Driver to drive?

On Saturday, March 25, 2017 at 1:26:53 PM UTC+11, k...@notreal.com wrote:

On Fri, 24 Mar 2017 09:08:31 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

tabbypurr@gmail.com wrote:
On Thursday, 23 March 2017 19:49:33 UTC, Michael Terrell wrote:
Kevin Aylward wrote:
"Cursitor Doom" wrote in message newsaruc8$b5u$4@dont-email.me...
On Mon, 20 Mar 2017 20:23:37 -0400, krw wrote:

It's obvious you're illiterate.

no point in reading further

I feel I should at this point apologise for the remarks made by my fellow
countryman, Kev. He and the poster "tabbypurr" are both singularly ill-
informed on this issue. Their ignorance is only matched by their
indefatigable ability to repeat the same dogma over and over and over
again. You will never win an argument against them; they simply won't
listen to reason. Do yourself a big favour and mark the thread "ignore"
in your newsreader. You'll save yourself from a huge amount of wasted
time.

I appreciate the support.

He's offering bs not support. In case there's any confusion I agree with kevin's conclusions.


In that case, you have my pity.

The willfully stupid deserve no pity.

Krw neither gets it nor deserves it.

--
Bill Sloman, Sydney

 

[Michael A. Terrell]

Kevin Aylward wrote:

wrote in message news:mnq8dcpnbekopn07j0cu3crq12hq0905l1@4ax.com...

On Thu, 23 Mar 2017 14:58:23 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

krw@notreal.com wrote:
On Sun, 19 Mar 2017 14:19:57 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Sat, 18 Mar 2017 20:03:50 -0400, krw wrote:

That's impossible, which is the whole "reasonable" thing.

Nothing whatsoever impossible about it!

Not at all. There is always doubt. It may be an unreasonable doubt
but there is _always_ doubt (what if the Earth was really flat?).
Hence, "beyond reasonable doubt".


What do you think of this sorry piece of work?

http://www.wftv.com/news/local/ayala-to-explain-why-she-wont-seek-death-penalty-against-murder-suspect-markeith-loyd/503151996


She should *immediately* be removed from office for violating her oath
of office to follow the constitution and laws of the state of Florida.
That decision isn't hers to make.

Ho hummm..

Like, what specific law says that anybody has to demand the death of
someone else? Dah....

It's her job tpoo follow the laws, not decide which ones she likes.
In that case, he murdered a police officer in front of a lot of people,
and he has a long history of violence, If she can't or won't do her job,
she needs to be fired.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

 

[Michael A. Terrell]

Cursitor Doom wrote:

On Fri, 24 Mar 2017 15:31:03 +0000, Kevin Aylward wrote:

Of course, assuming the allegations are true, then the crimes are
horrendous, and would certainly warrant life in prison, with no
possibility of parole

A most costly decision. Do you have any idea how much it costs to
incarcerate a prisoner in that category for that length of time? We
have an overcrowding crisis right now because the system is clogged
up by 'bed-blockers' who could easily be removed at zero further cost
to the taxpayer.

Indeed. Give him life, and he'll file appeal after appeal, until he's
dead. It can run into millions of dollars.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

 

[Michael A. Terrell]

krw@notreal.com wrote:

On Fri, 24 Mar 2017 09:08:31 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

tabbypurr@gmail.com wrote:
On Thursday, 23 March 2017 19:49:33 UTC, Michael Terrell wrote:
Kevin Aylward wrote:
"Cursitor Doom" wrote in message newsaruc8$b5u$4@dont-email.me...
On Mon, 20 Mar 2017 20:23:37 -0400, krw wrote:

It's obvious you're illiterate.

no point in reading further

I feel I should at this point apologise for the remarks made by my fellow
countryman, Kev. He and the poster "tabbypurr" are both singularly ill-
informed on this issue. Their ignorance is only matched by their
indefatigable ability to repeat the same dogma over and over and over
again. You will never win an argument against them; they simply won't
listen to reason. Do yourself a big favour and mark the thread "ignore"
in your newsreader. You'll save yourself from a huge amount of wasted
time.

I appreciate the support.

He's offering bs not support. In case there's any confusion I agree with kevin's conclusions.


In that case, you have my pity.

The willfully stupid deserve no pity.

It's a pity that they can't be helped.


--
Never piss off an Engineer!

They don't get mad.

They don't get even.

They go for over unity! ;-)

 

[Kevin Aylward]

wrote in message news:lvkbdchdo7t336iks3rn1o5k49g6hcde8e@4ax.com...

On Fri, 24 Mar 2017 23:46:21 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Fri, 24 Mar 2017 04:58:23 -0700, tabbypurr wrote:

You're wasting your time with him.

You don't know our Kev. He's not wasting his time one bit.


I'm all for sensible discussion but
once k & CD resort to stupid bs I don't see the point.

I haven't kept up with this thread and I don't know exactly what krw has
said, but I personally do maintain there is a perfectly solid case for
the death penalty when:

Kevin believes that all killing is murder.

I think anyone reading my posts will know that at no time have I said that.
I have specifically pointed out to the contrary.

I have noted that one, arguable, definition of murder, is killing not in
direct defence of a life.

Since he is unwilling to
use a common language in his argument, there is no point continuing.

No idea what this rambling line means.

I have drawn attention to the fact that cold bloodied, deliberate
calculating killing of another, not in direct defence of a life is indeed
the same description that can be applied to Jury's deciding whether to give
a death penalty, the judge imposing such a death penalty, and the
individuals carrying out the sentence.

I don't see that the notion that the person being killed, has killed someone
else, makes any relevant difference.

I also understand the historical implications of allowing states to murder
their citizens.

An issue with you, is that you don't seem able to view the ethical issues
involved other than in the most simplistic of manners.

You seem quite oblivious to ideas such as "one mans terrorist, is another
mans freedom fighter".

You point of view appears to be that what has been "legally" declared by the
person with the biggest stick, is ethically, the correct one. Clearly, the
fact that many western societies have removed the death penalty, indicates
that there are others with different sticks.

I understand the sort of reasons that you have to support the death penalty,
I don't agree with them. On your side, you show no evidence, that you have
any understanding that what the legal system does in death penalty cases, is
physically and mentally almost identical.

You have presented no support whatsoever on what distinguishes the two
sceneries. You just continue with Ad hominem attacks.

>You can't argue with a liar.

I would refer to your above quote where you stated a verifiable untruth on
the matter of what I said.

It is difficult to know whether you are a liar, drunk, illiterate, or just
having some minor difficulties in English comprehension because your dog
just died.

I would guess that if you were able to produce a rational argument, as to
why the Jury/Judge debating killing someone is superior, ethically, you
would have done so, rather than resorting to the unfounded personally
criticisms.



-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html

 

[Kevin Aylward]

"Cursitor Doom" wrote in message newsb4c9f$rev$4@dont-email.me...

On Fri, 24 Mar 2017 15:31:03 +0000, Kevin Aylward wrote:

Of course, assuming the allegations are true, then the crimes are
horrendous, and would certainly warrant life in prison, with no
possibility of parole

A most costly decision. Do you have any idea how much it costs to
incarcerate a prisoner in that category for that length of time?

Yes.

The however, is that it costs 3 times as much to run the gauntlet of appeals
is a death penalty case, according to the sources I posted in my other
posts, somewhere...

A quick search pops up:

http://www.amnestyusa.org/our-work/issues/death-penalty/us-death-penalty-facts/death-penalty-cost

--California Commission on the Fair Administration of Justice, July 1, 2008
"Using conservative rough projections, the Commission estimates the annual
costs of the present system ($137 million per year), the present system
after implementation of the reforms ... ($232.7 million per year) ... and a
system which imposes a maximum penalty of lifetime incarceration instead of
the death penalty ($11.5 million)."

So, like 10:1 from that reference.

Its a no brainer. Other then the satisfaction of revenge, the death penalty
achieves nothing positive, that is if you can count revenge as a positive.


-- Kevin Aylward
http://www.kevinaylward.co.uk/gr/index.html
http://www.kevinaylward.co.uk/qm/index.html

 

[Cursitor Doom]

On Fri, 24 Mar 2017 22:23:46 -0400, krw wrote:

Kevin believes that all killing is murder. Since he is unwilling to use
a common language in his argument, there is no point continuing.
You can't argue with a liar. You should know that by your dealings with
Slowman.

The main problem with Kev is that he just enjoys a good argument. Kev
will argue the hind leg off a donkey just for the sake of it. You will
never get the better of him; he will just wear down any interlocutor by
attrition until they give up from exhaustion. It's what he does. If I may
quote from an early 80s movie, "The only way to win [against Kev] is not
to play".
HTH.

 

On Sunday, March 26, 2017 at 12:43:43 AM UTC+11, k...@notreal.com wrote:

On Sat, 25 Mar 2017 13:29:03 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Fri, 24 Mar 2017 22:23:46 -0400, krw wrote:

Kevin believes that all killing is murder. Since he is unwilling to use
a common language in his argument, there is no point continuing.
You can't argue with a liar. You should know that by your dealings with
Slowman.

The main problem with Kev is that he just enjoys a good argument. Kev
will argue the hind leg off a donkey just for the sake of it. You will
never get the better of him; he will just wear down any interlocutor by
attrition until they give up from exhaustion. It's what he does. If I may
quote from an early 80s movie, "The only way to win [against Kev] is not
to play".
HTH.

Like Sloman, he'll lie to do it, too.

Actually, neither of us does. Unfortunately, krw's only test for the the truth of statement is whether he agrees with it, and he is convinced that his own opinion is not only reliable, but also universally shared, so anybody who disagrees with him isn't just wrong, but actively putting forward a proposition they know to be wrong, which is to say lying.

Obviously this is totally lunatic, but that's our krw ...

--
Bill Sloman, Sydney

 

On Sat, 25 Mar 2017 13:29:03 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

On Fri, 24 Mar 2017 22:23:46 -0400, krw wrote:

Kevin believes that all killing is murder. Since he is unwilling to use
a common language in his argument, there is no point continuing.
You can't argue with a liar. You should know that by your dealings with
Slowman.

The main problem with Kev is that he just enjoys a good argument. Kev
will argue the hind leg off a donkey just for the sake of it. You will
never get the better of him; he will just wear down any interlocutor by
attrition until they give up from exhaustion. It's what he does. If I may
quote from an early 80s movie, "The only way to win [against Kev] is not
to play".
HTH.

Like Slowan, he'll lie to do it, too.

 

On Sat, 25 Mar 2017 03:32:41 -0400, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

Kevin Aylward wrote:
wrote in message news:mnq8dcpnbekopn07j0cu3crq12hq0905l1@4ax.com...

On Thu, 23 Mar 2017 14:58:23 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

krw@notreal.com wrote:
On Sun, 19 Mar 2017 14:19:57 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Sat, 18 Mar 2017 20:03:50 -0400, krw wrote:

That's impossible, which is the whole "reasonable" thing.

Nothing whatsoever impossible about it!

Not at all. There is always doubt. It may be an unreasonable doubt
but there is _always_ doubt (what if the Earth was really flat?).
Hence, "beyond reasonable doubt".


What do you think of this sorry piece of work?

http://www.wftv.com/news/local/ayala-to-explain-why-she-wont-seek-death-penalty-against-murder-suspect-markeith-loyd/503151996


She should *immediately* be removed from office for violating her oath
of office to follow the constitution and laws of the state of Florida.
That decision isn't hers to make.

Ho hummm..

Like, what specific law says that anybody has to demand the death of
someone else? Dah....


It's her job tpoo follow the laws, not decide which ones she likes.
In that case, he murdered a police officer in front of a lot of people,
and he has a long history of violence, If she can't or won't do her job,
she needs to be fired.

Exactly. She doesn't have to like the law, she just has to prosecute
it to the best of her abilities, a she's sworn to do. If she can't,
or won't, she should be removed or in prison, herself.

 

[amdx]

On 3/25/2017 12:13 AM, dagmargoodboat@yahoo.com wrote:

On Friday, March 24, 2017 at 11:46:48 PM UTC-4, amdx wrote:
On 3/24/2017 11:40 AM, dagmargoodboat@yahoo.com wrote:
On Friday, March 24, 2017 at 10:13:18 AM UTC-4, amdx wrote:
On 3/24/2017 8:44 AM, amdx wrote:
On 3/23/2017 11:58 PM, amdx wrote:
On 3/23/2017 6:48 PM, dagmargoodboat@yahoo.com wrote:
On Thursday, March 23, 2017 at 2:52:11 PM UTC-4, amdx wrote:

OK, The circuit is built, I haven't tested it. I'm testing just the
circuit just the circuit posted.
I want to know how to drive the input.
Say I connect a 9 inch piece of RG58, that's 19pf, is that to much?
I want to drive it with a 50 ohm sig/gen.
Can I terminate the RG58 with 50 ohms or do I need to feed the RG58
with
a high impedance? Maybe a series 1Mohm.
I don't see how to separate the sig/gen cable from the input cable.
May I just need to connect it to the LC and see what I get.
Thank, Mikek


How about one step at a time? First, calibrate your input cap:

C1
.---. 0.3pF
| ~ |--------||----+----> A
'---' |
10V --- C2
--- 100pF
|
===

Measure V(A), calculate (don't forget to add your measuring instrument's
c.in to C2).


Easier said than done.
I have a pretty good capacitance tester. I made a .3pf cap :-/
and used an 82pf cap plus the probe, together they measured 106.7pf.
I applied 16Vpp and measured 0.06Vpp at A.
16 / 0.06 = 266.6 The voltage ratio is 266.6.
106.7 / 266.6 = 0.4
That makes my cap look like 0.4pf

Yes.

I measured the capacitance of a 6" x 8" piece (48sq in) of the PCB I
make my caps from, it measured 990 pf. 990 / 48 = 20.63pf per sq in.
My cap is 1/8" diameter or 0.01227 sq in.
So, 1sq in / 0.01227 sq in = 81.53
20.62pf/sq in / 81.53 = 0.253pf per 1/8" dia.
So fringing and lead to lead capacitance, I'm in the ballpark, just not
sure what field.
If you have any suggestions, I'm willing.
Way past my bedtime, good night.
Mikek

You're close enough for our purposes. The first measurement may be being
affected by stray capacitances, dunno. In the end all we'll care about
(when you use this thing) is getting 100mV out for 100mV in.

PS. PCB is Rogers Duroid 5880, I could not find a capacitance per sq in
number online.


I got out my better probe (Tek 6122 11pf) and made curly cues for the
probe tip.
Here's a picture of the tightened up circuit.
https://www.dropbox.com/s/sixe91dvxs40f1z/P1010193.JPG?dl=0


The new total capacitance, probe plus 82pf cap is 94pf. (measured)
16Vpp input, V(A) is 0.068Vpp. Then 16/0.068 = 235.3
235.3 / 94 = 2.5pf.

No, that should be 94pF * (.068V / 16V) = 0.4 pF.

This is a tighter measurement and also agrees with my calculation of
0.253 that I calculated for the pcb capacitance per sq in.
Rather than fight with a new piece of pcb material just slightly over
1/8" in diameter.
I'm going to go with a new value input cap of 0.25pf.
If you see this as a bad idea, let me know and I'll fumble around
and make a larger cap. I used a 1/8' paper punch to make this cap,
I could use a 1/4" and grind it down, but it's a chore.

It looks to me like your input cap is good, and 0.4pF. No need to change
it.

Now for the next measurement.
Is this with a T1 in the completed circuit?
Or, do I add the probe + 82pf back in to get a ratio?
Ya, I'm now confused.

Yes, it's time to use your calibrated in the completed, working circuit.
We'll want to measure the a.c. signal at the FET source first, then the
FET's drain.

I think we might want the voltage at the gate, but I
think that would be an impossible measurement. ie putting 11pf
probe across a 0.3pf cap ?
Thanks, Mikek



Ok, I tried this, out of circuit, just the FET.



T1 |--
.---. 0.3pF |
| ~ |--------||------>|--.
'---' | T1.s = 0.06Vpp
16Vpp |
|---probe tip
82pf –--
--- 12pf
|---probe ground
|
---
///

So, 16Vpp / 0.6Vpp = 266.6
266.6 / 94 = 2.84pf
2.84pf - 0.3pf = 2.54pf for the Cgs.
I think that's to low, I thought it was 5pf,
but I'm looking for your thoughts.

Thanks Mikek

Sorry, I wasn't clear enough. We're measuring in-circuit.

To check the effective input capacitance we want to know the attenuation
of the input a.c. voltage, as measured at point (A).

Rationale: The input voltage will be divided across your 0.40pF input
capacitor and the circuit's input capacitance:

Ccoupling
0.40pF .. .. ..
Vin >---||----:--+--o V(A)
: |
: --- Ceff
: ---
: |
: ===
'.. .. ..

We can't measure at the gate--that's too high impedance--so we're measuring
at FET T1's source terminal, point (A).

If 63% of the voltage is lost across the 0.40pF series cap, then the
effective input capacitance is dropping 37%, which means the series
cap is 63% of the total reactance and Ceff is 37% of the total reactance.

More formally, Ceff = 0.40pF * (Vin - V(A)) / V(A).

(We're trying to measure Ceff.)

You can measure Vac at the FET source on the original circuit for comparison,
too. That's a good way to assess the relative performance of the new circuit
vs. the original (after correcting for any differences in the input coupling
caps, of course.)

(Kleijer said his input division ratio was 17:1, indicating his circuit's
input capacitance (Ceff) was 16 units, and his coupling cap was 1 unit of
capacitance, or Ceff = 16 x Ccoupling.)

We want to know the a.c. voltage @ (B) just to gauge how well our drain
portion of the bootstrap is working. The closer Vac(B) is to Vac(A), the
better we're doing. 1:1 would be ideal. 0.9 would be okay, less than 0.9
indicates a problem.


AC Voltage at B just slightly less than AC Voltage at A. I had to look
several times just to make sure there was a difference.

Okay, that means the drain bootstrap should be working.

Here's the circuit, for reference, with probe points (A) and (B) marked:

(Remember, I'm showing a boot-strapped coax on the input, but we're not
using that yet. We want to keep the comparisons apples-to-apples, and
change only one thing at a time.)


Preliminary data.
I have just a wire input like the original.
I have added my measured DC voltages to the schematic below.
With 1Vpp input, T1s has 0.25Vpp and the output is 0.24Vpp.
So, I think that means the bootstrap is working, I don't know how much
change to expect, but that seems good.

The voltage gain, input-to-output, is about 1/4, or roughly 4x better than
Kleijer's 1/17. But I was expecting to do a little better still and would
like to figure out what's up, if you're game for poking and prodding this
thing a bit more.

Your measurements mean we're dropping .75V across the 0.4pF coupling cap,
and 0.25V across our input capacitance at the FET gate. Our input
capacitance is thus about three times the coupling cap, or about 1.2pF.


In the morning I will compare this to the original.
Thanks, Mikek

You can compare to the original easily--temporarily connect R3 to ground
instead of to R4. That disables all of the bootstrapping, which makes the
new circuit operate as the original. Measure, and compare output voltage
without bootstrapping to the value obtained with bootstrapping. The
ratio tells us how much better we're doing than the original.

Everything checks as expect.
With bootstraping T1s is 0.225 Ratio about 4
When R3 is grounded T1s is 0.60 Ratio about 17
(Just to be complete, I also lift the base of Q2)

This also is identical to the first circuit I built.
ie, Ratio 17. 1 / 0.6 = 16.6666
I measured it this morning.

Also interesting: for the full circuit, 1V p-p input,
o Output voltage w/C2 connected vs. disconnected? (Tells us how effectively
the drain bootstrap is working.)

w/C2 coonected Vpp = 0.245
w/C2 disconnected Vpp = 0.13

o Output voltage with 100pF temporarily shorting the 0.4pF? (So we can measure
the FET-follower voltage gain.)

I think you want me to put 100pf in parallel with my 0.4pf cap.
When I do that the T1s voltage .98 Vpp
When I remove parallel 100pf, I get 0.25 Vpp.

(T1s seems to be ever so slightly increasing, I'm not sure if that is
the sig/gen or the scope warming up, or some other change.
I'll ignore it for now.)

Thanks, Mikek

Cheers,
James Arthur


+12V +12V
-+- -+-
| |
| [22k] R5
Q1 \| | 8.0v
BC547B |---+-------.
7.4v .<| | | input 1Vpp
| | | T1s 0.25Vpp
(B)| [47k] R6 | output 0.24Vpp
(shield) T1 |--' | |
----- BF256C | === |
----------||-+----->|--. |
---+- .4pF| (A)| Vdd --- C2
| | | -+- ---100n
| | | | |
| R1 [10M] | |/ Q2 |
| | 3.4v +---| BC547B |
| | | |>. |
| | R3 [470] |2.7v |
| | | | | C3
| | | | | 100n
| +----||---+-----+-------+-----||---> to ampl.
| | C1 | |
| R2 [10M] 100pF R4 [470] --- C4
| | | --- 100n
| === === |
| |
'------------------------------+
|
Cin ~200fF [2.2k] R7
|
===
HTH,
James Arthur

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

On Saturday, March 25, 2017 at 10:29:57 AM UTC-4, amdx wrote:

On 3/25/2017 12:13 AM, dagmargoodboat@yahoo.com wrote:
On Friday, March 24, 2017 at 11:46:48 PM UTC-4, amdx wrote:
On 3/24/2017 11:40 AM, dagmargoodboat@yahoo.com wrote:
On Friday, March 24, 2017 at 10:13:18 AM UTC-4, amdx wrote:
On 3/24/2017 8:44 AM, amdx wrote:
On 3/23/2017 11:58 PM, amdx wrote:
On 3/23/2017 6:48 PM, dagmargoodboat@yahoo.com wrote:
On Thursday, March 23, 2017 at 2:52:11 PM UTC-4, amdx wrote:

OK, The circuit is built, I haven't tested it. I'm testing just the
circuit just the circuit posted.
I want to know how to drive the input.
Say I connect a 9 inch piece of RG58, that's 19pf, is that to much?
I want to drive it with a 50 ohm sig/gen.
Can I terminate the RG58 with 50 ohms or do I need to feed the RG58
with
a high impedance? Maybe a series 1Mohm.
I don't see how to separate the sig/gen cable from the input cable.
May I just need to connect it to the LC and see what I get.
Thank, Mikek


How about one step at a time? First, calibrate your input cap:

C1
.---. 0.3pF
| ~ |--------||----+----> A
'---' |
10V --- C2
--- 100pF
|
==
Measure V(A), calculate (don't forget to add your measuring instrument's
c.in to C2).


Easier said than done.
I have a pretty good capacitance tester. I made a .3pf cap :-/
and used an 82pf cap plus the probe, together they measured 106.7pf.
I applied 16Vpp and measured 0.06Vpp at A.
16 / 0.06 = 266.6 The voltage ratio is 266.6.
106.7 / 266.6 = 0.4
That makes my cap look like 0.4pf

Yes.

I measured the capacitance of a 6" x 8" piece (48sq in) of the PCB I
make my caps from, it measured 990 pf. 990 / 48 = 20.63pf per sq in.
My cap is 1/8" diameter or 0.01227 sq in.
So, 1sq in / 0.01227 sq in = 81.53
20.62pf/sq in / 81.53 = 0.253pf per 1/8" dia.
So fringing and lead to lead capacitance, I'm in the ballpark, just not
sure what field.
If you have any suggestions, I'm willing.
Way past my bedtime, good night.
Mikek

You're close enough for our purposes. The first measurement may be being
affected by stray capacitances, dunno. In the end all we'll care about
(when you use this thing) is getting 100mV out for 100mV in.

PS. PCB is Rogers Duroid 5880, I could not find a capacitance per sq in
number online.


I got out my better probe (Tek 6122 11pf) and made curly cues for the
probe tip.
Here's a picture of the tightened up circuit.
https://www.dropbox.com/s/sixe91dvxs40f1z/P1010193.JPG?dl=0


The new total capacitance, probe plus 82pf cap is 94pf. (measured)
16Vpp input, V(A) is 0.068Vpp. Then 16/0.068 = 235.3
235.3 / 94 = 2.5pf.

No, that should be 94pF * (.068V / 16V) = 0.4 pF.

This is a tighter measurement and also agrees with my calculation of
0.253 that I calculated for the pcb capacitance per sq in.
Rather than fight with a new piece of pcb material just slightly over
1/8" in diameter.
I'm going to go with a new value input cap of 0.25pf.
If you see this as a bad idea, let me know and I'll fumble around
and make a larger cap. I used a 1/8' paper punch to make this cap,
I could use a 1/4" and grind it down, but it's a chore.

It looks to me like your input cap is good, and 0.4pF. No need to change
it.

Now for the next measurement.
Is this with a T1 in the completed circuit?
Or, do I add the probe + 82pf back in to get a ratio?
Ya, I'm now confused.

Yes, it's time to use your calibrated in the completed, working circuit.
We'll want to measure the a.c. signal at the FET source first, then the
FET's drain.

I think we might want the voltage at the gate, but I
think that would be an impossible measurement. ie putting 11pf
probe across a 0.3pf cap ?
Thanks, Mikek



Ok, I tried this, out of circuit, just the FET.



T1 |--
.---. 0.3pF |
| ~ |--------||------>|--.
'---' | T1.s = 0.06Vpp
16Vpp |
|---probe tip
82pf –--
--- 12pf
|---probe ground
|
---
///

So, 16Vpp / 0.6Vpp = 266.6
266.6 / 94 = 2.84pf
2.84pf - 0.3pf = 2.54pf for the Cgs.
I think that's to low, I thought it was 5pf,
but I'm looking for your thoughts.

Thanks Mikek

Sorry, I wasn't clear enough. We're measuring in-circuit.

To check the effective input capacitance we want to know the attenuation
of the input a.c. voltage, as measured at point (A).

Rationale: The input voltage will be divided across your 0.40pF input
capacitor and the circuit's input capacitance:

Ccoupling
0.40pF .. .. ..
Vin >---||----:--+--o V(A)
: |
: --- Ceff
: ---
: |
: ==> >>> '.. .. ..

We can't measure at the gate--that's too high impedance--so we're measuring
at FET T1's source terminal, point (A).

If 63% of the voltage is lost across the 0.40pF series cap, then the
effective input capacitance is dropping 37%, which means the series
cap is 63% of the total reactance and Ceff is 37% of the total reactance.

More formally, Ceff = 0.40pF * (Vin - V(A)) / V(A).

(We're trying to measure Ceff.)

You can measure Vac at the FET source on the original circuit for comparison,
too. That's a good way to assess the relative performance of the new circuit
vs. the original (after correcting for any differences in the input coupling
caps, of course.)

(Kleijer said his input division ratio was 17:1, indicating his circuit's
input capacitance (Ceff) was 16 units, and his coupling cap was 1 unit of
capacitance, or Ceff = 16 x Ccoupling.)

We want to know the a.c. voltage @ (B) just to gauge how well our drain
portion of the bootstrap is working. The closer Vac(B) is to Vac(A), the
better we're doing. 1:1 would be ideal. 0.9 would be okay, less than 0.9
indicates a problem.


AC Voltage at B just slightly less than AC Voltage at A. I had to look
several times just to make sure there was a difference.

Okay, that means the drain bootstrap should be working.

Here's the circuit, for reference, with probe points (A) and (B) marked:

(Remember, I'm showing a boot-strapped coax on the input, but we're not
using that yet. We want to keep the comparisons apples-to-apples, and
change only one thing at a time.)


Preliminary data.
I have just a wire input like the original.
I have added my measured DC voltages to the schematic below.
With 1Vpp input, T1s has 0.25Vpp and the output is 0.24Vpp.
So, I think that means the bootstrap is working, I don't know how much
change to expect, but that seems good.

The voltage gain, input-to-output, is about 1/4, or roughly 4x better than
Kleijer's 1/17. But I was expecting to do a little better still and would
like to figure out what's up, if you're game for poking and prodding this
thing a bit more.

Your measurements mean we're dropping .75V across the 0.4pF coupling cap,
and 0.25V across our input capacitance at the FET gate. Our input
capacitance is thus about three times the coupling cap, or about 1.2pF.


In the morning I will compare this to the original.
Thanks, Mikek

You can compare to the original easily--temporarily connect R3 to ground
instead of to R4. That disables all of the bootstrapping, which makes the
new circuit operate as the original. Measure, and compare output voltage
without bootstrapping to the value obtained with bootstrapping. The
ratio tells us how much better we're doing than the original.

Everything checks as expect.
With bootstraping T1s is 0.225 Ratio about 4
When R3 is grounded T1s is 0.60 Ratio about 17
(Just to be complete, I also lift the base of Q2)

This also is identical to the first circuit I built.
ie, Ratio 17. 1 / 0.6 = 16.6666
I measured it this morning.

Also interesting: for the full circuit, 1V p-p input,
o Output voltage w/C2 connected vs. disconnected? (Tells us how effectively
the drain bootstrap is working.)

w/C2 coonected Vpp = 0.245
w/C2 disconnected Vpp = 0.13


o Output voltage with 100pF temporarily shorting the 0.4pF? (So we can measure
the FET-follower voltage gain.)

I think you want me to put 100pf in parallel with my 0.4pf cap.
When I do that the T1s voltage .98 Vpp
When I remove parallel 100pf, I get 0.25 Vpp.

(T1s seems to be ever so slightly increasing, I'm not sure if that is
the sig/gen or the scope warming up, or some other change.
I'll ignore it for now.)

Thanks, Mikek

Okay, nice work on the measurements.

Summary:
o The FET-as-voltage follower has a gain of 0.98, which is quite
decent for our purposes.
o Input capacitance is 1.2pF.
o We've reduced the input capacitance by a factor of about 4 compared
to Kleijer, but it's still not as low as expected.

The shield driver + BNC isn't going to work, not until we get the gain closer
to 1, rather than 0.25.

Based on your report I think the culprit limiting our improvement is likely
the drain driver, Q1 and related components. If you could 'scope (A) and
(B), a.c.-coupled, with the 'scope set to subtract the two channels,
(A)-(B) would tell us if our drain bootstrap is up to snuff.

I might have to cobble one of these together so I can probe it myself...

Nice work Mike. You've made something that's 4x better, even as it is.

Cheers,
James Arthur

+12V +12V
-+- -+-
| |
| [22k] R5
Q1 \| | 8.0v
BC547B |---+-------.
7.4v .<| | | input 1Vpp
| | | T1s 0.25Vpp
(B)| [47k] R6 | output 0.24Vpp
(shield) T1 |--' | |
----- BF256C | === |
----------||-+----->|--. |
---+- .4pF| (A)| Vdd --- C2
| | | -+- ---100n
| | | | |
| R1 [10M] | |/ Q2 |
| | 3.4v +---| BC547B |
| | | |>. |
| | R3 [470] |2.7v |
| | | | | C3
| | | | (C)| 100n
| +----||---+-----+-------+-----||---> to ampl.
| | C1 | |
| R2 [10M] 100pF R4 [470] --- C4
| | | --- 100n
| === === |
| |
'------------------------------+
|
Cin ~200fF [2.2k] R7
|
===

 

[Cursitor Doom]

On Sat, 25 Mar 2017 18:05:27 +0000, Kevin Aylward wrote:

I may not always agree with Bill, but I have never seen any evidence
that Bill lies.

<boggle>

 

[rickman]

On 3/24/2017 4:36 PM, Joerg wrote:

On 2017-03-24 10:59, rickman wrote:
On 3/24/2017 1:14 PM, Joerg wrote:
On 2017-03-20 02:06, Tauno Voipio wrote:

[...]

Please do not use PVC as RF insulation or support pieces.
It is lossy to extremely lossy at RF.


Plasticized PVC ain't stellar but not horrid.

http://g3ynh.info/zdocs/comps/part_6.html

Or do they add a lot of vispipuuro into the mix in Finland?

Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1
MHz. That is in no way acceptable for the sort of high Q circuits that
are being discussed. That's comparable to wood, 0.059.

This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ 0.01.


The losses in ferrite rods are nothing to sneeze at in comparison. I
have used both in ham radio a lot when I was young. I built kilowatt
level RF power amps, impedance matching boxes and similar gear. Ferrite
rods in transmitters sometimes became so hot that you could barely touch
them while inductors wound on some random piece of PVC pipe remained
cool. I don't remember the PVC type other than that it was remnants they
sold for pennies in the plumbing department so that was very likely well
plasticized.

Maybe I don't recall the context of the ferrite, but the receiving
antennas in much of this thread and described in detail at Kleijer's web
site showed measurable losses with better plastics than PVC. Even
cardboard was a poor support relatively speaking. Seems he would use a
foam type plastic to get some rigidity with a minimum of loss. Foam PVC
was not bad, but his Q measurements increased significantly with foam
polypropylene. Obviously foam is better because there is less actual
material. Solid PVC would show more pronounced losses.

He does some amazingly detailed work. You might find it interesting.
The LC experiments were reported in a series of web pages. Page 10
doesn't have a link to page 11, but otherwise they are all chained.

http://www.crystal-radio.eu/enlctest.htm

I found it very illuminating his tests with the variable capacitors.
Even parts like bushings were found to make a difference.

--

Rick C

 

[Kevin Aylward]

wrote in message news:cvscdch64l7a38q206pib2jo4pa607k3t3@4ax.com...

On Sat, 25 Mar 2017 13:29:03 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

On Fri, 24 Mar 2017 22:23:46 -0400, krw wrote:

Kevin believes that all killing is murder. Since he is unwilling to use
a common language in his argument, there is no point continuing.
You can't argue with a liar. You should know that by your dealings with
Slowman.

The main problem with Kev is that he just enjoys a good argument. Kev
will argue the hind leg off a donkey just for the sake of it. You will
never get the better of him; he will just wear down any interlocutor by
attrition until they give up from exhaustion. It's what he does. If I may
quote from an early 80s movie, "The only way to win [against Kev] is not
to play".
HTH.

Like Slowan, he'll lie to do it, too.

I may not always agree with Bill, but I have never seen any evidence that
Bill lies. However, there is significant evidence in these threads that you
make claims as to what posters say, that are provably not true.

Its this thing about ethics, that you seem to miss. Some of us have some,
some don't.

-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html

 

[Kevin Aylward]

wrote in message news:s1tcdctmds0hl22fo9hpbh5enshegc86gm@4ax.com...

On Sat, 25 Mar 2017 03:32:41 -0400, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

Kevin Aylward wrote:
wrote in message news:mnq8dcpnbekopn07j0cu3crq12hq0905l1@4ax.com...

On Thu, 23 Mar 2017 14:58:23 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

krw@notreal.com wrote:
On Sun, 19 Mar 2017 14:19:57 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Sat, 18 Mar 2017 20:03:50 -0400, krw wrote:

That's impossible, which is the whole "reasonable" thing.

Nothing whatsoever impossible about it!

Not at all. There is always doubt. It may be an unreasonable doubt
but there is _always_ doubt (what if the Earth was really flat?).
Hence, "beyond reasonable doubt".


What do you think of this sorry piece of work?

http://www.wftv.com/news/local/ayala-to-explain-why-she-wont-seek-death-penalty-against-murder-suspect-markeith-loyd/503151996


She should *immediately* be removed from office for violating her oath
of office to follow the constitution and laws of the state of Florida.
That decision isn't hers to make.

Ho hummm..

Like, what specific law says that anybody has to demand the death of
someone else? Dah....


It's her job tpoo follow the laws, not decide which ones she likes.
In that case, he murdered a police officer in front of a lot of people,

Please cite the exact law that says that a prosecutor must demand the death
penalty.

Sure, a prosecutor may well be obliged to do what is in the best interest of
society, in which case the evidence appears to show that the "best" course
of action, is to not seek the death penalty.

http://www.amnestyusa.org/our-work/issues/death-penalty/us-death-penalty-facts/death-penalty-cost


-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html

 

[rickman]

On 3/22/2017 4:25 PM, Kevin Aylward wrote:

"bitrex" wrote in message news:IAiAA.71782$Hf3.16044@fx37.iad...

On 03/19/2017 01:23 PM, Cursitor Doom wrote:
On Sun, 19 Mar 2017 09:07:05 -0700, tabbypurr wrote:

People make a mockery of reason too often. Maybe you should spend some
time watching groups of people making such decisions.

I don't agree with you and probably never will, but - in what must be a
Usenet first - I can at least see where you're coming from here.


One might argue that in a society which is intrinsically just, the
chances are good that the death penalty will be used, in the main, for
just reasons.

And just who determines what constitutes "just"?

When someone talks about our "justice" system, I try to correct them to
call it our legal system.

--

Rick C

 

[rickman]

On 3/24/2017 9:03 AM, Michael A. Terrell wrote:

krw@notreal.com wrote:
On Thu, 23 Mar 2017 14:58:23 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

krw@notreal.com wrote:
On Sun, 19 Mar 2017 14:19:57 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Sat, 18 Mar 2017 20:03:50 -0400, krw wrote:

That's impossible, which is the whole "reasonable" thing.

Nothing whatsoever impossible about it!

Not at all. There is always doubt. It may be an unreasonable doubt
but there is _always_ doubt (what if the Earth was really flat?).
Hence, "beyond reasonable doubt".


What do you think of this sorry piece of work?

http://www.wftv.com/news/local/ayala-to-explain-why-she-wont-seek-death-penalty-against-murder-suspect-markeith-loyd/503151996


She should *immediately* be removed from office for violating her oath
of office to follow the constitution and laws of the state of Florida.
That decision isn't hers to make.


The Governor has removed her from the case, but she want to sue over it.

Disbar the jackass.

What did she do wrong? It is in the prosecutor's domain to decide how
to prosecute a case. I haven't looked up the law, but I seriously doubt
it says the death penalty is mandatory in all cases.

--

Rick C

 

[rickman]

On 3/25/2017 3:34 AM, Michael A. Terrell wrote:

Cursitor Doom wrote:
On Fri, 24 Mar 2017 15:31:03 +0000, Kevin Aylward wrote:

Of course, assuming the allegations are true, then the crimes are
horrendous, and would certainly warrant life in prison, with no
possibility of parole

A most costly decision. Do you have any idea how much it costs to
incarcerate a prisoner in that category for that length of time? We
have an overcrowding crisis right now because the system is clogged
up by 'bed-blockers' who could easily be removed at zero further cost
to the taxpayer.


Indeed. Give him life, and he'll file appeal after appeal, until he's
dead. It can run into millions of dollars.

I believe the cost of executing someone is even higher.

--

Rick C

 

[rickman]

On 3/25/2017 3:32 AM, Michael A. Terrell wrote:

Kevin Aylward wrote:
wrote in message news:mnq8dcpnbekopn07j0cu3crq12hq0905l1@4ax.com...

On Thu, 23 Mar 2017 14:58:23 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:

krw@notreal.com wrote:
On Sun, 19 Mar 2017 14:19:57 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Sat, 18 Mar 2017 20:03:50 -0400, krw wrote:

That's impossible, which is the whole "reasonable" thing.

Nothing whatsoever impossible about it!

Not at all. There is always doubt. It may be an unreasonable doubt
but there is _always_ doubt (what if the Earth was really flat?).
Hence, "beyond reasonable doubt".


What do you think of this sorry piece of work?

http://www.wftv.com/news/local/ayala-to-explain-why-she-wont-seek-death-penalty-against-murder-suspect-markeith-loyd/503151996



She should *immediately* be removed from office for violating her oath
of office to follow the constitution and laws of the state of Florida.
That decision isn't hers to make.

Ho hummm..

Like, what specific law says that anybody has to demand the death of
someone else? Dah....


It's her job tpoo follow the laws, not decide which ones she likes.
In that case, he murdered a police officer in front of a lot of people,
and he has a long history of violence, If she can't or won't do her job,
she needs to be fired.

What law did she violate?


--

Rick C