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/