Another M^3: The Michigan Micro Mote

Move over Michigan Mighty Mite and Mate for the Mighty Midget.   There's a new M^3 in town.  And it is SMALL. 

Hack-A-Day had an article on this today, and while it seems only tenuously connected to ham radio, I found it intriguing.  

Check it out.  Who knows, someday people may be operating in "dust mode":  

https://hackaday.com/2021/10/04/snails-sensors-and-smart-dust-the-michigan-micro-mote/#more-498450

Dean KK4DAS Builds an EI9GQ 16 Watt RF Amplifier (and Noodles in the Process)

 

I really like Dean's description of the building process, especially where he describes the need to sit down with paper and pencil for some noodling.   We see that in the picture above.  Too often we hear from guys who seem to be looking for detailed, step-by-step instructions, and then get frustrated and stuck when this kind of detail isn't available. Dean shows what to do in this situation:  noodle! 

Check out Dean's blog post on this project: 

https://kk4das.blogspot.com/2021/10/ei9gq-16-watt-power-amp-start-to-finish.html

Dean's post made me think about the origin of the verb "to noodle."  We know it has its origins in music.  Google provided this interesting explanation: 

To noodle around on something, while it does make use of the noodle (head), may derive from the regional German nudeln, to improvise a song, or from the late-19th-century Scottish sense of noodling as humming a song to oneself. By 1937, to noodle was to fool around with notes to create music.

We noodle around with parts and schematics to create rigs. 

Scott WA9WFA's Mate for the Mighty Midget Receiver is WORKING! (Video)

Wow, Scott got his Mate for the Mighty Midget receiver to work and he is obviously overjoyed with the result.  All of us who have struggled with a homebrew project know just what this feels like.  And it is very cool that Scott got some useful guidance from Charlie Morris in far-off New Zealand.   Congratulations Scott.  I'm really glad you stuck with it.  

Scott's success comes at a good time:  Pete N6QW is building W4IMP's three tube "IMP" SSB transmitter (also from the 1960s).   I accept responsibility for naming Pete's project:  It will be known as "Pete's IMP" or, memorably,  "The PIMP."  For a look at Pete's rig go here: 

http://n6qw.blogspot.com/2021/09/lets-build-something-with-vacuum-tubes_23.html

Scott had problems getting Lew McCoy's 455 kc crystal filter to work.  So did I.  It turns out that this is a very old problem, going back to World War II.  In Don Stoner's 1959 "New Sideband Handbook" on page 54 he writes of homebrew filters in the 400 to 500 kc range:  

"Inexpensive crystal filters constructed from war surplus FT-241 type low frequency crystals are very popular with the 'do it yourself' hams. These CT cut crystals have been plentiful and relatively cheap for a number of years and are in the hands of many Amateurs. The general run of war surplus crystals may or may not be good. Experience has shown that one out of four of these crystals are usually defective in one way or another." 

Stoner was writing just 14 years after the war.  Add another six decades to the age of these crystals -- often decades spent in musty basements -- and you can imagine the percentage of bad 455 kc FT-241  crystals increasing.  So I think Scott is wise to seek an alternative to McCoy's crystal filter. 

Scott's original build of the MMMRX receiver is just so nice.   In the video he says he plans to go back to it after he gets the expanded version fully functional.  He should definitely do that -- his  original version looks so good.  I think it is probably very close to working properly. 

Thanks Scott, and again, congratulations OM. 

Selenium RECTIFIED

Selenium rectifiers. The name kind of sounds like Dilithium crystals, possibly related to flux capacitors. 

Anyway, there were two of them in the Globe Electronics V-10 VFO Deluxe that I recently bought.  Obviously they had to go, so I took them out yesterday, replacing them with a 1N5408 silicon rectifier.  

The new diode had a significantly lower voltage drop than the selenium rectifiers -- this pushed the output voltage from the power supply up to around 200V.  It is supposed to be around 185 V.  So I put a 470 ohm,  5 watt resistor (found in the junkbox) in series.   This brought the output voltage to 167 V.  Close enough.  VFO seems to be working fine.  

I'm glad I did the extraction before these aging components released their nasty toxic smoke. 

W3HWJ has a good article on replacing these nasty old parts, with some interesting info on their history:   http://www.w3hwj.com/index_files/RBSelenium2.pdf

Backgound on the element Selenium:  https://en.wikipedia.org/wiki/Selenium

Chuck Penson's Amazing New Book about Heathkit Amateur Products

 

I was very pleased to read that Chuck Penson WA7ZZE was publishing a book about Heathkit's amateur radio products.  His book is a really great guide, providing a lot of fascinating information, stuff that even those of us who have spent decades with pieces of Heath gear didn't know.  For example, I never knew that an after-market dial had been available for the HW-101.   And I didn't know that the Indian names used for many of the Heath rigs (Comanche, Apache, etc.) resulted from a suggestion from Roger Mace's wife, who was Native American. 

Chuck's book arrived just as I was putting my DX-40 novice transmitter back on the air after almost 50 years.  TRGHS.  Who knew that there were TWO versions of the DX-40?  I didn't, but Chuck did, and his book explained how to spot the difference (flashlight through the side vents -- I have the very slightly more modern version). 

When I opened the book for my first peek inside, the page opened to the QF-1 Q multiplier.  I immediately felt guilty about having brutally cannibalized several (well maybe more than several) of these things.  But right there in the text Chuck repeats my justification for the carnage:  He notes that the tuning cap has a nice 14:1 turns ratio.  Exactly.  How could I NOT pull those beautiful variable caps out of that old regen device, for re-use in superhet receivers and BITX transceivers?  

This is a wonderful book that belongs in the workshop libraries of all those who have used and loved Heathkits over the years.   

Order yours here:  

https://wa7zze.com/amateur-radio

Thanks a lot Chuck for making such a great contribution to the radio art and to ham radio literature. 

N2CQR (WN2QHL) Novice Station Re-Created

 

There it is.  The 2021 re-creation of the WN2QHL Novice Amateur Radio Station.  This is what I had when I first went on the air in April 1973 from Congers, NY. 

-- I got my first Lafayette receiver (WITH JEWELED MOVEMENTS!) for Christmas in 1972.  My mom drove all the way into New Jersey to get it for me. 

-- I bought my first DX-40 and the Globe VFO Deluxe from someone in the Crystal Radio Club.

For this re-creation station: 

-- I got this recently acquired Lafayette free-for-pickup from a very kind SWL in the Shenandoah valley.  (I've discussed this receiver extensively here.) 

-- The DX-40 is the result of a couple of junkers that I bought in a hamfest some 23 or 24 years ago.  It might have been the Timonium Hamfest.  I cannabalized one of them and made one good DX-40 out of the two.  Parts of the cannabalized unit carry on the good fight as pieces of my balanced  antenna tuner (the coils were useful there) and as the chassis for my first SSB transmitter. 

-- The Globe VFO Deluxe was harder to recover.  There are just not a lot of these things around.  I actually put up a plea for one of these on the SolderSmoke blog.  Not even the IBEW could come up with one of these things.  But then, last week on Facebook I came across a fellow who was selling one.  Deal!  Check our the nice Juliano Blue light indicating 40 meter operation. 

Putting these three devices together was more challenging than I thought.  To get them to work together decently three different things had to happen as the result of throwing one switch: 

1) Antenna had to switch from receiver to transmitter. 

2) Receiver had to be largely muted (leaving some key-down signal for sidetone).  

3) VFO had to be turned on (I left it running and just keyed the DX-40).  

Fortunately I have almost 50 years more experience than I did when I first set this station up.  So I was able to do this better in 2020 than I did in 1973.   I had a 3PDT relay that I had built for a DX-60 station.  I was able to use it to do all three things described above. 

Muting the Lafayette was a bit tricky.  On the back octal connector they have two post  (1 and 3) that are normally connected.  Disconnecting 1 from 3 completely mutes the receiver by cutting off a needed ground connection to the RF amplifier and to an IF amplifier.  The Lafayette manual tells you to connect these terminals to the "muting voltage" presented by your transmitter.  The DX-40 doesn't have such a voltage, and I was reluctant to connect any voltage to this terminal for fear of blowing up the RF and IF amplifiers.  I figured that just putting a big resistor across 1 and 3 would mostly mute the receiver.  The 3PDT relay shorts this resistor on receive, un-muting the receiver. I use a 500,000 ohm resistor.  It works well, but the sidetone is chirpy while the actual signal is not.  This is a bit annoying. 

I re-capped the DX-40 when I got it back in the late 90's.  Those caps are still good. 

The Globe VFO had also been recapped.  But it still has selenium rectifiers in there.  I will change them ASAP.  Also, the Globe VFO had a somewhat mysterious second transformer in there.  I wondered what that was.  I measured the output:  6.3 V.  That is a filament transformer.  My guess is that the filament winding in the main transformer went open, maybe as a tube failed. Instead of replacing the whole transformer, they just popped in a replacement filament transformer.  That's fine. 

I've been on the air with this rig, mostly on 40, as I was as a Novice.   I can work anyone I hear on 40 meter CW and my CQ's are heard in Europe (as shown by the RBN). 

I'm struck by how physically BIG these pieces of gear are.  Much bigger than our beloved BITXs. 

Regarding T/R switching:   There was a line in the 1973 ARRL Radio Amateurs Handbook that really got to me back in 1973:  Page 640, in the chapter entitled "Assembling A Station:" "

"In any amateur station worthy of the name, it should be necessary to throw no more than one switch to go from the 'receive' to the 'transmit' condition." 

By this standard, my station was probably unworthy of the name.  I don't remember how I handled T/R changeover, VFO keying, receiver muting and sidetone,  but it almost certainly involved throwing more than one switch.  But now, I am happy to report, my novice station is finally up to the ARRL's high standards.  As Pete says, "When you know stuff you can do stuff." 

The World Friendship Society of Radio Amateurs

Rod Newkirk, W9BRD wrote the "How's DX?" column of QST magazine from 1947 to 1978.  He had a wonderful writing style.  His column was an inspiration for many of us -- I write about the impact it had on me in my book SolderSmoke -- Global Adventures in Wireless Electronics and here on the SolderSmoke blog. 

Rod's son David Newkirk is radio wizard himself and has produced many great articles for QST and other publications.  His dad is a Silent Key and David has taken his call.  

This morning I was looking at an article on David's web site in which he looks at some of his dad's old QSL cards.  Most of the affiliations on the cards (ARRL etc.) are easily recognizable, but there was one that was unclear:  WFSRA.  

David figured out what it was: 

--------------------------------------

A W9BRD Affiliation Mystery Solved

My father's pre-World-War-Two QSL cards include the usual list of affiliations: ORS (Official Relay Station), RCC (Rag Chewer's Club), WAC (Worked All Continents), A-1 Op (A-1 Operator's Club). One affiliation, WFSRA, remained mysterious. A clue in the correspondence column in March 1938 QST pointed me to an "I. A. R. U. News" item on page 74 of July 1935 QST, and I had my answer:

W.F.S.R.A.:
    The World Friendship Society of Radio Amateurs has requested publication of the following pledge, which is the sole obligation for membership in the Society:
    "I hereby promise that I will, to the best of my ability, make such use of my amateur radio station as will be conducive to international friendships; that I will never voluntarily permit by station to be used as the tool of selfish nationalistic interests; and that I will do what I can, as a radio amateur and as an individual, to promote world peace and understanding. (To be followed by the signature, address and station call.)"
    Membership in the Society is open to all amateurs in all countries. All that is necessary to become a member is to copy and sign the pledge, and send it to the secretary, Duane Magill, W9DQD, 730 N. 6th St, Grand Junction, Colorado, U.S.A. Copies are preferably to be made in English or French, but may be made in the language of the member."

----------------------------------- 

The WFSRA was apparently one of the many, many peace organizations that were born in the interwar period in response to the carnage of WWI.  In addition to the QST correspondence mentioned by David, Google shows WFSRA in many articles in UK ham and SWL publications, and  there is one mention of it in the May 1954 edition of Boy's Life magazine.    

Much as the CBLA seems to have been presaged by the FMLA, the IBEW seems to have much in common with the WFSRA. 

Lighthouse Larry's GE Sideband Handbook

 

There is lot of information about early SSB and DSB operations in the GE Sideband Handbook (1961).  Lighthouse Larry is very informative.  Early in the book there is a guide to help homebrewers select intermediate frequencies that will work well in SSB and DSB rigs. 

Here is the book.   Remember, we are dealing with tubes and high voltage here: one hand behind your back.  Volts jolt but mills kill!  

http://www.rsp-italy.it/Electronics/Books/_contents/radio/Sideband%20handbook%20-%20GE%20-%201961.pdf

VE7SL's Beautiful Single Tube Transmitter and Single Tube Regen Receiver

Just stunning, in their simplicity and beauty.  Really amazing work.  Kind of reminiscent of my ET-2, but with tubes, and much nicer construction.  More details here: 

RECEIVER: https://qsl.net/ve7sl/neophyte.html

TRANSMITTER: https://qsl.net/ve7sl/neotx.html?fbclid=IwAR3cM6tSRjyTsNouHWVz_buuzz4C9O-IwQbdZM5dekkle69ZW7-JBQcHTVI

Three cheers for Steve VE7SL!  I've been linking to his blog for several years, but somehow I missed this magnificent red rig.   

Steve's online notebook: https://www.qsl.net/ve7sl/

Steve's blog: http://ve7sl.blogspot.com/

Video: N2CQR Talks About Homebrew SSB with The Vienna Wireless Society's Makers Group

It must have been great to have been a ham during the heyday of homebrew gear.  Imagine walking into your local club and finding a dozen or so people who share your passion for melting solder and homebrewing your own equipment.  Well, I got a taste of that thanks to the Vienna Wireless Society's Makers Group.  Led by Dean KK4DAS, this group of intrepid radio amateurs has built versions of Pete Juliano's Simple SSB transceiver.  They are finalizing the rigs; many are already finished.  And I could tell from the questions and the discussion that I was talking to a bunch of guys who knew which end of the soldering iron to grab.  It was really wonderful to talk to people who had gone through the experience of building an SSB transceiver, who knew from personal experience that it is not as easy as it seems. And I could tell from the questions that many of these guys are already thinking of their next projects, of how to put to use the experience they gained building Pete's SSB rig. 

Dean asked me to talk to the group about my recently completed "Mythbuster" rig.  This was a good topic for the group because my rig is similar enough to the Simple SSB that they could relate to it, but different enough that it could give them ideas about how they might do things differently next time. 

I really enjoyed this session.  I'm glad that VWS captured it on video.  I think SolderSmoke listeners and readers will like watching this video.  

Thanks to Dean KK4DAS and the VWS Makers group for hosting me.  And thanks to Jacek KW4EP for helping with the video. 

Here is the Vienna Wireless Society's YouTube Channel: 

https://www.youtube.com/c/ViennaWirelessSociety

Great News for Homebrewers: JF1OZL's Amazing Web Site is Back!

I was very happy to read this morning (on the G-QRP e-mail list) that the amazingly useful web site of Homebrew Hero Kazuhiro Sunamora has been resurrected after too many years in 404 status. 

Here it is:

https://www.qrp-ja.net/jf1ozl/index.html 

There is a LOT of tribal knowledge and lot of great ideas on his site.  Kazuhiro-san has apparently quit wireless, but is climbing mountains near his home.  We hope is doing well and that he will someday return to radio (perhaps for the peak of cycle 25).  

We last posted about him back in 2011.  In the comments to that post you can see the sad news about the demise of his web site (which is now back on the web): 

http://soldersmoke.blogspot.com/2011/12/homebrew-hero-kazuhiro-sunamura-jf1ozl.html

JF1OZL's bio: 

My name is Kazuhiro Sunamura. I am a 50 year old mechanical engineer, born in 1956. I am not an engineer in electronics. I have been interested in electricity and radio from the age of ten. For the last ten years, I have been active on my ham radio station JF10ZL. I have also written articles about my some of my radio projects in Japanese for the Japanese CQ Magazine. Now I have decided to get onto the internet and will take the opportunity of showing you my equipment and ideas. Please have a look at my schematics. I will be very happy if this material helps you with your own radio projects. I am a member of the J.A.R.L. affiliated Tsuchiura Club, the local ham club in my home town.

Some Initial Thoughts on FT-8

 -- This is really interesting technology.  Three cheers for Joe Taylor and colleagues.  This mode would obviously be very useful for fast, weak signal contacts as are needed on meteor scatter or EME. 

-- FT-8 does give you the chance to work DX that would have been difficult on other modes. 

-- Chinese hams showing up on FT-8 -- more than other modes. 

-- I think FT-8 is good for hams who just want to have a lot of "contacts." It is definitely not for the rag-chewer. 

--  I find it it kind of cold and antisocial.  More like a computer game than ham radio. A bit like sending  short text messages on a cell phone. 

--  I think FT-8 contacts are in some ways more meaningless than a "59!" contest exchange -- unless you look, you don't even know the report you got,  nor do you know the report you sent. 

--  For me it is more impersonal than CW.  But at least we let the technology decode the characters instead of having to memorize dot and dash sounds.  In a phone contact you can hear the other person's laugh.  In a CW QSO, you hear him key "HI HI."  FT-8?  No laughter at all. 

-- With PSK Reporter, FT-8 gives you a good feel for how propagation changes during the day. But it is kind of like 2-way WSPR.  As with WSPR, it is -- at first -- fascinating, but then it loses its charm. Yes, everyday you are heard in Belgium. 

-- It seems to be getting kind of crowded.  The passband for FT-8 contacts is often full, and it is hard to find an open space.

-- There is little opportunity for the homebrewer.  I hooked it up to my homebrew transceivers and had a small bit of fun using a 2N3904 as a switch triggered by the RTS signal for T/R.  But that's about it. 

-- I get the sense that the ham himself is not really needed in FT-8.  This mode seems like it could easily be automated or run by an AI.  Just tell it to go out there, make a lot of contacts and log them.  Maybe prioritize the DX you "need."  Has this already been done? 

--  After a session with FT-8, I had a really nice 17 meter ragchew SSB QSO.  That SSB contact left me happy.  The FT-8 session was a bit like spending time on social media or a video game.  It left me edgy.  FT-8 made me appreciate phone even more.

But hey, to each his own.  A lot of people really like FT-8.  I hope they have fun.