Au contraire. My backgrounds lay scattered around in other fields, each of
which have their own parallel tales where art, personalities, business, and
legacy technologies/processes combine to produce unanticipated results.
I learn something from every one of the “uninteresting” stories about the
at the problem ;)
> Leon
>
>
> -- Forwarded message --
> From: Ben Bradley
> To: Discussion of precise time and frequency measurement <
> time-nuts@lists.febo.com>
> Cc:
> Bcc:
> Date: Sat, 11 Apr 2020 23:22:29 -0400
> Subject: Re: [time
-
From: Ben Bradley
To: Discussion of precise time and frequency measurement <
time-nuts@lists.febo.com>
Cc:
Bcc:
Date: Sat, 11 Apr 2020 23:22:29 -0400
Subject: Re: [time-nuts] OCXO and fluctuations after EFC adjustment
Despite my interest in the precision high-end of electronic des
Unwind a foot or so of wire and measure the resistance to figure the wire
size. If possible, then unwind the entire choke to find its proper
resistance. This will determine the original value from the inductor data
sheet. If not calculate the resistance from the volume of the winding.
On Saturda
Hi
In most cases, the “new part” (and three or four other candidates) were each
built
into their own batch of a couple hundred oscillators along with batches using
the
currently qualified parts. The normal production process / production testing
was
done on the batches. That was followed by a
Hi
Well…..
Once upon a time, there was a design review on a space part. There
was an tantalum cap used in a couple of places in the design. It was
a 50V part and running at 12V.
We got dinged for it. Turns out if you over derate electrolytics (of any sort)
there is a failure mechanism that c
Am 12.04.20 um 05:22 schrieb Ben Bradley:
More recently, I saw this Kemet presentation on Digikey about tantalum
capacitors. Certainly for aluminum electrolytic capacitors, the rated
voltage is "the rated voltage" and as long as the capacitor never goes
ABOVE that voltage (and has no overcurren
On 4/11/20 8:22 PM, Ben Bradley wrote:
=
More recently, I saw this Kemet presentation on Digikey about tantalum
capacitors. Certainly for aluminum electrolytic capacitors, the rated
voltage is "the rated voltage" and as long as the capacitor never goes
ABOVE that voltage (and has no overcurrent t
Despite my interest in the precision high-end of electronic design
(and thus being a subscriber to this list), I have very little
experience with such high-fallutin' designs. Still, I've done and seen
some "interesting" things in my career. It's amazing how the minutiae
of even jelly bean component
Taka,
it was possible, to do without computer, although the computer is a very
big help particularly for routine works, but it is possible not just
trouble shoot but design, very complicated circuits to, and there are
out there areas where computers still do not help today, Bob Peasa even
cach
kb...@n1k.org said:
> Somehow I doubt anybody would make it past the first page â¦.
rich...@karlquist.com said:
> By now, few people besides Bob are still reading this. :-)
But this time nuts.
I would enjoy hearing stories about how you figured out that batch X or part Y
didn't work and/or
I'm STILL reading this, with interest.
I want to know the method of fault discovery, thought process that ensued,
analysis conducted, testing process, and eventual root cause analysis. We rely
too much on automated processes and computers. I want to know how engineers
did more with less. Befo
Hi
> On Apr 11, 2020, at 8:10 PM, Richard (Rick) Karlquist
> wrote:
>
>
>
> On 4/11/2020 2:25 PM, Bob kb8tq wrote:
>> Hi
>> Would you *really* want to read a book about how from August of 1986 to
>> January of 1993 AVX NPO’s had some sort of issue ( not that the issue is
>> clearly known, ju
On Sun, Apr 12, 2020 at 1:11 AM Richard (Rick) Karlquist <
rich...@karlquist.com> wrote:
>
> By now, few people besides Bob are still reading this. :-)
>
>
>
On the contrary :)
Personally I'd love to read about the problems seen, debugged and fixed in
the manufacture of any generation of high qua
On 4/11/2020 2:25 PM, Bob kb8tq wrote:
Hi
Would you *really* want to read a book about how from August of 1986 to
January of 1993 AVX NPO’s had some sort of issue ( not that the issue is
clearly known, just that they are flakey) and that by 1994 the parts with
values below 220 pf in 0805 seeme
Hi
Would you *really* want to read a book about how from August of 1986 to
January of 1993 AVX NPO’s had some sort of issue ( not that the issue is
clearly known, just that they are flakey) and that by 1994 the parts with
values below 220 pf in 0805 seemed to be fixed?
Again, the task was nev
That caught my attention. Could you please say more.
A DDS introduces spurs. They move around as you change the adjustment
parameters.
Are the spurs small enough that they are not a problem with most applications?
What applications do/don't get along with spurs?
What do spurs look like on a
I wish such persons would write a book about the subject. Audience will be
small that it probably wouldn't make it a profitable venture.
As to coding, I wonder why it's a "touchy" subject In assembly time,
porting one architecture to another was a major undertaking. One didn't
"port", but
Hi
One use for zener diodes is as RF noise generators ….. the
coil probably was there to quiet things down.
Bob
> On Apr 11, 2020, at 4:42 PM, ed breya wrote:
>
> Rick said:
> "In the case of the 10811, I have already posted about the reference diode of
> special characteristics. I don't rem
Hi
Spurs on an ADEV plot look like ripples in the curve. If you have a part
with good close in phase noise / good short tau ADEV, you probably
can see effects from spurs that 120 db down in the vicinity of 10 Hz.
Bob
> On Apr 11, 2020, at 4:22 PM, Hal Murray wrote:
>
>
> rich...@karlquist.c
Rick said:
"In the case of the 10811, I have already posted about the reference
diode of special characteristics. I don't remember all the exact details
of how it was chosen, but it was based on proprietary knowledge."
This reminds me of something unusual I found in a Vectron 10 MHz OCXO
many
rich...@karlquist.com said:
> At this time, I will give my usual speech about IMHO the fact that since the
> invention of the DDS on a chip, EFC should no longer be used for high
> performance oscillators.
That caught my attention. Could you please say more.
A DDS introduces spurs. They mov
On 4/11/2020 12:15 AM, John Moran, Scawby Design wrote:
During my 50 years in the electronics industry I have always been puzzled about
one aspect of crystal oscillators. They go to great lengths to use a precise
piece of quartz as the heart, because of its unique properties, and then add
s
:24:45 -0400, time-nuts-requ...@lists.febo.com
wrote:
Re: time-nuts Digest, Vol 189, Issue 18
>
> Message: 4
> Date: Fri, 10 Apr 2020 13:23:22 -0400
> From: Bob kb8tq
> To: Taka Kamiya , Discussion of precise time and
> frequency measurement
> Subject: Re: [time-nuts]
On 4/11/20 6:04 AM, Bob kb8tq wrote:
Hi
Bottom line is that, as long as one is careful about *which* vendors supply
which
parts, normal parts do the job. Nobody is going to publish that selection
process
or the results. They very much want the “other guy” to have to do it on their
own.
This
t; Subject: Re: [time-nuts] OCXO and fluctuations after EFC adjustment
> Message-ID: <99642a49-8cdf-42d4-9039-7a5e7ff23...@n1k.org>
> Content-Type: text/plain; charset=us-ascii
>
> Hi
>
> EFC changes by themselves are pretty much instantaneous. If you are seeing
> po
(e.g. 15V 200uF +/- 10%) seems to
> be cost (cheapest == best).
>
> Sad isn't it.
>
> David
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Bob
> kb8tq
> Sent: 11 April 2020 14:05
> To: Discussion of precise t
ebo.com] On Behalf Of Bob
> kb8tq
> Sent: 11 April 2020 14:05
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] OCXO and fluctuations after EFC adjustment
>
> Hi
>
> Bottom line is that, as long as one is careful about *which* vendors s
.com] On Behalf Of Bob kb8tq
Sent: 11 April 2020 14:05
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OCXO and fluctuations after EFC adjustment
Hi
Bottom line is that, as long as one is careful about *which* vendors supply
which
parts, normal parts do the job.
Hi
Bottom line is that, as long as one is careful about *which* vendors supply
which
parts, normal parts do the job. Nobody is going to publish that selection
process
or the results. They very much want the “other guy” to have to do it on their
own.
The 78L12 might look just like one from 5
On Fri, 10 April 2020 14:31:53 -0700 Rick wrote:
>At this time, I will give my usual speech about IMHO the fact that
>since the invention of the DDS on a chip, EFC should no longer be used
>for high performance oscillators.
During my 50 years in the electronics industry I have always been puzz
On 4/10/20 2:31 PM, Richard (Rick) Karlquist wrote:
At this time, I will give my usual speech about IMHO the fact that
since the invention of the DDS on a chip, EFC should no longer be used
for high performance oscillators.
Rick N6RK
Yes..
The only case I can think of is where the osc
On 4/10/2020 12:51 PM, ed breya wrote:
looking for. Also, moving the frequency far away from "ideal" changes
the tempco, since it's no longer at the ideal center of the turnover
point. In reality, this may not matter much, since after all these
years, things may have drifted and aged way ou
This sort of behavior shouldn't be surprising at all. When you change
the EFC (especially by a fairly large amount to move it a few Hz), you
change the (transient and steady-state) operating points of the
circuitry, so it has to drift gradually to stabilize at the new
conditions. The effects ma
Hi
EFC changes by themselves are pretty much instantaneous. If you are seeing
post tune drift, it likely is from the pot or from things like a temperature
change
(or draft) when you go near the part.
If your grounds are a bit intertwined, the change in oven current will give you
a delta voltage
I have a few HP10811 and was thinking of making an interesting setup: A setup
where frequency is purposely offset by user defined amount by few Hz, and make
it selectable.
Under normal setup, I would use a potentiometer and EFC control the frequency.
When I adjust EFC, the frequency immediate
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