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Groups > sci.electronics.design > #743308 > unrolled thread

about electronics

Started byjohn larkin <jl@glen--canyon.com>
First post2026-04-24 08:55 -0700
Last post2026-05-06 15:58 +1000
Articles 20 on this page of 79 — 11 participants

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Contents

  about electronics john larkin <jl@glen--canyon.com> - 2026-04-24 08:55 -0700
    Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-25 02:14 +1000
      Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-24 09:39 -0700
        Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-25 03:32 +1000
          Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-24 10:46 -0700
            Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-25 14:44 +1000
              Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-25 08:03 -0700
                Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 02:28 +1000
                  Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-25 10:56 -0700
                    Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 21:27 +1000
                Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 21:11 +1000
                Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 21:16 +1000
                Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 21:50 +1000
            Re: about electronics Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-04-25 17:52 +0000
              Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-25 11:17 -0700
                Re: about electronics Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-04-26 17:12 +0000
          Re: about electronics someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-04-26 05:45 +0000
            Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-26 03:29 -0700
            Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 20:55 +1000
              Re: about electronics Someone <864c855e3d64399dc06fa30ebb75526c2c2e73db7216b16a3d4cf03e8a52ec3b@example.com> - 2026-04-28 20:15 +0000
                Re: about electronics Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-04-28 16:39 -0400
                  Re: about electronics someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-04-30 05:30 +0000
                    Re: about electronics Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-04-30 11:19 +0000
                      Re: about electronics someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-05-05 18:15 +0000
                        Re: about electronics Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-05-05 19:10 +0000
            Re: about electronics Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-04-26 12:53 +0000
            Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-26 07:57 -0700
              Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-27 01:33 +1000
        Re: about electronics Someone <864c855e3d64399dc06fa30ebb75526c2c2e73db7216b16a3d4cf03e8a52ec3b@example.com> - 2026-04-28 20:15 +0000
          Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-29 14:36 +1000
    Re: about electronics Buzz McCool <buzz_mccool@yahoo.com> - 2026-04-24 10:10 -0700
      Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-24 10:38 -0700
        Re: about electronics Buzz McCool <buzz_mccool@yahoo.com> - 2026-04-24 11:22 -0700
        Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-25 15:07 +1000
          Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-25 08:14 -0700
            Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 02:20 +1000
              Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-25 11:08 -0700
                Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 21:34 +1000
                  Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-27 13:24 -0700
                    Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-28 17:44 +1000
                      Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-28 09:22 -0700
                        Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-29 03:24 +1000
                          Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-28 18:58 -0700
                            Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-29 14:27 +1000
    Re: about electronics bitrex <user@example.net> - 2026-04-24 23:20 -0400
      Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-04-24 21:50 -0700
        Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-25 08:26 -0700
        Re: about electronics Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-04-25 17:53 +0000
          Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-04-25 11:34 -0700
            Re: about electronics Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-04-26 16:51 +0000
    Re: about electronics someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-04-26 05:45 +0000
      Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-26 03:39 -0700
        Re: about electronics Buzz McCool <buzz_mccool@yahoo.com> - 2026-04-28 15:38 -0700
          Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-04-28 15:57 -0700
            Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-28 19:07 -0700
            Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-29 10:39 -0700
              Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-04-30 22:43 +1000
                Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-30 07:19 -0700
                  Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-05-01 00:41 +1000
              Re: about electronics JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-30 15:54 +0100
                Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-30 09:27 -0700
                  Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-05-01 03:26 +1000
                    Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-30 11:38 -0700
                  Re: about electronics JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-30 18:45 +0100
                    Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-04-30 13:00 -0700
                    Re: about electronics Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-05-01 21:24 +0000
                      Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-05-02 16:27 +1000
                  Re: about electronics john larkin <jl@glen--canyon.com> - 2026-04-30 11:40 -0700
            Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-05-03 14:35 -0700
              Re: about electronics john larkin <jl@glen--canyon.com> - 2026-05-03 14:41 -0700
              Re: about electronics joegwinn@comcast.net - 2026-05-03 19:54 -0400
                Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-05-03 17:53 -0700
                  Re: about electronics joegwinn@comcast.net - 2026-05-04 19:54 -0400
                    Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-05-04 17:33 -0700
                      Re: about electronics joegwinn@comcast.net - 2026-05-05 13:35 -0400
                        Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-05-05 14:08 -0700
                  Re: about electronics Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-05-05 21:29 +0000
                    Re: about electronics Don Y <blockedofcourse@foo.invalid> - 2026-05-05 14:43 -0700
                      Re: about electronics Bill Sloman <bill.sloman@ieee.org> - 2026-05-06 15:58 +1000

Page 3 of 4 — ← Prev page 1 2 [3] 4  Next page →


#743509

Fromjohn larkin <jl@glen--canyon.com>
Date2026-04-28 09:22 -0700
Message-ID<osm1vkljfruma48ancfu6o719gjblhbot4@4ax.com>
In reply to#743498
On Tue, 28 Apr 2026 17:44:47 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:

>On 28/04/2026 6:24 am, john larkin wrote:
>> On Sun, 26 Apr 2026 21:34:01 +1000, Bill Sloman <bill.sloman@ieee.org>
>> wrote:
>> 
>>> On 26/04/2026 4:08 am, john larkin wrote:
>>>> On Sun, 26 Apr 2026 02:20:43 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>> wrote:
>>>>
>>>>> On 26/04/2026 1:14 am, john larkin wrote:
>>>>>> On Sat, 25 Apr 2026 15:07:29 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>>> wrote:
>>>>>>
>>>>>>> On 25/04/2026 3:38 am, john larkin wrote:
>>>>>>>> On Fri, 24 Apr 2026 10:10:53 -0700, Buzz McCool
>>>>>>>> <buzz_mccool@yahoo.com> wrote:
>>>>>>>>
>>>>>>>>> On 4/24/2026 8:55 AM, john larkin wrote:
>>>>>>>>>> Summary: very few people understand electronics.
>>>>>>>>>
>>>>>>>>> Edit: Very few people understand electronics as well as you.
>>>>>>>>>
>>>>>>>>> A few years ago you had some posts with typical interview questions you used.
>>>>>>>>> I collected these and sent them to my now freshly minted EE child who will
>>>>>>>>> be starting work next month. So don't think that people aren't listening.
>>>>>>>>
>>>>>>>> I hope your kid understands electricity. Most ce/ee grads don't, and
>>>>>>>> AI may make them into grocery store clerks.
>>>>>>>
>>>>>>> Probably not. AI is essentially mindless plagiarism.
>>>>>>> It gets stuff right about 90% of the time, rather like junior engineers,
>>>>>>> but needs to be backed up by people with deeper understanding
>>>>>>>
>>>>>>>>> If you have more pearls of wisdom to share, please do. Years ago Phil shared
>>>>>>>>> an article about how the front page of ceramic cap datasheets are a pack of
>>>>>>>>> lies, which was very revealing to me. Even now in the 4th quarter of my career
>>>>>>>>> I want to understand more about electronics.
>>>>>>>>>      
>>>>>>>> Ceramic caps are awful. Buy a 22uF 10v cap and you might get 3 uF at
>>>>>>>> 10v.
>>>>>>>
>>>>>>> Ceramic caps can be voltage dependent - but it does depend a lot on the
>>>>>>> actual ceramic. Reading the data sheet carefully can be informative.
>>>>>>
>>>>>> It's rare for a ceramic cap data sheet to even mention the cap fallout
>>>>>> with voltage, much less quantify it.
>>>>>>
>>>>>>> NPO ceramics are about as good as it gets. Ceramics with higher
>>>>>>> dielectric constants offer more - but less predictable - capacitance.
>>>>>>
>>>>>> NPOs are great, but only come in small values.
>>>>>
>>>>> That's what I just said.
>>>>>
>>>>>>> https://en.wikipedia.org/wiki/Ceramic_capacitor
>>>>>>>
>>>>>>> does talk about this. Class 1 ceramic capacitors can be very stable.
>>>>>>> Class 2 offers more capacitance but less stability, and Class 3 offers
>>>>>>> loads of capacitance in a small package but it can vary a great deal.
>>>>>>> John Larkin doesn't seem to read data sheets in detail, and he may have
>>>>>>> bought a class 3 capacitor for a Class 2 application.
>>>>>>
>>>>>> Classes, and categories like Z5U, are very crude. One has to test caps
>>>>>> when it matters, and then hope one can buy consistent parts.
>>>>>
>>>>> Crude they may be, but you didn't even mention that they existed.
>>>>>
>>>>>> We do buy big reels of custom-mixed caps with defined behaviors and
>>>>>> tempcos. I had Capax make us 5000 pieces of 3.3 pF 0805's, with -4700
>>>>>> ppm/degC tempco. They came out close. We have a lifetime supply.
>>>>>
>>>>> That implies more technical expertise than you exhibited above. Did one
>>>>> of your customers spell out the details, or that pesky Ph.D. that you fired?
>>>>
>>>> Neither. I use the NTCs to temperature compensate my instant-start LC
>>>> oscillators. FR4 has a radical positive TC. I typically wind up with a
>>>> parabolic frequency tempco, flat around 35c.
>>>>
>>>> Most things work like that. Compensate the first-order term, and
>>>> what's left is mostly second-order.
>>>
>>> The instant start LC oscillators are a bad idea. You can get much better
>>> timing out of a continuously running oscillator - you need two
>>> interpolation circuits rather than just one to find out where your
>>> interval started as well as where you want it to end, but the lower
>>> jitter on the continuously running oscillator makes that a better choice.
>
><snipped self-advertising>
>
>
>> There are lots of ways to make a triggered delay with XO accuracy and
>> jitter. Most involve a lot of insertion delay, and some have analog
>> s/h drift that is work to correct for.
>
>The ones that involve less insertion delay are more interesting.
>
>> Many users want minimal insertion delay.
>
>Most of them want the timing ramp to start a few nanoseconds before they 
>know they need to start it. Thiotimoline would solve that problem, if it 
>existed.
>
>https://en.wikipedia.org/wiki/Thiotimoline
>
>It can make more sense to redesign the experiment so that you can 
>control when it starts, but customers don't want to do that - they do 
>try to buy their way out of bad system design choices.
>
>> The instant-start oscillator is great in that respect.
>
>But not in others.
>
>> After it starts, we observe it for a while
>> and phase-lock it to a good OCXO but keep the timing based on the
>> trigger.
>
>Which inserts a delay.

About 3 nanoseconds. If the triggered oscillator is accurate and
low-jitter on its own, we can observe it and phase lock it at leisure.
No rush.

The HP 5359A time synthesizer used a triggered delay-line oscillator
and used a slow complex heterodyne system to phase-lock it to an OCXO.
Similar idea. But they didn't have access to fast ADCs and DACs like
we do now.

My favorite triggered oscillator uses a coaxial ceramic resonator, but
that has lots of real-world problems.

>
>>> You can't make a silk purse out of a sow's ear.
>> 
>> That's clever. Did you make that up?
>
>Like the emitter-coupled monostable, it isn't original.
>
>> Here's our benchtop DDG.
>> 
>> https://highlandtechnology.com/Product/P500
>> 
>> One nice feature is the GaN output stages that make super fast clean
>> pulses over a wide voltage range.
>
>Pity about the instant-start timing oscillator.

OK, you design a DDG and show me how.



John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

[toc] | [prev] | [next] | [standalone]


#743514

FromBill Sloman <bill.sloman@ieee.org>
Date2026-04-29 03:24 +1000
Message-ID<10sqqgs$3a6h3$1@dont-email.me>
In reply to#743509
On 29/04/2026 2:22 am, john larkin wrote:
> On Tue, 28 Apr 2026 17:44:47 +1000, Bill Sloman <bill.sloman@ieee.org>
> wrote:
> 
>> On 28/04/2026 6:24 am, john larkin wrote:
>>> On Sun, 26 Apr 2026 21:34:01 +1000, Bill Sloman <bill.sloman@ieee.org>
>>> wrote:
>>>
>>>> On 26/04/2026 4:08 am, john larkin wrote:
>>>>> On Sun, 26 Apr 2026 02:20:43 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>> wrote:
>>>>>
>>>>>> On 26/04/2026 1:14 am, john larkin wrote:
>>>>>>> On Sat, 25 Apr 2026 15:07:29 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> On 25/04/2026 3:38 am, john larkin wrote:
>>>>>>>>> On Fri, 24 Apr 2026 10:10:53 -0700, Buzz McCool
>>>>>>>>> <buzz_mccool@yahoo.com> wrote:
>>>>>>>>>
>>>>>>>>>> On 4/24/2026 8:55 AM, john larkin wrote:
>>>>>>>>>>> Summary: very few people understand electronics.
>>>>>>>>>>
>>>>>>>>>> Edit: Very few people understand electronics as well as you.
>>>>>>>>>>
>>>>>>>>>> A few years ago you had some posts with typical interview questions you used.
>>>>>>>>>> I collected these and sent them to my now freshly minted EE child who will
>>>>>>>>>> be starting work next month. So don't think that people aren't listening.
>>>>>>>>>
>>>>>>>>> I hope your kid understands electricity. Most ce/ee grads don't, and
>>>>>>>>> AI may make them into grocery store clerks.
>>>>>>>>
>>>>>>>> Probably not. AI is essentially mindless plagiarism.
>>>>>>>> It gets stuff right about 90% of the time, rather like junior engineers,
>>>>>>>> but needs to be backed up by people with deeper understanding
>>>>>>>>
>>>>>>>>>> If you have more pearls of wisdom to share, please do. Years ago Phil shared
>>>>>>>>>> an article about how the front page of ceramic cap datasheets are a pack of
>>>>>>>>>> lies, which was very revealing to me. Even now in the 4th quarter of my career
>>>>>>>>>> I want to understand more about electronics.
>>>>>>>>>>       
>>>>>>>>> Ceramic caps are awful. Buy a 22uF 10v cap and you might get 3 uF at
>>>>>>>>> 10v.
>>>>>>>>
>>>>>>>> Ceramic caps can be voltage dependent - but it does depend a lot on the
>>>>>>>> actual ceramic. Reading the data sheet carefully can be informative.
>>>>>>>
>>>>>>> It's rare for a ceramic cap data sheet to even mention the cap fallout
>>>>>>> with voltage, much less quantify it.
>>>>>>>
>>>>>>>> NPO ceramics are about as good as it gets. Ceramics with higher
>>>>>>>> dielectric constants offer more - but less predictable - capacitance.
>>>>>>>
>>>>>>> NPOs are great, but only come in small values.
>>>>>>
>>>>>> That's what I just said.
>>>>>>
>>>>>>>> https://en.wikipedia.org/wiki/Ceramic_capacitor
>>>>>>>>
>>>>>>>> does talk about this. Class 1 ceramic capacitors can be very stable.
>>>>>>>> Class 2 offers more capacitance but less stability, and Class 3 offers
>>>>>>>> loads of capacitance in a small package but it can vary a great deal.
>>>>>>>> John Larkin doesn't seem to read data sheets in detail, and he may have
>>>>>>>> bought a class 3 capacitor for a Class 2 application.
>>>>>>>
>>>>>>> Classes, and categories like Z5U, are very crude. One has to test caps
>>>>>>> when it matters, and then hope one can buy consistent parts.
>>>>>>
>>>>>> Crude they may be, but you didn't even mention that they existed.
>>>>>>
>>>>>>> We do buy big reels of custom-mixed caps with defined behaviors and
>>>>>>> tempcos. I had Capax make us 5000 pieces of 3.3 pF 0805's, with -4700
>>>>>>> ppm/degC tempco. They came out close. We have a lifetime supply.
>>>>>>
>>>>>> That implies more technical expertise than you exhibited above. Did one
>>>>>> of your customers spell out the details, or that pesky Ph.D. that you fired?
>>>>>
>>>>> Neither. I use the NTCs to temperature compensate my instant-start LC
>>>>> oscillators. FR4 has a radical positive TC. I typically wind up with a
>>>>> parabolic frequency tempco, flat around 35c.
>>>>>
>>>>> Most things work like that. Compensate the first-order term, and
>>>>> what's left is mostly second-order.
>>>>
>>>> The instant start LC oscillators are a bad idea. You can get much better
>>>> timing out of a continuously running oscillator - you need two
>>>> interpolation circuits rather than just one to find out where your
>>>> interval started as well as where you want it to end, but the lower
>>>> jitter on the continuously running oscillator makes that a better choice.
>>
>> <snipped self-advertising>
>>
>>
>>> There are lots of ways to make a triggered delay with XO accuracy and
>>> jitter. Most involve a lot of insertion delay, and some have analog
>>> s/h drift that is work to correct for.
>>
>> The ones that involve less insertion delay are more interesting.
>>
>>> Many users want minimal insertion delay.
>>
>> Most of them want the timing ramp to start a few nanoseconds before they
>> know they need to start it. Thiotimoline would solve that problem, if it
>> existed.
>>
>> https://en.wikipedia.org/wiki/Thiotimoline
>>
>> It can make more sense to redesign the experiment so that you can
>> control when it starts, but customers don't want to do that - they do
>> try to buy their way out of bad system design choices.
>>
>>> The instant-start oscillator is great in that respect.
>>
>> But not in others.
>>
>>> After it starts, we observe it for a while
>>> and phase-lock it to a good OCXO but keep the timing based on the
>>> trigger.
>>
>> Which inserts a delay.
> 
> About 3 nanoseconds. If the triggered oscillator is accurate and
> low-jitter on its own, we can observe it and phase lock it at leisure.
> No rush.

If you need to adjust the frequency, there's an accumulating phase error 
until you have got the frequency right. You can't get the frequency 
right in 3 nanoseconds.

> The HP 5359A time synthesizer used a triggered delay-line oscillator
> and used a slow complex heterodyne system to phase-lock it to an OCXO.
> Similar idea. But they didn't have access to fast ADCs and DACs like
> we do now.
> 
> My favorite triggered oscillator uses a coaxial ceramic resonator, but
> that has lots of real-world problems.
> 
>>>> You can't make a silk purse out of a sow's ear.
>>>
>>> That's clever. Did you make that up?
>>
>> Like the emitter-coupled monostable, it isn't original.
>>
>>> Here's our benchtop DDG.
>>>
>>> https://highlandtechnology.com/Product/P500
>>>
>>> One nice feature is the GaN output stages that make super fast clean
>>> pulses over a wide voltage range.
>>
>> Pity about the instant-start timing oscillator.
> 
> OK, you design a DDG and show me how.

One designs a digital delay generator for a particular customer - if you 
are lucky, a group of customers. I haven't got the customers for whom 
I'd generate the system design. The one I did build was for the 
Cambridge Instruments stroboscopic electron microscope.

It turned out to have elements in common with a two stage high precision 
mass spectrometer which I got involved with as stop gap job after the 
stroboscopic electron microscope job went sour. The system design for 
that was pretty horrible, and the customers apparently weren't open to 
redesigning their experiments to make the measurements easier.

-- 
Bill Sloman, Sydney

[toc] | [prev] | [next] | [standalone]


#743535

Fromjohn larkin <jl@glen--canyon.com>
Date2026-04-28 18:58 -0700
Message-ID<e7p2vktan5glu99odc76c4bi3pj0veo1rh@4ax.com>
In reply to#743514
On Wed, 29 Apr 2026 03:24:41 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:

>On 29/04/2026 2:22 am, john larkin wrote:
>> On Tue, 28 Apr 2026 17:44:47 +1000, Bill Sloman <bill.sloman@ieee.org>
>> wrote:
>> 
>>> On 28/04/2026 6:24 am, john larkin wrote:
>>>> On Sun, 26 Apr 2026 21:34:01 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>> wrote:
>>>>
>>>>> On 26/04/2026 4:08 am, john larkin wrote:
>>>>>> On Sun, 26 Apr 2026 02:20:43 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>>> wrote:
>>>>>>
>>>>>>> On 26/04/2026 1:14 am, john larkin wrote:
>>>>>>>> On Sat, 25 Apr 2026 15:07:29 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> On 25/04/2026 3:38 am, john larkin wrote:
>>>>>>>>>> On Fri, 24 Apr 2026 10:10:53 -0700, Buzz McCool
>>>>>>>>>> <buzz_mccool@yahoo.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> On 4/24/2026 8:55 AM, john larkin wrote:
>>>>>>>>>>>> Summary: very few people understand electronics.
>>>>>>>>>>>
>>>>>>>>>>> Edit: Very few people understand electronics as well as you.
>>>>>>>>>>>
>>>>>>>>>>> A few years ago you had some posts with typical interview questions you used.
>>>>>>>>>>> I collected these and sent them to my now freshly minted EE child who will
>>>>>>>>>>> be starting work next month. So don't think that people aren't listening.
>>>>>>>>>>
>>>>>>>>>> I hope your kid understands electricity. Most ce/ee grads don't, and
>>>>>>>>>> AI may make them into grocery store clerks.
>>>>>>>>>
>>>>>>>>> Probably not. AI is essentially mindless plagiarism.
>>>>>>>>> It gets stuff right about 90% of the time, rather like junior engineers,
>>>>>>>>> but needs to be backed up by people with deeper understanding
>>>>>>>>>
>>>>>>>>>>> If you have more pearls of wisdom to share, please do. Years ago Phil shared
>>>>>>>>>>> an article about how the front page of ceramic cap datasheets are a pack of
>>>>>>>>>>> lies, which was very revealing to me. Even now in the 4th quarter of my career
>>>>>>>>>>> I want to understand more about electronics.
>>>>>>>>>>>       
>>>>>>>>>> Ceramic caps are awful. Buy a 22uF 10v cap and you might get 3 uF at
>>>>>>>>>> 10v.
>>>>>>>>>
>>>>>>>>> Ceramic caps can be voltage dependent - but it does depend a lot on the
>>>>>>>>> actual ceramic. Reading the data sheet carefully can be informative.
>>>>>>>>
>>>>>>>> It's rare for a ceramic cap data sheet to even mention the cap fallout
>>>>>>>> with voltage, much less quantify it.
>>>>>>>>
>>>>>>>>> NPO ceramics are about as good as it gets. Ceramics with higher
>>>>>>>>> dielectric constants offer more - but less predictable - capacitance.
>>>>>>>>
>>>>>>>> NPOs are great, but only come in small values.
>>>>>>>
>>>>>>> That's what I just said.
>>>>>>>
>>>>>>>>> https://en.wikipedia.org/wiki/Ceramic_capacitor
>>>>>>>>>
>>>>>>>>> does talk about this. Class 1 ceramic capacitors can be very stable.
>>>>>>>>> Class 2 offers more capacitance but less stability, and Class 3 offers
>>>>>>>>> loads of capacitance in a small package but it can vary a great deal.
>>>>>>>>> John Larkin doesn't seem to read data sheets in detail, and he may have
>>>>>>>>> bought a class 3 capacitor for a Class 2 application.
>>>>>>>>
>>>>>>>> Classes, and categories like Z5U, are very crude. One has to test caps
>>>>>>>> when it matters, and then hope one can buy consistent parts.
>>>>>>>
>>>>>>> Crude they may be, but you didn't even mention that they existed.
>>>>>>>
>>>>>>>> We do buy big reels of custom-mixed caps with defined behaviors and
>>>>>>>> tempcos. I had Capax make us 5000 pieces of 3.3 pF 0805's, with -4700
>>>>>>>> ppm/degC tempco. They came out close. We have a lifetime supply.
>>>>>>>
>>>>>>> That implies more technical expertise than you exhibited above. Did one
>>>>>>> of your customers spell out the details, or that pesky Ph.D. that you fired?
>>>>>>
>>>>>> Neither. I use the NTCs to temperature compensate my instant-start LC
>>>>>> oscillators. FR4 has a radical positive TC. I typically wind up with a
>>>>>> parabolic frequency tempco, flat around 35c.
>>>>>>
>>>>>> Most things work like that. Compensate the first-order term, and
>>>>>> what's left is mostly second-order.
>>>>>
>>>>> The instant start LC oscillators are a bad idea. You can get much better
>>>>> timing out of a continuously running oscillator - you need two
>>>>> interpolation circuits rather than just one to find out where your
>>>>> interval started as well as where you want it to end, but the lower
>>>>> jitter on the continuously running oscillator makes that a better choice.
>>>
>>> <snipped self-advertising>
>>>
>>>
>>>> There are lots of ways to make a triggered delay with XO accuracy and
>>>> jitter. Most involve a lot of insertion delay, and some have analog
>>>> s/h drift that is work to correct for.
>>>
>>> The ones that involve less insertion delay are more interesting.
>>>
>>>> Many users want minimal insertion delay.
>>>
>>> Most of them want the timing ramp to start a few nanoseconds before they
>>> know they need to start it. Thiotimoline would solve that problem, if it
>>> existed.
>>>
>>> https://en.wikipedia.org/wiki/Thiotimoline
>>>
>>> It can make more sense to redesign the experiment so that you can
>>> control when it starts, but customers don't want to do that - they do
>>> try to buy their way out of bad system design choices.
>>>
>>>> The instant-start oscillator is great in that respect.
>>>
>>> But not in others.
>>>
>>>> After it starts, we observe it for a while
>>>> and phase-lock it to a good OCXO but keep the timing based on the
>>>> trigger.
>>>
>>> Which inserts a delay.
>> 
>> About 3 nanoseconds. If the triggered oscillator is accurate and
>> low-jitter on its own, we can observe it and phase lock it at leisure.
>> No rush.
>
>If you need to adjust the frequency, there's an accumulating phase error 
>until you have got the frequency right. You can't get the frequency 
>right in 3 nanoseconds.

Sure. It might take 10 usec or so to observe and lock. If the LC is
very good, it doesn't drift much meanwhile.

I think the HP took much longer to close the loop. 



>
>> The HP 5359A time synthesizer used a triggered delay-line oscillator
>> and used a slow complex heterodyne system to phase-lock it to an OCXO.
>> Similar idea. But they didn't have access to fast ADCs and DACs like
>> we do now.
>> 
>> My favorite triggered oscillator uses a coaxial ceramic resonator, but
>> that has lots of real-world problems.
>> 
>>>>> You can't make a silk purse out of a sow's ear.
>>>>
>>>> That's clever. Did you make that up?
>>>
>>> Like the emitter-coupled monostable, it isn't original.
>>>
>>>> Here's our benchtop DDG.
>>>>
>>>> https://highlandtechnology.com/Product/P500
>>>>
>>>> One nice feature is the GaN output stages that make super fast clean
>>>> pulses over a wide voltage range.
>>>
>>> Pity about the instant-start timing oscillator.
>> 
>> OK, you design a DDG and show me how.
>
>One designs a digital delay generator for a particular customer - if you 
>are lucky, a group of customers. I haven't got the customers for whom 
>I'd generate the system design. The one I did build was for the 
>Cambridge Instruments stroboscopic electron microscope.

How did that work?

>
>It turned out to have elements in common with a two stage high precision 
>mass spectrometer which I got involved with as stop gap job after the 
>stroboscopic electron microscope job went sour. The system design for 
>that was pretty horrible, and the customers apparently weren't open to 
>redesigning their experiments to make the measurements easier.

John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

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#743537

FromBill Sloman <bill.sloman@ieee.org>
Date2026-04-29 14:27 +1000
Message-ID<10ss1c9$3l5f0$1@dont-email.me>
In reply to#743535
On 29/04/2026 11:58 am, john larkin wrote:
> On Wed, 29 Apr 2026 03:24:41 +1000, Bill Sloman <bill.sloman@ieee.org>
> wrote:
> 
>> On 29/04/2026 2:22 am, john larkin wrote:
>>> On Tue, 28 Apr 2026 17:44:47 +1000, Bill Sloman <bill.sloman@ieee.org>
>>> wrote:
>>>
>>>> On 28/04/2026 6:24 am, john larkin wrote:
>>>>> On Sun, 26 Apr 2026 21:34:01 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>> wrote:
>>>>>
>>>>>> On 26/04/2026 4:08 am, john larkin wrote:
>>>>>>> On Sun, 26 Apr 2026 02:20:43 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> On 26/04/2026 1:14 am, john larkin wrote:
>>>>>>>>> On Sat, 25 Apr 2026 15:07:29 +1000, Bill Sloman <bill.sloman@ieee.org>
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>> On 25/04/2026 3:38 am, john larkin wrote:
>>>>>>>>>>> On Fri, 24 Apr 2026 10:10:53 -0700, Buzz McCool
>>>>>>>>>>> <buzz_mccool@yahoo.com> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> On 4/24/2026 8:55 AM, john larkin wrote:
>>>>>>>>>>>>> Summary: very few people understand electronics.
>>>>>>>>>>>>
>>>>>>>>>>>> Edit: Very few people understand electronics as well as you.
>>>>>>>>>>>>
>>>>>>>>>>>> A few years ago you had some posts with typical interview questions you used.
>>>>>>>>>>>> I collected these and sent them to my now freshly minted EE child who will
>>>>>>>>>>>> be starting work next month. So don't think that people aren't listening.
>>>>>>>>>>>
>>>>>>>>>>> I hope your kid understands electricity. Most ce/ee grads don't, and
>>>>>>>>>>> AI may make them into grocery store clerks.
>>>>>>>>>>
>>>>>>>>>> Probably not. AI is essentially mindless plagiarism.
>>>>>>>>>> It gets stuff right about 90% of the time, rather like junior engineers,
>>>>>>>>>> but needs to be backed up by people with deeper understanding
>>>>>>>>>>
>>>>>>>>>>>> If you have more pearls of wisdom to share, please do. Years ago Phil shared
>>>>>>>>>>>> an article about how the front page of ceramic cap datasheets are a pack of
>>>>>>>>>>>> lies, which was very revealing to me. Even now in the 4th quarter of my career
>>>>>>>>>>>> I want to understand more about electronics.
>>>>>>>>>>>>        
>>>>>>>>>>> Ceramic caps are awful. Buy a 22uF 10v cap and you might get 3 uF at
>>>>>>>>>>> 10v.
>>>>>>>>>>
>>>>>>>>>> Ceramic caps can be voltage dependent - but it does depend a lot on the
>>>>>>>>>> actual ceramic. Reading the data sheet carefully can be informative.
>>>>>>>>>
>>>>>>>>> It's rare for a ceramic cap data sheet to even mention the cap fallout
>>>>>>>>> with voltage, much less quantify it.
>>>>>>>>>
>>>>>>>>>> NPO ceramics are about as good as it gets. Ceramics with higher
>>>>>>>>>> dielectric constants offer more - but less predictable - capacitance.
>>>>>>>>>
>>>>>>>>> NPOs are great, but only come in small values.
>>>>>>>>
>>>>>>>> That's what I just said.
>>>>>>>>
>>>>>>>>>> https://en.wikipedia.org/wiki/Ceramic_capacitor
>>>>>>>>>>
>>>>>>>>>> does talk about this. Class 1 ceramic capacitors can be very stable.
>>>>>>>>>> Class 2 offers more capacitance but less stability, and Class 3 offers
>>>>>>>>>> loads of capacitance in a small package but it can vary a great deal.
>>>>>>>>>> John Larkin doesn't seem to read data sheets in detail, and he may have
>>>>>>>>>> bought a class 3 capacitor for a Class 2 application.
>>>>>>>>>
>>>>>>>>> Classes, and categories like Z5U, are very crude. One has to test caps
>>>>>>>>> when it matters, and then hope one can buy consistent parts.
>>>>>>>>
>>>>>>>> Crude they may be, but you didn't even mention that they existed.
>>>>>>>>
>>>>>>>>> We do buy big reels of custom-mixed caps with defined behaviors and
>>>>>>>>> tempcos. I had Capax make us 5000 pieces of 3.3 pF 0805's, with -4700
>>>>>>>>> ppm/degC tempco. They came out close. We have a lifetime supply.
>>>>>>>>
>>>>>>>> That implies more technical expertise than you exhibited above. Did one
>>>>>>>> of your customers spell out the details, or that pesky Ph.D. that you fired?
>>>>>>>
>>>>>>> Neither. I use the NTCs to temperature compensate my instant-start LC
>>>>>>> oscillators. FR4 has a radical positive TC. I typically wind up with a
>>>>>>> parabolic frequency tempco, flat around 35c.
>>>>>>>
>>>>>>> Most things work like that. Compensate the first-order term, and
>>>>>>> what's left is mostly second-order.
>>>>>>
>>>>>> The instant start LC oscillators are a bad idea. You can get much better
>>>>>> timing out of a continuously running oscillator - you need two
>>>>>> interpolation circuits rather than just one to find out where your
>>>>>> interval started as well as where you want it to end, but the lower
>>>>>> jitter on the continuously running oscillator makes that a better choice.
>>>>
>>>> <snipped self-advertising>
>>>>
>>>>
>>>>> There are lots of ways to make a triggered delay with XO accuracy and
>>>>> jitter. Most involve a lot of insertion delay, and some have analog
>>>>> s/h drift that is work to correct for.
>>>>
>>>> The ones that involve less insertion delay are more interesting.
>>>>
>>>>> Many users want minimal insertion delay.
>>>>
>>>> Most of them want the timing ramp to start a few nanoseconds before they
>>>> know they need to start it. Thiotimoline would solve that problem, if it
>>>> existed.
>>>>
>>>> https://en.wikipedia.org/wiki/Thiotimoline
>>>>
>>>> It can make more sense to redesign the experiment so that you can
>>>> control when it starts, but customers don't want to do that - they do
>>>> try to buy their way out of bad system design choices.
>>>>
>>>>> The instant-start oscillator is great in that respect.
>>>>
>>>> But not in others.
>>>>
>>>>> After it starts, we observe it for a while
>>>>> and phase-lock it to a good OCXO but keep the timing based on the
>>>>> trigger.
>>>>
>>>> Which inserts a delay.
>>>
>>> About 3 nanoseconds. If the triggered oscillator is accurate and
>>> low-jitter on its own, we can observe it and phase lock it at leisure.
>>> No rush.
>>
>> If you need to adjust the frequency, there's an accumulating phase error
>> until you have got the frequency right. You can't get the frequency
>> right in 3 nanoseconds.
> 
> Sure. It might take 10 usec or so to observe and lock. If the LC is
> very good, it doesn't drift much meanwhile.
> 
> I think the HP took much longer to close the loop.
> 
> 
> 
>>
>>> The HP 5359A time synthesizer used a triggered delay-line oscillator
>>> and used a slow complex heterodyne system to phase-lock it to an OCXO.
>>> Similar idea. But they didn't have access to fast ADCs and DACs like
>>> we do now.
>>>
>>> My favorite triggered oscillator uses a coaxial ceramic resonator, but
>>> that has lots of real-world problems.
>>>
>>>>>> You can't make a silk purse out of a sow's ear.
>>>>>
>>>>> That's clever. Did you make that up?
>>>>
>>>> Like the emitter-coupled monostable, it isn't original.
>>>>
>>>>> Here's our benchtop DDG.
>>>>>
>>>>> https://highlandtechnology.com/Product/P500
>>>>>
>>>>> One nice feature is the GaN output stages that make super fast clean
>>>>> pulses over a wide voltage range.
>>>>
>>>> Pity about the instant-start timing oscillator.
>>>
>>> OK, you design a DDG and show me how.
>>
>> One designs a digital delay generator for a particular customer - if you
>> are lucky, a group of customers. I haven't got the customers for whom
>> I'd generate the system design. The one I did build was for the
>> Cambridge Instruments stroboscopic electron microscope.
> 
> How did that work?

800MHz local oscillator phase locked to a good 1OMHz crystal oscillator.

We worked out when the start pulse had come in w.r.t. the local 
oscillator to about about 5psec (which took about 20nsec) and generated 
an output from the appropriate output from the 800MHz edge one cycle 
before the right time and generated a fine delay (to about 5psec).

The first try at the 800MHz oscillator didn't work and it's quick and 
dirty replacement had 60osec of jitter. We could have done better if 
we'd had to but our sampling pulse was 500psec wide and the 10pec was 
just the boss indulging in specmanship, and we had  more urgent problems 
to deal with.

-- 
Bill Sloman, Sydney

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#743341

Frombitrex <user@example.net>
Date2026-04-24 23:20 -0400
Message-ID<69ec32ef$1$24$882e4bbb@reader.netnews.com>
In reply to#743308
On 4/24/2026 11:55 AM, john larkin wrote:
> I went to a couple of hardware meetups and pitch sessions this week.
> 
> And I interview job and intern applicants.
> 
> And I see electronic projects in the online mags and on Youtube.
> 
> And there's SED of course.
> 
> Summary: very few people understand electronics.
> 
> 
> John Larkin
> Highland Tech Glen Canyon Design Center
> Lunatic Fringe Electronics

But somehow electronics are everywhere, anyway!

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#743343

FromDon Y <blockedofcourse@foo.invalid>
Date2026-04-24 21:50 -0700
Message-ID<10shh6d$jdc9$1@dont-email.me>
In reply to#743341
On 4/24/2026 8:20 PM, bitrex wrote:
> But somehow electronics are everywhere, anyway!

But fewer folks are involved in design.  Look at how many
prebuilt "modules" are folded into designs instead of designed
from scratch.  In the 70's, I'd start with an idea and a blank
sheet of paper.  When was the last time you designed a power
supply from scratch?  A counter?

Trend has been in place for a very long time as "integration"
reaches higher and higher levels.  Folks don't even bother
to put components on boards; easier to layer prebuilt boards
and components -- in the name of "economy" (until, of course,
you lose the ability to do those things!)

The same is true in software; folks just throw big chunks of
software together HOPING they understand how they work and
their limitations -- because actually understanding would
"cost" too much in time and personnel.  Can you even FIND
main()?

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#743354

Fromjohn larkin <jl@glen--canyon.com>
Date2026-04-25 08:26 -0700
Message-ID<4jmpuktb910hbjgtv83rvok6smg79pfvf6@4ax.com>
In reply to#743343
On Fri, 24 Apr 2026 21:50:18 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 4/24/2026 8:20 PM, bitrex wrote:
>> But somehow electronics are everywhere, anyway!
>
>But fewer folks are involved in design.  Look at how many
>prebuilt "modules" are folded into designs instead of designed
>from scratch.  

And there are dozens of identical Chinese products, all copies of some
original design.

>In the 70's, I'd start with an idea and a blank
>sheet of paper.  

I still design on paper, D-size vellum.

>When was the last time you designed a power
>supply from scratch?  A counter?

I did both recently, including a little high votage supply.
Autotransformer flyback driving a Cockcroft–Walton multiplier thingie
with the voltage controlled by one pin from the RP2040 CPU.

>
>Trend has been in place for a very long time as "integration"
>reaches higher and higher levels.  Folks don't even bother
>to put components on boards; easier to layer prebuilt boards
>and components -- in the name of "economy" (until, of course,
>you lose the ability to do those things!)

It's fundamental that if someone can slap some boards together, then
someone else can too. So the selling point becomes price, a race to
the bottom. No thanks.

I'm doing a board layout myself now. It's tricky enough that it's
easier to do than to explain all the constraints to someone else. I
don't even appreciate all the issues until I do it. I can change the
schematic interactively with the layout.



>
>The same is true in software; folks just throw big chunks of
>software together HOPING they understand how they work and
>their limitations -- because actually understanding would
>"cost" too much in time and personnel.  Can you even FIND
>main()?

John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

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#743365

FromNioclás Pól Caileán de Ghloucester <thanks-to@Taf.com>
Date2026-04-25 17:53 +0000
Message-ID<10siv2m$jn5v$4@paganini.bofh.team>
In reply to#743343
Don Y <blockedofcourse@foo.invalid> wrote:
|-------------------------------------------------------------|
|"The same is true in software; folks just throw big chunks of|
|software together HOPING they understand how they work and   |
|their limitations [. . .]"                                   |
|-------------------------------------------------------------|

Do they even hope so much, or instead do they hope that they might
manage to compile and run software which has a chance of doing what
they hope it will?
(S. HTTP://Gloucester.Insomnia247.NL/ fuer Kontaktdaten!)

[toc] | [prev] | [next] | [standalone]


#743370

FromDon Y <blockedofcourse@foo.invalid>
Date2026-04-25 11:34 -0700
Message-ID<10sj1gc$11q7d$1@dont-email.me>
In reply to#743365
On 4/25/2026 10:53 AM, Nioclás Pól Caileán de Ghloucester wrote:
> Don Y <blockedofcourse@foo.invalid> wrote:
> |-------------------------------------------------------------|
> |"The same is true in software; folks just throw big chunks of|
> |software together HOPING they understand how they work and   |
> |their limitations [. . .]"                                   |
> |-------------------------------------------------------------|
> 
> Do they even hope so much, or instead do they hope that they might
> manage to compile and run software which has a chance of doing what
> they hope it will?

Actually, it is more likely overconfidence on their part -- thinking
they understand something when, in fact, they are largely clueless.
"Enlightenment" possibly coming when they find they've shot
themselves in the foot.

[If something "unexpected" happens to a hardware design, it is quickly
dismissed as "outside the recommended operating conditions".  Wouldn't
it be nice to claim that same excuse for "misbehaving" software?]

Software is repeatable (in the absence of hardware errors).
So, seeing "something" once means there is some condition that
caused it to manifest.  Your inability to reproduce THAT
CONDITION doesn't mean the problem has gone away -- you're
just being lazy and HOPING for the best.

Do you see standard library (et al.) functions accounting for
the fact that the address space "wraps"?  Most will gladly
do what they are told -- regardless of how nonsensical it
may be (what does it mean to clear the last 100 bytes of
memory starting at LAST_MEMORY_ADDRESS - 72?)  Or, trying to
print "(unsigned) -1" digits with leading zero suppression?  Or, ...

How much stack does your piece of code (AND EVERYTHING ON WHICH IT
RELIES) *require*?  Do you even know how to go about getting a
DEFINITIVE answer?  What (specifically) will happen if you exceed
that value?

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#743417

FromNioclás Pól Caileán de Ghloucester <thanks-to@Taf.com>
Date2026-04-26 16:51 +0000
Message-ID<10slfpn$uf79$1@paganini.bofh.team>
In reply to#743370
Don Y <blockedofcourse@foo.invalid> wrote:
|---------------------------------------------------------------------|
|"Do you see standard library (et al.) functions accounting for       |
|the fact that the address space "wraps"?  Most will gladly           |
|do what they are told -- regardless of how nonsensical it            |
|may be (what does it mean to clear the last 100 bytes of             |
|memory starting at LAST_MEMORY_ADDRESS - 72?)  Or, trying to         |
|print "(unsigned) -1" digits with leading zero suppression?  Or, ..."|
|---------------------------------------------------------------------|

Ada libraries behave well.
(S. HTTP://Gloucester.Insomnia247.NL/ fuer Kontaktdaten!)

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#743391

Fromsomeone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com>
Date2026-04-26 05:45 +0000
Message-ID<18a9d1e3361fa0ff$161761$2713986$4026de73@news.newsgroupdirect.com>
In reply to#743308
The online stuff is a major disappointment. I don't know what this Stack Exchange thing is, but quite a few of their circuits that show up in searches are on the horrendous side. And from what I've seen, Reddit, another one I don't visit, is a mixed bag of some good and some bad. It can be a good starting point for further exploration. Whoever the audience is, they most certainly don't want an in-depth explanation of anything, or maybe don't know what in-depth means.

What technology is the Sofar buoy using for gyroscopic orientation? It doesn't look all that cutting edge, and the website is useless.

-- 
For full context, visit https://www.electrondepot.com/electrodesign/about-electronics-4401671-.htm

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#743399

Fromjohn larkin <jl@glen--canyon.com>
Date2026-04-26 03:39 -0700
Message-ID<h9qruk5ckr5ns4bmvneaksp0dgaei3bdk3@4ax.com>
In reply to#743391
On Sun, 26 Apr 2026 05:45:01 +0000, someone
<2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com>
wrote:

>The online stuff is a major disappointment. I don't know what this Stack Exchange thing is, but quite a few of their circuits that show up in searches are on the horrendous side. And from what I've seen, Reddit, another one I don't visit, is a mixed bag of some good and some bad. It can be a good starting point for further exploration. Whoever the audience is, they most certainly don't want an in-depth explanation of anything, or maybe don't know what in-depth means.
>
>What technology is the Sofar buoy using for gyroscopic orientation? It doesn't look all that cutting edge, and the website is useless.

I talked to the founder, an interesting guy. He's a surfer and scuba
diver and has always loved the ocean.

I don't know the details. He is using an RP2040 CPU and,  I think,
cell phone type sensors.

Their real focus is on the software. As is typical these days,
computer screens outnumber soldering irons about 20:1.

I saw the same thing touring the Cornell EE school. I counted 30
computer screens and one oscilloscope.



John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

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#743532

FromBuzz McCool <buzz_mccool@yahoo.com>
Date2026-04-28 15:38 -0700
Message-ID<10srctv$3g7fi$1@dont-email.me>
In reply to#743399
On 4/26/2026 3:39 AM, john larkin wrote:
> 
> Their real focus is on the software. As is typical these days,
> computer screens outnumber soldering irons about 20:1.
> 
> I saw the same thing touring the Cornell EE school. I counted 30
> computer screens and one oscilloscope.

An interesting ratio. Maybe screens to bench power supplies would be
a better measure of academic analog electronics rigor as oscopes in
an educational setting might be the USB type that plugs into a
computer.
  

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#743534

FromDon Y <blockedofcourse@foo.invalid>
Date2026-04-28 15:57 -0700
Message-ID<10sre1d$3go58$1@dont-email.me>
In reply to#743532
On 4/28/2026 3:38 PM, Buzz McCool wrote:
> An interesting ratio. Maybe screens to bench power supplies would be
> a better measure of academic analog electronics rigor as oscopes in
> an educational setting might be the USB type that plugs into a
> computer.

There's far less demand for electrical engineers.  Too much is
"slap together" from prefabbed modules -- designed by a relative
few people feeding multiple customer products.  And, their efforts
in typical product designs are relatively small (man-hours).

By contrast, the software/firmware in YOUR product is almost
certainly not the same as in some other product (even if you
leverage something like a Linux kernel).

Electrical Engineer salaries:  64,511 - 137,087 [$87,988]
Software Engineer:    75,449 - 209,993 [132,417]

(composite of a variety of market surveys)

There is downward pressure on pay for entry/early career
EE/SEs and considerable upward pressure on more experienced.

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#743536

Fromjohn larkin <jl@glen--canyon.com>
Date2026-04-28 19:07 -0700
Message-ID<7hp2vk15nn6jcgpvq26vf82nj304mhi5e2@4ax.com>
In reply to#743534
On Tue, 28 Apr 2026 15:57:47 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 4/28/2026 3:38 PM, Buzz McCool wrote:
>> An interesting ratio. Maybe screens to bench power supplies would be
>> a better measure of academic analog electronics rigor as oscopes in
>> an educational setting might be the USB type that plugs into a
>> computer.
>
>There's far less demand for electrical engineers.  Too much is
>"slap together" from prefabbed modules -- designed by a relative
>few people feeding multiple customer products.  And, their efforts
>in typical product designs are relatively small (man-hours).
>
>By contrast, the software/firmware in YOUR product is almost
>certainly not the same as in some other product (even if you
>leverage something like a Linux kernel).
>
>Electrical Engineer salaries:  64,511 - 137,087 [$87,988]
>Software Engineer:    75,449 - 209,993 [132,417]
>
>(composite of a variety of market surveys)
>
>There is downward pressure on pay for entry/early career
>EE/SEs and considerable upward pressure on more experienced.
>

Around here, the average EE salary is $151K.

The biggies, google and Apple, pay something like $300K. They bid
against one another.

What I meet is a lot of unemployed CE/EE people, coders, who don't
make the cut for the biggies.

https://www.sfchronicle.com/tech-layoffs/




John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

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#743561

Fromjohn larkin <jl@glen--canyon.com>
Date2026-04-29 10:39 -0700
Message-ID<agg4vk142bi43pvn0bm6qm2c37cqo8aqgt@4ax.com>
In reply to#743534
On Tue, 28 Apr 2026 15:57:47 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

>On 4/28/2026 3:38 PM, Buzz McCool wrote:
>> An interesting ratio. Maybe screens to bench power supplies would be
>> a better measure of academic analog electronics rigor as oscopes in
>> an educational setting might be the USB type that plugs into a
>> computer.
>
>There's far less demand for electrical engineers.  Too much is
>"slap together" from prefabbed modules -- designed by a relative
>few people feeding multiple customer products.  And, their efforts
>in typical product designs are relatively small (man-hours).
>
>By contrast, the software/firmware in YOUR product is almost
>certainly not the same as in some other product (even if you
>leverage something like a Linux kernel).
>
>Electrical Engineer salaries:  64,511 - 137,087 [$87,988]
>Software Engineer:    75,449 - 209,993 [132,417]
>
>(composite of a variety of market surveys)
>
>There is downward pressure on pay for entry/early career
>EE/SEs and considerable upward pressure on more experienced.
>

I wish we could hire good EEs for $137K.


John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

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#743584

FromBill Sloman <bill.sloman@ieee.org>
Date2026-04-30 22:43 +1000
Message-ID<10svip5$lq2e$1@dont-email.me>
In reply to#743561
On 30/04/2026 3:39 am, john larkin wrote:
> On Tue, 28 Apr 2026 15:57:47 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
> 
>> On 4/28/2026 3:38 PM, Buzz McCool wrote:
>>> An interesting ratio. Maybe screens to bench power supplies would be
>>> a better measure of academic analog electronics rigor as oscopes in
>>> an educational setting might be the USB type that plugs into a
>>> computer.
>>
>> There's far less demand for electrical engineers.  Too much is
>> "slap together" from prefabbed modules -- designed by a relative
>> few people feeding multiple customer products.  And, their efforts
>> in typical product designs are relatively small (man-hours).
>>
>> By contrast, the software/firmware in YOUR product is almost
>> certainly not the same as in some other product (even if you
>> leverage something like a Linux kernel).
>>
>> Electrical Engineer salaries:  64,511 - 137,087 [$87,988]
>> Software Engineer:    75,449 - 209,993 [132,417]
>>
>> (composite of a variety of market surveys)
>>
>> There is downward pressure on pay for entry/early career
>> EE/SEs and considerable upward pressure on more experienced.
>>
> 
> I wish we could hire good EEs for $137K.

It might be easier if you didn't interview them yourself.

-- 
Bill Sloman, Sydney

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#743590

Fromjohn larkin <jl@glen--canyon.com>
Date2026-04-30 07:19 -0700
Message-ID<96p6vkdb353fq0bmmg2vbdf0p26suk3alg@4ax.com>
In reply to#743584
On Thu, 30 Apr 2026 22:43:08 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:

>On 30/04/2026 3:39 am, john larkin wrote:
>> On Tue, 28 Apr 2026 15:57:47 -0700, Don Y
>> <blockedofcourse@foo.invalid> wrote:
>> 
>>> On 4/28/2026 3:38 PM, Buzz McCool wrote:
>>>> An interesting ratio. Maybe screens to bench power supplies would be
>>>> a better measure of academic analog electronics rigor as oscopes in
>>>> an educational setting might be the USB type that plugs into a
>>>> computer.
>>>
>>> There's far less demand for electrical engineers.  Too much is
>>> "slap together" from prefabbed modules -- designed by a relative
>>> few people feeding multiple customer products.  And, their efforts
>>> in typical product designs are relatively small (man-hours).
>>>
>>> By contrast, the software/firmware in YOUR product is almost
>>> certainly not the same as in some other product (even if you
>>> leverage something like a Linux kernel).
>>>
>>> Electrical Engineer salaries:  64,511 - 137,087 [$87,988]
>>> Software Engineer:    75,449 - 209,993 [132,417]
>>>
>>> (composite of a variety of market surveys)
>>>
>>> There is downward pressure on pay for entry/early career
>>> EE/SEs and considerable upward pressure on more experienced.
>>>
>> 
>> I wish we could hire good EEs for $137K.
>
>It might be easier if you didn't interview them yourself.

Good point. My company would hire more cheap duds.


John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics

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#743591

FromBill Sloman <bill.sloman@ieee.org>
Date2026-05-01 00:41 +1000
Message-ID<10svpmg$nuji$1@dont-email.me>
In reply to#743590
On 1/05/2026 12:19 am, john larkin wrote:
> On Thu, 30 Apr 2026 22:43:08 +1000, Bill Sloman <bill.sloman@ieee.org>
> wrote:
> 
>> On 30/04/2026 3:39 am, john larkin wrote:
>>> On Tue, 28 Apr 2026 15:57:47 -0700, Don Y
>>> <blockedofcourse@foo.invalid> wrote:
>>>
>>>> On 4/28/2026 3:38 PM, Buzz McCool wrote:
>>>>> An interesting ratio. Maybe screens to bench power supplies would be
>>>>> a better measure of academic analog electronics rigor as oscopes in
>>>>> an educational setting might be the USB type that plugs into a
>>>>> computer.
>>>>
>>>> There's far less demand for electrical engineers.  Too much is
>>>> "slap together" from prefabbed modules -- designed by a relative
>>>> few people feeding multiple customer products.  And, their efforts
>>>> in typical product designs are relatively small (man-hours).
>>>>
>>>> By contrast, the software/firmware in YOUR product is almost
>>>> certainly not the same as in some other product (even if you
>>>> leverage something like a Linux kernel).
>>>>
>>>> Electrical Engineer salaries:  64,511 - 137,087 [$87,988]
>>>> Software Engineer:    75,449 - 209,993 [132,417]
>>>>
>>>> (composite of a variety of market surveys)
>>>>
>>>> There is downward pressure on pay for entry/early career
>>>> EE/SEs and considerable upward pressure on more experienced.
>>>>
>>>
>>> I wish we could hire good EEs for $137K.
>>
>> It might be easier if you didn't interview them yourself.
> 
> Good point. My company would hire more cheap duds.

They might also get to hire people that your antics could have put off.
Asking potential hires really simple questions about electronics might 
save you from hiring a cheap dud, but it might put off somebody who 
might think that you hadn't bothered to read their CV (or worse, might 
think that you had not been able to understand it).

Job interviews are a two way street. The interviewee gets an insight 
into the people they might end up having to work with.

-- 
Bill Sloman, Sydney

-- 
Bill Sloman, Sydney

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#743593

FromJM <sunaecoNoChoppedPork@gmail.com>
Date2026-04-30 15:54 +0100
Message-ID<d6r6vkt6t1vneq2nvnq99nohfiaejajkhc@4ax.com>
In reply to#743561
On Wed, 29 Apr 2026 10:39:23 -0700, john larkin <jl@glen--canyon.com>
wrote:


>
>I wish we could hire good EEs for $137K.
>

That would get you about 3 engineers in the UK (ignoring the
overheads).

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