How to Organize a Small Shack

A YouTube comment from Paul VK3HN sent me back to "The Spirited Man" YouTube channel, and one of the first things I found was this video about how to organize a small space.  This is very relevant to my shacks in Virginia and in the Dominican Republic. 

Lots of good ideas here, but that propane heater kind of scared me.  And it seemed inconsistent with concerns behind the fire-preventing garbage can.  What do you folks think? 

Thanks Paul. 

 

Deep Space Station 43 -- Canberra, Australia

 

https://spectrum.ieee.org/apollo-era-antenna-voyager-2

From the IEEE article: 

The dish’s manufacturer took great pains to ensure that its surface had no bumps or rough spots. The smoother the dish surface, the better it is at focusing incident waves onto the signal detector so there’s a higher signal-to-noise ratio.

DSS-43 boasts a pointing accuracy of 0.005 degrees (18 arc seconds)—which is important for ensuring that it is pointed directly at the receiver on a distant spacecraft. Voyager 2 broadcasts using a 23-watt radio. But by the time the signals traverse the multibillion-kilometer distance from the heliopause to Earth, their power has faded to a level 20 billion times weaker than what is needed to run a digital watch. Capturing every bit of the incident signals is crucial to gathering useful information from the transmissions.

The antenna has a transmitter capable of 400 kilowatts, with a beam width of 0.0038 degrees. Without the 1987 upgrade, signals sent from DSS-43 to a spacecraft venturing outside the solar system likely never would reach their target.

https://spectrum.ieee.org/apollo-era-antenna-voyager-2

Paul VK3HN's Video on Scratch-Building and SOTA

It was great to get a comment from Paul VK3HN -- this led to a re-establishment of contact.  Apparently Google knows who I have been e-mailing, so this great video appeared on my YouTube screen.  Thanks Google! 

-- Great to hear Paul's shout out to Pete Juliano N6QW, and Pete's concept of noodling. 

-- Paul's emphasis on testing each stage independently is really important. 

-- Wow, ferric chloride!  It is great to see someone doing this (instead of just sending Gerber files to China). 

-- Books.  This reminds me that I have to get Drew Diamond's books. 

-- Paul's comment on the usefulness of a general coverage receiver.  Right on target Paul.  

-- On the test gear, we can now add the TinySA Ultra.  And you don't have to win the Lotto! 

-- Finally, Paul is absolutely right on the need to constantly update and publish changes to schematics. I am guilty of not doing this. (I hang my head in shame.)   This became a problem in our simple High-School receiver project -- I would make changes to circuits and fail to communicate these changes to Dean KK4DAS.  Paul's method would have solved this problem.  

-- Thanks Paul! 

A Low-Power (QRP) Contact from Australia to Spain (with video from both sides!)

A recent comment on the blog put me back in contact with an old friend of SolderSmoke:  Paul VK3HN.  Paul is an amazing homebrewer -- it was great to hear from him.   He sent along this video of a portable Summit on the Air activation from the Melbourne Australia area.   Paul managed to contact Ignacio EA2BD in Spain.  Ignacio was also running low power with a portable set up.  The remarkable thing is that we have video from both sides of the contact.  FB!  Thanks to Paul and Ignacio. 

A Look at Old Radios in Australia (video)

I thought you guys would like Peter Parker's latest video.  And in it, Dean KK4DAS might see a clue or two for his Halli restoration/repair project.  

What really struck me was the dial markings on the Australian radios.  They seem to be mostly oriented toward the reception of Australian AM or LW broadcasters -- not many exotic DX locations are marked.  Australia is big! 

Looks like a lot of crystal detectors in glass tubes.  At first I thought they might have been coherers, but I think they are crystal detectors. 

Many variometers visible. 

I saw one Geloso-Milano Communications 8 receiver.  Va bene! 

I also saw one "Tasma 780" Superhet.  Cool name! 

What is up with the "Green Theme"? 

I have some of the headphones they showed. 

Please note in the Comments section anything special that you noted in watching Peter's FB video. 

More on the coil winding machine here: 

https://hackaday.com/2023/08/30/all-mechanical-coil-winder-is-a-scrap-bin-delight/#more-612604

Ciprian YO6DXE Puts the Michigan Mighty Mite on AM! (video)

Excellent work Ciprian!  

Here we have a Michigan Mighty Mite being modified for AM in Romania, with input from Hungary, and inspiration from Melbourne, Australia (Peter Parker VK3YE).  With a very nice shout-out to SolderSmoke.  

I really like Ciprian's emphasis on having fun with the electronics. 

TRGHS! 

Australia and Apollo 11 -- Honeysuckle Creek

Trevor reminded me that Parkes ("The Dish") was not the only Australian antenna at work during Apollo 11.  This very nice video gives a more complete description of what happened.  

I saw one piece of Collins gear.  And some of Curious Marc's HP frequency counters.  

More on the Honeysuckle Creek Tracking Station here: https://honeysucklecreek.net/

VK2BLQ Builds the High-School Direct Conversion Receiver

It is truly a thing of beauty.  Stephen VK2BLQ built it just as we designed it, so his build (like those of several others) serves as confirmation that this design is ready for the high school students. 

Stephen writes: 

Bill,

Don't worry, you are not alone out there.

Here is my build; sorry that the front panel is overexposed and hard to see, but it is plywood.

I did follow the schematic but due to the contents  of the junk box there have been some component changes.

The only thing that I had to buy was the 3/16 x 50 mm (2 inch) brass screw.

My calculations for the coils for the PTO and  BPF  were  a little  bit off necessitating padding down the PTO with a further 100 pF (easier than remaking the coil and mounting)  and removing a few turns from the T50-6 toroids.

Like other people have found: the audio takes off at full volume; I am thinking but not yet tried adding decoupling between R5 (15K) and C2(47 uF). It isn't the actual values of the electros as I had to use 100 uF so might be the audio output getting back into the earlier stage.

The tuning range I get is  our 7000 to 7200 KHz and some shortwave stations above and below, Turning the screw is a little bit fiddly, but once tuned the vfo is quite stable and the audio sounds good.

Best wishes,

Stephen

VK2BLQ

I really like the ruler near the tuning control.  Is that (I hope!) the frequency readout? 

But why? Why Can't I Listen to DSB (or AM) on my Direct Conversion Receiver?

I've said this before:  I just seems so unfair.  We just should be able to listen to DSB signals with our beautifully simple homebrew Direct Conversion receivers. I mean, building a DSB transmitter is a natural follow-on to DC receiver construction.  And we are using AM shortwave broadcast stations (Radio Marti --I'm looking at you)  to test our DC receivers for AM breakthrough.  But when we tune these stations in, they sound, well, awful.  So unfair!  Why?   Unfortunately it has to do with laws.  Laws of physics and mathematics.  Blame Fourier, not me.  

Over the years there has been a lot of handwaving about this problem.  From Doug DeMaw, for example: 

In his "W1FB's Design Notebook," Doug wrote (p 171):  "It is important to be aware that two DSSC (DSB) transmitters and two DC receivers in a single communication channel are unsatisfactory.  Either one is suitable, however, when used with a station that is equipped for SSB transmissions or reception. The lack of compatibility between two DSSC (DSB) transmitters and two DC receivers results from the transmitter producing both USB and LSB energy while the DC receiver responds to or copies both sidebands at the same time."

That's correct, but for me, that explanation didn't really explain the situation.  I mean we listen to AM signals all the time.  They produce two sidebands, and our receivers respond to both sidebands, and the results are entirely satisfactory, right?  Why can't we do this with our Direct Conversion receivers?  I struggled with this question before: https://soldersmoke.blogspot.com/2015/07/peter-parker-reviews-dsb-kit-and.html  You can see in that post that I was not quite sure I had the answer completely correct. 

It took some discussion with a fellow Vienna Wireless Society member, and some Googling and Noodling for me to figure it out.  But I think I've got it: 

Imagine a station transmitting a DSB signal at 7100 kHz with a 1 kHz tone at the AF input.  There will be signals at 7101 kHz and at 7099 kHz.  Assume the carrier is completely suppressed. 

We come along with our DC RX and try to tune in the signal. 

Remember that they heart of the DC RX is a product detector, a mixer with the VFO (or PTO) running as close as we can get it to the suppressed carrier frequency (which we can't hear).  

Lets assume that we can somehow get our VFO or PTO exactly on 7100 kHz.  The incoming signals will mix with the VFO/PTO signal.  We are looking for audio, so we will focus on the difference results and ignore the sum results of the mixing.  

The difference between 7101 and 7000 is 1 kHz.  Great! And the difference between 7099 and 7000 is 1 kHz also.  Great again, right?  We are getting the desired 1 kHz signal out of our product detector, right?  So what's the problem?  

Here it is: SIDEBAND INVERSION.  Factoring in this part of the problem helps us see the cause of the distortion that plagues DSB-DC communication more clearly. 

Remember the Hallas Rule:   Whenever you subtract the modulated signal FROM the unmodulated signal, the sidebands invert.  So, in this case, we are subtracting that 7099 "lower sideband" signal FROM the 7100 VFO/PTO signal.  So it will invert.  It will become an upper sideband signal at 1 kHz.  We will have two identical 1 kHz signals at the output.  Perfect right?   Not so fast. Not so PERFECT really.  

The perfect outcome described above assumes that our VFO/PTO signal is EXACTLY on 7100 kHz.  And exactly in phase with the suppressed carrier of the transmitter.  But if it is even SLIGHTLY off, you will end up with two different output frequencies, signals that will move in and out of alignment, causing a wobbling kind of rapid fade-in, fade-out distortion.  You can HEAR this happening in this video by Peter Parker VK3YE, starting at 6:28:

And you can see it in this LTSpice simulation.  

This LTSpice model just shows two diode ring mixers.  The transmitter is on the top, the receiver is on the bottom. The transmitter has RF at 7100 kHz at L1 and audio at 1 kHz at R1.   The receiver has the VFO at 7100.001 L7,  DSB from the transmitter at L12 with audio appearing at R4.  It is instructive to watch the output as you move the VFO frequency.  If you move the VFO freq away from the transmit carrier osc frequency you will see the distortion.  Here is the netlist for the LTSpice simulation: 

http://soldersmoke.com/DSBDC.net

On paper, using simple mixer arithmetic, you can tell that it will be there. With the VFO/PTO just 1 Hz (that's ONE cycle per second) off, you will end up with outputs at 1.001 kHz and at .999 kHz.  Yuck.  That won't sound good. These two different frequencies will be moving in and out of alignment -- you will hear them kind of thumping against each other.    And that is with a mere deviation of 1 Hz in the VFO/PTO frequency!  We are scornful when the SDR guys claim to be able to detect us being "40 Hz off."  And before you start wondering if it would be possible to get EXACTLY on frequency and in phase, take a look at the frequency readout on my PTO.  

Now consider what would happen if the incoming signal were SSB, lets say just a tone at 7101 kHz.  We'd put our VFO at around 7100 kHz and we'd hear the signal just fine.  If we were off a bit we'd hear it a bit higher or lower in tone but there would be no second audio frequency coming in to cause distortion.  You can hear this in the VK3YE video:  When Peter switches to SINGLE Sideband receiver, the DSB signals sound fine. Because he is receiving only one of the sidebands. 

The same thing happens when we try to tune in an AM station using a Direct Conversion receiver:  Radio Marti sounds awful on my DC RX, but SSB stations sound great. 

My Drake 2-B allows another opportunity to explore the problem.  I can set the bandwidth at 3.6 kHz on the 2-B, and set the passband so that I will be getting BOTH the upper and the lower sidebands of an AM signal. With the Product Detector and the BFO on,  even with the carrier at zero beat  AM sounds terrible.  It sounds distorted.  But -- with the Product Detector and BFO still on --  if I set the 2-B's  passband to only allow ONE of the sidebands through,  I can zero beat the carrier by ear, and the audio sounds fine. 

There are solutions to this problem:  If you REALLY want to listen to DSB with a DC receiver, build yourself a synchronous detector that gets the your receivers VFO EXACTLY on frequency and in phase with the transmitter's oscillator.  But the synchronizing circuitry will be far more complex than the rest of the DC receiver. 

For AM, you could just use a different kind of detector.  That will be the subject of an upcoming blog post. 

Please let me know if you think I've gotten any of this wrong.  I'm not an expert -- I'm just a ham trying to understand the circuitry. 

Another Trivial Electric Motor

The above video popped up on the BBC channel a few days ago.  Three cheers for the Beeb for doing this, but I'd like to point out that we have been building Trivial Electric Motors for at least 16 years.  We were inspired by Alan Yates VK2ZAY W7ZAY. 

 Below is a video from 2006: 

And there are several links (and a video) about Alan and the Trivial Electric Motor here: 

https://soldersmoke.blogspot.com/search?q=Trivial+Electric+Motor

Thanks again Alan! 

Building a Workshop (or a Shack) in a Crawl Space

At first, this video made me think of Michael AA1TJ and his underground Hobbit Hole workshop.  Then I started thinking about my own crawlspace -- it looks remarkably similar to the one in this video.  Hmmm...  But no, I think I will stay above ground. 

One thing that would DEFINITLY not work for us would be the flooring that kind of eats small parts that get dropped.  I would all soon have large numbers of small parts under those mats.  This would drive me nuts.  

But lots of good ideas from Australia in this video.  

SolderSmoke Podcast #156 -- November 4, 2013 -- Interview with Peter Parker VK3YE of Melbourne, Australia

November 4, 2013
Special hour-long interview with Peter Parker, VK3YE
-- Early experiences with radio
-- CW
-- DSB Gear
-- Simple gear, and gear that is TOO simple
-- VXOs, Super VXOs and Ceramic Resonators
-- Building receivers
-- Chips vs. Discrete
-- Making the leap to SSB
-- The Knob-less wonder and the BITX
-- No need for a sophisticated workshop
-- Advice for new phone QRPers

Peter's Blog: https://vk3ye.com/

Peter's YouTube Channel:  https://www.youtube.com/user/vk3ye/featured

VK3IO's Wonderful Antenna Tuning System

 

I have been ridiculed because my manual antenna tuner (that is screwed into the wall of our car port) requires me to step outside into the cold or heat to change bands. 

On August 18, 2022  -- with my Hex Beam, not with the tuner -- I worked Ron VK3IO on 20 SSB.  Check out Ron's antenna tuning system.  He used the same balanced tuner that I use, but he has them set up for FIVE bands.  FB.  The wire antenna was working very well -- with 100 watts to the wire Ron was booming into Northern Virginia. 

Ron's QRZ.com page: 

https://www.qrz.com/db/VK3IO

Watch out for those spiders Ron!  

Hex DX! First Long-Haul Contact with the New Hex Beam - VK4KA on 20 SSB

This morning at around 1345 UTC I had the chance to try out my new Hex beam on some "down under" DX.  9,548 miles, 15,222 km    The DX Spot page told me that VK4KA was on 14.255 MHz.  QRZ.com said the beam heading for me was 270 degrees.   He was quite strong.  He was working a fairly huge pileup, going through callsign numbers.  He was on the 6s when I tuned in, so I had some time to test the Hex beam.  Above you can see a rough front-to-back test.  Below you can see a comparison with my old 75 meter doublet.  

A few minutes after the second video, in spite of the pileup I called VK4KA and made the contact.  I congratulated him on his homebrew Moxon.  https://www.qrz.com/db/VK4KA

It was fun to reach Australia with the new antenna. 

Thoughts on Homebrew, Makers, DIY, and Hams -- from Lex PH2LB

Sometimes we get a comment that is so good that we elevate it to the main blog page.  That was the case with Lex PH2LB's comment on the blog post of Owen Duffy (yesterday). 

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

When I started the hobby, it arose out of technological curiosity, the interest in understanding things and the will to make things myself (designing myself was not my main goal). It doesn't matter to me whether it is 100% DIY or a kit (such as Heathkit, Elecraft, QRP-Labs etc) which is modified or not after construction. Just having fun with the hobby and pushing boundaries. And yes I also have some off-the-shelf transceivers (I'm super happy with my FT817ND) and my QO-100 uplink is also a kit (which is then already soldered a little more than average). As far as new tools are concerned: here at home are 2 types of 3D printers, various tools for SMT assembly, and I have a nice workshop equipped with tools and equipment for metal / plastic / wood processing. And every day I try to learn something new, because I stand by the IBEW moto : If you know stuff, you can do stuff.

Am I a maker then? I wouldn't call myself that. Just like I don't call myself a hacker because I'm quite handy with computers, technology and have certain skills. I'm just a hobbyist who wants to do and make things after work.

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

Lex is a true member of the International Brotherhood.  He is the one who took our beloved stickers onto the European continent and into a Netherlands pub.  He is the one who -- unforgettably -- saw the parallels between ham shacks and the "pleasure room" of "50 Shades of Gray" (See below -- apropos of his current message, we labeled his meme "50 Shades of Homebrew") For more on Lex see: https://soldersmoke.blogspot.com/search?q=PH2LB

Lex's web site (Shack on the Internet):  https://www.ph2lb.nl/blog/index.php?page=hamradio

 Thanks Lex! 

Australian Homebrew: Owen Duffy ex VK1OD now VK2OMD. Are Hams Makers?

This week I stumbled upon this amazing blog from Australia.  I had to check with Australian friends to find out more about the author.  Owen Duffy has for many years been a rigorous homebrewer who has documented his findings on his blog:  https://owenduffy.net/blog/

For example, Owen asks the question, "Are hams makers?" https://owenduffy.net/blog/?p=122

There is a lot of great material on this blog.  It goes back to 2013.  Peter Parker notes that an earlier version of the blog (before Owen was forced to change his callsign from VK1OD to VK2OMD) goes back even further and is accessible via the Way-Back Machine:  https://web.archive.org/web/*/vk1od.net

Check it out.  Lots of really useful and interesting material there.   Thanks Owen.  And thanks to the Australian friends who provided background info. 

Ruby Payne-Scott and Early Australian Radio Astronomy

Click on the cartoon for a better view

Read the full article here: 

https://womenyoushouldknow.net/ruby-payne-scott-first-woman-radio-astronomer/

VK2BLQ's Two-Tube Regen with a SolderSmoke Dial

 

Thanks to Peter Marks VK3TPM ("a bloke with too many hobbies") for alerting us to this magnificent homebrew receiver with the especially magnificent tuning dial.   

http://blog.marxy.org/2022/03/a-two-valve-regenerative-receiver-for.html 

We have used old CDs as dials for many years.  I have one on my Q-31 Quarantine SW receiver.  But never have we seen one with SolderSmoke emblazoned on it. FB OM. 

Stephen VK2BLQ should make sure that those 6U8s haven't gone old on him.  I recently replaced the 6U8s in my Mate for the Mighty Midget with 6EA8s.  This seemed to rejuvenate the receiver.  

Also, it is shame that Stephen doesn't keep that rig at 12 volts.  250 V?  Yikes.  As I often say, you CAN hurt yourself with 12 volts, but you really have to work at it.  Not so with 250 V.   One hand behind your back Stephen! 

Thanks to Peter and Stephen. 

VK3HN's Amazing Summit Prowler 9 Homebrew Transceiver - A Masterpiece of Miniaturization (VIDEO)

I was wondering what Paul VK3HN was up to. Now we know: the Summit Prowler 9 transceiver. 

This is yet another amazing rig by Paul, with GREAT documentation.   

I was impressed by those bandpass filters.  I will try to do something similarly robust on my 17/12 rig. 

Paul's miniaturization of this rig is really astonishing.  I would go nuts trying to keep it this small. I just couldn't do it. 

Look closely at the boards he uses.  They look like printed circuit boards, but with all the components and all the soldering on one side.  This is very smart -- this makes it easier to troubleshoot and to change components.  

I was glad to see at least one NE-602 in there.  FB. 

The video is above.  Check out Paul's blog for more info: 

https://vk3hn.wordpress.com/2021/02/27/sp-9-a-compact-five-band-ssb-cw-qrp-transceiver/ 

Thanks Paul!

Peter Parker VK3YE Inducted Into QRP Hall of Fame

Wow, I was really pleased to learn that Peter Parker VK3YE was a 2021 inductee into the QRP Hall of Fame.  

This is a richly deserved honor.   Peter Parker  has been making extraordinary contributions to QRP and homebrewing for many years.  I remember reaching out to him when I was just getting started with homebrew phone gear.  I considered him a guru of DSB.  He helped me a lot.  Peter Parker was interviewed on the SolderSmoke podcast in 2013: 

https://soldersmoke.blogspot.com/2013/11/soldersmoke-podcast-156-special.html

Peter has published many books and has produced many YouTube videos.  He hosts an annual QRP gathering in his beloved home-town of Melbourne Australia that gets attention from solder-melters around the world.  

Three cheers for Peter Parker!  

Congratulations Peter! 

VK3YE's Web Site: https://vk3ye.com/

VK3YE's QRZ.com page:   https://www.qrz.com/db/VK3YE 

Thanks to VK3HN for alerting me to this.