Driver to drive?

[John Robertson]

On 2017/03/25 11:16 PM, Michael A. Terrell wrote:

rickman wrote:
On 3/24/2017 9:07 AM, Michael A. Terrell wrote:
Jeroen Belleman wrote:
On 2017-03-23 20:49, Michael A. Terrell wrote:


I would rather have a 'redneck' on my side in a fight, than an
'ineffectual' intellectual.


A redneck can help you win a fight, but you need the intellectuals
to have a chance to win the war.


How many intellectuals put their lives on the line, to win that war?
They sit in offices and decide what are acceptable levels of casualties
among the actual fighters.

Or they crack codes that save thousands of lives and ultimately win the
war!


The wars started by other 'intellectuals', of course.

G. W. Bush started the biggest war of the current generation. That means
he was an intellectual then? Or is that 'intellectual' for him?

WWII? Hitler and the rest of the Axis gang were 'intellectuals'?

WWI? Kaiser Wilhelm?

John

 

[Kevin Aylward]

"Michael A. Terrell" wrote in message
news:r-mdnXJ9t9cNxkrFnZ2dnUU7-b2dnZ2d@earthlink.com...

Kevin Aylward wrote:

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

Please show the exact law that allows employees to refuse to do their
jobs, yet keep their jobs.

It is absolutely stunning that some can not understand truly simple points.
She has not refused to do her job. This is trivially obvious.

What part of "Please cite the exact law that says that a prosecutor must
demand the death penalty."

Do you not understand?

"Ayala said she plans to file a notice to withdraw the intent to seek the
death penalty in those cases that have not yet gone to trial"

In what shape or form does this imply that she is refusing to do her job?
She is simply not going to seek the death penalty. Dah...

Her job is not to kill people.


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

 

[rickman]

On 3/26/2017 2:07 AM, Michael A. Terrell wrote:

rickman wrote:
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.


You are truly a Sloman. She refuses to do it for any case brought
before her. If you would actually look at links instead of firing from
the lip, you wouldn't look like someone with the IQ if ice water.

What did she do that was illegal? What rule did she break that should
get her fired?

--

Rick C

 

[rickman]

On 3/26/2017 2:09 AM, Michael A. Terrell wrote:

krw@notreal.com wrote:
On Sat, 25 Mar 2017 14:20:46 -0400, rickman <gnuarm@gmail.com> wrote:

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.

Utter nonsense. It's the appeal after appeal, until he's dead that's
the expensive part. There is absolutely *no* reason it should take 20
years.

All appeals should have to be completed within two years. Also,
someone other than the public should have to pay the costs for any new
trials.

"Someone"? So if you can't afford it you don't get justice?

--

Rick C

 

[rickman]

On 3/26/2017 2:30 AM, John Robertson wrote:

On 2017/03/25 6:26 PM, Jasen Betts wrote:
On 2017-03-25, Cursitor Doom <curd@notformail.com> 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?

Last I Heard it ws cheaper than death row.


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.

Letting them out seems kind of recklesxs


Part of the problem appears to be that the USA locks up more people per
capita than any other developed nation.

Why?

Because we have more "bad hombres"? If Mexico would keep all their
rapists to themselves we wouldn't need any prisons! Also, we wouldn't
be number 1 anymore.

--

Rick C

 

[rickman]

On 3/26/2017 2:11 AM, Michael A. Terrell wrote:

Kevin Aylward wrote:
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



Please show the exact law that allows employees to refuse to do their
jobs, yet keep their jobs.

Show me the law that makes it a crime!!!

--

Rick C

 

[rickman]

On 3/26/2017 2:12 AM, Michael A. Terrell wrote:

rickman wrote:
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?


What laws do you obey?

Every one I have to. How about you?

So can you answer the original question? What law did she violate?

--

Rick C

 

[rickman]

On 3/26/2017 3:01 AM, John Robertson wrote:

On 2017/03/25 11:16 PM, Michael A. Terrell wrote:
rickman wrote:
On 3/24/2017 9:07 AM, Michael A. Terrell wrote:
Jeroen Belleman wrote:
On 2017-03-23 20:49, Michael A. Terrell wrote:


I would rather have a 'redneck' on my side in a fight, than an
'ineffectual' intellectual.


A redneck can help you win a fight, but you need the intellectuals
to have a chance to win the war.


How many intellectuals put their lives on the line, to win that war?
They sit in offices and decide what are acceptable levels of casualties
among the actual fighters.

Or they crack codes that save thousands of lives and ultimately win the
war!


The wars started by other 'intellectuals', of course.



G. W. Bush started the biggest war of the current generation. That means
he was an intellectual then? Or is that 'intellectual' for him?

WWII? Hitler and the rest of the Axis gang were 'intellectuals'?

WWI? Kaiser Wilhelm?

Hey! What are you doing??? Don't confuse us with the facts!!!

--

Rick C

 

[rickman]

On 3/26/2017 2:18 AM, Michael A. Terrell wrote:

rickman wrote:
On 3/24/2017 6:02 AM, Jeroen Belleman wrote:
On 2017-03-23 20:49, Michael A. Terrell wrote:


I would rather have a 'redneck' on my side in a fight, than an
'ineffectual' intellectual.


A redneck can help you win a fight, but you need the intellectuals
to have a chance to win the war.

How about redneck intellectual?


You would be surprised how smart some Rednecks are, if you weren't so
stupid. The original 'rednecks' were farmers, who worked out in the hot
sun from dawn till dark.

What makes you think I'm *not* a redneck?

--

Rick C

 

[rickman]

On 3/26/2017 2:03 AM, Michael A. Terrell wrote:

rickman wrote:
On 3/23/2017 3:49 PM, Michael A. 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.

I did find the word "illiterate" somewhat amusing in as much as that it
is typically the "intellectuals" that present the reasoned arguments on
ethical issues rather than the redneck southerners.


I would rather have a 'redneck' on my side in a fight, than an
'ineffectual' intellectual.

Which is better would depend on whether the fight was on the Charlie
Rose show or Jerry Springer!



Do you watch that garbage? It's intended for the low intelligence
liberals. Oh! Sorry, I forgot who I was asking that.

Lol! I know which one I think is garbage. I can only guess you think
both shows are garbage.

--

Rick C

 

On Sunday, March 26, 2017 at 6:13:29 PM UTC+11, rickman wrote:

On 3/26/2017 2:30 AM, John Robertson wrote:
On 2017/03/25 6:26 PM, Jasen Betts wrote:
On 2017-03-25, Cursitor Doom <curd@notformail.com> 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?

Last I Heard it ws cheaper than death row.


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.

Letting them out seems kind of recklesxs

Part of the problem appears to be that the USA locks up more people per
capita than any other developed nation.

Why?

Because we have more "bad hombres"?

Apparently not. You have roughly the usual number of bad hombres, but you lock them up for longer.

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

If Mexico would keep all their rapists to themselves we wouldn't need any
prisons! Also, we wouldn't be number 1 anymore.

Not true, but I'm sure that they are US politicians who will tell you that.

--
Bill Sloman, Sydney

 

On Sunday, March 26, 2017 at 10:21:12 PM UTC+11, bill....@ieee.org wrote:

On Sunday, March 26, 2017 at 6:13:29 PM UTC+11, rickman wrote:
On 3/26/2017 2:30 AM, John Robertson wrote:
On 2017/03/25 6:26 PM, Jasen Betts wrote:
On 2017-03-25, Cursitor Doom <curd@notformail.com> 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?

Last I Heard it ws cheaper than death row.


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.

Letting them out seems kind of recklesxs

Part of the problem appears to be that the USA locks up more people per
capita than any other developed nation.

Why?

Because we have more "bad hombres"?

Apparently not. You have roughly the usual number of bad hombres, but you lock them up for longer.

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

If Mexico would keep all their rapists to themselves we wouldn't need any
prisons! Also, we wouldn't be number 1 anymore.

Not true, but I'm sure that there are US politicians who will tell you that.

--
Bill Sloman, Sydney

 

On Sunday, March 26, 2017 at 9:53:46 PM UTC+11, Cursitor Doom wrote:

On Sat, 25 Mar 2017 23:38:20 +0000, Kevin Aylward wrote:

"Cursitor Doom" wrote in message newsb6gtd$rl8$1@dont-email.me...

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

https://www.youtube.com/watch?v=NX45hc0aZt0

Very good; classic. But it's because of people like Bill Sloman with
their dumbing down agenda that shows like this with their rich and
complex use of language will never be made again.

Interesting logic. Cursitor Doom seems to believe everything he reads in the
Express, which is dumb, yet he seems to think that my sceptical agenda involves some kind of "dumbing down".

Granting that Cursitor Doom is extremely dumb, one can understand how he might come up with such a completely nonsensical argument, and how he could be dumb enough to post it.

"Yes, Minister" and "Yes, Prime minister" were wonderful, but Anthony Jay died in August 2016 at the age of 86, and it may be a while before another writer comes up with the same sort of insider insight into politics, and the same facility with language. Jonathan Lynn seems to have been more responsible for making sure that the result was comical as well as informative.

--
Bill Sloman, Sydney

 

On Sunday, March 26, 2017 at 9:36:52 PM UTC+11, Cursitor Doom wrote:

On Sat, 25 Mar 2017 20:24:16 -0400, krw wrote:

That's *exactly* the point, moron. If the other person is lying, there
is no intention of having a conversation. It's the favorite tool of you
lefties.

Krw thinks that everything he knows is absolutely correct, and that everybody has access to the same database, and also knows that it is absolutely correct.
Thus krw accuses everybody who disagrees with him of lying - he knows he's right, so they must also know that he is right.

This is insane, but krw doesn't seem to be violent with it, so nobody has bothered locking him up yet.

No, the favourite tool of the Lefties is to scream 'racist!' at you
whenever you get the better of them in an argument (which inevitably is
every time).

I can't say that I've noticed this. The phrase I find myself using most frequently is "ill-informed", and Cursitor Doom's claim that "racist" is the preferred epithet may reflect his personal experience - somebody who reads the Express may quote rather more of that paper's racist bilge than is good for their relationship with the wider world.

--
Bill Sloman, Sydney

 

[amdx]

On 3/25/2017 11:00 PM, rickman wrote:

On 3/25/2017 11:42 PM, amdx wrote:
On 3/25/2017 8:32 PM, rickman wrote:
On 3/25/2017 9:10 PM, amdx wrote:
On 3/25/2017 5:25 PM, dagmargoodboat@yahoo.com wrote:
On Saturday, March 25, 2017 at 3:20:31 PM UTC-4, rickman wrote:
On 3/25/2017 2:33 PM, dagmargoodboat@yahoo.com wrote:

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.

The gain of 0.25 is not because of the voltage follower, it's from
the
series cap.

The net gain's a result of the *divider* formed by the series coupling
cap
and (the FET input capacitance + strays), multiplied by the follower
gain.
I asked Mike to measure the follower gain so we could then calculate
the
input capacitance.

Are you suggesting you can get the amp input capacitance
down to 10x less than the series cap?

Bootstrapping should reduce the FET input capacitance by a factor of
1/(1-G), where G = the gain of the bootstrap.

Another approach would be to put the series cap outside the box in
the
probe tip as is done in o'scopes. Then the gain of the amp would be
sufficient to tie the coax shield to the output of the amp.

That's true. Mike could use a shielded connector and cable if he
didn't
mind putting his series cap at the probe.

The plan is to permanently wire the coax end to the tuning cap, and
then
swap different coils to it.
I was about to say that a series cap at the probe not a good plan,
but I
could put some type of permanent connection on my tuning cap to hold
the
0.4pf cap and the connect the coax to that. I suspect I'd be adding
capacitance with that though.

If you add the 0.4 pF cap with the coax on the amplifier side of the
cap, you will be adding 0.4 pF capacitance maximum. If you add the coax
without the cap or put the cap on the amplifier end of the coax without
the amplifier driving the shield, you will likely be adding a lot more
than 0.4 pF.

Why do you want to add the coax permanently?

I don't care if it is coax or a pair of wires. I want a battery
operated fixed testing setup. The 50 ohm output will after a peak
detector or demodulator and then a meter, may need a log amp. With it I
could compare the output of different ferrite antennas. I could drive an
antenna with my sig/gen and measure Q using the 3 db method, etc.

Ok, I understand now. I wasn't getting that this is a test fixture. It
will never be operated without the amp. Where you put the captive coax
doesn't matter then.

Since your series cap can be made pretty consistently, I would suggest
adding it to the fixture before the coax. Then the entire coax and
amplifier capacitance impacts to the test fixture will be minimized
regardless of how well you can mitigate the capacitance through the
bootstrap circuit.

If you need another cap for another type of test, you can hole punch
another fairly easily and it should have pretty much the same
capacitance. One advantage of having a significantly larger capacitance
at the amp input is that it will have less impact on the end to end gain
if it varies.

How long a cable will you use? By that I mean how many pF?

I have no understanding of how putting the 0.4pf cap at the end of
the coax makes it easier to cancel. I probably need to go back and read
the thread.

Re, how many pf of coax, I was thinking maybe 6 inches of RG58, maybe
13pf. This a question of component layout to minimize losses. However,
it look to me like I could just set the tuning capacitor on top of the
amplifier housing, Probably even have physical contact between the
stator frame and the amp housing. That would only leave a 2-1/2" wire to
connect the amp input pin the the rotor tab on the capacitor.
Here is a picture of my first thought.
> https://www.dropbox.com/s/ifgklgfxavb7ash/Cap%20and%20amp%20connections.jpg?dl=0
Ignore the added trim cap, it was needed for a test. Although I will
probably include the trim cap, but I will mount it forward about an inch.
The trim cap was too big and I had to remove six plates, I'll
probably remove at least one more, as it was still hard to peak
some of my coils.
Mikek



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

 

On Sunday, March 26, 2017 at 11:04:36 PM UTC+11, k...@notreal.com wrote:

On Sat, 25 Mar 2017 23:30:39 -0700, John Robertson <spam@flippers.com
wrote:

On 2017/03/25 6:26 PM, Jasen Betts wrote:
On 2017-03-25, Cursitor Doom <curd@notformail.com> 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?

Last I Heard it was cheaper than death row.


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.

Letting them out seems kind of recklesxs

Part of the problem appears to be that the USA locks up more people per
capita than any other developed nation.

Why?

Because we have more criminals. Duh! The left has made a permanent
underclass of losers.

Not actually true.

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

suggests that the higher incarceration rate isn't due to a larger number of criminals, but rather a sentencing system that puts them into prison with longer sentences. The wikipedia article does provide links to a more detailed discussion of this point, but since krw isn't going to change what he thinks merely because the facts don't support him, there's not a lot of point in providing more information.

--
Bill Sloman, Sydney

 

[rickman]

On 3/26/2017 5:00 AM, amdx wrote:

On 3/25/2017 11:00 PM, rickman wrote:
On 3/25/2017 11:42 PM, amdx wrote:
On 3/25/2017 8:32 PM, rickman wrote:
On 3/25/2017 9:10 PM, amdx wrote:
On 3/25/2017 5:25 PM, dagmargoodboat@yahoo.com wrote:
On Saturday, March 25, 2017 at 3:20:31 PM UTC-4, rickman wrote:
On 3/25/2017 2:33 PM, dagmargoodboat@yahoo.com wrote:

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.

The gain of 0.25 is not because of the voltage follower, it's from
the
series cap.

The net gain's a result of the *divider* formed by the series
coupling
cap
and (the FET input capacitance + strays), multiplied by the follower
gain.
I asked Mike to measure the follower gain so we could then calculate
the
input capacitance.

Are you suggesting you can get the amp input capacitance
down to 10x less than the series cap?

Bootstrapping should reduce the FET input capacitance by a factor of
1/(1-G), where G = the gain of the bootstrap.

Another approach would be to put the series cap outside the box in
the
probe tip as is done in o'scopes. Then the gain of the amp would be
sufficient to tie the coax shield to the output of the amp.

That's true. Mike could use a shielded connector and cable if he
didn't
mind putting his series cap at the probe.

The plan is to permanently wire the coax end to the tuning cap, and
then
swap different coils to it.
I was about to say that a series cap at the probe not a good plan,
but I
could put some type of permanent connection on my tuning cap to hold
the
0.4pf cap and the connect the coax to that. I suspect I'd be adding
capacitance with that though.

If you add the 0.4 pF cap with the coax on the amplifier side of the
cap, you will be adding 0.4 pF capacitance maximum. If you add the
coax
without the cap or put the cap on the amplifier end of the coax without
the amplifier driving the shield, you will likely be adding a lot more
than 0.4 pF.

Why do you want to add the coax permanently?

I don't care if it is coax or a pair of wires. I want a battery
operated fixed testing setup. The 50 ohm output will after a peak
detector or demodulator and then a meter, may need a log amp. With it I
could compare the output of different ferrite antennas. I could drive an
antenna with my sig/gen and measure Q using the 3 db method, etc.

Ok, I understand now. I wasn't getting that this is a test fixture. It
will never be operated without the amp. Where you put the captive coax
doesn't matter then.

Since your series cap can be made pretty consistently, I would suggest
adding it to the fixture before the coax. Then the entire coax and
amplifier capacitance impacts to the test fixture will be minimized
regardless of how well you can mitigate the capacitance through the
bootstrap circuit.

If you need another cap for another type of test, you can hole punch
another fairly easily and it should have pretty much the same
capacitance. One advantage of having a significantly larger capacitance
at the amp input is that it will have less impact on the end to end gain
if it varies.

How long a cable will you use? By that I mean how many pF?


I have no understanding of how putting the 0.4pf cap at the end of the
coax makes it easier to cancel. I probably need to go back and read
the thread.

What I meant was, the point of adding the 0.4 pF cap in line is to limit
the capacitance seen by the device being measured. If you leave off the
cap the device being tested sees the entire capacitance of the measuring
device. If you add the cap in front of all the added capacitance the
device being measured only sees the combination which will always be
less than the 0.4 pF cap (series capacitors combine like parallel
resistances, 1/Ctot = 1/C + 1/C2).

If you put the cap at the end of the coax right next to the unit you are
testing, then all capacitance after that point is isolated so the unit
doesn't "see" it. That's the advantage of putting it there.

This does nothing about the impact of the added capacitance of the coax
and the input capacitance of the amp in terms of affecting the amplitude
of the signal. The larger this capacitance, the more the signal is
attenuated at the input of the amp. So it will help the gain of the
overall amp circuit to reduce the input capacitance of the amp.

That said... Since you can add gain after the input stage, why exactly
is it important to reduce the impact of the amplifier input capacitance
to nearly nothing? The original amp had a voltage loss of 17:1 from the
capacitance voltage divider, if I am reading it all correctly. This is
now reduced to 4:1. When you add the capacitance of a coax to the
circuit the voltage divider ratio will go back up significantly.

I would try to minimize the length of the coax to minimize the
capacitance. If you can improve the bootstrapping of the circuit that
will be great. But when you reach the limit of what it will do, it will
be easy enough to set the gain of the following stages to make the
overall gain what you want, which is 1. I think it will be more
important to construct this so the gain is stable rather than trying to
get the gain of the first stage to be as close to 1 as possible.

Re, how many pf of coax, I was thinking maybe 6 inches of RG58, maybe
13pf. This a question of component layout to minimize losses. However,
it look to me like I could just set the tuning capacitor on top of the
amplifier housing, Probably even have physical contact between the
stator frame and the amp housing. That would only leave a 2-1/2" wire to
connect the amp input pin the the rotor tab on the capacitor.
Here is a picture of my first thought.
https://www.dropbox.com/s/ifgklgfxavb7ash/Cap%20and%20amp%20connections.jpg?dl=0

Ignore the added trim cap, it was needed for a test. Although I will
probably include the trim cap, but I will mount it forward about an inch.
The trim cap was too big and I had to remove six plates, I'll
probably remove at least one more, as it was still hard to peak
some of my coils.

I would say the mounting looks like a good idea. I'm not sure I would
bother with a coax. I'd use a stiffer wire so it is less likely to
bend, maybe 14 gauge. As it moves around it changes the capacitance
which changes the gain. If you do use coax, I would use a big, fat,
stiff coax with a low capacitance and low loss. I know it wouldn't be
much loss in a few inches of cable, but I was amazed at the small things
that would affect Kleijer's circuits including bushings on the variable
capacitors. So I can only imagine the coax materials will make a
difference.

--

Rick C

 

[Cursitor Doom]

On Sat, 25 Mar 2017 20:25:14 -0400, krw wrote:

Either Kevin is dumber than a stump, a troll, or liar. Perhaps all
three.

Well, one thing's for certain and that is he does love to argue - and far
too much for my liking. He might benefit from a session with some
therapists:

https://www.youtube.com/watch?v=kQFKtI6gn9Y

 

[Cursitor Doom]

On Sat, 25 Mar 2017 17:20:13 -0700, tabbypurr wrote:

On Saturday, 25 March 2017 13:32:03 UTC, Cursitor Doom wrote:

The main problem with Kev is that he just enjoys a good argument. Kev

no, he enjoys a stupid one.

Say no more:

https://www.youtube.com/watch?v=kQFKtI6gn9Y

 

[Cursitor Doom]

On Sun, 26 Mar 2017 02:18:31 -0400, Michael A. Terrell wrote:

You would be surprised how smart some Rednecks are, if you weren't
so stupid. The original 'rednecks' were farmers, who worked out in the
hot sun from dawn till dark.

Yes, they worked hard and there was nothing they couldn't fix-up for
themselves when they had to. Resourceful, productive people - unlike all
those scheming cunts in Washington.