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Saturday, June 15, 2024

Sticker Madness, HI7, April 1

Our friend Lex astutely focused on the date of the release of our report about legal prosecution by the City of San Francisco.  The truth is that we made almost all of this up.  We did put a sticker on a lamp post at Haight and Ashbury.   Dave AA7EE did visit the site and report that the sticker had been removed.  But all the rest was made up.  We did catch several people in this annual April 1 joke.  Unfortunately, not everyone who was taken in was outraged by the city's supposed action. In fact, we got one e-mail SUPPORTING the prosecution.  This fellow said, essentially, that we were getting what we deserved, that we should take this as a life lesson, and stop with the sticker-vandalism.  He was serious.  Jeez.  APRIL FOOL!   We will talk more about this in the next podcast. 

I know the podcast has been delayed by a lot, but I am still getting things set up here in HI7 land.  I hope we will soon be podcasting with particpation from California (N6QW), Northern Virginia (KK4DAS), and the Dominican Republic (HI7/N2CQR).  

Happily, my Dominican ham radio license came through  -- I will be HI7/N2CQR for the next year.  At some point I hope to take the Dominican exam and get a real Dominican call. 

Lex has been our main point of contact in Europe on sticker distribution (aka VANDALISM!). Lex writes:   

Hello all,

Shocked to hear about the "Legal action against Soldersmoke" in podcast : 


Which could mean a few things : 
  1. some official is trying to make a career and he will be very busy because there are a lot of stickers in San Fransisco to remove.
  2. somebody did remove the sticker because they are highly collectable and somebody at soldersmoke HQ saw a opportunity to made one of the best april fools jokes in soldersmoke history pulling the listeners (and readers) leg. 
  3. somebody use photoshop and made one of the best april fools jokes in soldersmoke history pulling the listeners (and readers) leg. 

Looking at the release date of the soldersmoke podcast 251, IMHO #3 is the most possible with #2 as a good second. When #1 is the real reason, that sucks big time :-(  (so I'm hoping for the april fools joke outcome)

Let's continue and get on topic to this e-mails subject.

My XYL and I are just back from a holiday to Berlin and aside of the architecture, visiting a large number of museums and historical exhibitions, there was one place on my personal list I wanted to visit : the "Teufelsberg". 

*  The "Teufelsberg" (Devil's Mountain) is a artificial mountain build with rumble of the ruins of Berlin on top of the “Wehrtechnische Fakultät”, covert soil and plated full with trees. In the early 70's the location became one of the most important locations for the United States’ National Security Agency (NSA) outside the United States. The facility monitors Soviet and Eastern Bloc communications and gathers important information on the activities of Warsaw Pact countries. 1992 the side got intrest of creative minds and started to get covert by street art.
More info about the history can be found on there website:  https://www.teufelsberg-berlin.de/en/history/

Not only the historical part of the site, but also because the XYL and I love street art, we took a day visit it. Aside from the nice walk to it, the excellent view and the great pieces of street art, when you are at a site where street art is present all over the place and even is encouraged (and legal) and you "accidently" just happen to have a few soldersmoke stickers in you bag, you just have to use them. So as of this moment, Soldersmoke is present a the formal National Security Agency (NSA) spy station in Berlin. 

I added a few images as a attachment to this e-mail including one to show the great view over Berlin when you on the top deck (only showing one placement, the other 2 are hidden in plane site). 

In short : when you can apricate street art and visit Berlin, a visit to the "Teufelsberg" is almost a must. IBEW bonus : there are a few soldersmoke stickers hidden on the top dek for you to find ;-)

73 from PA 

Lex PH2LB 

mail : lex@ph2lb.nl
home : http://www.ph2lb.nl/   
twitter : https://twitter.com/lex_ph2lb  
call : PH2LB 

"Life's like a role playing adventure. You
need to solve the puzzles first before
they let you go to the next level."

Friday, June 14, 2024

Greetings from Low Earth Orbit

We are in the Dominican Republic for a little while. Yesterday we got Starlink working.   The picture show me holding the cell phone heralding the good news.  I am setting up SolderSmoke Shack South.  More to follow.  

Saturday, June 1, 2024

Farhan Talks Radio Tech at SolderSmoke HQ (EAST) (TWO VIDEOS!)

Great stuff!  We were really fortunate to have Farhan and Humera visit the SolderSmoke East shack after Dayton and FDIM.  Dean and I had a chance to talk BITX with the creator. Here is the two part video.  Most of the tech talk is in Part II (below).  


Farhan and his zBITX

Dean and Farhan with three sBITXs

Dean's homebrew sBITX

Farhan Phone

Wednesday, May 29, 2024

2014 "Off the Shelf" Regen Comes Off the Shelf (Two Videos)

Walter KA4KXX spotted an error in the schematic of my 2014 "Off the Shelf" regen receiver: The source resistor on the MPF-102 should be 2200 ohms, not 2.7 ohms. See:

Walter's e-mail caused me to take this old receiver off the shelf. In this video you can listen to it in action on the shortwave broadcast bands. In a second video I put it on the 40 meter ham band and listen to some SSB.

Monday, May 27, 2024

Ham Radio in China -- Interesting info from 高大伟 David Cowhig

Chinese Radio Licenses and Operating Certificates

David Cowhig (aka WA1LBP,  aka Gao Da Wei) was Hambassdor for 73 Magazine on Okinawa when I held a similar "position" on the island of Hispaniola.  David is a real Asia hand, and is fluent in both Mandarin and Japanese.   He is uiniquely sitated to provide info on ham radio in China.  In a recent post he provides this info, and describes how we may soon be hearing from ham Taikonauts in space:  


Thanks David! 

Sunday, May 26, 2024

A Really Cool Homebrew Computer

Wow, very cool.  On Hack-A-Day this morning:

It caught my eye because the architecture seems similar to that of the MostlyDIYRF PSSST rig.  

There is a lot to learn from this little machine, especially for an analog guy like me. 


Saturday, May 25, 2024

Pete Juliano's Amazing Videos -- 318 of Them!

Blogs come and go, but (hopefully) YouTube is more permanent and accessible.  This morning I re-found Pete N6QW's YouTube channel.  When you use it, I suggest you click on "oldest" first.  This will take you back 14 years,  to Pete's time in the Pacific Northwest.   The video above (him playing guitar) was shot just before he and his XYL moved back to California.  

Here is Pete's YouTube channel:  

This is a tremendous resource for ham radio homebrewers.  It should be preserved and protected. 

Thanks Pete! 

Friday, May 24, 2024

Version II of 15-10 Rig -- Updates on Bal Mod, AF amp, and RF Amp, DX

Version II of the 15-10 rig is mostly done. I did a lot of work on the AF amp, balanced modulator, Mic amp, carrier oscillator, and filter. Dean KK4DAS and I continue to test and measure the RF power amplifier. I describe the brutally simple, non-sequenced T/R switching arrangement, and the spread-out open air construction style.

Version I of this rig is on its way to the Dominican Republic. Version II will stay in Virginia. I have already worked a lot of SSB DX with this rig, including, Thailand, Taiwan, China, India, Kenya, Australia, American Samoa, and others.

This video was inspired by the recent work of Nick M0NTV and Charlie ZL2CTM. And of course, Pete Juliano N6QW.

Thursday, May 23, 2024

Charlie ZL2CTM's New Receiver

It is truly a thing of beauty.  

I really like that variable capacitor.  (Where did that come from?  How can I get one?)   

Charlie's calculations on each of the stages is -- as always -- really nice.  

I like the J-310 infinite impedance detector,  Charlie's use of solder wick,  the wooden base, and his decision to keep the circuitry visible.   

I also like Charlie's decision NOT to put that VFO in a metal box.  Too often we see projects that try to convince us that the receiver just won't work unless everything is hermetically sealed in submarine-like boxes.  Not true!  And Charlie's receiver demonstates this.   

Charlie is clearly keeping up the Kiwi tradition of fine homebrewing exemplified by the Tucker Tin 2,  ZL2BMI's DSB rig,  and many other FB HB projects from ZL. https://soldersmoke.blogspot.com/search?q=New+Zealand+DSB

Thanks Charlie!  Be sure to check out the rest of his YouTube channel: https://www.youtube.com/@CharlieMorrisZL2CTM

Wednesday, May 22, 2024

Rigs on Vertical Boards -- Then and Now

I saw this on Facebook today.  G1AVQ (SK) Rig

The G1AVQ rig reminded me of the N3FJZ rig that I worked in 2015:

I am a big fan of breadboards, and have recently been following the lead of Frank Jones W6AJF in using pine boards as the bases for my homebrew rigs.  Mine are more horizontal, but we see here from N3FJZ and G1AVQ that a vertical orientation works too.  

Tuesday, May 21, 2024

Laser Communication in London 2007 -- a Pointer, a VW Solar Panel, and Radio Kismet

Hack-A-Day has an article today about using a laser for data transmission.   This reminded me of a discussion I had with Mike KL7R about similar systems.  My son Billy and I built a very simple version in London in 2007.  Check out the podcast above.  Scroll foward to 19 minutes 15 seconds and you will hear how we did this.  

This was Mike's last podcast.  He was killed in a car accident in Hawaii about 10 days later.  RIP Mike.  73 OM.  

Mike KL7R

Friday, May 17, 2024

Band Imaging Rigs (Receivers and Transceivers) -- Video from WA7MLH

In the video above (from 16 years ago) we see Jeff Damm, WA7MLH's  band-imaging receiver for 75 and 40 using an IF of 1.750 MHz and a VFO of 5.2 - 5.7 MHz,  For a signal at say 3.579 MHz (!) you subtract the signal from the VFO and you end up at the IF.  For a signal at say 7.030 MHz you subtract the VFO frequency from incoming signal and get to the IF.  (By the Hallas rule you get sideband inversion on 75/80 meters, but Jeff was on CW so this doesn't really matter.)  

Sixteen years ago this receiver was a work in progress and Jeff was having some trouble with the bandpass filters. I had similar trouble with bandpass filters. Like Jeff, I eventually got this sorted.  

I was happy to see a comment from my friend Joanthan-san on Jeff's old video.  

Jeff has an awesome and rececntly updated QRZ site:  https://www.qrz.com/db/wa7mlh

Band imaging like this is an old idea, and a very good one:  I used a slightly different scheme:   Start out planning on using a single conversion design.  Pick two bands you are interested in.  Select an IF midway between the two.  Build a single VFO that --when added to the incoming (or the outgoing) signal will get you to one of the bands, and when subtracted from the signal will get you to the other one.  Bob is then your uncle.  Two bands, with minimal switching. 

I got started with band switching with my Mythbuster rig:  I would get 75 and 20 meters.  The IF was midway between the two at 5.2 MHz.   My VFO (from an old Yaesu FT-101) ran around 9 MHz.  Boom, it worked, with the added benefit of receiving and transmitting LSB on 75 and USB on 20 with no switching of the BFO/Carrier Oscillator.

Then I did 17 and 12 meters.  Kind of a WARC-band special.  IF was at 21.4 Mhz.  VFO ran around 3.5 MHz.  So by adding the incoming modulated signal 18 MHz signal and the VFO, you get to 17 meters.   By subtracting the VFO from the incoming 24.9 MHz signal you get to 12 meters.  And both are on USB (apply the Hallas rule), so again, no switching of BFO/Carrier frequencies are required. 

Finally,  at solar max, I built rigs for 15 and 10.  Here the IF was 25 MHz.  Again the VFO was around 3.5 MHz.  Adding the incoming 21 Mhz signal to the VFO gets you to 25 MHz, subtraction of the VFO frequency from the in coming 28 MHz signal takes you to 25 Mhz and thus 10 meters.  Again, no sideband inversion (Hallas rule).   Both signals are USB and stay on USB. (I built two versions of this rig -- one stays in Virginia, the other is heading to the Dominican Republic.) 

In the ARRL book QRP Classics, there is an article from the 1990 Handbook entitled "A Band-Imaging CW Receiver for 10 and 18 MHz."  The article may have been based on a receiver built by Dave Newkirk AK7M (Rod Newkirk's son). Unfortunately in the write-up for the ARRL handbook, the drafters repeat the oft-repeated myth about how 9 MHz IF and a 5.2 MHz VFO would supposedly produce LSB on 75 and USB on 20.  This just doesn't work.   But if you put the IF at 5.2 MHz and the VFO at 9 MHz, it does work, as demonstrated by my Mythbuster rig. 
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column