The Tropics Defined: Sun Directly Overhead on July 31 in Punta Cana DR

July 31, 2024  12:30 Local Time

Check out the shadow at my feet.  The sun is directly overhead.  This happens here on July 31, shortly after noon.  We define "the tropics" as the area of the earth at which -- as some point in the year -- the sun will be directly overhead.   Here we are at about 18 degrees North latitude, so for us, the overhead date is July 31.  We are definitely in the tropics.  A good graphical description of what is happening appears here: 

https://www.suncalc.org/#/18.5548,-68.3853,12/2024.07.31/12:37/1/3

A Wonderful Aeronatical Mobile Contact

 29 July 2024

20S 0943Z 0543L K8JSM/AM Sean, pilot on a 757/300. En route from San Francisco to Orlando with 246 souls on board, including a bunch of kids going to Disneyland.  Was 35,000 feet over Louisiana (12 miles East of Shreveport) when I first spoke to him.  (He had been in QSO with Andrew VK6IK in Western Australia.  I could hear Andrew also.) Sean was using the 400 W Rockwell-Collins transceiver on the plane (that's his picture of the control panel, above), with the antenna vertical in the back vertical stabilizer (rudder). I told him I was running 20 watts from a homebrew rig to a vertical ¼ wave ground plane antenna about 70 feet up; he speculated that the fact that we were both vertically polarized must have been helping.   Sean said he also pilots 767s transatlantic. 

I really had two contacts with him,   Around 0600 local he was calling CQ and no one was answering.  So I called him again and we continued:  I told him about the Aeronautical Mobile contact I had had from Samana.  I also told him about my contacts with MIR and RS-10 (and the RS-10 robot!) from the Dominican Republic 1992-1996.  I told him that Elisa had been present for many of the contacts with Norm Thagard on Mir station (Elisa walked in the HI7 shack at around this time – Sean said hello.)  Sean said he has been a ham for a long time – since before he was a pilot.  He has built a 2 meter “tape measure and PVC”  antenna.  I told him we have a little aircraft radio and use it to listen to the tower at Punta Cana airport, and to aircraft calling the regional ATC in Santo Domingo.  Sean says he too has a little airband receiver and often uses it to listen to airplane tower traffic.  Sean said the airline encourages this kind of contact because it is a way to keep pilots alert on long overnight flights (other pilots have other activities to do the same).  As we spoke he was waiting for a meal (salmon).  He mentioned that he could see the constellation Orion out the window;  I told him I had been looking at Orion in low in the East just before talking to him.  In the end, Sean  had to sign as the plane crossed into Florida and aircraft pilot duties took precedence.  

More info on Sean here: https://www.qrz.com/db/K8JSM     

Thanks Sean!

A Message from Walter KA4KXX -- On Bias Setting, the Joys of Al Fresco Rigs, Lawn--Sign Radio Base

 

Dear Dean KK4DAS:

...

3) Note that a rule of thumb I have used successfully in adjusting RF Power MOSFET

bias is to increase the voltage in 100mV steps, measuring the RF Output Power 

each time, and stop as soon as you start to see significantly diminishing returns.

4)  Although I did mention a plexiglass cover (the idea was from the Electroluminescent 

Receiver in photo below) in a 2017 entry I made on my QRZ page, I never built one, because I  have found a cover of any kind to be unnecessary and even detrimental based on operating portable outdoors in a public park with my rigs once every month for 10 years.  

From these experiences I have enjoyed the wonderment and respect I have received 

from fellow hams as well as passersby who have universally admired my creations. 

If the truth were known, my homebrew Alfresco transceivers might be the most 

photographed radios in all of ham history!  

Therefore, the only box I bring to my ham radio outings is for my lunch, because nobody

really gets excited about photographing just another box.

However, I do use plastic carrying cases per the photo for any rigs I carry 

in the trunk of my car.  If it rains, the top of the carrying case can be used as a 

temporary cover, so I know contacts can be made in a light rain because I have done it.

[Of course, credit card hams are not capable of operating portable even on a cloudy day

or their $$$$ radios would suffer from high humidity disease and need to be sent 

back to the offshore factory for $$$ refurbishment!]

5)  Lastly I will mention that I have never used any type of wood for a radio base because

wood is too heavy (and 1/8 inch aircraft plywood is too expensive), and the strength of

wood is not necessary to support a measly 5 pounds of electronic parts. 

Instead, per the photo, I have used Coroplast yard sign material (usually two sheets

with the channels crosswise then taped or glued together with the top covered using copper tape) common school science fair poster board, or good heavy duty cardboard such as from a TV set box.

Either light or heavy-duty double-sided tape and 4-40 or 6-32 nuts, bolts, and washers (sometimes oversized) are used to hold everything on board.  Occasionally L brackets, standoffs, hot glue, and foam or balsa wood support pieces are also utilized. 

In summary, keep up your good work as the new star on the Soldersmoke Podcast and 

please be certain Bill pays you as much as Pete.

72,

Walter

KA4KXX

Some Pictures of SolderSmoke Shack South

That's me at the operating position.   Window looks out to the terrace and to the ocean to the East, the  Mona channel.  The shack is on the top (seventh) floor. 

Here is the view from the terrace, looking South.  The big terrain feature is Cabo San Rafael. 

From the terrace looking North. 

Looking East into the morning sun 

From the terrace looking West. 

Antennas will go up there.  Perhaps solar panels too.  

A bog portion of the shack is a workbench with tools and test gear.  

Yesterday an old friend from Santo Domingo, Luis Ernesto HI8LEZ stopped by.  Thirty years ago we were pioneers in the use of amateur radio satellites from the Dominican Republic.  Luis Ernesto is in the book! 

SolderSmoke 252 Audio Podcast is Published

The delay was caused by my being at SolderSmoke Shack South and not having an Audacity audio editor in my ancient Chrome book.   Thanks to Dean KK4DAS for doing the editing, and for stripping the audio from the YouTube video.  I am getting a better computer so things should be back to normal soon. 

Here is the link to the audio podcast: 

http://soldersmoke.com/soldersmoke252.mp3

Are Hackers the Future of Amateur Radio? Thoughts from Lex PH2LB

Thanks Lex:  Your message reminded me of a comment sent to me on the YouTube channel.  The commenter seemed to criticize my use of a digital oscilloscope.  Well, the criticism came to me via the internet, computers, and Starlink, so, yes, there are great advantages to using new technology!  73 from HI7   Bill  N2CQR

Hello Bill and Pete,

On hackaday there is a post with the question : Are Hackers the future of amateur radio?

See: https://hackaday.com/2024/07/18/are-hackers-the-future-of-amateur-radio/ 

I want to share my thoughts on this.

 

Although the term "hackers" is only seen by the masses as a term for someone who gains unauthorized access to computer systems (it even appears in the dictionary that way), IMHO it is much broader. I always explain it as someone who is interested in technology and uses techniques to use things in a different way than what they where intended or to add new functionality to existing things. But also inventing new things, whether or not to satisfy his curiosity, or to learn new things in order to expand his knowledge or be able to make new things. 

With this in mind let us go back to the question: "Are hackers the future for amateur radio?"

I think that from the beginning of amateur radio, the OMs were a kind of "hackers" who satisfied their curiosity and tried things out by making things themselves. And I think it will certainly remain that way. The fact that we have started using more computer technology / digital things in our hobby is nothing but progress. You take technology as you can or want to use it. Think about the analog VFO from Bill and the Si5351 VFO from Pete, or petrol cars and electronics cars. Both have the same goal, just different tech. Or for example you can tighten a screw by hand, but you can also use a cordless drill. Do you have less technical skills? No, I don't think so, you are just more efficient, digital technology and computer technology have added efficiency to our hobby. And if other invent new things that we can use, who are we not to use those techniques to be more efficient our self or make new things?

Dan, KB6NU's put some nice HamRadio Hacking examples in his presentation (https://www.kb6nu.com/there-is-hope-for-amateur-radio/) like the SBITX (Full SDR with Raspberry PI), creating new firmware for Chinese ports, etc.  We could even return to the question discussed earlier on soldersmoke: Are radio hams 'makers'. 

And yes, the availability of off-the-shelf transmitters/receivers allows OMs, who are not so technically skilled or don't want to spend the time on it, to practice facets of our wonderful and broad hobby. So you don't have to be a "hacker" to enjoy our hobby.  And to all the (self-styled) soldering iron moral knights who criticize these OMs, take a look around your shack, you probably didn't (or even can) make everything yourself and once you have bought things. It could be that boatanchor, your  brass morse key or your first rig. And have you ever thought about you soldering iron, multi meter, magnifier lamp, wire cutters etc. . . Ok I'm just teasing now, but you all get the point. 

Most of all, aside from the question if hackers are the future of amateur radio, lets enjoy our great hobby and when you like to melt some solder . . . Just do it. 

73 from PA

Lex PH2LB 

SolderSmoke Podcast #252 -- First Podcast from SolderSmoke Shack South

For the moment this podcast is video only.  The video appears above.  Here is the URL for the video: 

https://www.youtube.com/watch?v=NeNTv3YjiHU  We will try to get the usual audio podcast version out soon. 

-- This is the first podcast from SolderSmoke Shack South:   Eastern tip of Island of Hispaniola.  Cap Cana, DR, 70 feet up, 1 mile from Mona Channel.  Seventh floor shack with view of the ocean.  Antennas:  Dipoles for now, maybe Moxons or Hex later. STARLINK

- The San Francisco case against me.  One guy thinks we DESERVE prosecution!  Get off of my lawn! 

Like the library cop on Seinfeld: https://www.youtube.com/watch?v=D9tP9fI2zbE

But one fellow wrote letter to the mayor asking for leniency.  Proposes "Bill Meara Day in SF." FB!  I fell victim myself this year:  Mike WU2D got me with WA1HLR on SSB video. https://www.youtube.com/watch?v=NLvCNJ_OnEc

-- Dean:  Fighting a spur in the sBITX.  Filters? 

-- Dean:  Exploring Class A, Class AB and the RD06HHF1

-- Dean: Extensive work on getting flat gain from FETs up through 10 meters. 

-hh- Dean and Bill:  OIP3 measurement and setting the bias on an RD06HHF1

-- Pete:  Discovers for all of us "RF Man"   In spite of all the CB stuff, he is the THE MAN!  On YouTube:https://www.youtube.com/@rfmanchannel6915

-- Pete fixes Dean's relay chattering problem: SUBTHRESHOLD CONDUCTION!  Yikes!  

-- Pete's refurb and rejuvenation of the Drake Twins, 

-- MXM news.  New docs, and ads from WD5L. All on the blog. 7030 crystals.  Why MXM? Chuck Adam's mods, Joh DL6ID's questions about VFO.  Yes!  VFO from RX.  Was Bruce Williams an early Swan Designer? 

-- Weird paradox with 25 MHz filter:  Low profile xtals have higher Q, but produce more rounded passbands.  Why?  I note that Minima's 20 MHz filter also had curved passband. 

-- Allison's wisdom on filters at higher frequencies.  The importance of physical layout.  Diodes in the dark!  It is indeed more difficult up there.  But don't let the perfct be the enemy of the good!

-- Is Bill  the only one to ever build a 10-15 Dual Bander using a 25 MHz crystal filter.  Why?  Farhan's Minima has a 20 MHz 6 pole QER crystal filter.  And it too had a rounded passband.  But it tooc WORKED.  

-- Did my receiver sound tinny due to rising frequency response of uBITX Rev 4 amp?  Yes! So I put in a  TJ DC RX Af amp.

-- Bill BLOWS UP a Tiny SA Ultra. Ooops.  But quickly got a new one from R&L Electronics.  Very, very useful.  I knew 25 MHz IF rigs were inferior, but by how much?  How much was the carrier suppressed?  Which filters worked better?  What was the opposite sideband rejection.  TinySA permitted measurement and comparison. 

-- Bill quit 15 meter SSB (for a moment) and went to the 1.22 nanometer band with a Wilson Clound Chamber.  Videos on the blog. 

SHAMELESS COMMERCE:  Thanks to new Patreon sponsors.  I am sending some additional video content to the sponsors.

MAILBAGg

-- Thanks to Bob Crane W8SX for FDIM interviews.  I will get them out! 

--Wes -- W7ZOI has a new TIA amp with variable gain on his web site: https://w7zoi.net/

-- Geoff N6GWB's Rad Receiver https://soldersmoke.blogspot.com/2024/04/the-rad-receiver-from-n6gwb.html

-- Dave K1KA sent Ensemble RTX SDR parts.   Thanks Dave. 

-- Chuck Adams AA7FO provided good background on my MXM rig, including the meaning of MXM (1990) . Again, great to hear from Chuck, a true homebrew hero.

-- Gerardo HI8P collecting info on the other HI8P, my friend Pericles (SK) 

-- Alvin N5VZH picked up a Silktronix CB VFO.  What to do? 

-- Jorgen SM4WWG listening from Sweden, and making PCBs.  FB! 

-- Mike WN2A  Wondered about opposite sideband rejection of MXM.  Not great. 

-- George WB5OYP loaned me a book from Elmer Bucher.  THE Elmer?   https://k9zw.wordpress.com/2020/01/24/on-the-origins-of-elmer-a-reasonable-theory/

-- Wes W7ZOI, Farhan VU2ESE -- Thanks for help on filter issue. Thanks too to Alan W2AEW and G3UUR

-- Josh G3MOT -- Nice message of support in our "struggle" with SF authorities. Going portable to Vancouver island in August.  VE7/G3MOT

-- Paul VK3HN -- Antipodean solidarity.  Thanks Paul. 

-- Rogier PA1ZZ -- great input and help. Thanks

-- Tony G4WIF reminded me of G3ROO's  parasets.  See Blog

-- Pavel CO7WT His experiences (building, freezing, heating) the VFO in the Jaguey DSB rig.

-- Grayson KJ7UM Sent latest ER with his Collins 51S-1 story. Thanks Grayson. 

-- Allison KB1GMX  Commiserating on higher freq crystal filters. Thanks Allison 

-- Wes W4JYK Notes that Dewey, Cheatam and Howe are based in SF. Can they help with sticky sticker problem? 

15/10 SSB Rig On-The-Air from HI7

I'm going to move the antenna up onto the roof (out of sight). 

 

Electromagnetic Waves -- Sir Lawrence Bragg -- Royal Institution (Video)

This is a really wonderful video.  I especially liked his presentation on the nature of the EM spectrum, and his use of the centimeter waves to demonstrate wave behaviour.   The two slit experiment was very nice.  Sir Lawrence's presentation on SWR was brilliant.  

Still, you wonder how would all this be done if those waves of Sir Lawrence (and Young, Maxwell and Faraday) were considered to be the photons that they also really are? 

In any case, three cheers for the Royal Institution: https://soldersmoke.blogspot.com/search?q=Royal+Institution  

A Paraset and the Heathkit SG-6 Signal Generator (Video)

Mike WU2D put out this nice video (above) about whether or not he should part out his Heath SG-6 signal generator, using the parts in a Paraset construction project.  I faced a similar question years ago: 

https://soldersmoke.blogspot.com/search?q=SG-6

I just solid stated the SG-6.  I was influenced by Farhan and the drinking straws that he picked up with his kids at a McDonalds in Hyderabad. 

As with the QF-1, I say to Mike: GO FOR IT OM!  You need those parts for other projects.  Don't feel bad about the SG-6.  But keep that switched coil assembly -- it is quite useful. 

Ham Radio Workbench: Stuffing Digital Stuff Into Poor Old Boatanchors

Let me start by saying that I LIKE Ham Radio Workbench.  But I found a lot in the current edition that I disagreed with.  The whole panel seems to be chuckling at the older gear.  And the guest is from... Flex radio.   So what do you expect?  The title was "Radio Rejuvenation" -- I expected something different.  I thought we'd hear more about how to get old tube radios going.  Instead, the  focus seems to have been on how to take an old radio and stuff an RTL dongle, or a Raspberry Pi, or a Flex radio in there.  Yuck.  

At one point they are laughing at old magic eye tubes!  They wonder if there is a digital way of recreating this tube in digital form.  Sorry fellows, that has already been done: 

https://hackaday.com/2023/04/12/the-eyes-have-it-with-this-solid-state-magic-eye/

Even an analog guy like me spotted that one. 

Here is the show:  

https://workbench.libsyn.com/hrwb-213-radio-rejuvenation-with-dan-quigley-n7hq

But hey, like I always say:  To each his own.  I'm sure many people like this approach.  It is just not for me. 

Will KI4POV on QSO Today with Eric 4Z1UG

I really liked Eric's interview with Will KI4POV:  

https://www.qsotoday.com/podcasts/KI4POV

Will has appeared on this blog and podcast before: 

https://soldersmoke.blogspot.com/search?q=KI4POV

There were a lot points in Eric's interview with Will that resonated with me: 

-- Will told about how his very understanding and perceptive wife KNOWS when a homebrew project is not going well.  Yea, we have the same situation here!

-- Will mentions the wisdom of Wes Hayward, Doug Demaw, and Pete Juliano.  

-- Eric mentioned that there is a bit of his own blood in most of his homebrew projects. One slip of he screwdriver is often enough.  My projects also often have a bit of my A+ in them.  This adds soul to the new machine. 

-- Will spoke of S-38s and HW-8s.  I have both these devices here with me in the Dominican Republic. I  have used both of them here.

-- Will mentioned the magic that comes when you listen with a receiver you built yourself.  Yes. 

-- NanoVNA.  Yes, very useful.  

Lots more great stuff in this interview.  Thanks Eric and thanks Will.