Author: William Meara

Tim Hunkin’s “The Radio Set” Drawing, and The Secret Life of the Radio (Remastered)

Click on the image for a better view. Click here for the whole drawing:

I really liked this, and there is a lot more like it on the site of Tim Hunkin, the fellow who made all the great Secret Life of Machines shows. His site: https://www.secretlifeofmachines.com/index.shtml

They remastered the show about radios. It is worth watching:

Thanks Tim!

The Workshop and Bench of the QRP Home Builder, Todd VE7BPO

What a treat! We have been learning so much, for so long from Todd VE7BPO. I was really pleased to have this look at the workshop where all the magic happens.

While my technical abilities are far inferior to his, I was pleased to see some scenes and some shelves that are similar to those that can be found here.

Thanks Todd!

Update on the Direct Conversion Receiver — Now only 4 transistors

I took a new look at the receiver, did some measurements, and decided to take out the RF amplifier and the AF pre-amp. The receiver works fine without them, another indication that they were unnecessary. Line-up is now: Band-pass filter, Mixer, VFO, AF amp. I think there is only 49 db of gain in the entire receiver, but it is useable with an un-amplified speaker, and is a bit too loud on ear buds. Not bad for just 4 transistors. And I think we could do this with just 3 (no need for the VFO buffer).

Here is the AF amplifier I used:

Sticker News (from Holland)

Lex PH2LB sends this really interesting Vice story about stickers and sticker culture. Who knew? The original article is in Dutch, but just hit the Google Translate button and Bob will be your uncle.

https://www.vice.com/nl/article/wxnpp5/wie-zijn-de-mensen-die-overal-stickers-plakken

I shared with our Solder-Sticker Community these thoughts:

Really cool Lex. This reminds me that we need more stickers. And maybe a new design. The IBEW thing confuses Americans — here it looks like a labor union thing.

The Color Burst Liberation Army logo (below) is one possible element that we might want to include. I think our new stickers should exhort people to DO something:

“BUILD A SHORTWAVE RECEIVER!”

“LIBERATE 3.579 MHz!”

“MELT SOLDER!”

“RESIST FT-8!”

“JUST SAY NO TO SDR!”

Things like that.

Thoughts? Discuss.

Bandsweep with the New Homebrew 40 meter Direct Conversion Receiver

It is inhaling nicely but some improvements are still pending. Click on the video above to see and listen to the bandsweep done on 40 this morning.

— The front end consists of capacitive divider input impedance matching circuit, followed by one LC circuit and an FET RF amp.

— The VFO is a super-simple Colpitts design by Farhan. The two feedback capacitors do double duty in the LC tan circuit.

— I am using an old variable capacitor instead of the PTOs that we have been experimenting with.

— The mixer is singly balanced using one trifilar toroid and two diodes. We have found out that even with these three simple devices, there is significant variation in how people connect them to VFO, RF in and audio out. I think we have found the best way to do this: Be sure to put the VFO on the primary of the transformer, and let this signal turn the diodes on and off.

— For the AF amplification, I have one FET, followed by two BJTs. I have a small audio transformer between the speaker and the final AF amp. There is plenty of audio.

You may wonder why, after all the SSB superhet transceivers, I am building a simple Direct Conversion receiver. Well, we hope to help a bunch of high school kids build one, so we need to be really familiar with how it works. And I find that as simple as it is, there is still a lot to learn in a project like this.

A Bout of Direct Conversion-ism in Northern Virginia — DC Receivers Under Construction

There I was, minding my own business, when suddenly I was dragged into the construction of Direct Conversion receivers.

Here is a video about my latest effort. But I feel the urge for more simplification — I may go back to the seminal DC receiver designed by Wes W7ZOI and presented in the November 1968 issue of QST. It is on page 15 here: https://worldradiohistory.com/Archive-DX/QST/60s/QST-1968-11.pdf

SolderSmoke Podcast #130 Feb 5, 2011 Trivia Questions! Recorded on a D-104! Heroic efforts to Suppresssss Ssssibilant SSSSs

February 5, 2011

For many reasons, this is a pretty amazing SolderSmoke episode. We presented some radio-electronic trivia questions. This is the one where I used an Astatic D-104 microphone to record the show. I even describe putting Starburst candies, Chicklet gum, and even Duct Tape on my teeth in an effort to get rid of the sibilant S problem. This was truly heroic podcasting my friends! There is lots of other great stuff in this one. Maria arrives in the shack with both Tyson the cat and Cappuccio the dog! Lots of space talk. The story of Grote Reber’s name. Much more: Some important trivia questions (answers will be given in the podcast): What is the connection between radio amateur (and pioneer radio astronomer) Grote Reber and world famous astronomer Edwin Hubble? In the world of radio-controlled helicopters, what is “TBE”? In Britain they have radio “rallies,” but at one time they had hamfests.” When did this happen? Only one terrain feature on Venus is named for a man. He is man of radio. Who is he? What music did Neil Armstrong listen to on his way to the moon? Plus: — The Air and Space Museums — Our music — The SolderSmoke D-104 — NASA asks for our help — Telescope repairs — A BFO for the Trans-O — Back on Echolink MAILBAG! Please send reports on the D-104 audio!

Open Circuits: Cutting Open Components for a Look inside — First Chapter Free

Bob KD4EBM sent me this:

“…. Eric Schlaepfer (@TubeTimeUS) and Windell Oskay (co-founder of Evil Mad Scientist)’s latest book, Open Circuits, is a celebration of the electronic aesthetic, by literally opening circuits with mechanical cross-sections, accompanied by pithy explanations and illustrations. Their masterfully executed cross-sectioning process and meticulous photography blur the line between engineering and art, reminding us that any engineering task executed with soul and care results in something that can inspire feelings of awe (“wow!”) and reflection (“huh.”): that is art. …”

I saw on Hack-A-Day today that the first chapter of the book is available as a free download:

https://nostarch.com/download/OpenCircuits_Chapter1.pdf

Many of our favorite parts are dissected in that chapter. The innards of a ceramic disc capacitor, for example, are shown above.

Thanks Bob!


Nick’s “Shelf-17” Al Fresco Homebrew Transceiver — Frank Jones Would Approve!

This is a really wonderful video from Nick M0NTV.

Some reactions:
— Wow, a real celebration of Al Fresco! And of the wooden chassis — Frank Jones would be so pleased.

— Nick’s description of the tales of woe caused by metal boxes is right on the mark, as is his description of the benefits of leaving the circuitry visible. He’s right — this is an art and science kind of thing.

— That’s a shelf, but it is FAR from being a shelf of shame!

— I am jealous of the S-meter. I may need to include one of those in future rigs.

— Great to hear the shout outs to VK3HN, ZL2CTM, and N6QW — we are are indeed the IBEW!

— I think we can see the N6QW influence in Nick’s decision to use a steerable filter/IF amp board. FB.

— I liked hearing Helio PV8AL in Boa Vista. When I was building simple Direct Conversion receivers for 40 meters, I knew that I had it right when I could hear Helio’s roosters in the morning!

Be sure to watch this video, and to subscribe to Nicks Channel: https://www.youtube.com/c/M0NTVHomebrewing
He has done many other videos providing more details on the various stages that make up this rig.

I hope to work Nick on 17 HB2HB soon.

Thanks Nick!

The James Webb Space Telescope — Background Video and Update Article

The Scientific American video (above) has some really interesting info on how they built the JWST and what its capabilities are. For example, they tell us that it could detect the heat from a single bumble bee at the distance of the surface of the moon. How the mirror was made, and how it is adjusted in space is really amazing.

The Scientific American article provides a good, balanced view of how the initial results from JWST are calling into question the basic models of cosmology:

Video version of SolderSmoke Podcast #240

Show notes appear in blog post below.

I had some technical problems that caused audio distortion, but we talked about so much good stuff that I decided to go ahead and post the podcast. We can’t let the perfect be the enemy of the good enough.

Thanks again to Pete Juliano for his willingness to use a big chunk of his very limited free time.

SolderSmoke Podcast #240 NIMCELS? Hex DX, CBLA RX, PTO? Solid State HT-37? Exotic caps, Benches, SBE-33, TenTec 540, KWM-1 MAILBAG

SolderSmoke #240

Monday September 19, 2022

http://soldersmoke.com/soldersmoke240.mp3

Sorry, I had some technical difficulties so my audio is a bit distorted.

NIMCELS? Niche Internet Micro Celebrities. I dunno…. Can our listeners come up with an acronym that describes our place in the universe?

Sponsors: Parts Candy. Carlos in Chicago. Great leads. Don’t scrimp with a crimp! You need some good quality test leads on your workbench. Get yours from Carlos. Click on the picture on the blog page or go to PartsCandy on e-bay.

“Techno Wizardry”? Our lawyers at Dewey Cheatham and Howe will be after them for that!

Bill’s Bench:

Hex Beam has made me a DXer. 91 countries. Having fun. Mozambique (Long path), San Andres island, and Saudi Arabia, all on Friday. All homebrew SSB 100 watts.

Put my old 20 meter CW station back on the air: Barebones superhet and the VXO 6 watter. WYKSYCDS. This may be one of very few CBLA Receivers in the world!

Been getting active in the Vienna Wireless Society. Dean KK4DAS is President and a lot is happening in the Club. Makers group. Lunch with the group on Tuesdays. Lots of fun.

We are looking at Farhan’s Daylight Again Analog rig. Using parts from Dean’s 3D printer, we have made PTOs. See blog post for picture. (But are they really PTOs? Or just Variable Inductors?)

VFO madness. Solid stating an HT-37 VFO. Grayson: “You have clearly lost your mind.” Perhaps. 100 MHz FM broadcast RFI. This brought me to capacitors and linear tuning:

SLC, SLW, SLF and Midline/Centerline caps. Do special caps explain why some VFOs have linear tuning while others do not? NO, not really. You can get linear tuning with ordinary caps. See blog post

Working on the bench. Reading Adam Savage’s book on workshops and tools. (link to the book in the right hand column of the blog. Some other workbench links on the blog. Upgrading tools and test gear. I have a proper bench power supply. Better side cutters. Engineering rulers. Digital calipers. Better solder (I was talking to Ron WA6YOU – a real solder authority – about this. Kester 60/40 ).

SHAMELESS COMMERCE DIVISION:


mostlydiyrf.com

Currently offering seven items:

· UDVBM-1 (in three versions)

· PG-TIA Broadband IF Amplifier

· TIA-AGC IF Amplifier

· Dual-Gate MOSFETs

· OA741D Op-Amp (discrete components)

· 8-Pole QER Crystal Filter

· I2C Rotary Encoder

Three more are shown as coming soon:

· GP Audio Amp (general-purpose audio amp)

· HyCas IF Amplifier with AGC

· M-Cubed (Michigan Mighty Mite kit)

· Mostly DIY RF offers hardware for hardware-defined radio. That’s not a comment on software-defined radio. SDR is cool and useful, and it has its place.

· In fact, I believe in explicitly making use of technology from all eras (vacuum tubes, discrete semiconductors, and integrated circuits

· What does “mostly” DIY mean? It means making what you want and using ready-made for the rest. Even the most fanatic DIY’ing home brewer does this without much thought. He uses components he didn’t fabricate, electricity he didn’t generate, and theoretical knowledge he didn’t discover. One can’t fight all battles, one has to choose which to fight and which to leave to others. If an appliance-operating Ham doesn’t want to fight at all, that’s okay, but Mostly DIY RF has nothing to offer him.

————–

I need YouTube viewing hours. So I am putting some of the best SolderSmoke podcasts up on the YouTube channel. Please listen/watch on YouTube. Here is the playlist: https://www.youtube.com/playlist?list=PLv9MEKq1quk-gnxog7eBqY_y7cpQadf6T

Google feed no longer sending our e-mails. So please follow the blog, Get yourself a blog feed reader. I use Feedly. It is free. Download, search in Feedly for SolderSmoke, hit subscribe and you are done. https://feedly.com/i/discover Follow Pete’s blog too! It is easy.

Pete’s Bench

Resurrections:

SBE-33!

TenTEC Model 540

KWM-1

Mailbag:

Dan KC5VPI getting into homebrewing. No longer WRONG!

Michael AG5VG built subharmonic DC receiver, put it on 40 and 20. FB.

Mike AA9IL working on old tube stuff including a DX-100 AMD UUHF gear up to 122GHz.

Ed WA4MZS liked the SolderSmoke book. USCG vet. As is Mike Rainey AA1TJ Semper Paratus!

Clint KA7OEI – The Music of the Beams – My Hex does not sing! So far!

Walter KA4KXX – The Knack started early. Video of getting a toolbox for Christmas. And working on PTOs! He likes them!

Phillip G4HOJ Also working with subharmonic mixers – using the more complex 4 diode version.

Peter GW4ZUA Built an amazing rig from RADCOM (1980s) Cool VFO with varactor fine tuning and a coil with a dust core that was cut in half to minimize temp effect. Box now holds 3 band version of Pete’s SimpleCeiver. FB.

Bruce KC1FSZ building 25 Watt amp for his Peppermint Bark rigs. We won’t turn him in to the QRP authorities.

Grayson KJ7UM tested the 12BY7A from my DX-100 VFO. It was in fact weak. Thanks Grayson.

Charles Smith KV4JT has some really interesting stuff on how to solid state tube gear. Especially R-390s. https://soldersmoke.blogspot.com/2022/08/trigger-warning-solid-stating-old-tube.html

Gianfranco I0ZY Old friend from Rome. Amplifier manufacturer. FB.

Paul WA1MAC getting started again after long hiatus.

Vasily.. I mean Todd VE7BPO. Always great tech info. Thanks.

Mark WB8YMV building a superhet with a 455 kc IF.

I sent Farhan some comments on his Daylight Again video: He wrote back “I marvel at their stamina to watch an hour long video of a man talking with a funny accent!”

Building Farhan’s PTO — But Is This Really a PTO?

Farhan has a PTO in his Daylight Again transceiver. This caught the attention of homebrewers around the world. Walter down in Orlando built one. Dean KK4DAS and I have built versions also. Dean has a 3D printer and made the coil support used in my version (above). Thanks Dean!
I had a little trouble at first because one of the capacitors I had in there was not NP0, so the device drifted a lot. But once I straightened that out (I put in a Silver Mica cap in its place) the oscillator became very stable. Mine moves about 25 kHz with each turn of the bronze screw — this is nicely linear tuning. But I think I will have to use a San Jian counter to keep track of the frequency. The long plastic tube on mine is there to eliminate had capacitance effects.

One of the guys in the Vienna Wireless Society questioned whether we should really call this a PTO. After all, bronze has a permeability equal to that of free space. So we are not really changing the permeability. Frank Harris points out that the bronze screw really acts as a shorted secondary. What do you guys think? Is this a PTO, or do we need another acronym to describe it?

This has been a really fun project. I never built an oscillator like this before. I will probably follow up by building the rest of the Daylight Again rig.

BTW WA6OTP has a nice PTO design: http://www.wa6otp.com/pto.htm

Thanks again to Dean, and to Farhan.

Fixing Up An Old Homebrew Rig — Barebones Superhet and VXO 6 Watter

I’m not exactly sure why I pulled this old rig off the shelf, but I’ll write up what I did — I often use this blog as a kind of notebook. I can look back and easily see what I did on my last encounter with the rig.
The receiver is Doug DeMaw’s Barebones (aka Barbados) Superhet. This was my first superhet receiver. I built in in 1997. The transmitter was my first real homebrew project — it is the VXO 6 watter from QRP classics. I built it in the Dominican Republic, probably in 1993 or 1994. I built the power supply so that I could say that the entire rig is homebrew.

This rig is getting a bit long in the tooth: The receiver is built with 40673 Dual-Gate MOSFETs, an some of the transistor cans have gotten rusty. The frequency readout on the receiver is the top of a coffee can fitted onto the reduction drive behind the tuning knob from a Drake 2-B (not MY 2B!).

Here are two 2013 videos that I did on this receiver:

— I put the crystal filter back in CW mode. I had widened it so that I could listen to 20 meter SSB, but I decided to go back to its original configuration. When I built the receiver in 1987, I didn’t characterize the crystals — I just used the capacitor values that Doug DeMaw had in his article. I pretty much did that again this time, just putting caps that are close in value to what Doug had. DeMaw used color burst crystals at 3.579 MHz. So I guess this would be a GREAT receiver for the Color Burst Liberation Army!

— I used My Antuino (thanks Farhan!) to check the passband. Here is what it looks like. I just put the Antuino across the 10k resistors on either side of the input and output transformers. The coil cores had become very loose — I just tried put them in the right place. I may need to put some wax in there to allow them to better stay in place. I think they could have used toroids instead — that would have been easier. One of the transformer connections was open — they don’t work well that way, once I fixed that, the passband looks like this:
— Each of the horizontal divisions is 500 Hz. The passband is not pretty, but it is OK, and I didn’t feel like doing too much work on this to get it in better shape.

— The filter peak was a bit lower in frequency than expected. I found that trimmer cap C3 in series with the BFO crystal would not allow me to lower its frequency sufficiently. So I moved C3 to a position in parallel with the crystal. With this mod, I could get the BFO frequency to 3578.69. This produces a 690 Hz tone when the received signal is at the peak of the IF passband. Opposite sideband rejection is quite good.

March 2013 Rebuild of the VXO 6 watter

— I didn’t have to do any real work on the transmitter. The RF amplifier in the transmitter had served for a time as the RF amp in by 17 meter DSB rig (I had added a bias circuit, which I removed when I put the amplifier back in Class C). Some time ago I rebuilt the oscillator circuit (which had been literally cut off the board when I used the amplifier in the DSB rig).

— I did have to reconfigure the muting circuit — the T/R switch in the transmitter switches the antenna and also — through a two wire circuit — cuts off 12 V DC to the transmitter when in receive mode.

— For sidetone I just put a small piezo buzzer through a 1k resistor between 12 V DC and the key line.

It all worked fine — I talked to three stations on the high end of the 20 meter CW band.

SolderSmoke (Old Smoke) Podcast #103 — March 15, 2009 — From Rome — QRSS, Knights and Wizards, LTSpice, and an Echolink QSO with Jeff KO7M (the guy with the Piper Cub)

15 March 2009 

Beware the Ides of March! Ostia Beach and Ostia Antica 248 Knights of QRSS. And Wizards! ET Phones Home (with QRSS?) Possible new grabbers in VK6 and Dubai Telescope, Satellites... REAL QRP QSOs on 80 and 40 Saving an old Toshiba Laptop ECHO-QSO WITH JEFF, KO7M: -- Piper Cubs and MFJ Cubs -- Satellite QSOs -- LT Spice and test gear MAILBAG: Gene W3PM listens from QE2, HB WSPR rig Jim AL7V sending parts for my W3PM rig Jim AB3CV's color burst Gnat Jason NT7S on Tektronix guys and SolderSmoke Kevin ZL3KE on old computers Paul M1CNK's DDS 30-based QRSS beacon Soeren OZ2DAK on exercise bikes to power beacons

SolderSmoke Podcast #85 With Mike Herr WA6ARA June 8, 2008 WIZARD ISLAND!

When I was putting this podcast up on YouTube, I needed a picture of Mike Herr WA6ARA who was my guest on this episode. I found a picture of Mike activating a summit… THE SUMMIT OF WIZARD ISLAND! That is Wizard Island (above). Mike and his wife are shown at the summit (below).

I really liked talking to Mike, and to listening again to our conversation. But I realize now I should have asked him about parachutes! I’d been talking about the great picture of the Phoenix lander under canopy as it descended to Mars. Mike made and tested parachutes for NASA!

You can listen to this 2008 podcast here: (15) SolderSmoke Podcast #85 Jun 8, 2008 Pheonix Lander, The Woodpecker, Echolink QSO with Mike WA6ARA – YouTube

You can fire up a YouTube playlist that will bring you a steady stream of SolderSmoke podcasts here:
(15) Videos of the SolderSmoke Podcast – YouTube
Here is a report from Mike on the Wizard Island activation:
http://www.pnwsota.org/blog/k7atn/2016-november-12/wa6ara-activates-wizard-island-or-august-2014

Great Technical Info and Tribal Knowledge from GQRP

Thanks to Tony Fishpool G4WIF for sending us this link.

https://www.gqrp.com/tech.htm

There is a lot of great tech info and Tribal Knowledge on the GQRP page. This is all related to our discussion of how to set up an electronic workbench or workshop.

Thanks Tony and thanks to GQRP.

Workbench and Workshop Tips — Please Put Suggestions in the Comments

During a recent visit to Barnes and Noble I picked up Adam Savage’s book (please use the Amazon link in the righthand column) about Making and workshops. Adam’s book reminded me of the importance of giving thought to the organization and set-up of your workbench or workshop. I found more tips on YouTube:

Wow, watch the KatVoltage video (above). Unlike the person in a recent unfortunate advertisement, Kat clearly knows which end of the soldering iron to grab. She is setting up a good workshop — you can tell from how she is organizing the bench. I wish her a lot of luck. htt(s://www.youtube.com/watch?v=1NcVzTu7TbE&t=54s

Andreas (the guy with the white glove and the Swiss accent) has some good ideas:https://www.youtube.com/watch?v=inW57njiq1A

The EEVblog guy has a good guide to the basic stuff that you need to build an electronics workshop. It is a bit dated (2011) but the guidance is still very good (I wouldn’t go with the homebrew or kit-built power supplies): https://www.youtube.com/watch?v=R_PbjbRaO2E

Van Neistat has a very good Top Ten List of things NOT TO DO in a workshop. NO FLATHEAD SCREWS. I’m with you Van. NO HOARDING. etc. https://www.youtube.com/watch?v=3bAZQ9nWybM&ab_channel=VanNeistat Paul VK3HN suggests we develop a similar list for ham radio homebrewers. Please put your suggestions in the comment section below.