From a Student of C.F. Rockey, W9SCH

C.F. Rockey W9SCH

We have discussed the monumental work of C.F. Rockey, W9SCH, SK before.  Yesterday a comment appeared under that post that is just too good to leave buried in the comments.  It appears below.   Jeff's comment also caused me to dig up my small collection of "The Five-Watter" issues from the Michigan QRP Club.  Rockey wrote a column for that magazine.  It contains a lot of tribal knowledge.  Here is Jeff's look back:  


This turned up for me in a Google search for "Charles Rockey QRP ARRL" during a phone call with a friend of mine who was bemoaning that he never got a novice license because he could not master Morse code (he is in his mid-60s, as am I). I was taken back to the communications electronics class I had my freshman year at New Trier East in Winnetka (not Wilmette) IL in 1971. That class was taught by none other than C.F. Rockey, known to us students as The Rock. I think about him fairly often because I grew up to become a very hands-on engineer and can recall parts of his class quite clearly, even at this remove. Somewhere I still have the reports we had to write (typed on a typewriter) each week. He was a huge influence on me and I was saddened to have his passing undeniably confirmed for me. I have the little chemistry book he authored beside me now *Electrons, Atoms and The World* and am glad to be able to read his obit. One thing needs to be added to it: He won the ARRL 5000 mile-per-watt award for working Anzio, Italy from his home north of Chicago on 5W. I am very lucky to have had him as a teacher and mentor for those years. Thanks for sharing. Cheers, Jeff Mizener, DFW-TX

For those rare occasions when things go well....

SolderSmoke Podcast #218: S-38E Woes; CW filter for uBITX; A Teensy Explosion; Mint, Cheese and Peaberries; Mailbag; A SPECIAL PLEA FOR FEEDBACK

SolderSmoke Podcast #218 is available 

http://soldersmoke.com/soldersmoke218.mp3

SolderSmoke 218 is Sponsored by AF4K Crystals: 
 Bry Carling can get you the crystals you need. 

Go to:  http://www.af4k.com/crystals.htm

Flying drones with Billy.  Amazing tech out there.  In the 50 buck range with video cameras and facial recognition and tracking.  Check out Air Pix. 

Bill's Bench: 

Active CW filter in uBITX. 

Hi-Per-Mite from 4 State QRP.  Easy to do. Works well. 

uBITX to 5 W level. 

S-38E adventure.  

Replaced antenna input coil BUT -- it came from an earlier S-38 and doesn't resonate. 

So I bought a junker on e-bay and will take the E model coil out of that one. 

Had to re-string the dial!  And add rosin to it from Maria's old violin. 

BFO was not working.  Bad buzz sound. 

So:  Re-cap, Re-tube, Re-string, Re-align, Re-build power supply.  

Shortwave sounds good.  Nice to hear music coming from our machines.  

SHAMELESS COMMERCE DIVISION:   Please use the Amazon Search Box in the upper right hand portion of the blog.

Pete's Bench

A teensy-weensie explosion and fire

Mint!  Kl7FLR

60 Meters

Cheese    Microscopes

Peaberry

Radig

California hams using online SDR receivers for local nets.  

News You Can Use!

J-310s in LTSpice

MAILBAG

K5HCT August via Regen and YouTube

Doug WB5TKI and his wife read "Us and Them."

Rich K7SZ finally following SolderSmoke Podcast.  Welcome aboard Rich. 

Rick KD4KRA  His son was one of the kids in the MIR-Classroom contact that I monitored around 1993...

David AD8Y  Read SolderSmoke Book.  Similar Knack story.  Shared 1978 story:  Homework net on 75 meters.  

Paul KL7FLR Tapping and other tribal knowledge. 

Dave K8WPE   Says I'm fortunate to have a supportive wife.  So true. 

SPECIAL REQUEST:   IT IS VERY DIFFICULT FOR US TO KNOW HOW MANY PEOPLE ARE LISTENING TO THIS.  SO PLEASE, SEND AN E-MAIL TO SOLDERSMOKE@YAHOO.COM   JUST SAY THAT YOU LISTENED TO PODCAST #218 AND TELL US HOW YOU LISTENED TO IT (ITUNES, DOWNLAD FROM BLOG, STITCHER, PODBEAN, WHATEVER...  THANKS

http://www.af4k.com/crystals.htm

TRGHS: Hearing K5HCT Through a Single 12AU7 Tube with 12 Volts on the Plate (Video)

The lower portion of the column on the right-hand side of this blog is where I put links to interesting blogs, YouTube channels, and web sites.  Yesterday one of the links there led me to the above video. It presents a regen receiver using one 12AU7 tube and a 12 volt power supply.   Wow! I have many of those tubes.  And at 12 volts I am unlikely to electrocute myself.  Count me in.  

In the final minute or so of the video, the builder tunes around the 40 meter phone band.  Suddenly I heard a familiar voice.  It wasn't recorded long enough for the callsign to be heard, but I was pretty sure it was our old friend August, K5HCT (Here Comes Texas) from Odessa. 

Odessa, Texas is a good skip distance from both California and Virginia, so Pete and I have both talked to August many times. When I was testing out new homebrew contraptions, August was often there to help me out.  

I was pretty sure it was August in the video.  I checked with Pete -- he too recognized the voice.  Then I got an e-mail response from August -- yea, it was him.  

On the air, I often recognize a voice before I hear a callsign.  In this case it happened via a somewhat wobbly regen and the internet.  

THE RADIO GODS HAVE SPOKEN. 

Now where did I leave those 12AU7s? 

VK3HN's AM Pulse Width Modulated Homebrew Transmitter

I'm still working on trying to match the excellent results Paul achieved with his AM receiver.  Then this morning I wake up to a Hack-A-Day article describing his even more impressive achievement with his AM transmitter.  

There was one line from the Hack-A-Day article that made me think of Pete Juliano: 

Younger hackers will note the Arduino Nano at the heart of the project, running the VFO and handling all the relevant transmit/receive switching. We can only imagine how welcome modern microcontrollers must have been to old hands at amateur radio, making synthesizing all manner of wild frequencies a cinch.

Indeed.  

And once again this story about Paul's AM operations has made me jealous of the obviously great AM homebrew culture that exists in Australia. 

FB Paul! 

PH2LB's Homebrew Hi-Per-Mite CW Filter in his uBITX

I really like the way Lex PH2LB measures and demonstrates the effectiveness of the Hi-Per-Mite CW filter designed by David Cripes NM0S.   Watch the short video above.  The blue trace is the audio input to the filter, the orange trace is the output.  Watch the output change as Lex sweeps the audio frequency range. 

He wrote: 

After studying the schematic I shifting through my spare parts stock to collected the components and build one according there design on a breadboard (I changed the center frequency from 700 to 600Hz).
I hooked up my signal generator with a amplitude of 2v max and sweeped it from 250Hz to 2KHz looking at the output on my rigol osciloscoop. On 2khz VMAX=0.04V, 885Hz=0.2V, 700Hz=1.5V, 662-585Hz=2V, 400Hz=0.2V, 500Hz=0.9V, 250Hz=0.04V. So a nice flat top between 585Hz to 662Hz.

A full description of Lex's project (with more videos) is here: 

https://www.ph2lb.nl/blog/index.php?page=ubitx-mods3#ubitx-mod14

Lex's Knack Story and the intro to his blog is here: https://www.ph2lb.nl/blog/index.php?page=history

Tribal Knowledge: More on Tapping Metal

Back in 2014, when I was putting together my EB-63A solid state amplifier, I had to learn how to tap aluminum so that I could attach my transistors to the heat sink.  I did short YouTube video on how I did this (with tales of woe!).  This video turned out to be amazingly popular -- more than 27,000 views!  Apparently there is a great thirst for this kind of knowledge out there.  Recently someone in Alaska came across my video and shared with us some more useful information on how to tap metal.  Here is some tribal knowledge from Paul KL7FLR:  

Hi Bill and Pete,

Stumbled over Bill’s YouTube video about tapping in Aluminum and I would like to add my experience doing such. I have probably tapped over a 1000 holes in various metals, cast iron, steel, aluminum, bronze and brass from 0-80 to ¾-20. Each metal poses its own problems and solutions. There was nothing in error with your video or the method you presented.

My comments:

What causes broken taps is the tap is not being perpendicular to the work. A hole not perpendicular to the work, a worn/dull tap (this applies to the drill bit too) and lack of lube.
Every hole to be drilled and tapped must be perpendicular to the metal. A hand drill electric or battery will not be perpendicular unless two other people can spot the drill operator. Not possible when you are alone in the shop.

Any serious homebrewer should have a drill press. A small bench drill is very inexpensive. Even the $69 Harbor Freight model is adequate for the average ham’s workshop.  I see these items at flea markets and on Craigslist all the time cheap. Estate sales not so cheap but sometimes on last day you might get a bargain. Adjustable from 500 to 3600 rpm will cover all the normal sizes of drills. An x-y table could be added ($$) for added accuracy if desired. (search x-y table for examples and sources)

The size of hole you drill makes a difference too. Most drill charts assume you are tapping at 75% of thread contact. This is amount of the male thread of the bolt/machine screw threads contact the female thread in the piece. This is about the max you can expect without some precision tooling that won’t be in the average home shop.  75% provides maximum strength of the fasteners.  So unless you’re working on something that requires strength like a tower support bracket or the wings of an airplane you don’t need 75% as 50% thread contact is more than adequate. So when the drill chart shows that a #43 you can instead use a #42 or a 3/32 drill. A little bit larger hole will be a lot easier to tap threads.

The type of tap will also influence the difficulty of tapping threads. The typical hardware store tap is a straight 3 or 4 flute taper tap. The chamfer of a taper tap is 9 threads making tapping much easier. This is the tap for hand tapping.  The plug tap has a chamfer of 5 threads and is best used in a tapping head or fixture. The bottom tap is for tapping threads in a blind hole, usually after started with a taper tap. That increases the pucker factor x10. The normal taper tap cuts as it is rotated in a clockwise direction or counter-clockwise for left hand threads. The cuttings will clog the tap and you must back the tap out frequently to clean the cuttings from the flutes preventing the tap from seizing and possibly breaking the tap. Breakage is easily done with the smaller taps but also will happen to a larger tap too.  There is a style of tap called a spiral point tap. It will push the cuttings up to the top of the hole and not clog the flutes as easily as the straight flute taps. I still back it out and clean it out of habit. These don’t cost any more than the hardware taps. A 4-40 is about $2.90 the last time I bought one.

Avoid “carbon steel” taps. These will break easier than “high speed tool steel” taps and they are usually a few cents cheaper too.

Lubrication is necessary. Bill’s use of 3-in-1 oil is a good lube but “Tap Magic 20016A Aluminum” fluid is better for tapping aluminum and regular “Tap Magic” for everything else. https://www.amazon.com/Tap-Magic-20016A-Aluminum-Yellow/dp/B00065VEUO

The metal you are tapping can be an exercise in patience. “Hardware” store aluminum comes in various grades from crappy to real crappy. They are of an alloy best suited for the extrusion process and are not wonderful for the tapping process. Aircraft grade aluminum is nice stuff to work with but not cheap. Comes in many grades from 1000 series to 8000 to match the application. Grade 2024 is communally found and is easy to work with while 7075 works like steel.  Since most of us won’t be buying a 21 foot stick of aluminum or a 5x8 foot sheet we must take the hardware store grade into account when tapping holes and lean towards the 50% thread engagement, plenty of lubrication and lots of patience. I frequent several aluminum boat building firms and they let me pick through their scrap piles and I’ve made frequent donations of a case of soft drinks or a can of coffee to the break room fund and have also paid the going scrap price for the scrounging privilege.

Worn taps:  These get dull with use and will break at the worst possible time and in an expensive  workpiece. Broken taps  can be removed but are time consuming and require some expertise in doing so. Best to retire them when worn. I used to keep a chart of how many holes a particular tap had been used and at 35 holes for the small taps they got retired. 50 holes for taps larger than ¼”.  I once spent over a week of evenings extracting a worn tap from a locomotive cylinder casting. Never again! As my mentor said many times, “dull tools cause accidents and ruined work”.

Clamp the work to be tapped stationary if possible. You don’t want it moving around thus inviting a broken tap. Use some method of a tap guide (as Bill did with a block of wood, not great but better than nothing). I use what is called a “Piloted tap wrench”, https://www.amazon.com/Set-Wrench-Piloted-Spindle-Capacity/dp/B077SVQD4S .

Picture is of my setup.
Step 1: Work clamped securely to table at desired hole location.
Step 2: Drill hole.
Step 3: Use piloted tap wrench to tape hole.
Step 4: Done.

Hi-Per-Mite Active Audio CW Filter Installed in uBITX (video)

Coming home from the Dominican Republic, this was a major item on my list of desired mods for the uBITX: a narrower passband for CW.  Using the 2.3 kHz SSB passband, you could have many CW QSOs audible in your headphones.  Narrow that passband to 200-300 Hz and life gets a lot easier. 

Farhan had discussed adding a 12 Mhz IF filter of suitable CW bandwidth, but this seemed difficult to me. Besides, I have long wanted to use an active audio filter for this purpose. 

The Hi-Per-Mite filter from 4 State QRP Group is just what I needed. I built the kit without problems in about an hour, then I put it in the uBITX box, with  switch on the front panel that lets me put it in the circuit or take it out -- this is very satisfying and a lot of fun.  

The Hi-Per-Mite just goes between the uBITX audio out and the speaker/headphone connection. I built mine for "no gain" -- the uBITX provides plenty of audio. 

The selectivity with the Hi-Per-Mite compares favorably to that of my Drake 2-B with the 500 Hz LC filter.  You can get an idea of the performance in the video. 

Three cheers for the 4 State QRP Group and their Hi-Per-Mite!  Here is the page with all the info: 

http://www.4sqrp.com/hipermite.php

K6RRE's One Tube Rig Project

Mike will send us more info later... 

The Elektor SDR Kit: Arduinos, Si5351s, Sound Cards, WSPR, QRP Transceiver (video)

Obviously a lot of potential here.  Thanks to Hack-A-Day for the alert. 

https://hackaday.com/2020/02/14/rf-shield-turns-arduino-and-pc-into-shortwave-radio/#more-398447

The Si4730 Radio Chip (Luddite Alert!) (video)

I have misgivings about this.  Hack-A-Day presents it as a DIY radio project and wonders if this might be the modern equivalent of the crystal radio projects of days-gone-by.  But notice that the "build" video focuses mostly on building the box.  The electronic "building" of this radio mostly involves plugging in two chips, or two boards with chips. My questions are: 

1) When this project is finished, who REALLY built it? You, or the Si4730 manufacturer?  

2)  After you've "built" this thing, would you have the same sense of accomplishment that you get from an analog, discrete component project?  Or even from that crystal radio?  

Of course, to each his own.   This is all for fun.  Have fun with the Si4730.  But today I'll be working on my Hallicrafters S-38E. 

https://hackaday.com/2020/02/12/all-band-radio-uses-arduino-and-si4730/

TRGHS: Hallicrafters S-38E will NOT be Discarded (video)

My Hallicrafters S-38E was on very thin ice.  I had grown tired of the little beast.  Its dangerous no-transformer power supply had caused me to risk death and to fry one of the RF input coils (that happens if you short the antenna input to an inadvertently hot chassis). It is rickety and old and I just got tired of working on it.  I had down in the basement, awaiting disposal of some kind.  (I'd been afraid to give it away, fearing that the recipient might electrocute himself.)  But recently I've been doing some shortwave listening and this caused me to reconsider the S-38E.  

Around this time, while looking at e-bay, I saw some guy selling just the RF input coil that I had fried.  So I bought it.  Then I pulled the S38-E out of the basement and fired it up.  I realized that I had already done a lot of work on it.  I had put in an isolation transformer, so the receiver was no longer quite so dangerous.  I'd already replaced most of the capacitors.  It sounded pretty good on the AM broadcast band.  Then, in my first scan of the shortwave bands, I heard the William Tell Overture pouring from the speaker (see video).  Could it be?  Perhaps a replay of the Jean Shepherd show?  No, but I soon heard the familiar voice of Tim WA1HLR -- he was doing his show on (I think) WBCQ shortwave, just above our 40 meter band.     

THE RADIO GODS HAVE SPOKEN.  THE S-38E STAYS!  

Volcano Light in Chile

This popped up on Twitter today.  It is from 2018 -- the Villarrica volcano in Chile.   Interesting shot. The label said it was taken during a snowstorm, but I don't think that is right -- the "snow" is actually stars and that big white thing in the cone of red light is the Large Magellanic cloud.  

https://www.reuters.com/news/picture/photos-of-the-week-idUSRTS209HO

W6IQY's Homebrew SSB Transceiver from the mid-1960s

Oh wow, it is definitely a thing of beauty.  Bob W9RAN acquired this homebrew gem and put it back on the air.   Bob also wrote a very nice article about the rig and how it was made.  (Mike WU2D should brace himself -- many surplus rigs were cannibalized in the process.)  It is especially fitting that I post this today because February 9 is the day of the Classic Exchange on-the-air event.  (My DX-100 is warming up.) 

Here is the article:   http://tinyurl.com/rjqq6eo

Bob's site has some more really wonderful articles.  You can read about Heathkit monobanders, DX-60s. ELMAC power supplies and -- my favorite --  Mike Hopkins and the Five Meter Liberation Army.   The FMLA was, of course, the forerunner and inspiration for our current Color Burst Liberation Army. 

See it all here: 

https://www.rantechnology.com/index.cfm?key=browse_resources&PostDate=all&CategoryID=8E884CE4-9CED-4957-872B-5EBDB058D540 

Thanks Bob! 

AM Rally Report -- Great Contacts on 40 AM

The AM Rally this past weekend was a lot of fun.  I was reminded of how the guys that you talk to on AM are just so much more likely to be running interesting homebrew or vintage gear.

First contact was with Howard VE2AED who has one of the most amazing antenna farms I have ever seen.  Take a look:  
https://www.qrz.com/db/VE2AED
He also has an R-390 and a KWM2 in his shack. 

Next I spoke to Robert W0VMC (Voice Modulated Carrier) out in Wisconsin.  Robert is a homebrewer of AM gear with a Knack story that is very familiar:  http://w0vmc.com/

Next up was W4GON.  Joel was on the homebrew AM transmitter that we reported on back in 2017:
https://soldersmoke.blogspot.com/2017/08/thermatrons-al-fresco-w4gons-fb-hb-am.html

Joel has completed his rig, adding a FB front panel.  Here it is: 

Then came the W1AW contact.   See the video above. 

Finally, I talked to Jack W9GT who was running a rig that must be unique on the amateur bands: A Federal 167 B Maritime transmitter.  You can see this magnificent transmitter here: 

https://www.qrz.com/db/w9gt

SolderSmoke Podcast #217 -- Beach trip, '30s station, uBITX mods, HRO RX AM, ELMAC, Teensy, MAILBAG

Bill's Bavaro DR Beach Station
uBITX in the box, HB key

SolderSmoke Podcast #217 is available: 

http://soldersmoke.com/soldersmoke217.mp3

1 February 2020

Travelogue!  Dominican Republic trip.  uBITX on the Beach.  EFHW.  LiPo Battery.  First contact of the new year. 

Bill's Bench Report

Following up on proposed uBITX mods: 

-- Put pot on sidetone line from Raduino to keep the sidetone a bit quieter. 

-- Fixed the key -- pounding brass

-- Will install 4 States QRP Active AF filter. 

-- Need to reduce power on CW to 5W

-- Stereo to mono headphone adapters. 

-- Turning off display and mic amp circuit not really worth it -- they don't pull much current. 

Pete's Bench Report: 

ELMAC Power Supply project 

1930s era transmitter? 

Teensy and SDR

PETE'S IDEA ABOUT GETTING LSB AND USB FROM BITX40

KWM-2 suggestions

Back to Bill's Bench:

Working on HRO-ish Receiver. 

Bad SBL-1  

Got idea for wider ceramic filter from Paul VK3HN

Ordered parts from Mini-kits in Australia.  They sent 6kc filters. 

Bruce KK0S sent me some 10 kc filters too. 

Installed 6 kc filter with L network matching networks.  Works great. 

Also installed Infinite Impedance Detector that Paul used. 

Needed some additional amplification ahead of the IID, so I used one stage of BITX amp. 

Works great. I can tune full 40 meter band AND 49 meter SW band.  Radio Romania, China, Radio Marti, Brazil, South Carolina. 

Beefed up the shielding to cut down on AM detection. 

MISCELLANY

-- AM and DSB in LTSpice

-- Duly Noted:  Paul  VK3HN's RIG:  "THIS MACHINE KILLS KILOWATTS"  

Kanji YC3KNJ's QRPesso Expresso Coffee in the field

-- The DANGERS of powerful magnets. 

MAILBAG: 

--KK4DAS Dean doing great things.   MMM heard at Penn State.  Where is the rest of the CBLA?

-- Thanks to Don for kind donation to the SolderSmoke cause

-- Dale BA4TB -- First SolderSmoke feedback from China.  Thanks Dale!  

--Steve Silverman:  Sideswipers and bugs were made to handle "carpal tunnel of the day"  So do I need a keyer for casual CW work? 

-- Peter VK8VWA on the limited knowledge gained from kit building. Listens to podcast while walking on the beach in Australia. 

-- Allan Hale -- Clothes Pins as Toroid holders.  Yes!  More Clothes Pins   Wild Woody Keys from Dave Ingram 

-- Pete WB9FLW  100 Watt Amp from WA2EUJ  

-- Dave Wilcox K8WPE   A medical question:  Does the Michigan Mighty Mite work differently depending on what kind of medicine was in the pill bottles used for the coil form?  Good question Doc!   Dave suggest that putting CBD on the coil or the crystals.   Anything to mellow out the ham bands... 

Pete's Plank SDR
When you know stuff, you can do stuff!

WA2EUJ's NXP RF Power Amplifier Design Challenge Entry -- Won First Place Prize!

Congratulations to Jim WA2EUJ.   First Place the NXP Design Challenge. 

You can buy the board here: 

https://sites.google.com/site/rfpowertools/home/nxp-mrf-101

Thanks to Pete Eaton WB9FLW for alerting us to this. 

Mountain Topping in Indonesia -- Very Cool Video

OM Kenji has an awesome video about a mountain topping trip that took place in Indonesia just yesterday.  Very nice.  

I like the use of the neodymium magnets to attach the paddles to the rig.  I may try that with my homebrew straight key and the Samana-uBITX. Or I may have to get a keyer and learn (finally!) to use paddles.  (But simplicity is a virtue and there is nothing more simple than a straight key.) 

Kenji is obviously an amazing cook, even in the field.  I like the coffee-making technique. 

Check out more of his videos (and subscribe) at his YouTube Channel page: 

https://www.youtube.com/channel/UCpfn1viFoqVmWk6x891nKaQ   

Thanks Kenji! 

DK7IH's New HOMEBREW Transceiver Raises the Bar for All of Us

And that, my friends, is a HOMEBREW transceiver.  Wow, amazingly well done.  After I showed this to Pete N6QW (no slouch in the homebrew packaging department), in frustration with his self-perceived shortcomings he threatened to give up on homebrewing and to throw away all his rigs. Don't do it Pete!   

Peter Rachow, DK7IH has carefully documented his project through as series of blog posts: 

Here is Part 1: 

https://radiotransmitter.wordpress.com/2020/01/03/an-experimental-hf-6-band-ssb-transceiver-part-1-basic-outline/

Part 9 deals with mechanical construction, packaging and what George Dobbs used to call "socketry."

Thank you Peter for taking the time to share your project with all of us.  It is really inspirational. 

Junk Box Ethics -- I Plead Guilty! (video)

I cringed when, at about the 32 minute mark,  during a discussion of the moral necessity of preserving old gear, Michael appeared on the screen with a Heathkit Q multiplier sitting right there next to him.  It was as if he was talking about me.  I felt as if I had been hauled into Ham Radio Court, Judge Michael Murphy presiding. 

I have already REPEATEDLY admitted to sacrificing MULTIPLE Q MULTIPLIERS.  But I did it for good reasons:  

1)  I have some objections to use of regeneration, especially in superhet receivers.  After all, Armstrong created the superhet in part to free us from the tyranny of regeneration (that he had also invented).  

2)  This is a case where the parts ARE greater than the sum.  Specifically that variable cap WITH reduction drive.  And that perfectly sized metal box. Those capacitors are currently in service in at least two of my homebrew SSB transmitters. And as I look around the shack, I see one of those boxes housing an Si5351 VFO, and another holding the dual-digital frequency displays for my DX-100/HQ-100 AM station.    

3)  Mike notes that these Q-multipliers are being sold for TWO DOLLARS at hamfests.  At prices like this, temptation is just too strong. 

So I plead guilty, your honor.  But I ask the court to consider the circumstances under which I dismantled this obsolete gear, and the good uses that I made of the parts that I obtained.  Also, I'd like to make note of the fact that I salvaged from a junk pile a Heath VF-1 (I completely rebuilt it) AND I restored to usefulness a Heath DX-40 -- both these devices appeared in the WU2D video.  Finally, if anyone really needs the remaining parts from the now deceased QF-1s, I'd be willing to donate them (in an effort to redeem myself). 

Thanks Mike!  

How to Generate an AM Signal (and DSB!) in LTSpice

Pretty cool and very useful.   You can also do this by using the Modulator symbol, but I found this technique easier and more straightforward. 

But be sure to watch all the way to the end of the video.  Early on, he forgets the step that causes the carrier to stay in the simulation, but then shows how to correct this.  In the process we learn how to create a DSB (suppressed carrier)  signal in LTSpice. 

Lebanon's First Radio Website

I found this site through Paul VK3HN.  He took the AM detector circuit for his AM receiver from one these Lebanese homebrew radios.  

There is some really great information on this wonderful website.  It has been online for some 20 years -- I wish I had found it earlier.  The author shares his Knack story -- this is a wonderful example of the International Brotherhood of Electronic Wizards (IBEW). 

http://www.midcenturyradios.com/index.html

And he has very cool schematics, really well done.  Click on image to enlarge: 

Wild Woody WARC Keys

From the NAQCC newsletter: "The key is Dave's own unique invention called the WILD WOODY WARC KEY, and each key is consecutively serial numbered. (My key is number 476). WILD WOODY WARC KEYs have a place of honor in the ARRL Headquarters, and in the offices of Kewnwood, Icom and other such places. Dave, as some of you may know writes a monthy column for CQ Magazine and is the author of several books on keys, QRP operation and other subjects. The WILD WOODY WARC KEY is pictured below. Ingenous simplicity -- a true work of wonder. Thank you Dave."

I post this for several reasons.  

1) A friend recently complained that telegraph keys are getting expensive.  "Ha!" I said.  This proves me right.   Clothes pins are not expensive. 

2) I think we should make more use of clothes pins in ham radio.  They were used in my 20/15 meter dipole in the Dominican Republic. 

3) I worked K4TWJ several times -- twice from the Dominican Republic, and once from Virginia using a homebrew transceiver that he had inspired.  He was pleased.  It was cool. 

4) As a little kid, I liked Woody the Woodpecker. 

4) On Thursday morning my wife and I saw a Pileated Woodpecker (just like Woody!) in our neighborhood.  TRGHS. 

Mr. Carlson's Lab Attacked by Dangerous Canadian Snow Static! (Video)

Even when describing something as simple and basic as snow, Mr. Carlson is electronically awesome.   This video made me realize that in the event of an EMP, his will probably be the only lab to survive.

The SolderSmoke Daily News took up the topic of snow static back in 2011.  Be sure to read the comments, especially the one from KC7IT about the QUARTER INCH ARCS that woke him up in the dorm at MIT.  Check it out: 

https://soldersmoke.blogspot.com/2011/10/snow-static.html#comment-form

I've got to get one of Mr. Carlson's 2020 calendars! 

  

Hack-A-Day and Copper Tape

https://hackaday.com/2020/01/15/the-flexible-permanence-of-copper-tape-circuits/

and

https://halestrom.net/darksleep/blog/039_coppertape/

The End Fed Half Wave Antenna and EFHW Tuners

In the SPRAT 179 (Summer 2019) article describing their Peregrino (Pilgrim) transceiver,  Joan EA3FXF and Eduardo EA3GHS recommend the use of an End Fed Half Wave (EFHW) antenna. Their circuit incorporates an EFHW tuner and an SWR indicator.  As I planned my trip to the Dominican Republic with a uBITX, I had this antenna system idea in mind.  I was attracted by the possibility of avoiding having to carry coax with me.  And it seemed that an EFHW antenna would be easier to get up in the air than a coax-fed dipole. 

When searching for schematics for EFHW tuners I came across the QRPguys tuner kits.   

https://qrpguys.com/end-fed-half-wave-sota-antenna-tuner

This looked like just what I needed, so I ordered one.  But I placed my order kind of late, and I started to worry that I might not get the tuner kit in time.  So I decided to homebrew my own (just in case!) 

As it turned out, QRPguys got the kit to me in plenty of time. It went together very quickly and is a really useful piece of gear.  My homebrew version works fine, but I prefer the QRPguys device. 

You can check out the manual here: 

https://qrpguys.com/wp-content/uploads/2019/09/efhw_40m_tuner_assy_090119.pdf

The circuits are interesting.  The EFHW antennas present an impedance not of 50-70 ohms, but of 3000-5000 ohms.   The Peregrino and the the QRPguys circuits use a matching transformer to change the high impedance to 50 ohms.  In both circuits polivaricon capacitors are used to tune for resonance. The QRPguys circuit uses an N7VE LED absorption bridge -- I found it very satisfying to put the circuit into "tune" mode and then just adjust the capacitor until the LED went out.  That means the antenna system is presenting 50 ohms to the transmitter. 

SOTA beams has a good explanation of the EFHW antenna here: http://sotabeams.co.uk/efhw/
I did use a counterpoise. 

The Experimenter

https://www.americanradiohistory.com/The_Experimenterr.htm?fbclid=IwAR2k7bmbXoRXg6rTiy411riH1WfWUvqso1lpGEn8cEEGk2JKb8FKB4OT7zo

I think I have a set of those headphones. 

Thanks to the K9YA Telegraph for alerting us to this.   

Mike WU2D on QSO Today with Eric Guth 4Z1UG

Eric Guth has a great interview with homebrew and boatanchor guru Mike WU2D.  

Listen here: 

https://www.qsotoday.com/podcasts/WU2D

Wow: "My receiver was from a Sherman tank." 

His story about getting in trouble after "borrowing" his friend's callsign was really great. 

I also liked his wise comment about how anyone who homebrews simple gear will collect some "wallpaper" from official observers and the FCC.   Mike is right:  we shouldn't get too concerned about minor transgressions. If we do, we run the risk of becoming so careful, cautious, and fearful that we never BUILD anything.  

There is a wonderful discussion of the Paraset. 

Mike coins a term that we might want to add to the SolderSmoke lexicon:  RetroQRP.  (Over to you Steve Silverman.  Your call OM.) 

Notes From the Dominican Republic on possible uBITX mods

It was really great to have the multiband and CW/SSB capabilities of the uBITX with me in the Dominican Republic.  And even with my large wooden box, the rig and all its accouterments fit into my carry on baggage (and there were no problems with airport security). (In the picture above you can see the cloth case that held the whole station, including the antenna.)  

As I used the rig, I thought about possible mods for future operations.   Here are some ideas: 

-- Filter for CW?  Definitely.  Farhan suggested switching in a more narrow 12 MHz IF filter for CW operations, but that seems like a bit too much work.  I am going to try to use an audio frequency filter.  I've ordered the active CW filter from QRPguys.  I've long been intrigued by these kinds of filters, but they didn't seem very wirthwhile with a DC receiver.  With a superhet like the uBITX they make a whole lot more sense. 

-- Sidetone volume control.   Need it, especially with fellow vacationers trying to sleep nearby.  Should be easy -- just a pot on the side-tone line.

-- Low impedance mono headphones.  Need them.  

-- An LED light for logging.  Would help. 

-- Switch to turn off the 16X2 display to save power?  I thought about this but I checked after we got back and the whole display pulls only about 20 ma.   So it probably isn't worth it to put in a switch. 

-- Internal protective cover for the uBITX board.    I used the extra space in my big wooden box to store the key, the mic, the battery, the tuner, etc.    They all bounce around a bit and could damage the uBITX board.  So I will try to build in some internal physical shielding, perhaps from a BITX plastic box. 

-- Brass contacts for my homebrew CW key.   I think brass is better than the copper foil I am currently using.  I already did this with some brass bolts from the local hardware store.  Mush improved.  Pounding brass is better than pounding copper tape. 

-- I installed an additional stage of microphone amplification but I have this stage running even on receive.  But I checked and the amount of current pulled by this stag is so small that it is not even worth changing the power supply line. 

--  Reduce output to below 5 watts on CW.   To make the rig "QRP Compliant."  

In the pictures you can also see my homebrew straight key, the QRPguys EFHW tuner, my mic (the original SolderSmoke podcast mic!), the 3 amp-hour LiPo battery, the additional stage of mic amplification.   The little relay that you see just above the mic amp allows for the keying of an external amplifier. 

Aeronautical Mobile Contact from the Dominican Republic

767

On the morning of January 9, 2020, I was up early, sitting alone out in my open-air tropical hamshack on Bahia Rincon on the Samana peninsula of the Dominican Republic.   I had been looking at the stars. As the sky brightened I was listening to band noise from a still-dead 20 meter band on my uBITX.  

Skies were partly cloudy.  The Big Dipper hung upside down in front of me.  I had also seen Corvus, Scorpio, Andromeda, and Leo.  There were a few meteors and one bright satellite.  

But 20 was quiet... until, suddenly,  BOOM! A very loud and clear SSB signal came through.  It was KX4WE/Aeronautical Mobile.  Mike was in a 767.  I called him and he came back right away, giving me a 57 report. He gave his position as 170 miles Northwest of San Juan, Puerto Rico.  He was heading to Port-o-Spain, Trinidad from Miami.  We had a quick QSO -- it reminded me a lot of my contacts with the MIR space station from Santo Domingo in the mid-1990s.  Suddenly Mike's signal dropped very significantly.  I figured that he had moved further south and was no longer line-of-site with me. I had some hills to my south and they were now attenuating Mike's signal.  I could hear him working M0NKL.  We were Mike's only two contacts on 20. 

I realized later that had I looked up, I might have seen the lights of the plane.  Below is the track of the aircraft.  He was at 35,000 feet when he passed over the DR. 

This contact was a lot of fun. Thanks Mike! 

Contacts from the Dominican Republic

Below I have my log from the Dominican Republic.  A few noteworthy contacts highlighted in yellow.  The first contact was actually on 30 meters,  My guess is that the 20 meter EFHW and the counterpoise got close to half wave on 30. 

AE7KI's was a famiiar voice. Terry transmits from Tennessee but his voice is from down under.  I recognized him before I heard the callsign.  

F6HKA was a familiar call.  I checked -- he was a Straight Key Night contact from one year ago.  Great to meet up with Bert again. 

The Aeronautical Mobile contact was icing on the cake.  More on this tomorrow...

Thanks to all who contacted me or tried. 


In the Dominican Republic 30 December 2019 – 11 Jan 2020

4Jan2020 

30 meter CW HK1ANP Fred.  I was in Bavaro.  30 meters on an 20 meter EFHW!

All subsequent DR contacts on 20 meters from Samana near Las Galeras

6Jan2020

0922 CW EW1I Alex in Belarus.

0959 SSB KG4ZEC. A net on 14.300

1657 CW KB3WAV Md

1701 SSB AE7KI Terry – old friend from Tennessee and Australia.

7 Jan 2020

0917 CW F6HKA Bert near Limoges 14.050 SKCC 60693

1500 CW KN4ZQ Dave in Palmyra Va. Me 599

1523 NO CONTACT but close,  CW KC2OHL

1800 CW KC5F Steve – he answered my  CQ   NC SKCC 21092T

8 Jan

CW N3JB John in Va. Me 599

CW W9YXX Bob in Ind. Me 569

1749 CW W8TK Tom in Tuscon Az.

9 Jan

0700 SSB KX4WC/AM Me 57 767 170 miles NW of San Juan

0840 SSB KI5PZE Miguel, Lake City Fla. In Spanish.

0908 SSB W1FDY Jack in SE Va. Me 58 

The point of the Pen shows where we were in Samana. Bavaro is on the Eastern tip if the island.

N2CQR Portable with uBITX in the Dominican Republic (video)

More to follow... 

KK4DAS Michigan Mighty Mite Heard by WEB SDRs -- CBLA Mobilized!

Dean KK4DAS continues to do great things with his Michigan Mighty Mite.  He has been calling CQ on the Color Burst Liberation Army (CBLA) frequency of 3579 kHz.  I think I was the first one to hear him, but since that memorable moment he has been picked up by multiple Web SDR receivers, including the one at Penn State (PETE JULIANO'S ALMA MATER!)  (screen shot above, listen by clicking URL below).  He has also been heard by Web SDRs in Concord Mass,  Newport News Va, and Cleveland, Ohio.  FB Dean.  

So come on folks -- this is a mobilization call for the CBLA!  Get those MMMs on the air.  Send us reports and recordings from Web SDRs or the RBN. 

Listen to Dean's MMM as received at the Penn State Web SDR: 

http://soldersmoke.com/KK4DAS MMM.wav

It sounds great!  And nice CW Dean!  

Santa Came to SolderSmoke! From Australia!

Oh wow!  Santa Claus made a really long distance DX trip to SolderSmoke's East Coast HQ last night.   His chief Elf this time was Peter VK2EMU who crafted the AMAZING Morse key you see in these pictures.  This is truly a work of art.  I will indeed put it on the air with a homebrew transmitter.  And we will keep on soldersmoking.  

Thanks very much Peter.  This was really great.  

Merry Christmas to all!  

Dean KK4DAS Puts Michigan Mighty Mite on the air! And is heard in Falls Church, Virginia! (video)

QRZ.com says we are 5.9 miles away.   The U.S. Postal Service almost prevented this from happening -- they objected to my just putting the crystal in an envelope and mailing it.  Dean's wife had to pay postage due.   

The rig didn't work at first, but Pete N6QW provided sage advice and tribal knowledge.  Adjustments were made and Dean experienced the Joy of Oscillation.  Then, he connected an antenna and was heard at the SolderSmoke East Coast HQ. 

Obviously the beret was the key to Dean's success: 

This was a lot of fun.   And it is a reminder of the power of the MMM.   Dust off those Mighty Mites!  Call CQ and see if you can be picked up by the Reverse Beacon Network.  Let us know if you succeed.   

Getting ready

Done!  Dean's MMM