I'm modelling an incandescent lamp and internally, to calculate things
like filament temperature and radiated power, I'm using behavioral
voltage sources. Of course, when I plot the curves, they display as
voltages. Is there any way to tell LTspice that the units should be
Kelvins and Watts?
Jeroen Belleman
Jeroen Belleman <jeroen@nospam.please> wrote:
I'm modelling an incandescent lamp and internally, to calculate things
like filament temperature and radiated power, I'm using behavioral
voltage sources. Of course, when I plot the curves, they display as
voltages. Is there any way to tell LTspice that the units should be
Kelvins and Watts?
Jeroen Belleman
In the plot window, ctl-a to bring up the dialog, then plot rCLV(out)*1W/1KrCY
The plot window is a bit of an _idiot savant_, especially in noise sims.
It knows to combine noise sources in RSS fashion, but is too stupid to get the right units for input referred currents other than inoise.
In a TIA, one would like to plot, say, V(Q1)/gain, but in order to get the right units to plot on the same axes as inoise, you have to go V(Q1)*inoise/V(onoise).
Inelegant.
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
Jeroen Belleman <jeroen@nospam.please> wrote:
I'm modelling an incandescent lamp and internally, to calculate things
like filament temperature and radiated power, I'm using behavioral
voltage sources. Of course, when I plot the curves, they display as
voltages. Is there any way to tell LTspice that the units should be
Kelvins and Watts?
Jeroen Belleman
In the plot window, ctl-a to bring up the dialog, then plot rCLV(out)*1W/1KrCY
1W/1V
The plot window is a bit of an _idiot savant_, especially in noise sims.
It knows to combine noise sources in RSS fashion, but is too stupid to get >> the right units for input referred currents other than inoise.
In a TIA, one would like to plot, say, V(Q1)/gain, but in order to get the >> right units to plot on the same axes as inoise, you have to go
V(Q1)*inoise/V(onoise).
Inelegant.
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
Jeroen Belleman <jeroen@nospam.please> wrote:
I'm modelling an incandescent lamp and internally, to calculate things
like filament temperature and radiated power, I'm using behavioral
voltage sources. Of course, when I plot the curves, they display as
voltages. Is there any way to tell LTspice that the units should be
Kelvins and Watts?
Jeroen Belleman
In the plot window, ctl-a to bring up the dialog, then plot oV(out)*1W/1Ko
1W/1V
The plot window is a bit of an _idiot savant_, especially in noise sims.
It knows to combine noise sources in RSS fashion, but is too stupid to get >> the right units for input referred currents other than inoise.
In a TIA, one would like to plot, say, V(Q1)/gain, but in order to get the >> right units to plot on the same axes as inoise, you have to go
V(Q1)*inoise/V(onoise).
Inelegant.
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote: |---------------------------------------------|
|"Phil rCLIrCOve a mind to demand a refundrCY Hobbs"| |---------------------------------------------|
A lecturer told us that companies which were early users of Spice
had complained to students responsible for Spice that Spice
simulations are wrong, so students have answered that those companies
got Spice for virtually gratis so they should not expect much.
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
|---------------------------------------------|
|"Phil oIAve a mind to demand a refundo Hobbs"|
|---------------------------------------------|
A lecturer told us that companies which were early users of Spice
had complained to students responsible for Spice that Spice
simulations are wrong, so students have answered that those companies
got Spice for virtually gratis so they should not expect much.
They could have hired them to fix it.
LTspice is pretty good at what it does, i.e. integrating sparse systems of >nonlinear ODEs. Of course any application to a real circuit depends
entirely on the quality of the device models and
on how accurately the deck represents the actual circuit.
Strays, transmission line effects, and so on are the designerAs >responsibility.
And of course board-level models all stink. But have a nice day. ;)
Cheers
Phil Hobbs
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
|---------------------------------------------|
|"Phil "I've a mind to demand a refund" Hobbs"|
|---------------------------------------------|
A lecturer told us that companies which were early users of Spice
had complained to students responsible for Spice that Spice
simulations are wrong, so students have answered that those companies
got Spice for virtually gratis so they should not expect much.
They could have hired them to fix it.
LTspice is pretty good at what it does, i.e. integrating sparse systems of >>nonlinear ODEs. Of course any application to a real circuit depends >>entirely on the quality of the device models and
on how accurately the deck represents the actual circuit.
Strays, transmission line effects, and so on are the designer's >>responsibility.
And of course board-level models all stink. But have a nice day. ;)
Cheers
Phil Hobbs
LT is indeed pretty good. Things that we simulate most always work as expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to
see what happens. That works too.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
LT is indeed pretty good. Things that we simulate most always work as
expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to
see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as
expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to
see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
John May clearly knew what he was doing, and I went to the trouble of explaining what I thought was going on when I posted my
Spice net list.
Getting a Ph.D. is basically doing a bit of scientific research and writing it up clearly enough that you could get it published
(not that I ever got around to that), so it should leave you equipped to explain what you are doing in terms clear enough that
other people can follow.
You certainly don't have to get a Ph.D. to acquire that particular skill, but if you have got it, getting a Ph.D. can be way of
getting more money out of it.
--
Bill Sloman, Sydney
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as
expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to
see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
In any case I now have a circuit which does 150dB in a simulation and
it isn't anything like the one you mention above. What it does in reality
is, of course, anybody's guess and better than 90dB would surprise me.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators
or damping resistors are needed.
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well - and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and
it isn't anything like the one you mention above. What it does in reality
is, of course, anybody's guess and better than 90dB would surprise me.
Lots of thing surprise you.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators
or damping resistors are needed.
Your conception of what's going on is unlikely to be realistic.
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well - and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and
it isn't anything like the one you mention above. What it does in reality >>> is, of course, anybody's guess and better than 90dB would surprise me.
Lots of thing surprise you.
I don't know your exact definition of "Lots" but please give as many examples >as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators
or damping resistors are needed.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
I make no claim at all about the performance of the following circuit
except that an FFT with a Blackman Harris window on a small sample
near the end of the simulation measures 150dB down on harmonics.
It is likely that there are reasons why a real circuit would not be able
to do this but I'm not about to spend money on test equipment which
can come anywhere close to measuring it.
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well - and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and
it isn't anything like the one you mention above. What it does in reality >>> is, of course, anybody's guess and better than 90dB would surprise me.
Lots of thing surprise you.
I don't know your exact definition of "Lots" but please give as many examples as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators
or damping resistors are needed.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well - and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and
it isn't anything like the one you mention above. What it does in reality >>>> is, of course, anybody's guess and better than 90dB would surprise me.
Lots of thing surprise you.
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators
or damping resistors are needed.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
I make no claim at all about the performance of the following circuit
except that an FFT with a Blackman Harris window on a small sample
near the end of the simulation measures 150dB down on harmonics.
It is likely that there are reasons why a real circuit would not be able
to do this but I'm not about to spend money on test equipment which
can come anywhere close to measuring it.
A sub-PPM distortion sine generator wouldn't be difficult, if you had
some way to measure it.
On 16/06/2026 2:38 am, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot
better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better
when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well -
and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and
it isn't anything like the one you mention above. What it does in reality >>>> is, of course, anybody's guess and better than 90dB would surprise me.
Lots of thing surprise you.
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators
or damping resistors are needed.
It's simulating slowly as I type, and the amplitude is still creeping up. It's not obvious what's going to limit it. It seems to
be diode clipping at D1 and D2, which isn't going to produce a temperature stable or all that predictable output amplitude.
It's usual in these sorts of circuits to provide a mechanism that controls the amplitude at a well-defined and predictable level.
I've put three terminal references into my circuits to let me do this. This does involve feedback, and stabilising a negative
feedback loop to give a dead-beat response isn't rocket science. You seem to be congratulating yourself on having avoided doing
any of this, but self-congratulation is one of your defining characteristics.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
I could try, but I don't seem to be able to dumb down my arguments far enough to make them comprehensible for you.
--
Bill Sloman, Sydney
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well - and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and >>>>> it isn't anything like the one you mention above. What it does in reality >>>>> is, of course, anybody's guess and better than 90dB would surprise me. >>>>Lots of thing surprise you.
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators >>>>> or damping resistors are needed.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
Tailoring the explanation to the audience's capacity to understand it is
a skill. I can dumb down stuff enough to let managers and junior
engineers understand what I am saying, but I've had less practice with >less-well-informed audiences. My wife wasn't all that well-informed
about electronics, but she was remarkably clever (FRS, foreign member of
the US academy of sciences) and probably not an ideal practice object.
I make no claim at all about the performance of the following circuit
except that an FFT with a Blackman Harris window on a small sample
near the end of the simulation measures 150dB down on harmonics.
It is likely that there are reasons why a real circuit would not be able >>> to do this but I'm not about to spend money on test equipment which
can come anywhere close to measuring it.
A sub-PPM distortion sine generator wouldn't be difficult, if you had
some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not
all that much higher. Phase sensitive detectors can pick out quite low >signal levels at specific - known - frequencies in the presence of much >higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that >doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the >low-distortion oscillator, but not all that more difficult.
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110qrqi$u3kr$1@dont-email.me...
On 16/06/2026 2:38 am, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot
better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better
when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well -
and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and >>>>> it isn't anything like the one you mention above. What it does in reality >>>>> is, of course, anybody's guess and better than 90dB would surprise me. >>>>Lots of thing surprise you.
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has
no overshoot, undershoot or any kind of shoot at all. No integrators >>>>> or damping resistors are needed.
It's simulating slowly as I type, and the amplitude is still creeping up. It's not obvious what's going to limit it. It seems to
be diode clipping at D1 and D2, which isn't going to produce a temperature stable or all that predictable output amplitude.
If you really do want to be 150dB down and measure it then you can afford
to keep your diodes at constant temperature and adjust R1 for correct output level
when everything is at a stable temperature.
--It's usual in these sorts of circuits to provide a mechanism that controls the amplitude at a well-defined and predictable level.
I've put three terminal references into my circuits to let me do this. This does involve feedback, and stabilising a negative
feedback loop to give a dead-beat response isn't rocket science. You seem to be congratulating yourself on having avoided doing
any of this, but self-congratulation is one of your defining characteristics.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
I could try, but I don't seem to be able to dumb down my arguments far enough to make them comprehensible for you.
On Tue, 16 Jun 2026 17:58:32 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well - and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and >>>>>> it isn't anything like the one you mention above. What it does in realityLots of thing surprise you.
is, of course, anybody's guess and better than 90dB would surprise me. >>>>>
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has >>>>>> no overshoot, undershoot or any kind of shoot at all. No integrators >>>>>> or damping resistors are needed.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
Tailoring the explanation to the audience's capacity to understand it is
a skill. I can dumb down stuff enough to let managers and junior
engineers understand what I am saying, but I've had less practice with
less-well-informed audiences. My wife wasn't all that well-informed
about electronics, but she was remarkably clever (FRS, foreign member of
the US academy of sciences) and probably not an ideal practice object.
I make no claim at all about the performance of the following circuit
except that an FFT with a Blackman Harris window on a small sample
near the end of the simulation measures 150dB down on harmonics.
It is likely that there are reasons why a real circuit would not be able >>>> to do this but I'm not about to spend money on test equipment which
can come anywhere close to measuring it.
A sub-PPM distortion sine generator wouldn't be difficult, if you had
some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not
all that much higher. Phase sensitive detectors can pick out quite low
signal levels at specific - known - frequencies in the presence of much
higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that
doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the
low-distortion oscillator, but not all that more difficult.
Tell us how to measure 1 PPM distortion on an audio-range signal, and
I'll tell you how to build the sub-PPM variable-frequency source.
On 16/06/2026 11:59 pm, john larkin wrote:
On Tue, 16 Jun 2026 17:58:32 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...<snip>
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote: >>>>>>>>
LT is indeed pretty good. Things that we simulate most always work as
expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to
see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well - and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and >>>>>>> it isn't anything like the one you mention above. What it does in realityLots of thing surprise you.
is, of course, anybody's guess and better than 90dB would surprise me. >>>>>>
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has >>>>>>> no overshoot, undershoot or any kind of shoot at all. No integrators >>>>>>> or damping resistors are needed.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
Tailoring the explanation to the audience's capacity to understand it is >>> a skill. I can dumb down stuff enough to let managers and junior
engineers understand what I am saying, but I've had less practice with
less-well-informed audiences. My wife wasn't all that well-informed
about electronics, but she was remarkably clever (FRS, foreign member of >>> the US academy of sciences) and probably not an ideal practice object.
I make no claim at all about the performance of the following circuit >>>>> except that an FFT with a Blackman Harris window on a small sample
near the end of the simulation measures 150dB down on harmonics.
It is likely that there are reasons why a real circuit would not be able >>>>> to do this but I'm not about to spend money on test equipment which
can come anywhere close to measuring it.
A sub-PPM distortion sine generator wouldn't be difficult, if you had
some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not >>> all that much higher. Phase sensitive detectors can pick out quite low
signal levels at specific - known - frequencies in the presence of much
higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that >>> doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the
low-distortion oscillator, but not all that more difficult.
Tell us how to measure 1 PPM distortion on an audio-range signal, and
I'll tell you how to build the sub-PPM variable-frequency source.
I just did. If you could have understood the advice, your claim to be
able to offer advice on building the sub-ppm distortion audio generator >might be plausible.
None of the low distortion sine wave sources that have been offered here >were designed to offer much variation in output frequency. Ganged
Beckman ten-turn pots might get you a decade, but covering much of a >frequency range does make the project more difficult.
On 16/06/2026 11:23 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110qrqi$u3kr$1@dont-email.me...
On 16/06/2026 2:38 am, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
LT is indeed pretty good. Things that we simulate most always work as >>>>>>>>> expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to >>>>>>>>> see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot
better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better
when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well -
and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and >>>>>> it isn't anything like the one you mention above. What it does in realityLots of thing surprise you.
is, of course, anybody's guess and better than 90dB would surprise me. >>>>>
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has >>>>>> no overshoot, undershoot or any kind of shoot at all. No integrators >>>>>> or damping resistors are needed.
It's simulating slowly as I type, and the amplitude is still creeping up. It's not obvious what's going to limit it. It seems to
be diode clipping at D1 and D2, which isn't going to produce a temperature stable or all that predictable output amplitude.
If you really do want to be 150dB down and measure it then you can afford
to keep your diodes at constant temperature and adjust R1 for correct output level
when everything is at a stable temperature.
There are lots of other ways of doing it, and most of them are a whole lot more elegant.
Most of the circuits you have been parodying use a non-linear element to let you set up a controllable close-to-linear gain. You
rectify the output to determine it's amplitude, compare that DC output with a reliable reference DC voltage, and use feedback to
control the gain to get your circuit to run at a stable output. You have chosen to go for minimal clipping to control the output
amplitude, which is a simpler approach, but not all that easy to get to work in practice.
I have spelled this out before, but you don't seem to have got the message.
It's usual in these sorts of circuits to provide a mechanism that controls the amplitude at a well-defined and predictable
level.
I've put three terminal references into my circuits to let me do this.
This does involve feedback, and stabilising a negative
feedback loop to give a dead-beat response isn't rocket science. You seem to be congratulating yourself on having avoided doing
any of this, but self-congratulation is one of your defining characteristics.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
I could try, but I don't seem to be able to dumb down my arguments far enough to make them comprehensible for you.
--
Bill Sloman, Sydney
On Wed, 17 Jun 2026 01:21:01 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 16/06/2026 11:59 pm, john larkin wrote:
On Tue, 16 Jun 2026 17:58:32 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
A sub-PPM distortion sine generator wouldn't be difficult, if you had >>>>> some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not >>>> all that much higher. Phase sensitive detectors can pick out quite low >>>> signal levels at specific - known - frequencies in the presence of much >>>> higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that >>>> doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the
low-distortion oscillator, but not all that more difficult.
Tell us how to measure 1 PPM distortion on an audio-range signal, and
I'll tell you how to build the sub-PPM variable-frequency source.
I just did. If you could have understood the advice, your claim to be
able to offer advice on building the sub-ppm distortion audio generator
might be plausible.
Details matter. Very good resistors have ppm/volt coefficients. And
caps distort. Opamps too.
None of the low distortion sine wave sources that have been offered here
were designed to offer much variation in output frequency. Ganged
Beckman ten-turn pots might get you a decade, but covering much of a
frequency range does make the project more difficult.
Make the sines digitally and use DACs. Simple. The problem is still
measuring the distortion.
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110rkv5$15d4p$1@dont-email.me...
On 16/06/2026 11:23 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110qrqi$u3kr$1@dont-email.me...
On 16/06/2026 2:38 am, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...<snip>
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote: >>>>>>>>
LT is indeed pretty good. Things that we simulate most always work as
expected. And it has transmission lines.
I sometimes "design" with LT Spice, just poke parts here and there to
see what happens. That works too.
Ssh don't say that when Bill is only hours away.
We'll have another mega thread about why only PhDs should be allowed to design anything.
You don't have to get a Ph.D. to learn how to read a data sheet. John Larkin got his degree at Tulane, but Tulane can't be
blamed
for his unwillingness to read stuff and learn from it.
Messing about with a Spice simulation isn't much different from messing about with a real circuit. Both work a whole lot
better
if
you have some idea what you are doing. At least one of the Spice simulations that you have posted here worked rather better
when
John May took out four transistor and marginally better than that when I added another one.
That must be the 128735th time you've mentioned that Bill.
Probably not. It was certainly an interesting incident. You had a good idea - even if you couldn't realise it all that well -
and
that was unexpected.
In any case I now have a circuit which does 150dB in a simulation and >>>>>>> it isn't anything like the one you mention above. What it does in realityLots of thing surprise you.
is, of course, anybody's guess and better than 90dB would surprise me. >>>>>>
I don't know your exact definition of "Lots" but please give as many examples
as you can of things which surprise me.
The startup characteristic should give you an orgasm because it has >>>>>>> no overshoot, undershoot or any kind of shoot at all. No integrators >>>>>>> or damping resistors are needed.
It's simulating slowly as I type, and the amplitude is still creeping up. It's not obvious what's going to limit it. It seems to
be diode clipping at D1 and D2, which isn't going to produce a temperature stable or all that predictable output amplitude.
If you really do want to be 150dB down and measure it then you can afford >>> to keep your diodes at constant temperature and adjust R1 for correct output level
when everything is at a stable temperature.
There are lots of other ways of doing it, and most of them are a whole lot more elegant.
Sure.
I could have a computer monitor the output level and control a motor to adjust R1.
Most of the circuits you have been parodying use a non-linear element to let you set up a controllable close-to-linear gain. You
rectify the output to determine it's amplitude, compare that DC output with a reliable reference DC voltage, and use feedback to
control the gain to get your circuit to run at a stable output. You have chosen to go for minimal clipping to control the output
amplitude, which is a simpler approach, but not all that easy to get to work in practice.
I have spelled this out before, but you don't seem to have got the message.
Of course Headmaster.
It's usual in these sorts of circuits to provide a mechanism that controls the amplitude at a well-defined and predictable
level.
I've put three terminal references into my circuits to let me do this.
Congratulations.
I've put stawberry jam on chicken and found it worked well.
--This does involve feedback, and stabilising a negative
feedback loop to give a dead-beat response isn't rocket science. You seem to be congratulating yourself on having avoided doing
any of this, but self-congratulation is one of your defining characteristics.
Your conception of what's going on is unlikely to be realistic.
Ah well in that case perhaps you could explain it to me.
I could try, but I don't seem to be able to dumb down my arguments far enough to make them comprehensible for you.
The point about the low distortion sine wave oscillators is that they
are cheap.
I've put stawberry jam on chicken and found it worked well.
Bill Sloman <bill.sloman@ieee.org> wrote:
[...]
The point about the low distortion sine wave oscillators is that they
are cheap.
I may have missed the point here but why are you trying to generate and measure infra-low distortion sine waves?
Any harmonics120dB or more below the signal will be lost in the noise
floor and can only be recovered by narrow-bandwidth techniques, so which practical applications require distortion levels below those obtainable
from common existing oscillators?
On 17/06/2026 2:23 am, john larkin wrote:
On Wed, 17 Jun 2026 01:21:01 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 16/06/2026 11:59 pm, john larkin wrote:
On Tue, 16 Jun 2026 17:58:32 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote:
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
A sub-PPM distortion sine generator wouldn't be difficult, if you had >>>>>> some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not >>>>> all that much higher. Phase sensitive detectors can pick out quite low >>>>> signal levels at specific - known - frequencies in the presence of much >>>>> higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that >>>>> doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the
low-distortion oscillator, but not all that more difficult.
Tell us how to measure 1 PPM distortion on an audio-range signal, and
I'll tell you how to build the sub-PPM variable-frequency source.
I just did. If you could have understood the advice, your claim to be
able to offer advice on building the sub-ppm distortion audio generator
might be plausible.
Details matter. Very good resistors have ppm/volt coefficients. And
caps distort. Opamps too.
Not that you can detail how.
None of the low distortion sine wave sources that have been offered here >>> were designed to offer much variation in output frequency. Ganged
Beckman ten-turn pots might get you a decade, but covering much of a
frequency range does make the project more difficult.
Make the sines digitally and use DACs. Simple. The problem is still
measuring the distortion.
DACs aren't that good, which is the kind of detail you ought to know. Or
at least DACs anybody here could afford to use.
The point about the low distortion sine wave oscillators is that they
are cheap. I've got a version built around a pair of AD734 four-quadrant >multipliers, but they cost almost $60 each, so I'm not offering it as an >option.
A twin-T notch filters can block a pure sine wave very effectively
(though you do have to keep re-tuning it) to the point where you can
amplify the residual signal to the point where the first four harmonics
are detectable.
You can lock a sixty time higher frequency VC0 to the pure sine wave you >want to look at - a 4046 will do it - and generate the in-phase and >quadrature square waves that you'd need to detect the fundamental and
the first four harmonics.
The twin-T filter will mess up the amplitude and phase of what you
measure, but to a stable and predictable, and thus corrigible, degree.
On Wed, 17 Jun 2026 16:12:16 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 17/06/2026 2:23 am, john larkin wrote:
On Wed, 17 Jun 2026 01:21:01 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 16/06/2026 11:59 pm, john larkin wrote:
On Tue, 16 Jun 2026 17:58:32 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs >>>>>>>>>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
A sub-PPM distortion sine generator wouldn't be difficult, if you had >>>>>>> some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not >>>>>> all that much higher. Phase sensitive detectors can pick out quite low >>>>>> signal levels at specific - known - frequencies in the presence of much >>>>>> higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that >>>>>> doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the
low-distortion oscillator, but not all that more difficult.
Tell us how to measure 1 PPM distortion on an audio-range signal, and >>>>> I'll tell you how to build the sub-PPM variable-frequency source.
I just did. If you could have understood the advice, your claim to be
able to offer advice on building the sub-ppm distortion audio generator >>>> might be plausible.
Details matter. Very good resistors have ppm/volt coefficients. And
caps distort. Opamps too.
Not that you can detail how.
None of the low distortion sine wave sources that have been offered here >>>> were designed to offer much variation in output frequency. Ganged
Beckman ten-turn pots might get you a decade, but covering much of a
frequency range does make the project more difficult.
Make the sines digitally and use DACs. Simple. The problem is still
measuring the distortion.
DACs aren't that good, which is the kind of detail you ought to know. Or
at least DACs anybody here could afford to use.
AD5791 is a nice fast 1 PPM DAC. It can make a pretty good sine wave.
Add a 16-bit DAC off to the side to tweak out the residual distortion.
IF you can measure it somehow. One could do the same trick using
cheaper DACs.
That's the issue: how to measure sub-PPM distortion. If you can
measure it, you can easily tweak out the harmonics.
The point about the low distortion sine wave oscillators is that they
are cheap. I've got a version built around a pair of AD734 four-quadrant
multipliers, but they cost almost $60 each, so I'm not offering it as an
option.
A twin-T notch filters can block a pure sine wave very effectively
(though you do have to keep re-tuning it) to the point where you can
amplify the residual signal to the point where the first four harmonics
are detectable.
You can lock a sixty time higher frequency VC0 to the pure sine wave you
want to look at - a 4046 will do it - and generate the in-phase and
quadrature square waves that you'd need to detect the fundamental and
the first four harmonics.
4046s have ghastly jitter.
The twin-T filter will mess up the amplitude and phase of what you
measure, but to a stable and predictable, and thus corrigible, degree.
Just the passive parts will have PPMs of distortion.
On 17/06/2026 10:04 pm, john larkin wrote:
On Wed, 17 Jun 2026 16:12:16 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 17/06/2026 2:23 am, john larkin wrote:
On Wed, 17 Jun 2026 01:21:01 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote:
On 16/06/2026 11:59 pm, john larkin wrote:
On Tue, 16 Jun 2026 17:58:32 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs >>>>>>>>>>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
Nioclbs P<l Cailebn de Ghloucester <thanks-to@Taf.com> wrote: >>>>>>>>>>>>>>>> Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote:
<snip>
A sub-PPM distortion sine generator wouldn't be difficult, if you had >>>>>>>> some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not
all that much higher. Phase sensitive detectors can pick out quite low >>>>>>> signal levels at specific - known - frequencies in the presence of much >>>>>>> higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that
doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the >>>>>>> low-distortion oscillator, but not all that more difficult.
Tell us how to measure 1 PPM distortion on an audio-range signal, and >>>>>> I'll tell you how to build the sub-PPM variable-frequency source.
I just did. If you could have understood the advice, your claim to be >>>>> able to offer advice on building the sub-ppm distortion audio generator >>>>> might be plausible.
Details matter. Very good resistors have ppm/volt coefficients. And
caps distort. Opamps too.
Not that you can detail how.
None of the low distortion sine wave sources that have been offered here >>>>> were designed to offer much variation in output frequency. Ganged
Beckman ten-turn pots might get you a decade, but covering much of a >>>>> frequency range does make the project more difficult.
Make the sines digitally and use DACs. Simple. The problem is still
measuring the distortion.
DACs aren't that good, which is the kind of detail you ought to know. Or >>> at least DACs anybody here could afford to use.
AD5791 is a nice fast 1 PPM DAC. It can make a pretty good sine wave.
And it costs about $100. That's an extravagant solution
Add a 16-bit DAC off to the side to tweak out the residual distortion.
Pull the other leg. You have to map the distortion before you can
correct it, and you are skeptical about measuring the distortion in the >first place.
IF you can measure it somehow. One could do the same trick using
cheaper DACs.
Do show us how.
That's the issue: how to measure sub-PPM distortion. If you can
measure it, you can easily tweak out the harmonics.
You measure it by blocking out the sine wave with a notch filter and
look at what's left over. Twin-T filters make pretty good notches, but
you do have to tune them carefully and keep tuning them as the
temperature drifts. I suppose you could automate that but it would take >work.
The point about the low distortion sine wave oscillators is that they
are cheap. I've got a version built around a pair of AD734 four-quadrant >>> multipliers, but they cost almost $60 each, so I'm not offering it as an >>> option.
A twin-T notch filters can block a pure sine wave very effectively
(though you do have to keep re-tuning it) to the point where you can
amplify the residual signal to the point where the first four harmonics
are detectable.
You can lock a sixty time higher frequency VC0 to the pure sine wave you >>> want to look at - a 4046 will do it - and generate the in-phase and
quadrature square waves that you'd need to detect the fundamental and
the first four harmonics.
4046s have ghastly jitter.
But it won't matter in this application. You want to pull out just the >harmonics, and if the square waves repeat at the right intervals a
little uncertainty on when the switching occurs won't introduce
cumulative errors.
The twin-T filter will mess up the amplitude and phase of what you
measure, but to a stable and predictable, and thus corrigible, degree.
Just the passive parts will have PPMs of distortion.
Really? Great excuse for not trying.
On Thu, 18 Jun 2026 01:50:31 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 17/06/2026 10:04 pm, john larkin wrote:
On Wed, 17 Jun 2026 16:12:16 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 17/06/2026 2:23 am, john larkin wrote:
On Wed, 17 Jun 2026 01:21:01 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:<snip>
On 16/06/2026 11:59 pm, john larkin wrote:
On Tue, 16 Jun 2026 17:58:32 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 16/06/2026 2:44 am, john larkin wrote:
On Mon, 15 Jun 2026 12:38:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110o3uj$4j3m$3@dont-email.me...
On 14/06/2026 4:15 pm, Edward Rawde wrote:
"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:110legq$3dir2$1@dont-email.me...
On 14/06/2026 11:58 am, Edward Rawde wrote:
"john larkin" <jl@glen--canyon.com> wrote in message news:reqr2l9uf6gcj66bcotm1d5nrg3lqcjf6v@4ax.com...
On Sat, 13 Jun 2026 22:41:51 -0000 (UTC), Phil Hobbs >>>>>>>>>>>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>>>>>>>> Niocl|is P||l Caile|in de Ghloucester <thanks-to@Taf.com> wrote:
Phil Hobbs <pcdhSpamMeSenseless@Electrooptical.net> wrote: >>>>
I just did. If you could have understood the advice, your claim to be >>>>>> able to offer advice on building the sub-ppm distortion audio generator >>>>>> might be plausible.A sub-PPM distortion sine generator wouldn't be difficult, if you had >>>>>>>>> some way to measure it.
The distortion consists of higher harmonics of the basic sine wave - not
all that much higher. Phase sensitive detectors can pick out quite low >>>>>>>> signal levels at specific - known - frequencies in the presence of much
higher amplitude signals at different frequencies.
Edward Rawde doesn't seem to have the kind of skill set needed, but that
doesn't seem to inhibit his efforts.
Making the measuring gear would be as big a project as making the >>>>>>>> low-distortion oscillator, but not all that more difficult.
Tell us how to measure 1 PPM distortion on an audio-range signal, and >>>>>>> I'll tell you how to build the sub-PPM variable-frequency source. >>>>>>
Details matter. Very good resistors have ppm/volt coefficients. And
caps distort. Opamps too.
Not that you can detail how.
None of the low distortion sine wave sources that have been offered here >>>>>> were designed to offer much variation in output frequency. Ganged
Beckman ten-turn pots might get you a decade, but covering much of a >>>>>> frequency range does make the project more difficult.
Make the sines digitally and use DACs. Simple. The problem is still
measuring the distortion.
DACs aren't that good, which is the kind of detail you ought to know. Or >>>> at least DACs anybody here could afford to use.
AD5791 is a nice fast 1 PPM DAC. It can make a pretty good sine wave.
And it costs about $100. That's an extravagant solution
Add a 16-bit DAC off to the side to tweak out the residual distortion.
Pull the other leg. You have to map the distortion before you can
correct it, and you are skeptical about measuring the distortion in the
first place.
IF you can measure it somehow. One could do the same trick using
cheaper DACs.
Do show us how.
Sum a couple of 16-bit DACs, coarse and fine. Make a sine wave with
the big DAC and fine-tune out the harmonics with the fine one.
Easy. The problem becomes measuring the harmonics.
That's the issue: how to measure sub-PPM distortion. If you can
measure it, you can easily tweak out the harmonics.
You measure it by blocking out the sine wave with a notch filter and
look at what's left over. Twin-T filters make pretty good notches, but
you do have to tune them carefully and keep tuning them as the
temperature drifts. I suppose you could automate that but it would take
work.
The point about the low distortion sine wave oscillators is that they
are cheap. I've got a version built around a pair of AD734 four-quadrant >>>> multipliers, but they cost almost $60 each, so I'm not offering it as an >>>> option.
A twin-T notch filters can block a pure sine wave very effectively
(though you do have to keep re-tuning it) to the point where you can
amplify the residual signal to the point where the first four harmonics >>>> are detectable.
You can lock a sixty time higher frequency VC0 to the pure sine wave you >>>> want to look at - a 4046 will do it - and generate the in-phase and
quadrature square waves that you'd need to detect the fundamental and
the first four harmonics.
4046s have ghastly jitter.
But it won't matter in this application. You want to pull out just the
harmonics, and if the square waves repeat at the right intervals a
little uncertainty on when the switching occurs won't introduce
cumulative errors.
The twin-T filter will mess up the amplitude and phase of what you
measure, but to a stable and predictable, and thus corrigible, degree.
Just the passive parts will have PPMs of distortion.
Really? Great excuse for not trying.
You just admitted that "It's a fairly silly game."
But I'm designing a PPM-class programmable voltage DC source, so
things like resistor voltage coefficients matter.
Not so much cap voltage coefficients, for DC. Dielectric absorption
might matter.
DAC1220 is a real 20-bit DAC, only $11, but it's too slow for audio.
There are some audio delta-sigma DACs that could do low distortion.
Edward Rawde <invalid@invalid.invalid> wrote:
[...]
I've put stawberry jam on chicken and found it worked well.
When I tried it, the chicken broke its neck trying to peck the jam off - after that it didn't work at all.
--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message news:1rwufgd.qg63xvutcqf4N%liz@poppyrecords.invalid.invalid...
Edward Rawde <invalid@invalid.invalid> wrote:
[...]
I've put stawberry jam on chicken and found it worked well.
When I tried it, the chicken broke its neck trying to peck the jam off -
after that it didn't work at all.
Now that blueworldhosting has recovered after a three day outage I can reply.
You are missing a vital part needed for system stability.
Although it's not shown with a chicken, the necessary part is shown here: https://www.amazon.com/Licking-TORJOY-Recovery-Elizabethan-Adjustable/dp/B0C749XX9L
| Sysop: | Amessyroom |
|---|---|
| Location: | Fayetteville, NC |
| Users: | 70 |
| Nodes: | 6 (0 / 6) |
| Uptime: | 39:15:41 |
| Calls: | 948 |
| Calls today: | 2 |
| Files: | 1,325 |
| Messages: | 280,644 |