Glowing Numerals for the Lafayette HA-600A (With Jeweled Movements)

 

I really like this receiver.  I have strong sentimental ties: it was my first SW receiver.  But the frequency readout situation was kind of rough -- depending on where you put the Main Tuning cap, your Band Spread dial could be WAY off.  

China to the rescue!  Specifically the very nice San Jian PLJ-6 frequency counter boards.  I have used these in several projects.  I like them a lot. I get mine on e-bay.  They are very cheap.  Here is the manual with specs: 

https://www.mpja.com/download/35057tebasic%20manual.pdf

As I did with my BITX20, I put mine in an Altoids-sized box.  I got to use my Goxawee rotary tool with circular metal blade to cut the rectangular hole.  Hopefully future efforts will yield neater results, but the flying sparks were fun;  they made me feel like one of those car-part  "fabricators" on cable TV. 

To tap the VFO frequency, I just put a bit of small coax at the point where the 10 pf cap from the VFO circuit enters the first mixer.  I ran this cable to the unused "Tape Recorder" jack on the back of the Lafayette -- this connects to the input of the counter.  I attached 11 volts from the power supply to an unused terminal on the accessory jack of the Lafayette -- this powers the counter.

Having a counter on the VFO proved very illuminating -- in more ways than one.  I measured the Center Frequency (CF) of my IF to be at 456 kHz.  I set the PLJ-6 to display the VFO frequency MINUS 465 kHz.   For AM broadcast signals, this worked fine:  I'd tune the signal for peak S-meter reading.  This meant that the carried was right at the CF.  

For SSB, things were a bit different.  I set the BFO knob  to be RIGHT AT 465 kHz when the dot is in the center position.  With the BFO there, I could tune in SSB signals.  The suppressed carrier would be right at the center of the IF passband, with the audio information above or below the suppressed  carrier frequency.  But it didn't sound good this way -- it sounded better if I would tune an LSB signal 2 kHz down from the center, then adjust the BFO down about 2 kHz.  This put most of the the audio in the peak portion of the IF filter(s) curve.  Doing it this way means that I have to remember that the number displayed on the PLJ-6 is 2 kHz down from the actual suppressed carrier frequency of the transmitting station.  I can live with that.  

I am going to leave the Lafayette on the corner of my workbench so that I can easily tune in hams  and SW broadcast stations.  Having modified the product detector and added the digital frequency readout makes listening to this receiver even more pleasing.  The jeweled movements are as smooth as ever. 

So 2021 is off to a good start on my workbench.  HNY to all!  

So Many Wonderful Things on W7ZOI's Site

 

There he is.  Wes Hayward, W7ZOI in 1957.  I had never seen this picture before.  I found it on Wes's recently updated "shackviews" web page: http://w7zoi.net/shackviews.html . 

There are so  many treasures on that page, and on all the other portions of Wes's site.

Some highlights for me: 

-- Wes's description of the station in the above picture. 

-- On his page about Doug DeMaw, Wes mentions that after Doug edited Wes's 1968 article about direct conversion receivers, Doug built some himself, experimenting with different product detector circuits. Having used Doug's mixer circuit in many of my rigs, and having recently experimented with different product detectors for my HA-600A, I kind of felt like Doug was watching over my shoulder, guiding me along as I experimented. 

-- Wes's use of a digital Rigol oscilloscope.  Makes me feel better about giving up on my Tek 465. 

-- The page about Farhan's visit to Wes, and the awesome gathering of homebrew Titans that ensued... 

-- Wes's meeting with Chuck Adams.  

Thanks Wes.  Happy New Year and best of luck in 2021!  

Ross Hull and Clinton DeSoto -- Ham Radio and R/C Planes

Rogier PA1ZZ sent me a video that linked Ross Hull and Clinton DeSoto to the development of today's killer drones.  While it looks like that is quite a stretch (I'm sure Rogier would agree), the involvement of these two radio guys in the early development of radio-controlled planes is very interesting.  

An article, “Radio Control of Model Aircraft,” by Ross A. Hull and Roland B. Bourne, was the first to describe in detail a working radio system suitable for model aircraft.  They wrote: “Most hams are usually far from being one-hobby men and one discovers, almost invariably, an interest in the other sciences and the crafts. A common interest in ham radio, aeronautics, model building, and photography is almost the rule. We happen to be built that way and our interest in aircraft led us, this summer, to take an active interest in this problem of radio control.” (QST, October, 1937) 

More here: 

https://jmrc.tripod.com/fa/days/days_2.htm

And here: 

 https://ethw.org/Ross_A._Hull

Listen to this! The Kearsarge Mountain Transmission System -- Winter Test Transmission -- 9670 kHz

This is a bit mysterious, but I think that is part of the allure.  Last week reports began to surface on reddit about a shortwave test transmission from a group called the Kearsarge Mountain Transmission System.  Kearsarge Mountain is in New Hampshire. Thomas K4SWL over at the SWLing Post Blog posted a link to a SoundCloud recording of the transmission:     

https://soundcloud.com/user-25048993/kmts-winter-test-transmission-9670-khz-17122020

I don't really know much about the origins of this recording, but -- like Thomas -- I really like it.  It is EXACTLY what you need to have playing in the background as you work on some piece of radio gear.  Trust me on this:  If you are a radio person, you WILL like this.   Have a listen at the link above. 

Here are some excerpts from the reddit posts on this: 

Notice of a KTMS winter test transmission beaming to Europe/USA on 9670 kHz at 2300 UTC on 17.12.2020. This transmission will consist of interval jingles, engineer test signals, rare re-media mixes of cult radio favorites, strange tones, and vox. Thank you for your continued attention as the KTMS crew continue working to bring the SWL community unique transmissions.

Our aim as the programmers of the KTMS Test Transmission is to entertain, edify and get SWLs excited about the possibilities inherent in radio. The crew of KTMS consists of amateur radio operators, community and college radio aficionados, antique radio restorationists, low budget radio astronomers looking for alien life and in general people who love the hobby of radio in all its many faceted aspects.

People who put their own funds towards creating radio on the shortwaves are helping to keep the shortwaves interesting and alive and bringing programming that is original and idiosyncratic to a medium that is often otherwise overrun by nationalists, spies, and fundamentalist preachers. They also help to keep shortwave stations on the air -something that ain’t so cheap. Rather, our view, is that by injecting some creative energy into a project such as our KTMS Winter Test Transmission we are giving back to the SWLing community by 1) creating a show for any listeners who happen to catch it, 2) giving the listeners a mystery that doesn’t revolve around numbers, 3) to do our part to keep the airwaves a little less stodgy.

We view this Test Transmission as an exercise in conviviality, surreality, and genuine love of all things radio and shortwave. 2020 has been such a serious minded year we aim to lighten that load with a bit of old fashioned fun.

For anyone who wishes to enjoy a nice winter evening around your set or online SDR we welcome you to get warm with us around the glowing tubes.

Thanks to all who tune in, and until then 73s.

Observations from the Mars 2020 Opposition

 

These are some of the drawings that I made during the Mars 2020 opposition. I would go out to my back porch with my 6 inch Dobsonian Newtonian telescope.  I would look closely at Mars, making mental note of what I was seeing. Then I would go to the shack and immediately draw what I'd seen. I would then look for relatively recent images of Mars made by people with more experience and better equipment, and I'd compare my drawings with their images -- this enabled me to understand what I was seeing.  Also useful was the Mars Profiler of Sky and Telescope magazine -- you just plug in the date and time and it displays the part of Mars that is facing us. 

I was especially pleased with the drawing and image above because I'd been reading a lot about the Hellas impact crater in Kim Stanley Robinson's Mars Trilogy.   (SCP should be SPC = Southern Polar Cap.)  

I came to think of this as the "M of Mars."  I think it is just Mare Cimmerium, Mare Hesperia, and Mare Tyrrhenum. 

bcastropics.com made this illustration of how Mars's apparent size has changed

The Parkes Radio Telescope Picks Up a Possible "Wow" Signal from Proxima Centauri (maybe)

An article about SETI and our favorite dish.  From Scientific American:  

https://www.scientificamerican.com/article/alien-hunters-discover-mysterious-signal-from-proxima-centauri/

A Very Clever Way to Build a Moxon for 17 and 20 meters

Jim AB9CN sent us Dan Zimmerman N3OX's page in response to my plea for help in SolderSmoke #227.   I think this is a very clever and attractive way to cover both bands with a single Moxon.  

http://www.n3ox.net/projects/2017moxon/

Of course there are other ways to do this -- other listeners wrote in with confirmation that it is indeed possible to nest a 17 meter element inside a 20 meter Moxon (as is done routinely with Hex beams), but this requires a lot of cut-and-try tuning of both antennas.  More in this in future posts.  Thanks Jim, and thanks to all who wrote in. 

I kind of like the N3OX approach.  I think his design makes it more of a workbench electronic project, as opposed to a mere wire and coax antenna project. But hey, that's just me. 

Grayson Evans KJ7UM's New Blog -- Lots of Great Technical Info

 

Our friend Grayson Evans KJ7UM, author of "Hollow State Design" has launched a new blog.  It is filled with great technical info.  The blog has links to the articles Grayson wrote for Electric Radio magazine.  

Check it out:  https://kj7um.wordpress.com/ 

SolderSmoke Podcast #227: Solar System, SDR, Simple SSB, HA-600A, BITX17, Nesting Moxons? Mailbag

SolderSmoke Podcast #227 is available: 

http://soldersmoke.com/soldersmoke227.mp3

Travelogue

Mars is moving away.  Jupiter and Saturn close in the sky.  And the Sun is back in action – Cycle 25 is underway.  Also, the earliest sunset is behind us.  Brighter days are ahead.

Book Review:  “Conquering the Electron”   With a quote from Nikola Tesla. 

No real travel for us:   Hunkered down.  Lots of COVID cases around us.  Friends, relatives, neighbors.  Be careful.  You don’t want to be make it through 10 months of pandemic only to get sick at the very end.  SITS: Stay In The Shack. 

Pete's Bench and Tech Adventures:  

 Backpack SDR  keithsdr@groups.io

 Hermes Lite 2

 Coaching SSB builders

 G-QRP talk  

 A new source for 9 MHz crystal filters

 Bill's Bench: 

Fixing the HA-600A Product Detector.  Sherwood article advice. Diode Ring wins the day.  Fixing a scratchy variable capacitor.  Studying simple two diode singly balanced detectors.  Polyakov.  Getting San Jian frequency counter for it.

 

Fixing up the 17 meter BITX.  Expanding the VXO coverage.  Using it with NA5B's KiwiSDR. 

Resurrecting the 17 meter Moxon.  But WHY can't I nest the 17 meter Moxon inside a 20 meter Moxon?  They do it with Hex beams.  Why so hard with Moxons? DK7ZB has a design, but I've often heard that this combo is problematic.  Any thoughts?   I could just buy a 20/17 Hex-beam but this seems kind of heretical for a HB station.

Suddenly getting RFI on 40 meters.  Every 50-60 Hz. Please tell me what you think this is (I played a recording).  

MAILBAG:  

Dean KK4DAS’s Furlough 40/20

Adam N0ZIB HB DC TCVR

Tony G4WIF  G-QRP Vids.  Video of George Dobbs. 

Grayson KJ7UM Collecting Radioactive OA2s. Why?

Pete found W6BLZ Articles

Rogier KJ6ETL PA1ZZ lost his dog.  And we lost ours. 

Steve Silverman KB3SII -- a nice old variable capacitor from Chelsea Radio Company. 

Dave K8WPE thinks we already have a cult following.

Dan W4ERF paralleling amps to improve SNR. 

Jim W8NSA -- An old friend. 

Pete Eaton   WB9FLW    The Arecibo collapse 

John WB4GTW old friend... friend of: 

Taylor N4TD HB2HB  

And finally, we got lots of mail about our editorial.   No surprise: Half supportive, half opposed.  Obviously everyone is entitled to their opinion.  And we are free to express ours.  It’s a free country, and we want it to stay that way. That is why we spoke out.

Yesterday the Electoral College voted, finalizing the results.  All Americans should be proud that the U.S. was able to carry out a free and fair national election with record turn out under difficult circumstances. And all loyal Americans should accept the results. That’s just the way it works in a democracy.

We are glad we said what we said. It would have been easier and more pleasant to just bury our heads in the sand and say nothing.  But this was a critically important election and we felt obligated as Americans to speak out.  We'd do it again. And in fact we reserve the right to speak out again if a similarly important issue arises.  

Pete Juliano's Presentation to the 2020 G-QRP Club Convention -- Building SSB Transceivers

It is a great day my friends.  G-QRP has posted on YouTube the presentations made at their 2020 convention. TRGHS! Above you can see the awesome FB contribution of Pete Juliano N6QW.  I watched it live on Zoom, but have been waiting patiently for the opportunity to share it with SolderSmoke readers and listeners. 

There are many other great videos of convention presentations on the G-QRP YouTube channel.  Here is the link to the channel: 

https://www.youtube.com/channel/UClhe-ybLZzpnJh80VmFuS-A 

Be sure to subscribe and give many "thumbs up" to the presentations. 

I see that our friend Alan Wolke W2AEW has a presentation on the NanoVNA in that channel. FB Alan. 

Thanks to G-QRP for running this event and for putting these videos on YouTube.