AoE x-Chapters, High-Speed op-amps section, DRAFT

[John Larkin]

On 21 Jul 2019 07:03:21 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

whit3rd wrote...

The better manufacturers that give lamp specs (Philips)
are promising 75 lm/w and years of service life.

Yes, I bought into this line of thinking.
I purchased about six of the more-expensive,
higher-quality Philips LED bulbs. Four of
the six have failed, many after only a few
hundred hours, and none anywhere near their
claimed lifetime. They were installed in
dropped-down-from-the-ceiling fixtures,
with lots of room and generous airflow.
No autopsies were performed.

I've used tons of the Philips bulbs of various sorts, and none have
failed. I think you get lightning up there in Mass, so maybe
transients kill them. We don't get lightning here. The cheap LED bulbs
do sometimes fail here.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[gray_wolf]

On 7/21/2019 9:16 AM, John Larkin wrote:

On 21 Jul 2019 07:03:21 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

whit3rd wrote...

The better manufacturers that give lamp specs (Philips)
are promising 75 lm/w and years of service life.

Yes, I bought into this line of thinking.
I purchased about six of the more-expensive,
higher-quality Philips LED bulbs. Four of
the six have failed, many after only a few
hundred hours, and none anywhere near their
claimed lifetime. They were installed in
dropped-down-from-the-ceiling fixtures,
with lots of room and generous airflow.
No autopsies were performed.

I've used tons of the Philips bulbs of various sorts, and none have
failed. I think you get lightning up there in Mass, so maybe
transients kill them. We don't get lightning here. The cheap LED bulbs
do sometimes fail here.

Years ago I lived in a house that had lights that didn't last long. Checked the
line voltage and it was 135 VAC.

 

[Winfield Hill]

gray_wolf wrote...

On 7/21/2019 9:16 AM, John Larkin wrote:
On 21 Jul 2019 07:03:21 -0700, Winfield Hill wrote:
whit3rd wrote...

The better manufacturers that give lamp specs (Philips)
are promising 75 lm/w and years of service life.

Yes, I bought into this line of thinking.
I purchased about six of the more-expensive,
higher-quality Philips LED bulbs. Four of
the six have failed, many after only a few
hundred hours, and none anywhere near their
claimed lifetime. They were installed in
dropped-down-from-the-ceiling fixtures,
with lots of room and generous airflow.
No autopsies were performed.

I've used tons of the Philips bulbs of various sorts, and none have
failed. I think you get lightning up there in Mass, so maybe
transients kill them. We don't get lightning here. The cheap LED bulbs
do sometimes fail here.

Years ago I lived in a house that had lights that didn't
last long. Checked the line voltage and it was 135 VAC.

Mine is 125Vac. Dunno about lightning, but our neighborhood
wiring is underground. My house has probably 20 TVS units.


--
Thanks,
- Win

 

[Clifford Heath]

On 18/7/19 3:10 am, John Larkin wrote:

On Tue, 16 Jul 2019 14:09:39 -0700, Jeff Liebermann <jeffl@cruzio.com
wrote:

On Tue, 16 Jul 2019 06:56:47 -0700, John Larkin
jjlarkin@highlandtechnology.com> wrote:

Here's the street. That's 22 megawatts right above those houses.
https://www.dropbox.com/s/4fzsmipz0rar4ke/Panoramic_Drive.jpg?raw=1

Nope. The 22 MegaWatts might be the EIRP (Equivalent Isotropically
Radiated Power), which is the transmitter RF output power, minus any
coax cable or waveguide loss, times the antenna gain.

I read the 22MW number in some article about the tower. It may be ERP
in some plane.

Such antenna systems are carefully designed not to waste power (and
human life!) by aiming it at the ground nearby. If you're near, most of
the power is aimed over your head, thank goodness!

Every transmitting site in Australia has to have published and measured
EMC designs as a condition of their license, all at the Radio Frequency
National Site Archive. Look up any of the bigger ones and you can see
the vertical lobe patterns.

Clifford Heath

 

[Clifford Heath]

On 18/7/19 1:16 am, John Larkin wrote:

America is great. So way are so many people rude and angry?
Well, a few of them are Australian. Are Australians especially rude?

There are one or two mentally-ill Australians here. They give the rest
of us a bad rep.

However, the rest of us don't tend to tolerate crap, and we fight fire
with fire. If you're wrong, stupid, or rude, you can expect a robust
response.

Clifford Heath

 

[Clifford Heath]

On 17/7/19 9:46 am, Joerg wrote:

On 2019-07-16 16:21, Clifford Heath wrote:
On 17/7/19 3:28 am, Joerg wrote:
AM in the US is usually vertically polarized because they use a very
tall tower fed at the bottom. In other countries that sort of expense
isn't always palatable so they sometimes use dipoles strung between a
couple of high points and then it's horizontal. Horizontal has the
downside of nulls in two directions, making the range non-circular and
that's bad for listener numbers and thus advertizing revenue.

A pair of dipoles fed in quadrature gives a turnstile antenna. A
reasonable solution if nulls are a problem.


That's what used to be on most apartment buildings in Germany for AM
reception, combined with FM/VHF/UHF, amplified and then fed into the
radio and TV lines to each apartment. I never saw it for a transmitter
though.

It is used for ARDF transmitters on 2m band, because a nice circular
pattern is desirable for direction-finding competition.

Clifford Heath.

 

On Sunday, 21 July 2019 15:15:19 UTC+1, gray_wolf wrote:

On 7/21/2019 9:03 AM, Winfield Hill wrote:
whit3rd wrote...

The better manufacturers that give lamp specs (Philips)
are promising 75 lm/w and years of service life.

Yes, I bought into this line of thinking.
I purchased about six of the more-expensive,
higher-quality Philips LED bulbs. Four of
the six have failed, many after only a few
hundred hours, and none anywhere near their
claimed lifetime. They were installed in
dropped-down-from-the-ceiling fixtures,
with lots of room and generous airflow.
No autopsies were performed.


Does anyone what know the common failure modes are?

mostly burned out leds. When one dies the whole string goes dead.


NT

 

[Winfield Hill]

tabbypurr@gmail.com wrote...

On Sunday, 21 July 2019, gray_wolf wrote:

Does anyone what know the common failure modes are?

mostly burned out leds. When one dies the whole
string goes dead.

The Hackaday study found only 10% due to bad LEDs,
60% was due to electronics, the rest packaging, etc.


--
Thanks,
- Win

 

[Gerhard Hoffmann]

Am 22.07.19 um 10:22 schrieb Winfield Hill:

tabbypurr@gmail.com wrote...

On Sunday, 21 July 2019, gray_wolf wrote:

Does anyone what know the common failure modes are?

mostly burned out leds. When one dies the whole
string goes dead.

The Hackaday study found only 10% due to bad LEDs,
60% was due to electronics, the rest packaging, etc.

My Osrams go into Morse code style operation, ON-Off-On_...
Ikea LEDARE seem to work better.

One can see who intends to stay in business and who is about
to sell the farm.

Gerhard

 

[Steve Wilson]

Gerhard Hoffmann <dk4xp@arcor.de> wrote:

My Osrams go into Morse code style operation, ON-Off-On_...
Ikea LEDARE seem to work better.

One can see who intends to stay in business and who is about
to sell the farm.

Gerhard

Do you mean buy the farm?

https://en.wiktionary.org/wiki/buy_the_farm

 

[Gerhard Hoffmann]

Am 22.07.19 um 14:21 schrieb Steve Wilson:

Gerhard Hoffmann <dk4xp@arcor.de> wrote:

My Osrams go into Morse code style operation, ON-Off-On_...
Ikea LEDARE seem to work better.

One can see who intends to stay in business and who is about
to sell the farm.

Gerhard

Do you mean buy the farm?

https://en.wiktionary.org/wiki/buy_the_farm

No, Osram is to be sold.

A fellow glider pilot provoked an off-field landing
because he knew the farmer had a pretty daughter.
Wheat fields are harmless.
It kinda worked.

Gerhard

 

[Gerhard Hoffmann]

Am 22.07.19 um 15:46 schrieb Steve Wilson:

Gerhard Hoffmann <dk4xp@arcor.de> wrote:

Am 22.07.19 um 14:21 schrieb Steve Wilson:
Gerhard Hoffmann <dk4xp@arcor.de> wrote:

My Osrams go into Morse code style operation, ON-Off-On_...
Ikea LEDARE seem to work better.

One can see who intends to stay in business and who is about to sell
the farm.

Gerhard

Do you mean buy the farm?

https://en.wiktionary.org/wiki/buy_the_farm

No, Osram is to be sold.

A fellow glider pilot provoked an off-field landing
because he knew the farmer had a pretty daughter.
Wheat fields are harmless.
It kinda worked.

Gerhard

How do you get a glider out of a farm field and back in the air?

That's easy. There is a car trailer for each glider, where it is
stored by default(unless you have a place in a hall). You drive that
to the farm. It takes 3 or 4 people to unmount the wings and put
everything into the trailer. That takes less than half an hour.
Off-field landings don't happen daily, but now & then.
They are planned-in and this is exercised.

Wheat fields may be harmless to gliders, but they may cause severe damage
to a powered plane because the landing speeds are much higher and can cause
taildraggers to nose over. They can conceal ruts that can rip the
undercarriage off a tricycle plane.

Gliders are not that much slower.

Corn fields are much worse. You land at an elevation of 6ft, and at the
very end you drop to the ground. Not much trouble for the plane, but
for the pilot's spine.

Fields of green are also not good. There are often fence wires that you
cannot see, and the cows may feel molested.

cheers, Gerhard

 

[Steve Wilson]

Gerhard Hoffmann <dk4xp@arcor.de> wrote:

Am 22.07.19 um 14:21 schrieb Steve Wilson:
Gerhard Hoffmann <dk4xp@arcor.de> wrote:

My Osrams go into Morse code style operation, ON-Off-On_...
Ikea LEDARE seem to work better.

One can see who intends to stay in business and who is about to sell
the farm.

Gerhard

Do you mean buy the farm?

https://en.wiktionary.org/wiki/buy_the_farm

No, Osram is to be sold.

A fellow glider pilot provoked an off-field landing
because he knew the farmer had a pretty daughter.
Wheat fields are harmless.
It kinda worked.

Gerhard

How do you get a glider out of a farm field and back in the air?

Wheat fields may be harmless to gliders, but they may cause severe damage
to a powered plane because the landing speeds are much higher and can cause
taildraggers to nose over. They can conceal ruts that can rip the
undercarriage off a tricycle plane.

 

[John Larkin]

On Sun, 21 Jul 2019 09:33:47 -0500, gray_wolf <g_wolf@howling_mad.com>
wrote:

On 7/21/2019 9:16 AM, John Larkin wrote:
On 21 Jul 2019 07:03:21 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

whit3rd wrote...

The better manufacturers that give lamp specs (Philips)
are promising 75 lm/w and years of service life.

Yes, I bought into this line of thinking.
I purchased about six of the more-expensive,
higher-quality Philips LED bulbs. Four of
the six have failed, many after only a few
hundred hours, and none anywhere near their
claimed lifetime. They were installed in
dropped-down-from-the-ceiling fixtures,
with lots of room and generous airflow.
No autopsies were performed.

I've used tons of the Philips bulbs of various sorts, and none have
failed. I think you get lightning up there in Mass, so maybe
transients kill them. We don't get lightning here. The cheap LED bulbs
do sometimes fail here.



Years ago I lived in a house that had lights that didn't last long. Checked the
line voltage and it was 135 VAC.

That happened to me once. The 120-N-120 feed had an open neutral.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Joerg]

On 2019-07-22 07:39, Gerhard Hoffmann wrote:

Am 22.07.19 um 15:46 schrieb Steve Wilson:
Gerhard Hoffmann <dk4xp@arcor.de> wrote:

Am 22.07.19 um 14:21 schrieb Steve Wilson:
Gerhard Hoffmann <dk4xp@arcor.de> wrote:

My Osrams go into Morse code style operation, ON-Off-On_...
Ikea LEDARE seem to work better.
One can see who intends to stay in business and who is about to sell
the farm.
Gerhard
Do you mean buy the farm?
https://en.wiktionary.org/wiki/buy_the_farm
No, Osram is to be sold.
A fellow glider pilot provoked an off-field landing
because he knew the farmer had a pretty daughter.
Wheat fields are harmless.
It kinda worked.
Gerhard

How do you get a glider out of a farm field and back in the air?

That's easy. There is a car trailer for each glider, where it is
stored by default(unless you have a place in a hall). You drive that
to the farm. It takes 3 or 4 people to unmount the wings and put
everything into the trailer. That takes less than half an hour.
Off-field landings don't happen daily, but now & then.
They are planned-in and this is exercised.

So did he marry her?

[...]

--
Regards, Joerg

http://www.analogconsultants.com/

 

On Monday, 22 July 2019 09:22:33 UTC+1, Winfield Hill wrote:

tabbypurr wrote...
On Sunday, 21 July 2019, gray_wolf wrote:

Does anyone what know the common failure modes are?

mostly burned out leds. When one dies the whole
string goes dead.

The Hackaday study found only 10% due to bad LEDs,
60% was due to electronics, the rest packaging, etc.

All I can tell you is a lot of people have had failures nearly all due to burned LEDs.


NT

 

[Joerg]

On 2019-07-22 16:23, Clifford Heath wrote:

On 23/7/19 12:39 am, Gerhard Hoffmann wrote:
Am 22.07.19 um 15:46 schrieb Steve Wilson:
Wheat fields may be harmless to gliders, but they may cause severe
damage
to a powered plane because the landing speeds are much higher and can
cause
taildraggers to nose over. They can conceal ruts that can rip the
undercarriage off a tricycle plane.

Gliders are not that much slower.

Corn fields are much worse. You land at an elevation of 6ft, and at the
very end you drop to the ground. Not much trouble for the plane, but
for the pilot's spine.

How does the poor farmer get recompensed? Everyone is worrying about
damage to the plans, but what about the crop?

Not sure about how it is among glider pilots but parachutists usually
offer to pay for damage. At least that's how it was in Belgium. I once
could not avoid a corn field, trying my best to steer into the "alley"
between stalk row. Looked around, darn, I had knocked one over. Ate some
of it, tasted horrible. I asked the farmer's son how much it costs and
he laughed. "Oh, nothing, And you can't eat that kind, it's food for pigs".

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Clifford Heath]

On 23/7/19 12:39 am, Gerhard Hoffmann wrote:

Am 22.07.19 um 15:46 schrieb Steve Wilson:
Wheat fields may be harmless to gliders, but they may cause severe damage
to a powered plane because the landing speeds are much higher and can
cause
taildraggers to nose over. They can conceal ruts that can rip the
undercarriage off a tricycle plane.

Gliders are not that much slower.

Corn fields are much worse. You land at an elevation of 6ft, and at the
very end you drop to the ground. Not much trouble for the plane, but
for the pilot's spine.

How does the poor farmer get recompensed? Everyone is worrying about
damage to the plans, but what about the crop?

Clifford Heath.

 

[Gerhard Hoffmann]

Am 23.07.19 um 01:23 schrieb Clifford Heath:

On 23/7/19 12:39 am, Gerhard Hoffmann wrote:
Am 22.07.19 um 15:46 schrieb Steve Wilson:
Wheat fields may be harmless to gliders, but they may cause severe
damage
to a powered plane because the landing speeds are much higher and can
cause
taildraggers to nose over. They can conceal ruts that can rip the
undercarriage off a tricycle plane.

Gliders are not that much slower.

Corn fields are much worse. You land at an elevation of 6ft, and at the
very end you drop to the ground. Not much trouble for the plane, but
for the pilot's spine.

How does the poor farmer get recompensed? Everyone is worrying about
damage to the plans, but what about the crop?

Clifford Heath.

That little bit of crop does not cost much. Of course, the
farmer was offered a compensation, but in this case, the net effect
was an invitation to Sunday afternoon coffee on the farm with the
helpers and effectively the pole position with the daughter
It's hard to top that in the north-German plains. You know: nothing,
barn, church, nothing, barn, church, nothing, ad nauseam. And the
prince comes, on a white horse, eh, aereoplan,--


We also had a case that led to a marriage, to answer JĂśrg.

Someone must have been sitting on the PTT switch, and a pilot and
his Co discussed the nice aspects of a girl, also a pilot.

On 116 MHz / 10W AM / 2000 meters that must have been heard even in
England on the gliders frequency. But yes, yes, yes, in all of Northern
Germany. And, quite positive for the girl.

Cheers, Gerhard

PTT = push to talk

 

[Joerg]

On 2019-07-22 18:07, Gerhard Hoffmann wrote:

Am 23.07.19 um 01:23 schrieb Clifford Heath:
On 23/7/19 12:39 am, Gerhard Hoffmann wrote:
Am 22.07.19 um 15:46 schrieb Steve Wilson:
Wheat fields may be harmless to gliders, but they may cause severe
damage
to a powered plane because the landing speeds are much higher and
can cause
taildraggers to nose over. They can conceal ruts that can rip the
undercarriage off a tricycle plane.

Gliders are not that much slower.

Corn fields are much worse. You land at an elevation of 6ft, and at the
very end you drop to the ground. Not much trouble for the plane, but
for the pilot's spine.

How does the poor farmer get recompensed? Everyone is worrying about
damage to the plans, but what about the crop?

Clifford Heath.

That little bit of crop does not cost much. Of course, the
farmer was offered a compensation, but in this case, the net effect
was an invitation to Sunday afternoon coffee on the farm with the
helpers and effectively the pole position with the daughter
It's hard to top that in the north-German plains. You know: nothing,
barn, church, nothing, barn, church, nothing, ad nauseam.

No, no, I grew up on in a rural area and it's different. Nothing, barn,
church, pub, nothing, barn, church, pub. I can't remember a church where
there wasn't a pub next door, including the one I was baptized in.

"Nothing" is also a matter of taste. For me a nice rural setting with
fields, forest and nature is much preferable to any kind of city.

... And the
prince comes, on a white horse, eh, aereoplan,--


We also had a case that led to a marriage, to answer JĂśrg.

Someone must have been sitting on the PTT switch, and a pilot and
his Co discussed the nice aspects of a girl, also a pilot.

On 116 MHz / 10W AM / 2000 meters that must have been heard even in
England on the gliders frequency. But yes, yes, yes, in all of Northern
Germany. And, quite positive for the girl.

I can see her blushing

My first foray into marketing after getting my engineering degree also
resulted in a marriage. Lasts to this day.

--
Regards, Joerg

http://www.analogconsultants.com/