Basic Radio Circuitry -- a 1971 film

This 1971 training film is pretty good.  I like how they break the RF circuitry into just four components, then describe the AM receiver stage by stage.  The way they handle diode (envelope) detection is exactly right.  But their description of how mixing moves the incoming signal from the broadcast band to the IF is overly simple, and sort of just repeats the hetrodyne story from music. Real mixing is, of course, more complicated than that, but too complicated for a 15 minute film. 

Bill N2CQR Appears as a Guest on the Ham Radio Workbench Podcast

https://www.hamradioworkbench.com/podcast/hrwb-223-a-conversation-with-bill-meara-n2cqr-from-the-soldersmoke-podcast 

Partly in an effort to make ammends for some overly harsh comments I made about the podcast's approach to the "rejuvenation" of old radios (it turned out to be overly digital for me) I appeared earlier this month on the Ham Radio Workbench podcast.  It was a lot of fun. They are a great  bunch of guys.  And I think we had a great discussion of homebrewing and HDR in the modern era. We talked about Jean Shepherd, Farhan, G-QRP, kits vs. homebrew, homebrew vs. commercial, SDR rigs, the sBITX, the NORCAL 40, the Gilbert Cell Mixer, our experience (bad) trying to get high school kids to build a DC receiver, and many other topics. 

Thanks George!  And thanks to the entire Ham Radio Workbench crew!

Remember, SolderSmoke has issued a challenge to the HRWB team:  We challenge them to build the 40 meter Direct Conversion receiver that we designed for our local high school.  We urged them to build it the way we designed it -- avoid the temptation to substitute stages, or use pre-fab circuit boards.  Build the four stages Manhattan style and get the receiver working on 40.  Here are the details on how we did it.  Here are our building documents:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

The challenge has been issued.  The gauntlet is on the ground.  Go for it HRWB!  Put those workbenches to use! 

Video -- Mythbuster II Rig Gets a Front Panel -- Circuit Build Almost Done

Yesterday I built a front panel for my Mythbuster II 20 meter SSB transceiver. 

I used 1/8 inch plywood available from Amazon. 

I cut holes for the main tuning knob and dial, for the AF gain control, for the mic plug and for a 6 figure PLJ PIC frequency counter.   This gives me 100 Hz read capability, but I can hit the lower button on the counter to get 10 Hz reolution.  This may help when the other guy complains bitterly that I am 40 Hz off frequency.  The counter added noise to the receiver, but I was able to knock this down completely with a resistor and a cap on the power line to the counter. 

I put copper tape on the inside of the panel. 

I added a reverse polarity protection circuit.  I now sleep more soundly. 

I increased the size of the heat sink on my RD06 final.  This decrease the danger of blowing up this device. 

I added a jack for the connector that will switch the outboard .1 kW linear from R to T.  

Video above. Comments welcome.  

 

FDIM 2024 Interview with Farhan VU2ESE

Thanks to Bob Crane W8SX we have some great interviews with those who made presentations at the Four Days in May event (FDIM 2024).  Sorry for the long delay -- it is all my fault, but I have excuses.  Our thanks to Bob W8SX, our correspondent at the FDIM event.  

Here is the interview with our friend Farhan, VU2ESE, the ham who has brought so much homebrew goodness to the hobby, starting years ago with the BITX 20 schematic. 

http://soldersmoke.com/FarhanVU2ESE.mp3

Thanks Bob!  Thanks Farhan! 

SolderSmoke #254 (Audio and Video Versions): Australian Hex Beam Eaters, Fake Wires, Hybrid Rig, Antennas, Mythbuster II Transceiver, Mailbag

Hex Beam Eater

November 13, 2024

SolderSmoke Podcast #254 is available: 

Audio Version here:  http://soldersmoke.com/soldersmoke254.mp3

Video Version here:  https://www.youtube.com/watch?v=ZiZwWY1CQgI

Opening:  Disturbing news from Australia!  VK5RS reports that his Hex beam was EATEN by Cockatoos!  So stop whining about your HOA problems, OK?  It could be much worse! 

FAKE WIRES FROM CHINA!  Oh no!  Even the wires?  There is a good video from Mattias.  I have it on the SolderSmoke blog.  https://soldersmoke.blogspot.com/2024/11/clip-leads-made-with-fake-wire-buy-good.html  Important to note that Parts Candy doen't have this problem.  Buy your test clip leads from our sponsor, Parts Candy.  Link in the column on the right or go to partscandy (that's one word).com

Bill's appearance on the Ham Radio Workbench.  (Bill made some overly harsh comments about radio rejuvenation, and was trying to make amends.)  But now we throw down the gauntlet.  WE CHALLENGE the HRWB guys to build -- to homebrew - our TJ DC RX.  They will experience JOO, JVO and the elite status that comes with having built their own ham radio receiver.  And if they go on to build a 10 minute transmitter, they can use it for CW contacts.  Like on POTA (Thomas!) 

Anniversary approaching:  In August 2025 we will mark 20 years of the SolderSmoke podcast.  And we have already passed TEN YEARS OF JULIANISMO!  Pete joined the podcast on May 26, 2013.  Thanks Pete! 

Question for the group:   Which SSB transceivers did Doug DeMaw build?  

Pete's Bench:  Thermatron-Transistor Hybrid Goodness.  https://n6qw.blogspot.com/2024/10/blog-post_20.html

Dean's Bench:  The new Hex Beam (watch out for Cockatoos!)  Now that Dean and I both have Hex Beams, we plan on pointing them at Southern California in an effort to talk to an elusive RADIO GENIUS. Stay tuned! 

Dean's Hex Beam -- A Thing of Beauty

Also homebrew random wire with T match tuner for attic.  RF Burns!  

SHAMELESS COMMERCE:   Please link to our blog and podcast!   Please become a Patreon supporter (I have been posting special content there).  Be sure to make use of the great boards, parts and kits available at Mostly DIY RF.   Still use the Amazon link on the SolderSmoke blog page. 

Bill's Bench: The new Mythbuster II (20 meters only).  Built in about 3 weeks. On-the-air, while still on the bench!  Worked Euope and South Africa QRP.   https://www.youtube.com/watch?v=6o9QerQ7jzg

Getting another CCI amp for the Dominican Republic. 

MAILBAG: 

-- Paul VK3HN,  talks about the nice sound of the Mythbuster II's receiver, and a new QRP rig from Dave Benson K1SWL. 

-- Rick N3FJZ sent some very kind words in support of the SolderSmoke podcast. Thanks Rick. 

-- Chris KD4PBJ sent us a very nice message.  Thanks Chris. 

-- Kevin from Belgium sent a nice blog post in support of SolderSmoke. 

-- John WB4BTL spotted his old call (from 1974) in my Novice Log.  

-- Dave KD2E spotted his Novice call in  my Novice log:  WN2TBB. He also  saw a good friend WN2EHE. 

-- Mehmet who has the awesome and useful WEBSDR of NA5B helped me with a Facebook problem.  Thanks Mehmet! 

-- Mike WN2A asked about the Yaesu FT-101 9 MHz VFOs. 

-- Phil W1PJE (from MIT!) writes about old broadcast radio shows. And some really nice words of encouragement. 

-- Grayson KJ7UM sent kind words of encouragement, and great background on hybrid rigs. 

-- Peter VK3TPM writes about the decline of blogging, but notes that blogs are useful repositories. 

-- Todd K7TFC sent me some additional Mostly DIY RF boards.  Thanks Todd! 

-- Ed DD5LP/G8GLM  Kind words on SolderSmoke, nice info on the G-QRP 50th edition. 

-- Bill AH6FC  Encouraging words and good info on solar.  Mahalo Bill!  

-- Michael AG5VG Building LC VFOs for 7 MHz.  FB OM!

-- Bob K7ZB An EE who likes the treatment of mixers in the SolderSmoke book.  

Two Satellites Spotted Pre-Dawn

 

I was out with Guapo the dog at 5:28 am EST on November 12, 2024.  I looked up and first saw one satellite moving from South to North.  Then another moving in the opposite direction.  Heavens Above provided details --see above.  

Clip Leads Made with FAKE WIRE! Buy Good Ones from PARTS CANDY!

We don't see many videos about clip leads,  but this one fits in well with our esoteric subject matter. 

Carlos of Parts Candy (our sponsor) responds: 

Interesting video. Yes the clips we make are nickel plated steel but the wire is tinned copper. When I was making custom orders I made some custom clip lead sets using 100% copper clips for a few people who really needed the low resistance. In most applications the steel clips should be fine. The resistance for 12” clips is about 12mOhms and the 32” clips are around 24mOhms, iirc.

The bottom lines:  1)  Don't scrimp with a crimp -- get a good solid soldered clip-wire connection from Parts Candy. 2) Parts Candy wires are not fake.  They are tinned copper 3) The metallic composition of Parts Candy clips does not degrade performance. 4) But if a customer really needs copper clips, Carlos can make them too. 

Parts Candy web site:  https://www.partscandy.com/

Video Update on the Mythbuster II 20 meter SSB Transceiver

I have added the transmit circuitry. I described building practices. We listen to the receiver again. I talk about plans for transmit/receive switching. After this I will build another CCI 100 watt RF amplifier for use in the Dominican Republic.

For the first look at this rig see:

https://soldersmoke.blogspot.com/2024/10/bill-n2cqr-builds-yet-another.html

 We will discuss this further in an upcoming Ham Radio Workbench Podcast, and in SolderSmoke Podcast #254 (mid-November 2024) 

Using a Photomultiplier THERMATRON to Detect Single Photons

I've been a fan of Jeroen's YouTube channel for a while now.  He has a very nice approach, combining theoretical knowlege with practical experiments and equipment builds.  Here we see him using a photomultiplier tube and a board acquired in flea market to build his photon detector.  

This video has a lot to offer us.  First, there is a single thermatron.  There is a tube socket.  There is a (really small!) high-voltage power supply.  He uses an oscilloscope. There is a laser.  There are photons.  And at one point, a single photon.  

Having recently built a simple Wilson Cloud Chamber, my attraction to this device is easy to explain.  I suspect our friend Grayson will be interested in it for Thermatronic reasons.   There is a Part II.   Check out the YouTube channel: 

https://www.youtube.com/@HuygensOptics  

Here is more info on the channel and it's creator: 

Hi, my name is Jeroen and on the Huygens Optics channel I publish videos on personal projects. My main fields of interest are optics, mechanics and photolithography. The videos aren't targeted towards a general audience but for people with a passion for science and technology (e.g. my fellow nerds). The channel is named after the famous Dutch mathematician, astronomer and inventor Christiaan Huygens (1629-1695). He was the first to publish a mathematical description of the wave properties of light, and also discovered Saturn's rings.

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

Thanks Jeroen

On the Election

This time around, in an effort to keep this blog focused on radio and electronics, I have decided to move my election recommendations to my other blog site.  So check it out there: 

https://tahplu.blogspot.com/2024/11/election-2024-vote-against-trump.html

More Background on the Mythbuster II Rig (and a short video)

Above is a short clip of me hearing an old friend on the new receiver.  TRGHS. 

A couple of guys on Facebook asked for a schematic for this rig.  I don't really have one -- as you will see it is a collection of different circuits from lots of different sources.  I was also thinking that if you need a schematic for a rig like this, you probably shouldn't try to build a rig like this.  But in an effort to be nice, I supply here some background info on some of the circuitry and parts sources.  And no, I don't have BOMs nor Gerber files.   

More info on the Yaesu VFO is here:

https://soldersmoke.blogspot.com/2021/07/mythbuster-video-3-using-vfo-from-yaesu.html

The VFO is kind of high in frequency. But it is very stable. I can't really take credit for this -- the credit goes to Yaesu. But I like the circuit because it is all analog and all discrete component. It even has a split stator temperature compensation variable cap! At Pete's recommendation, I originally bought these boxes thinking that I'd just get the anti-backlash gears and the reduction drives. But the sellers always sent the entire VFO boxes. They even come with a "clarifier" circuit which I now use as an "up 5-10" feature that lets me work the DX-peditions on 20.

As for the tape, I got mine from Amazon. It has conductive adhesive:
https://www.amazon.com/gp/product/B07QQJ4MX1/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The boards for the IF Termination Insensitive Amplifiers come from Todd K7 TFC at Mostly DIY RF:  https://mostlydiyrf.com/tia/

The little LM386 boards that I have been using are available here: https://www.amazon.com/dp/B00LNACGTY?ref=ppx_yo2ov_dt_b_fed_asin_title  I precede it with one stage of AF amplification from the original BITX 20 sechematic.  I put a 10K pot between this stage and the LM386 board. 

Here is the Amazon source for the 1/8 inch plywood that I will use for the case (I have used up all the pandemic treadmill packing material):  

https://www.amazon.com/dp/B0D5VCBBP4?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

More on How the AI Deep Dive Podcasts Were Made -- Soon: PeteGPT!

 

So, soon we may actually have these kinds of AI products using voices and even video images that are known to us, but, with the dialogue completely artificial.  Soon, we may hear and see N6QW badmouthing the Si5351, and singing the praises of LC VFOs.   Just a year ago this was the subject of an April 1 SolderSmoke joke.  Now it is becoming a real possibility.   We are living in the future my friends.  

Here is the new article on how they are doing this: 

https://deepmind.google/discover/blog/pushing-the-frontiers-of-audio-generation/

And here are our first two experimental uses of this AI technology: 

https://soldersmoke.blogspot.com/2024/09/a-new-experimental-podcast-about.html

https://soldersmoke.blogspot.com/2024/09/here-is-another-short-podcast-about.html