Ham Radio in the 1970s (and earlier, with some cool Jazz). What favorite rigs do you see?

Rogier PA1ZZ sent me this today.  I think I may have seen pieces of it before, but this restoration 

is really nice.  But ham radio seems to have been a lot cooler in California.  I don't remember it being so socially advantageous on the East Coast.   See Dilbert cartoon below. 

So many memories: 

-- The video opens with someone working on a QF-1 Q multipliers.  We have destroyed so many of these relics, in pursuit of the variable capacitors (which turn out to be not so good). 

-- A Drake 2-B on Field Day. 

-- An HT-37 in a shack.

--What looks like an HW-32a in a mobile rig. 

-- Maybe an HW-101. 

--  A BC-348. 

-- The ATV station with lots of homebrew gear was very cool. 

-- I also liked the single THERMATRON homebrew CW rig made from an old TV.  FB. 

-- The CW used in the video was all pretty good.  There was a lot of chirp.  This, of course, adds character to a signal.  FB.

After the video, they take a walk down memory lane, looking at ham radio magazines with some cool jazz playing in the background.  I saw a Swan 240 and a D-104.  The debauchery of the 1970s was evident on the magazine covers.  Even QST seemed to be caught up in this.  Check out the August 1975 cover of QST.  

Anyway, this video was a lot of fun.  Thanks Rogier!  

What favorite rigs do you see?   Make note of them in the comments. 

This video and the Dilbert cartoon reminded me of a discussion we had many years ago about THE KNACK: 

https://soldersmoke.blogspot.com/2008/11/cry-for-help-soldersmoke-responds.html

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. 

The Beginning of MY Radio Life...

 

Unlike Pete (see below), I don't have any cool pictures of me in front of an early station.   But in the picture above,  there I am, at the Thanksgiving table in 1973 age 15.  I was on the air by this date, on CW as WN2QHL.  Armed with a Lafayette HA-600A and a DX-40, I was tearing up the ham bands, especially 40 meters.  Look at the tension in my face, the grip of my fist... I just wanted to finish that turkey and get on the air!  But no, I had to have Thanksgiving dinner. 

I recently realised that I have been a ham for more than 50 years. Is there an HCWA?    

This and the recent movie from India led me to think about the timeline of my early radio days: 

-- Christmas 1972.  Santa brings me a Lafayette HA-600A general coverage receiver.  With jeweled movements.  Age:  14

-- April 27, 1973.  Novice Ticket becomes effective.  WN2QHL.  Age 14. 

-- July 19, 1973.  First contact (with Elmer WN2NEC).  Age 14.

-- February 1 and 2 1973.  A grumpy old-timer calls -- during the Novice Roundup! -- to tell me that I'm putting harmonics onto the 20 meter band.  I get scared and go off the air.  Geez!  I probably just needed to retune the tank circuit.  Age 15. 

-- February 23, 1974.  I go back on the air with a DX-100.  Age 15. 

-- March 5, 1974.  I take the General Class exam at the FCC office in New York City. I pass. Age 15. 

-- April 11, 1974.  I buy the Drake 2-B from WN2NEC. This revolutionizes my radio life.  Fifteen meter contacts become possible.   Age 15. 

-- April 13, 1974.  I work ZL2ACP on 15 meter CW.  I wake up my parents to tell them.  Age 15. 

-- April 21, 1974.  END OF NOVICE OPERATION.  Apparently we were still working under a one year limitation on Novice operation.  Could the expiration date have been marked on the license? 

At this point the FCC screwed up and sent me a Technician License instead of a General Class License.  My father got on the phone to Gettysburg and straightened this out.  Thanks Dad.  So I was only a Technician for a few weeks. 

-- April 9, 1974.  General Class License effective.  I become WB2QHL,  a man of substance.  Age 15. 

-- May-June 1974.  I acquire a Heathkit HW-32A 20 meter SSB transceiver from the Crystal Radio Club.  But I have to build the power supply from an old TV.  Somehow, I survive. Age 15. 

-- June 11, 1974.  First contact with the HW-32A.  Age 15.   

-- November 9, 1974.  Last contact with the HW-32A . Age 16. 

-- March 15, 1975.  First contact with my Hallicrafters HT-37. Age 16. 

Above is my only photo of my teenage ham radio station.  I can date it via the QSL card above the map. I still have that card.  I worked W7RUK on March 25, 1975.  That contact was on 20 SSB, but when this picture was taken I was on CW (the key is plugged in, not the microphone).   

-- June 1976   I graduate from High School.  Age 17.  

-- I was active and on the air through the summer of 1976. 

-- July 1976 -- QST article on the Herring Aid 5 receiver.  I try to build it and fail.  Age 17. 

-- October 1976 -- I depart for Army Basic Training. 

There is someone else who needs honorable mention here:  My sister Trish.  Here she is, next to me at the Thanksgiving table in 1973.  Trish helped me keep my ham radio log book.  Thanks Trish! 

Pete Juliano, Field Day, 1959.  With a DX-100B and (gasp!) a QF-1. 

Sunburst and Luminary: Apollo "Rope" Memory, and other items of interest

 

Wow.  That is the method that they stored computer memory for the moon missions.  When they were satisfied with a program they would say it was time to "put it on the rope."  

Here's an article on the women who built the rope memory (and the integrated circuits used in Apollo). This reminded me of the women's collective in Hyderabad that "wove" the ferrite core transformers for Farhan's BITX rigs: 

https://www.sciencenews.org/article/core-memory-weavers-navajo-apollo-raytheon-computer-nasa#:~:text=Core%20memory%20used%20metal%20wires,to%20create%20a%20particular%20pattern.

Here is a Wikipedia article on core rope ROM memory with some great illustrations: 

https://en.wikipedia.org/wiki/Core_rope_memory

The Rope

Other stuff of interest that I have spotted so far in the book Sunburst and Luminary -- An Apollo Memoir by Don Eyles:  

-- Not long before the fatal Apollo 1 fire, an MIT colleague of Don Eyles had a drink with Astronaut Gus Grissom.  Grissom unloaded about the poor state of the spacecraft, saying that, "What we have here is a Heathkit."  Grissom died in the fire. 

-- Eyles mentions the use of 6L6 tubes in analog audio amplifiers. 

-- MIT's Doc Draper used a Minox camera.  

-- When the Apollo 11 astronauts came back and were living for two weeks in an isolation chamber, NASA had bulldozers on standby to bury the whole thing ("astronauts, staff and all") in case some dangerous moon bug was detected.  (Is that true?) 

-- At one point soon before an important missile test, engineers realized that they needed an isolation transformer.  They did not have enough time to order one.  So they took an isolation transformer out of one of their soldering stations and used it in the missile.  It worked. Sometimes you just use what you have on hand. 

"Onda Corta" ("Shortwave") -- A Short Film about Ham Radio in Venezuela (Please ID the Boatanchors!)

https://youtu.be/J1QlKykhR2M?t=583

I have it cued up to 9:43 -- at that point Ramon is in his ham shack.  

Lots of good stuff in there! 

Please ID the rigs/parts you see and list them in the comments below. 

This version has subtitles in English.  I like it -- a nice story.  And the whole film is only about 15 minutes. 

Winterfest Loot: Who Can ID the Homebrew Receiver?

First a big congratulations to the Vienna Wireless Society and its President, Dean KK4DAS.  In spite of low temperatures that made the Winterfest Hamfest live up to its name, this year's 'fest was a big success with excellent turnout both by buyers and sellers.  There were a LOT of older rigs -- on one table I saw three HT-37s.   It was all great. Here is a video of the hamfest.  https://www.youtube.com/watch?v=oheht5jCuKE&t=619s  This was shot early on Sunday morning March 19, 2023, about 30 minutes after it opened.  An hour later there were a lot more customers. 

One of the first things I bought was the item pictured above.  I bought it mostly because we are currently building 40 meter receivers with the local high-school students.  I didn't have a screw driver, so I couldn't open up the box.   Something was rattling around in there.   I worried that the box might be mostly empty.  Or that it would have one PC board with a sad collection of ICs.  But in the hope that I would find something truly homebrew, I bought it.  

Below are pictures of what I found inside.  Can anyone tell us what this is?  ( I recognized it immediately.)  More on this device in due course. 

Other loot from the 'fest: 

The one on the left I've been using since around 1998!  It is getting beat up.  I bought the one on the right at the 'fest.  It is in much better condition.  5 bucks.  TRGHS. 

I always wanted one.  I had nice leather case, but I gave it to Dick Dillman years ago. I now feel like a real boatanchor guy.  I got for 15 bucks.  I see on Amazon they are selling for $466! 

I had one as a kid.  Will be useful in the DR.  In great shape. 

Eamon Skelton's book was a great find.  As were the early editions of SSB for the Radio Amateur.  Eight bucks for the whole lot.

I like homebrew speaker enclosures.  They add soul to the new machine. Perhaps a prize for the high-school project.  Three bucks. 

Finally, this thing.  Plagued by guilt for past cannibalizations of QF-1s,   I was going to pass on this one, but I realized that my friend Dean KK4DAS would be on his way, and if I didn't take it (and extract the variable capacitor) he would.  So I bought it.  But I may leave this one as is, for possible use as the The Radio Gods intended.  It could use some cleaning up.  It seems to have a coat of nicotine. Ten bucks. 

I also picked up a few larger knobs that may be of use with the high-school receivers. 

Thoughts on Homebrew, Makers, DIY, and Hams -- from Lex PH2LB

Sometimes we get a comment that is so good that we elevate it to the main blog page.  That was the case with Lex PH2LB's comment on the blog post of Owen Duffy (yesterday). 

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

When I started the hobby, it arose out of technological curiosity, the interest in understanding things and the will to make things myself (designing myself was not my main goal). It doesn't matter to me whether it is 100% DIY or a kit (such as Heathkit, Elecraft, QRP-Labs etc) which is modified or not after construction. Just having fun with the hobby and pushing boundaries. And yes I also have some off-the-shelf transceivers (I'm super happy with my FT817ND) and my QO-100 uplink is also a kit (which is then already soldered a little more than average). As far as new tools are concerned: here at home are 2 types of 3D printers, various tools for SMT assembly, and I have a nice workshop equipped with tools and equipment for metal / plastic / wood processing. And every day I try to learn something new, because I stand by the IBEW moto : If you know stuff, you can do stuff.

Am I a maker then? I wouldn't call myself that. Just like I don't call myself a hacker because I'm quite handy with computers, technology and have certain skills. I'm just a hobbyist who wants to do and make things after work.

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

Lex is a true member of the International Brotherhood.  He is the one who took our beloved stickers onto the European continent and into a Netherlands pub.  He is the one who -- unforgettably -- saw the parallels between ham shacks and the "pleasure room" of "50 Shades of Gray" (See below -- apropos of his current message, we labeled his meme "50 Shades of Homebrew") For more on Lex see: https://soldersmoke.blogspot.com/search?q=PH2LB

Lex's web site (Shack on the Internet):  https://www.ph2lb.nl/blog/index.php?page=hamradio

 Thanks Lex! 

Podcast (Audio) Version of Bill's Talk to the L'Anse Creuse Amateur Radio Club

Tony G4WIF suggested that I make this talk available as an audio recording.  Good idea. Here it is: 

http://soldersmoke.com/N2CQRHomebrewing.mp3

6EA8s in the Mate for the Mighty Midget, and WA9WFA Re-Builds a Heath HW-12

I reported to Scott and Grayson that I had finally gotten around to changing the three aging 6U8 tubes in my Mate for the Mighty Midget receiver.  I replaced them with three more youthful 6EA8s.  This switch really seemed to perk up the old receiver.   I'm listening to 75 meters on it right now. 

Speaking of 75 meters, Scott sent me this picture of his latest effort:  re-building a Heathkit HW-12.  FB.  This is a way of experiencing (or re-experiencing) the construction of a Heathkit.  I did something similar, but much less complicated)  with a Heathkit VF-1.  Scott did a wonderful job taking this old rig apart.  That PC board looks great (see photo below). 

Scott's e-mail:  

Hi Bill and Grayson, I’m glad to hear of your good results with the 6EA8’s in your MMMrx! I had similar results when I finally got rid of the 6U8’s with their iffy performance and went with the 6EA8’s.  I did put a set of 6GH8A’s and tried it out, it worked, but I don’t have any data on performance improvements.  After completing the outboard power supply and audio amplifier, I’ve taken a break from my MMMRx and it’s sitting there on the bench. I’ll get back to it in a while.  

 

In the meantime I’ve started a new project where I’m re-kitting a Heathkit HW-12 eighty meter transceiver.  I have completed the disassembly process including the pcb.  I bought a Hakko vacuum desoldering iron for taking all (ALL) parts off of the pcb, and it’s bare now.   I’m planning to start rebuilding this coming week.  73 Scott WA9WFA  

Bill Talking about Homebrew Radio with L’Anse Creuse Amateur Radio Club (Michigan) -- February 2, 2022 (Video)

This was a very nice meeting.  We just talked homebrewing and why it is such an important part of ham radio.  Video above

Topics included:

-- Jean Shepherd

-- Being "Electrically Inclined" 

-- The Herring Aid 5

-- Radio Clubs around the world

-- The Shame Shelf

-- Making mistakes, releasing smoke

-- Errors in ham radio magazines and schematics

-- The importance of understanding the circuit

-- The Michigan Mighty Mite

-- Building a power supply for the HW-32A

-- The origins of the SolderSmoke podcast

-- Knack stories, the IBEW and what we all have in common

-- The importance of books

Thanks to The L'Anse Creuse ARC for the invitation. 

Super-Regeneration is Super-Strange

Farhan VU2ESE is largely responsible for this.  He has recently been talking about VHF.  (More about this in due course.).  This started me thinking about my failed effort in London to get on 2 meter AM.   My plan was to use the transmit portion of this HW-30 (above) with a 2-to-10 downconverter and my trusty Drake 2-B for receive.  

Tony G4WIF also bears some responsibility:  When I expressed interest in Farhan's VHF work, Tony sent me two articles from SPRAT.  Both of them were about super-regenerative receivers.  

Farhan's comments caused me to pull the HW-30 out of storage.  I started poking around the transmitter.  But then I noticed something:  On receive, the AF amplifier was obviously working.  Then, when I tuned through the 2 meter band, the rest of the receiver seemed to be working too.  I fired up the HP-8640B sig gen on 2 meters and turned on the AM modulation.  Indeed, the old receiver was inhaling!  

This launched me into an effort to understand how super-regenerative receivers work.  There are a lot of really weak explanations out there. You get the distinct impression that the person explaining the circuit does not understand it himself.  This makes explaining it very difficult.  I am not the only one to notice this phenomenon:  Mike WU2D commented on this in one of his excellent super-regen videos.  This one:  

https://www.youtube.com/watch?v=QOhNPLT8R10

Mike very kindly said the operation of this circuit seems like "magic."  I was thinking more in terms of Voodoo.  

Howard Armstrong discovered super-regeneration years after he invented plain old regeneration.  The new discovery came around 1921.

It looks like VHF guru Frank Jones had very early misgivings about super-regeneration.  In his 1934 classic 5 Meter Radio Telephony, Jones seems unenthusiastic about the circuit and about our ability to understand it:  "To explain, simply, exactly how this form of detection takes place is not a simple matter, but some of its characteristics are easy to visualize."  In this book, Jones goes on to predict that super-regens will be superseded (!) by superhets.  Indeed, in his 1961 book VHF for the Radio Amateur there are no super-regen circuits; all the receive systems are down-converters to HF receivers. 

Still, with that HW-30 hissing away right next to me, I feel I need to understand how the super-regen works.  I'm not there yet, but I'm trying.  Here are some good resources: 

A good article from Wireless World 1946:  

http://www.r-type.org/articles/art-285.htm  

A student's write up of his effort to understand: 

https://folio.brighton.ac.uk/artefact/file/download.php?file=597679&view=111191

But the best so far (for me) is from Frederick Terman (one of the founders of Silicon Valley) in  his 1943 classic Radio Engineer's Handbook.  Click on the images for a clearer view. 

I will definitely try to get the HW-30's 5 watt AM transmitter going.  I am not so sure I'll do anything with the receiver.  I think this is a matter of picking your battles and "finding joy."   I didn't find joy in FT-8, so I stopped working with it.  Same with my HA-600A, DX-40 Novice rig.  Same with CW in general.  And the same with SDR.  I suspect that super-regen receivers may also fall into this category.  I mean, let's face it, if you are not fond of ordinary regens, is there any real chance that you will like SUPER-regens?  Even Frank Jones seems to have disliked them.  And there is a reason Howard Armstrong moved on to superhets -- they are better! But still, that receiver is hissing away at me...  Stay tuned. 

SolderSmoke Podcast #233: PIMP, Boatanchors, Novices, MMM, Heathkits, DC Receivers, Mailbag

SolderSmoke Podcast #233 is available. 

http://soldersmoke.com/soldersmoke233.mp3

Travelogue: Cape Cod. SST. Marconi Site.

The WFSRA:   The World Friendship Society of Radio Amateurs.

Pete's Bench:

The Pimp.
The NCX rig.
The Collins.
The many DC receivers built worldwide.
The parts shortages are real! Several key radios on hold. Si5351 sub.
Talk to G-QRP convention

Bill's Bench:

FT-8. Not for me. I tried it.
Novice Station Rebuild.
Globe V-10 VFO Deluxe.
Selenium rectifier removal CONTROVERSY?
Not crazy about my Novice station. Not crazy about CW. 
Mate for the Mighty Midget. Again. 
Mike W6MAB -- Detector problems LTSPICE Check
One more mod for MMM RX. Ceramic filter at 455.
Dropped screw inside tubular cap on Millen 61455 transformer. 
Talk to the Vienna Wireless Society
Thinking of a Moxon or a Hex beam.


BOOK REVIEW Chuck Penson WA7ZZE New Heathkit Book. http://wa7zze.com

Mailbag

-- New SPRAT is out! Hooray!
-- Todd K7TFC sent me copy of Shopcraft as Soulcraft. FB.
-- Dean KK4DAS building an EI9GQ 16 W amp. FB.
-- Jack NG2E Getting close on Pete's DC receiver.
-- JF1OZL's website is BACK!
-- Tony K3DY sent link to cool books. 
-- Sheldon VK2XZS thinking of building a phasing receiver.
-- Peter VK2EMU has joined the WFSRA. FB!
-- Ned KH7JJ from Honolulu spotted the Sideband Myth in the AWA video.
-- Chris M0LGX looking at the ET-2, asks about the variometer.
-- Pete Eaton Nov 64 anti HB rant in november 1964 QST. Wow.
-- Josh Lambert Hurley spreading FMLA stickers in the UK. FB
-- Stephen VE6STA getting ready to melt solder.
-- Got a great picture of Rogier PA1ZZ back on Bonaire.
-- Farhan reading the manual of Hans's new digital rig.
-- Paul G0OER wonders if FMLA getting ready to move on 5 meters.

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's Largest Heathkit Collection (Video)

And this was apparently AFTER they relocated and organized things a bit. 

I have my eye on those QF-1s.  Someone stop me before it's too late.

I also spotted a Globe VFO Deluxe.  

Chuck Penson WA7ZZE, Heathkits, and the Titan Missile Museum

                                             WA7ZZE Shack

The video above popped up in my Facebook feed today and reminded me of Chuck Penson WA7ZZE.  Chuck is the author of a wonderful book on Heathkits (and several other books). 

The Titan missile explosion (not of the warhead) in Arkansas is described in an excellent but horrifying book entitled "Command and Control" by Eric Schlosser.

https://www.amazon.com/Command-Control-Damascus-Accident-Illusion/dp/0143125788/ref=sr_1_4?dchild=1&keywords=Command+and+control&qid=1620478171&sr=8-4 

PBS made a video out of the book.  You can watch it here: 

https://www.pbs.org/video/american-experience-command-and-control-film/   

Here's an interesting article on nuclear weapons tourism.  It has a great title. 

https://www.nytimes.com/2007/01/05/travel/escapes/05atomic.html

It is easy to see how an interest in ln old technology would lead someone to both Heathkits and Titans.  I get that.  But on the other hand the Heathkits and the Titans are at completely opposite ends of the humanity spectrum:  Heath made friendly technology that ultimately brought people together on the ham bands.   We know that the Titans were supposed to do. 

In any case it was great to be reminded of Chuck WA7ZZE.  We last posted about Chuck more than 10 years ago: 

http://soldersmoke.blogspot.com/2009/08/chuck-penson-heathkits-nukes-and-qrp.html

In a comment to that post, Steve "Snort Rosin" Smith WB6TNL noted that Chuck had spoken at the 2009 CactusCon hamfest, and that the club pledged to put his presentation on-line.  But Google and I can't seem to find it.   Do any of the Scorpions or anyone else out there know where Chuck's hamfest talk is? 

Bob KD4EBM has been out there.  He reports that hams can bring their rigs and make use of the Titan site's large Discone antenna:

 https://titanmissilemuseum.org/museum/ham-radio-operators/

The VFO that I am looking for: The Globe VFO deluxe

 

I mentioned this in the last podcast.   I'm looking for one of these. I had one as a kid, and used it with a DX-40 and a Lafayette HA-600A.   It is now the only piece of gear that I need to recreate my novice station.  

Does anyone have one of these, perhaps gathering dust in some corner of the hamshack?  Please let me know.  Thanks. 

Here's the manual: 

http://www.oldtuberadio.com/data/Globe/GlobeV-10Manual.pdf

Guilt Trip: Video on the Heath QF-1 Q Multiplier

Hack-A-Day had a nice post about this piece of gear: 

https://hackaday.com/2021/01/18/q-multiplier-er-multiplies-q/

My radio emotions were swinging wildly as I watched this video. 

Readers may recall that over the years I have brutally cannibalized several QF-1s.   I was enticed into doing this precisely by the tuning cap that the videographer so alluringly describes.  It has a  built in 7:1 reduction drive!  How could I resist?  These wonderful caps live on in several of my homebrew rigs.  

I also put the conveniently sized metal cabinets to good use -- one holds frequency counters for my AM station, the other houses an Si5351 VFO/BFO that can be used with many rigs. 

After extracting the cap and putting the boxes to good use, I was left with the remainder of the circuitry.  I recently put even this stuff to use by using the coils to make a triple LC circuit filter for 455 kHz.  This may someday be used in a receiver.  So you see, I've not been wasteful. 

And the thing only cost 9 bucks back in the day...  So I didn't really do anything bad.  And besides, adding a regen circuit to a superhet is kind of backwards, right? 

But then the video producer started talking about how nice his QF-1 looks, even after more than 60 years.  And about how much it improved the performance of his AR-1.  And then, the kicker:  He said the QF-1s are now "relatively rare." 

I hang my head in shame.  I am a serial QF-1 killer.  And I don't know if I can stop. 

Improving the Product Detector in the Lafayette HA-600A

Diode product detector on the left, BFO amp in the right

As noted in an earlier blog post, I didn't like the sound of SSB and CW when using the product detector in my Lafayette HA-600A.  It just did not sound right.  The receiver sounded fine on AM with the diode detector.  But when I switched in the product detector, it sounded bad.  The BFO was fine.  The problem was there even when I used an external BFO.  And SSB sounded great when I just coupled some BFO energy into the IF chain and used the diode detector to listen to SSB.  My suspicions were focusing on the very simple BJT product detector. 

Steve N8NM built the HA-600A product detector both in LTSpice and in the real world.  It worked fine in both versions.  Steve even put the product detector into his S-38 receiver -- he reported it worked well there.  

I too built the thing in LTSpice.  Then I went and rebuilt the circuit on a piece of PC board.  I connected the new circuit to the HA-600A, using my external FeelTech sig generator as the BFO.  IT STILL SOUNDED BAD ON SSB.  

At this point I started Googling through the literature.  I found a promising article by Robert Sherwood in December 1977 issue of Ham Radio magazine entitled "Present Day Receivers -- Problems and Cures." Sherwood wrote: 

"Another area that could use additional work is the product detector.  As the name implies, its output should be the product of the two input signals. If BFO injection is removed, output should go to zero. If this is not the case, as in the Heath HW series, envelope detection is also occurring, which causes audio distortion." 

I checked my circuit.  When I removed the BFO signal from the product detector, envelope detection continued.  In fact, with the receiver in SSB mode, and with the BFO disconnected, I could listen to the music of WRMI shortwave.  It seemed that Sherwood was explaining well the problem I was having: Simultaneous envelope and product detection was making SSB sound very bad in my receiver.   What I was hearing just seemed to SOUND like what you'd get with a mixture of product and envelope detection: "scratchy" sounding SSB.  This also seemed to explain why SSB would sound fine when using the diode detector with loosely coupled BFO energy -- in that case it would be envelope detection only, with no ugly mixture of both kinds of detection.

So I built a better detector.  I had had great luck with the two diode one trifilar transformer singly balanced design used by both Doug DeMaw and Ashhar Farhan. I built the circuit using one of the trifilar toroids given to me by Farhan, and connected it in place of the original BJT product detector.  With the FeelTech Sig Gen as BFO, I got good results -- most of the signal disappeared with I disconnected the BFO.  Looking at the circuit, I realized that I was balancing out not the IF signal but instead the BFO signal.  To minimize envelope detection I needed to put the IF signal on the balanced input of the product detector (to L1 in the diagram above).  When I did this, envelope detection seemed to disappear completely and the receiver went silent when I disconnected the BFO.  

Finally, I needed to find a way to use the BFO in the HA-600A with the new product detector.  Obviously I needed more BFO signal -- I needed about 7 dbm, enough to turn on the diodes.  I converted the outboard product detector board into a simple amplifier and put it between the HA-600A BFO and the BFO input port of the new product detector.   This works fine. 

A few issues remain: 

1) The output from the HA-600A BFO through the above BFO amp (and across the 50 ohm resistor) is NOT a pretty 455 kc sine wave.  But the peaks of the distorted wave appear to be enough to turn on the diodes, and when I look at the voltages across each diode (on my two channel 'scope) I see mirror images -- one is on when the other is off.   Is this good enough? 

2) Moving the BFO input from L1 to the junction of the two 50 ohm resistors (that is actually a 100 ohm pot) has big implications for how this mixer works.  With the BFO energy going through the toroid, BOTH diodes are being alternately turned on and turned off.  But both are on, and then BOTH are off.  With the BFO energy going in through the other side, one diode turns on when the other is off.  I think the mixing result is the same, with AF coming out of the output port, but the way the mixer works in this configuration is very different. Does this sound right? 

Mike WU2D's Great Drake TR-3 Refurb Video -- Part 2

Mike WU2D made another very nice video about his Drake TR-3 refurb. 

He cracked me up when he noticed that one of the calibration oscillators was 30 Hz off.  "Let's pretend we care," said Mike.  Indeed. But it was probably wise to tackle this problem, given how upset modern hams seem to get with 30 Hz discrepancies.  Mike noted that the problem was casued by "aging cystals." Yikes! Another thing to worry about, along with the Southern Magnetic Anomaly. 

Once again Mike has added a useful term to our lexicon:   "The Dribble Method" of signal injection (or extraction):  Just wrap a few turns of insulated wire around the tube or IF can and inject or measure away.

Neutralization! Now there's a blast from the Thermatron past.  I haven't done that in a long time. I liked Mike's "reverse neutralization" method. 

Mike's video featured some real Boatanchor eye candy.   That Heathkit HR-10 receiver caught my eye, as did that HP signal generator. 

Thanks Mike.  One hand behind your back OM.