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Showing posts with label Gale -- Todd. Show all posts
Showing posts with label Gale -- Todd. Show all posts

Wednesday, October 7, 2026

About the Guy Who Brought Us the AADE L/C Meter -- Neil W. Heckt

 

There it is.  The AADE L/C meter.  Many of us have been using these things for years.  I have two of them -- the one that I bought is here in my shack in Virginia.  The other was given to be by Todd VE7BPO and it is in my shack in the Dominican Republic. I sometimes wondered who was behind Almost All Digital Electonics.   Today I got the answer. 

Rishav is from Nepal,  He has been studying in Germany.   He is working on homebrewing the test meter (the company shut down when Neil passed away).  In the course of his research, Rishav gathered some very nice info about Neil W. Heckt, the fellow who created AADE and the meters that so many of us used.  Thanks Rishav! 

Memories of Neil W. Heckt

My work with Tobias (KK7BCO/2M0TFF) on a LC meter as the fifth build in Red Summit RF's Homebrew Workbench series for beginners introduced me to the clever LC meter design of Neil Heckt. As we celebrate his work by building one ourselves, in this post I hope to celebrate his life through the memories of those who knew him.

Neils's AADE L/C Meter IIB was a great hit, with thousands of units sold both as kits and as fully assembled instruments. It is not difficult to find praise for the meter. Many owners have written about its accuracy, usefullness, limitations, and clever design. Scattered among those reviews, however, are also small glimpses of Neil himself—stories from people who corresponded with him, asked him for help, or sent their meters back to him for repair. The reviews of the AADE L/C Meter IIB on eHam.net are particularly valuable in this respect. Many are written by people who dealt with Neil directly, and aongside their praise for the meter they remembered his kindness, honesty, and unusually generous customer service.

Memories

There is surprisingly little written about the man behind the instrument. While trying to learn more about him, I found most of the biographical information in his obituary. While searching further, I came across a moving remembrance titled Celebrate the Sun, written by Jill L. Ferguson, Neil's daughter-in-law. It offered something quite different from the technical accounts and product reviews: a glimpse of Neil as a husband, father, and person. One story in particular reveals a wonderfully personal side of him:

She (Kay) said her favorite book and life philosophy came from Celebrate the Sun. Back before she and Neil dated she had told him about this book. Not only did he borrow her copy and read it, but he photocopied the whole thing and pasted page by page into a photo album and intermixed the pages with his own photographs of the sun, of himself on hikes, and of the two of them walking in the woods. He decorated the front of the book with black electrical tape and two die-cut pelicans as they are key characters in the book. After Neil and Kay moved in together and married, she found this book he had created but had never told her about. She intimated that part of the way she knew he was the man for her was because he had taken her interest in this book so seriously. On his last night, she had the book Neil had created with them in hospice center and was reading the end of it to him shortly before his passed.

I was deeply moved by the story and wrote to Jill to ask whether she might be willing to share a few more memories of Neil, and perhaps a photograph. She kindly replied that she would speak with Kay, Neil's wife, and with Neil's son, her husband.

Two days later, I received a message containing a wonderful remembrance written by Kay herself, together with a photograph of Neil as a younger man. I have reproduced both here.

Young Neil
Photograph of Young Neil, thanks to Jill, sent to me by Kay.

Neil Heckt worked for the Boeing Company for more than 30 years. He was a member of their early air and space team. In his earliest years he worked on getting satellites into orbit and later getting men onto the moon. He developed his first inventions during those years which, of course, were owned by Boeing.

When we met he was a few short years from retirement. He was anxious to start his own business and create new products unrelated to his work at Boeing. He named his company Almost All Digital Electronics.

The inventions that followed seemed focused on developing ways to measure very, small units of...? He invented an atomic clock. It is my understanding that the Bureau of Weights and Standards in Colorado used it and that it was displayed there. Here I must state that I am woefully unknowledgable about any aspects of his work. I am neither a business woman or an inventor so, though I found him brilliant I rarely understood what his inventions really did. We were very different in many ways but genuinely admired each other's talents.

The last invention was an L/C Meter kit for hobbyists. He did very well with that product. The arrival of the internet and eBay made it a commercial success.

I thought his philosophy about not patenting his products was unusual. He told me that he developed a product, sold as many as he could and when someone copied his work he would stop production and leaveit to someone else to deal with it while he invented something else.

He had talents and ideas brewing in his brain that craved to be made real. He told me that whenever he needed money he would invent something that people would buy and then he paid his bills.

He wasn't like me and the people in my world who took on a second or third job when we needed money. I found his confidence and creativity to be amazing!

Neil was scrupulously honest in his business . Once he purchased two antique vacuum tubes for less than $100 from an eBay customer. When they arrived he discovered that they were quite valuable. He wrapped one tube up and sent it back to the customer with a note telling him what it was worth. Instead of selling it and making a good deal of money he sent it back. I asked him why. He said it wouldn't be fair to the seller for him to keep all of it for himself because the guy just didn't know what he had.

If anyone had a problem assembling one of his kits they sent them to him and he would fix their problems without charge.

Neil was sick for many years before his death. His brilliant mind was with him to the end.

I hope these memories help preserve not only Neil Heckt’s work, but also something of the thoughtful, generous, and inventive man remembered by those who knew him.

***

Sunday, February 16, 2025

Why Should We Build Analog Gear When the World has Gone Digital?

Our friend Todd (Vasily) had recently been thinking about this on his excellent Popcorn Electronics blog: 

https://qrp-popcorn.blogspot.com/

There are many answers to this question.  Todd's post made me think about a message from Farhan VU2ESE on this same subject. See:  https://www.vu2ese.com/index.php/2022/08/04/daylight-an-all-analog-radio/ My comment and a quote from Farhan appears below: 

Hello Todd!  I have been thinking about the same things.  As you know there is a lot of magic in using gear that you have built yourself.  And it is still possible to do this.  But I think the builder has to make some choices:  Building it yourself might -- as you say -- require you to move away from the perfection, bells and whistles of the modern ICOM 7300 style rigs while embracing the simple functioning of analog rigs.  Farhan was thinking of this three years ago: 

"So here we are, talking analog radios in 2022.  Here is the memo : The analog never died. The world is analog all the way, until you descend into Quantum madness. The antennas are analog, Maxwell died a content, analog man. Our radios, ultimately, are analog machines and we are all analog beasts too. Amateur Radio technology has evolved into the digital domain. However,  it has only made it easier for us to do analog with computers to simulate and print our circuits.  So, it’s time to bid good bye to our Arduinos and Raspberry Pis and build an Analog Radio for ourselves. So let’s see what we can achieve in hindsight, a return to our native land and a rethink of our approaches. The radio is called Daylight Again, a nod to being back at the FDIM in 2022 after a gap of two years. It is named after the Crosby, Stills, Nash and Young’s song that had been humming all the time while put this radio together, emerging after 2 years of lockdown.  This radio that took two days to come together, no actually two years! That’s: parts of it got built and stowed away, thoughts were struck in the shower, questions popped up during early morning cycle rides and notes and circuits were scribbled in the notebook.  I must take the first of many diversion here: I hope you all maintain a notebook. Write down the date and whatever you thought or did on the bench and the result. Nothing is trivial enough to leave out. Wisdom comes to those who write notes.  I started to build this on Saturday the 14th May and I checked into the local SSB net on Monday morning, the 16th May 2022. Back to the radio.  What can an analog radio do that will appeal to us homebrewers?"

More to follow.  73  Bill  Hi7/N2CQR 

Thursday, January 30, 2025

Diode Ring VFO Part II: How Much LO into a Diode Ring?





Last week we were trying to determine how much LO injection we really need in the SolderSmoke Direct-Conversion receiver.  The answer seemed to be "enough to turn the diodes in the diode ring on and off."  Ok, but this brought us to the question of how far we should go with this.  Does it make sense to go for more LO signal? If so, why? And how much more?   Todd VE7BPO offered a very thoughtful comment.  He pointed out that for a simple receiver like this, turning the diodes on and off would probably be sufficient.  Sometimes we hear 7 dbm, others say 10 dbm, or even 0 dbm.  But what is the logic that underpins these figures?   Solid State Design for the Radio Amateur (SSDRA) provides the answer on page 120.  See above.  

With a diode ring (or other switching mixer) you want the LO (VFO or PTO) to be the signal that is switching the diodes  You do not want the incoming RF signal to also be strong enough to switch the diodes.  Having the RF do this would result in something of a mess at the output.  

If you have a weak LO signal going into the mixer, it might on peaks reach the level of turning the diodes on.  You will get some mixing action.  But as the SSDRA paragraph indicates, during much of the LO cycle the diodes will not be switched on.  And they won't be firmly turned off either.   A strong RF signal could come in, add to the LO voltage, and switch the diodes.  That would not be good. 

So if you put a strong LO signal in there, on half the cycle that signal will be turning two of the diodes on.  But on the other half of the signal, that same LO signal will bereversed in polarity,  turning those same diodes off.  Hard off.  Definitively off.  It would take one very strong RF signal to overcome the reverse bias signal put on those two diodes by that LO voltage.  That is the advantage of a stronger LO signal.  
 


Wednesday, January 15, 2025

Ugly and Manhattan Construction from Popcorn Electronics


Todd (oops, I mean Vasily) has a really nice video on Ugly and Manhattan construction techniques on his re-born Popcorn Electronics site.  See above for the video.  The site's URL is https://qrp-popcorn.blogspot.com/

Some people apparently dislike these techniques.  To each his own, but I like the Manhattan method.  In fact, in the SolderSmoke Direct Conversion project, we are recommending the use of Manhattan circuit board tecniques.  With Manhattan, you get a lot flexibility.  At one  point, for example, the High School students told us that they had forgotten to put a needed pad on the board.  No problem!  Just glue in a new one.  Or if you put in one too many, just take one off.  

You also keep all the circuitry and all the connections on one side of the board.  This facilitates repair or modification.  This kind of thing is not so easy when you have components on one side of the board and the connections on the other side.  You spend a lot of time flipping boards over, breaking wires,  trying to remember what goes where.  Also, because the pads push the connections a couple of millimeters above the ground plane, I find that Manhattan technique actually reduces the chances for an accidental short to ground. 

There has been some discussion of where the term "Manhattan style" comes from.  Having been born on Manhattan island, I too wonder about the origin of the term.  Some see it as the result of the grid pattern (like Manhatten's street grid) that results from the rectangular or square pads that are often used.  Others point to the vertical parts placement that we see when looking at a board from the side -- the parts look like the skyline of Manhattan.   Either explanation, I think, works.  

Here is a Manhattan-style board I recently built in the Dominican Republic for my homebrew 15-10 meter SSB transceiver. I couldn't find any Gorilla glue here, so I went with Loctite Coqui. Same stuff.   Latin American super glue! 

Tuesday, December 17, 2024

Popcorn Electronics is BACK! Yea!

 


Check it out at the URL above.  FB!  Thanks Todd!  And thanks Vasily!  

I never knew that Mike KL7R (the co-creator and first co-host of SolderSmoke) was responsible for the Popcorn nickname.  FB!

Monday, September 23, 2024

Ham Radio -- How To Build Stable Oscillators


Spasibo Vasily!  

Wow, thanks a lot Todd.   There is some great wisdom in your video.  You clearly demonstrate that it is possible to build your own stable LC VFOs.  Sure, for many the arrival of the synthesizer chip put an end to this kind of project.  But some of us still want to fully homebrew all the stages in our rigs, and not be dependent on mysterious chips and software written by others.  

I really liked the way Todd acknowedged the tremendous contributions of Wes, and Roy, and Rick and others. 

Of course, all of Todd's recommendations are right on the mark.  I have been following most of them (but I do fall short and occassionally use a Manhattan pad or two).  Todd even gets into the mysterious and arcane practice of boiling (three times!) toroidal transformers.  I do have a preference for air-core coils, but that boiling sounds like fun. 

One thing that Todd and Brad might also want to consider:   tuning linearity.  Too often LC VFOs end up having the frequency spacing very close at one end of the dial and very broad at the other end.  "Bob's Electron Bunker" provides some great tools for alleviating this problem:

Thanks again Todd! 

Friday, November 10, 2023

SolderSmoke Podcast #249 -- Travel, Pete's 6BA6 rig, Books!, VFOs, SDR, Computers, Spectrum Analysers, Transistor Man! MAILBAG

New VFO for 15-10 Transceiver
Schematic below

SolderSmoke Podcast #249 is available:  http://soldersmoke.com/soldersmoke249.mp3

There is also a video version of this podcast: https://youtu.be/5xyaYivtOhw

Travelogue:  

HAPPY VETERANS' DAY TO PETE AND GRAYSON AND TO ALL THE OTHER VETERANS WHO ARE LISTENING. 

Trip out to San Francisco. Sticker placed on the corner of Haight and Ashbury:  See picture below.  Note other sticker.  Really Groovy! 

Bill's DXCC-100.  DONE.   

Tribal Wisdom:  W1REX on HRWB https://soldersmoke.blogspot.com/2023/11/listen-to-rex-w1rex-lots-of-tribal.html

Pete's Bench:

Pete's 6BA6 rig

Pete's 6BA6 Rig

Pete Re-invents the Shirt-pocket SSB Rig

Pete's remake of the ShirtSleeve Transceiver

Pete Builds Two Computers 

Pete Adds a Second Band to his Homebrew SDR 
 

SHAMELESS COMMERCE DIVISION:  

BEZOS BUCKS ARE BACK!  PLEASE  BUY THERE! >>>>>>>>>>>>>>>>>>>>>>>

Mostly DIY RF:  Work proceeds in the Oregon Silicon Forest on P3ST kit development. Todd is confident the P3ST will be released on December 18th.Many other kits available now:  https://mostlydiyrf.com/ 

Sign up for the newsletter:  https://mostlydiyrf.com/subscribe/ 




Bill's Bench: 

Rebuild of the 15-10 VFO (for improved Dial Spread) (with yet another QF-1 capacitor) https://soldersmoke.blogspot.com/2023/10/dial-scale-linearity-spreading-out.html

Why Building for 10 meters is harder: https://soldersmoke.blogspot.com/2023/09/why-building-for-10-meters-is-harder.html

Copper Tape shielding of 15-10 rig. 

Crushing Spurs with Better Bandpass Filters (see blog post) https://soldersmoke.blogspot.com/2023/09/crushing-17-and-12-meter-spurs-with.html

Another 15-10 rig in the works... for SSSS.   Boards are accumulating... 

More problems discovered with the Herring Aid 5 Receiver . Lots of SS blog posts  Comment from Rick WD5L.  ) https://soldersmoke.blogspot.com/2023/10/a-big-error-discovered-in-1976-qst.html   Did you try to build one?  Did you succeed or did you fail?  Please let us know. 

The Basil Mahon books (blog posts) https://soldersmoke.blogspot.com/2023/11/basil-mahon-is-author-for-us-he.html

The Sunburst and Luminary book of Don Eyles (blog posts) 

The Art of Electronics by Horowitz and Hill (blog posts) 

Spectrum Analysers:  Tiny SA Ultra https://soldersmoke.blogspot.com/2023/09/the-tinysa-ultra-spectrum-analyser-video.html  and Polarad 632C-1; George WB5OYP gave me one of these spectrum analysers  (I NEED a manual! Does anyone have a manual or a schematic? )  : 

Polarad 632C-1

Stabilizing the EB63A (with Pete recommended LP filters from e-Bay. 


MAILBAG:

TRANSISTOR MAN T-SHIRTS!  Thanks to Roy WN3F! 

Todd VE7BPO on AF amplifiers.  Thanks Todd.  

Wes W7ZOI -- Always a privilege to exchange e-mail with Wes. 

E-mail from Jay Rusgrove W1VD. About the Herring Aid 5. 

E-mail from Eamon Skelton EI9GQ!  Amazing! 

HB2HB with Denny VU2DGR https://soldersmoke.blogspot.com/2023/09/hb2hb-contact-with-denny-vu2dgr.html

Nick M0NTV on diode matching for ring mixers: https://soldersmoke.blogspot.com/2023/10/does-matching-matter-diode-matching-for.html

Paul Taylor VK3HN on the new Elecraft CW rig. 

Dean KK4DAS fixed the noise in his Hallicrafters SW receiver.  A long battle, finally won. 

Dean also in contact with G3UUR. 

Ramakrishnan VU2JXN helping me set up a backup of blog on WordPress.  

Mark KA9OOI noticed that SS podcast archive appears gone.  In fact just temporarily relocated to http://soldersmoke.com/podcastarchive.html

(SS PODCAST Archive temporarily relocated to http://soldersmoke.com/podcastarchive.html) 

Andreas DL1AJG - Crystal radio video. https://soldersmoke.blogspot.com/2023/10/building-crystal-set-videos.html

George N2APB on the Herring Aid 5

Grayson KJ7UM experimenting with Varactors and Thermatrons! 

Thomas K4SWL on Mattia's DC receiver. https://soldersmoke.blogspot.com/2023/10/mattia-zamanas-amazing-direct.html

Bob Weaver of Dial Bandspread Linearity  fame.  Electron Bunker

Mike Bryce WB8VGE QRP Hall of famer -- he too couldn't get the Herring Aid 5 working. 

Kirk NT0Z wrote about the Wayback machine.  But this former ARRL staffer he also tried and failed to get the Herring Aid 5 going.  Way back when... https://soldersmoke.blogspot.com/2015/03/kirks-herring-aid-tuna-tin-and-regen.html


New 15-10 VFO with schematic

Dial Bandspread (Before)

At corner of Haight and Ashbury

Tuesday, February 9, 2016

Back to Divide by 4 -- Big Improvement in Receiver Performance

Thanks for all the comments and advice.  I have come to understand the wisdom of divide by 4 IQ circuits.  

Fortunately it was very easy to convert the divide by two 74AC74 circuit described earlier to a version of the divide by 4 scheme seen above.  (From the SDR Ensemble II Receiver:  http://www.wb5rvz.com/sdr/ensemble_rx_ii_vhf/04_div.htm)

This change provided a great way to observe 1) the improvement in the output signals from the VFO and 2) the resulting improvement in receiver performance, especially opposite sideband rejection.

Here are some numbers. I was very pleased to discover that my Rigol scope will measure duty cycle and phase difference. Thanks Rigol!

AD9850 Divide by 4 :  7.212 MHz  Duty cycle: 48.3  Phase Difference:  87-90 degrees

Si5351 Divide by 2:      7.212 MHz  Duty Cycle 49.6  Phase Difference:   83 degrees

Si5351 Divide by 4       7.212 MHz   Duty cycle 49     Phase Difference:  85-90 degrees

Additional improvement came when I switched the power supply to the IQ inverters and Flip Flops.  I switched from 3.3 to 5 volts:

Si5351 Divide by 4       7.105 MHz   Duty Cycle 49.7    Phase Difference:    90 degrees

When I took the VFO box and put it back in the receiver with the divide by 4 scheme and the 5 volt supply I immediately noticed a big difference in performance.  It was obvious that opposite sideband rejection was back to what I had had with the AD9850, perhaps better. 

I have a quick and dirty method of measuring opposite sideband rejection: I put an RF signal into the antenna connector.  I put the 'scope on the audio output.  I tune (on the desired sideband) for 1kHz audio and I measure the output voltage.  Then, with the audio gain and RF sig gen output in the same positions, I tune to the opposite sideband, again tuning for 1 kHz, again measuring audio output.  With the divide by 4 scheme and the 5 volt supply, the opposite sideband was so weak I had trouble measuring it.  I estimate the rejection to be at least 32 db -- this is back in the range of what I had with the AD9850, and significantly better than I had with the divide by 2 scheme. 

Now I just need to figure out how to get the Si5351 VFO sketch to tune above 42.94 MHz.  For some reason it quits at this point, switching down to 2 kHz output, and keeping me on 30 meters and below.

Thanks again to Todd VE7BPO for a lot of help with the hardware and to Tom AK2B for help with the Arduino code.  
   

Sunday, February 7, 2016

Ambition, Greed, and Experiments with a Divide by 2 IQ VFO

Fresh from a great success with the use of the M0XPD divide by 4 I and Q VFO in my Frankenstein Phasing Receiver, I got ambitious.  And greedy.  I wanted more.  More frequency coverage.  More bands.  Divide by 4 can really limit your frequency range.  The AD9850 only goes up to 40 MHz.  Divide by 4 and you can't even get the 30 meter band. 

So I started looking at other options.  Si570 looked nice, but here the lower limit was the problem: 10 MHz.   Even with divide by 4,  that knocks out 160 meters, a band I am very interested in lately, and that seems to sound especially good in a direct conversion receiver.

Once again, the controversial Si5351 was calling my name.  It would go down to 8 kHz and up to 160 Mhz.  Woo Hoo!  If I could build a divide by 2 IQ VFO, I could cover 160-6 meters.   

Here is the basic idea.  From:
http://www.markimicrowave.com/blog/2015/04/top-7-ways-to-create-a-quadrature-90-phase-shift/

 The Flip Flops are set up to change state when the input signal is going up.   By putting an inverter at the input of the bottom FF input, in effect you have that one changing state when the input signal is going down.  Look at this for a minute or so.  Look at the square waves at the bottom.  See it?  See how it takes an ordinary signal and spits out two signals, one 90 degrees off the other?  Pretty cool, don't you think?

With lots of hardware help from Todd VE7BPO, and software help from Tom AK2B (wizards both), I got my Si5351 divide by 2 circuit working today.  You can see the resulting I and Q in the picture at the top.   But I am discovering that there may have been wisdom  behind those divide by 4 circuits.  My opposite sideband suppression isn't as good with this /2 scheme as it was with the AD9850 divide by 4.  I'm still trying to figure out why. I may have to go back to divide by 4.  Stay tuned.    


Tuesday, December 23, 2014

VE7BPO's QRP POPS IS BACK!


We were all understandably concerned when Todd VE7BPO announced this Fall that he was taking down his beloved QRP POPS web site.    I'm pleased to report that Todd has transitioned from Web Site to blog.   The spirit of QRP POPS lives on here: 

http://qrp-popcorn.blogspot.com/

There are also links on this blog to all the great stuff that was on Todd's site: 


Three cheers for Todd!  Hip-hip...

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20