13, 2014
Colin's BITX
I enjoyed your video about your Arduino experiment. You bet me to it! I'm really looking forward to getting my version of an Arduino powered BITX up and running.
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
Saturday, November 8, 2014
Pete's "Let's Build Something" Audio Amplifier (video)
Who needs LM386 ICs? Pete goes discrete! Love the MePads. And I knew Pete was going to test it with his finger! He's just taking stray hum from the power lines and coupling it to the input through that Exacto knife.
Seems to me like these boards is getting close to actually receiving signals.
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
Pete's Mixer (Pictures)
Pete's video on this circuit appears below -- just scroll down a few.
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
Saturday, July 12, 2014
Thomas's Magnificent Minima
Wow, Thomas's page makes me really want to build a Minima. Note the Manhattan style with Rex Harper's Me-Pads. Excellent. Thomas provides a really great stage-by-stage description of the project with the kind of candid descriptions of mistakes that SolderSmoke listeners are so fond of!
http://www.sarfata.org/ham/minima/
Thomas himself has an interesting "international brotherhood" personal history:
http://www.sarfata.org/about.html
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
Saturday, May 10, 2014
FDIM Midnight Mojo Ceremony (Tuna Tin 2)
An important message From Rex,
Transcendental Titan of the Tuna Tin Twos:
If you have a little QRP rebel in you, like me, and are a fan of Ancient Sacred Relic, i.e. The Original Tuna Tin 2 transmitter, and all things housed in round metal containers usually designed for fish products and pineapple, and maybe cats if VERY thoroughly cleaned, then you might want to bring your Tuna Tin 2 rig to FDIM!
Around midnight, after the scrum leaves the FDIM Club night gathering, there will be a Tuna Tin 2 Midnight MOJO ceremony! THE one and only ORIGINAL Tuna Tin 2 transmitter will be on hand for this solemn occasion where major QRP MOJO is transferred from the Ancient Sacred Relic into the tuna can inductees in attendance. Admission is free but you MUST bring a MOJOee tuna can housed rig for entrance to the ritual.
NO rectangular or mint tin equipment will be admitted!! NO unaccompanied minors OR adults OR adults who act like minors will be admitted.
TT2 QRP MOJO will be transferred....FUN will be had.....PRIZES will be raffled off!
If you think you might like to be there for the Tuna Tin 2 Midnight MOJO ceremony remember to pack a tuna can or reasonable facimile (307 (3 + 07/16" diameter) industry standard 2 piece or 3 piece can) housed TT2 style rig in your travel bag!!
REMEMBER: NO rectangular or mint tin equipment will be admitted!! You must have a TT2 inspired rig in you personal possession to gain
admittance! NO exceptions!!
Respectfully submitted,
Rex W1REX The TUNA Tinman!
--------------------