On 11/09/2012 06:01 PM, Existential Angst wrote:

[snip]

My g-d electric blankeypoo dudn't WORK with my 1500 W fukn inverter!!!!!
WTF??????

And the reason quickly became clear: some electronics don't work with
modified (read: ****) sine wave power.
But, what electronics are in a g-d electric blanket???

I sometimes use a heating pad, for a heated seat. Many of those won't
work with an inverter.

[snip]

--
45 days until the winter celebration (Tue Dec 25, 2012 12:00:00 AM).

Mark Lloyd
http://notstupid.us

"...your belief in God is merely an escape from your monotonous, stupid
and cruel life." [Krishnamurti]

On Sat, 10 Nov 2012 00:06:51 -0500, micky
wrote:

On Fri, 09 Nov 2012 22:06:23 -0500, wrote:



What he NEEDS is a 12 volt blankie.

I didn't know thtey had such things, but
http://www.amazon.com/Heated-Fleece-.../dp/B000V8QVX6
http://www.walmart.com/ip/Maxsa-Comf...-Blue/10756183

Onlly 25 dollars for each.

My baby brother has been a long

They let babies drive trucks!

He turned 45 a couple weeks after the crash

distance trucker across north america, from Alaska to Florida - and
has 12 volt mattress warmer and 12 volt electric blanket for YEARS.

Lost 'em both when he rolled the truck last year. Bust his neck too,
but he's back on the road - doing mostly short haul flatland driving
hauling crude - less than 2 years after the crash.

Glad he's doing so well

Yea, he's only got less than 30 degrees total lateral movement, and
by the end od a day his neck is sore - but with convex mirrors on the
truck he's OK as long as he's carefull. Guess they figured it was
better to let him drive again than to try to retrain him for something
else.
Darn good driver. Other than being struck by lighning, a herd of
antelope, and about a hundred separate deer his record was very good
till he ditched and barrel rolled just west of Calgary 2 years ago May
24. Not sure how many million miles he and his little dog CB have
under thair belt - CB is 16 now and was on the road with him from the
time he was a pup antill about 6 months before the accident. (Jack
Russel /???? cross)

On Sat, 10 Nov 2012 00:28:53 -0500, "tm"
wrote:


wrote in message
.. .
On Fri, 09 Nov 2012 21:30:28 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"tm" fired this volley in news:k7khim$at3$1
:

Well, if it has a poorly designed triac controller, it may radiate RFI.

Even well-designed ones do on the turn-on. Only a lot of down-line
choking and shielding will get it down to reasonable levels.

But it's not likely that the RFI emitted from a 1/2-amp controller would
emit enough to be harmful to tissue. Could screw up your pacemaker, I
guess...

Lloyd
There ARE controllers that switch on the downward slope of the sine,
greatly reducung theRFI.

One thing for sure - an electric blanket sure plays havok with
magnetometers, like in electronic compases - and electronic gyros.

It's best when they switch on the zero crossings.
Which means either full on, half on, or off.

On Fri, 9 Nov 2012 19:01:11 -0500, "Existential Angst"
wrote:

OK.....

So ahm happier'n'a alcoholic workin the night shift in a Jack Daniels
distillery.... with my 400# deep cycle battery, 1500 W inverter (sitting
in the back seat of m'truck), and my brand new blue electric
blankey-poo.....
Now I can curl up in a fetal position -- in m'truck -- in compleat toasty
comfort.....

Now, don't ax me WHY I gotta curl up in a fetal position -- in m'truck.
Just suffice it to say, if you had my yob, you'd be curling up in a fetal
position in YOUR truck, too.

Your job? Your truck? Your blanket?

Luxury.

RL

On Sat, 10 Nov 2012 06:37:04 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

fired this volley in
:

There ARE controllers that switch on the downward slope of the sine,
greatly reducung theRFI.

Have you recently priced GTO triacs and SCRs? You won't find a turn-off
style controller at consumer prices.

LLoyd
In residential lighting dimmers, Lutron turn-off dimmers are about
double the cost of the turn-on type - which is still reasonable.

On Sat, 10 Nov 2012 08:51:39 -0500, "Jim Wilkins"
wrote:

wrote in message
news
...
The small standby UPS does no wave shaping when allowing the load to
run on "line " voltage - and most are, at best, modified sine wave
output.

A UPS "modified sine wave" is a sequence of positive and negative
square pulses at 160 to 170V, with enough off time between them to
reduce the average (RMS?) voltage to 120V. I've seen the pulse width
increase at higher loads that pulled down the peak voltage.

An APC Smart-Ups has a pure sine output on battery.
https://www.apc.com/products/family/index.cfm?id=165

But a SmartUPS is not a standby - a Back-UPS is.

Some of them can run off large external batteries without overheating.
Check the surplus stores for used ones. The downloadable manual shows
the simple but not obvious way to remove the old batteries.

That is not a "small standby UPS" by anyone's definition. It is an
online UPS - AKA dual conversion.

I just discovered that the sensor-logging feature of HWiNFO32 v4.06
freeware can record the run time of an unattended laptop on its
battery, It captures the battery voltage, the power drain and the
estimated percent of remaining capacity, which will show a sudden drop
to empty if the battery's microcontroller IC needs to recalibrate
itself with a full discharge cycle.
http://www.hwinfo.com/

I use recording TV and displaying Internet weather radar as
representative high and moderate power applications to check UPS run
time. During an outage I wouldn't let it run idle on precious battery
power though that's the easiest measurement to make. The Event Log
will capture shutdown time.

I haven't tried yet, but it should also show when the UPS or inverter
powering the laptop plus your test load shuts off and the laptop
switches to internal battery.

Michael A. Terrell wrote:
Jim Wilkins wrote:
"Michael A. Terrell" wrote in message
m...

That Bethany VOA site is now a stinking golf course.
It went the way of the American values it promoted.


It should have been turned into a museum. That site had a huge impact
on W.W. II It went from an empty pasture, to the most up to date Short
Wave Radio transmitter site in a very short period. It fed news & music
to the world, and was a huge boost to morale.

Switched wires radiate as per &E/&t (Maxwell's Eqns).
It's called sparks, and can nearly radiate all over the
radio+ spectrum.
Ken
PS: Wife & daughter used electric sheets prior to bed time.

On 11/9/2012 9:58 PM, tm wrote:

"Michael A. Terrell" wrote in message
...

tm wrote:

"Michael A. Terrell" wrote in message
m...

micky wrote:

Really older blankets might have a problem with low frequency
radiation.


Very doubtful, considering that one cycle is 5000000 meters long.
That's 5,000 Kilometers or about 3106 miles. How big is that blanket?

Well, if it has a poorly designed triac controller, it may radiate RFI.


Which wouldn't be low frequency.

Wouldn't that depend on your definition of "low frequency"? My AM radio
is low frequency

My frequency of urination is high. ^_^

TDD

wrote in message
...
On Sat, 10 Nov 2012 00:28:53 -0500, "tm"
wrote:


wrote in message
. ..
On Fri, 09 Nov 2012 21:30:28 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"tm" fired this volley in
news:k7khim$at3$1
:

Well, if it has a poorly designed triac controller, it may radiate
RFI.

Even well-designed ones do on the turn-on. Only a lot of down-line
choking and shielding will get it down to reasonable levels.

But it's not likely that the RFI emitted from a 1/2-amp controller would
emit enough to be harmful to tissue. Could screw up your pacemaker, I
guess...

Lloyd
There ARE controllers that switch on the downward slope of the sine,
greatly reducung theRFI.

One thing for sure - an electric blanket sure plays havok with
magnetometers, like in electronic compases - and electronic gyros.

It's best when they switch on the zero crossings.
Which means either full on, half on, or off.

So? You don't need a per cycle control. On-off every minute would be fine.
Or % of a minute.

"The Daring Dufas" wrote in message
...
On 11/9/2012 9:58 PM, tm wrote:

"Michael A. Terrell" wrote in message
...

tm wrote:

"Michael A. Terrell" wrote in message
m...

micky wrote:

Really older blankets might have a problem with low frequency
radiation.


Very doubtful, considering that one cycle is 5000000 meters long.
That's 5,000 Kilometers or about 3106 miles. How big is that
blanket?

Well, if it has a poorly designed triac controller, it may radiate RFI.


Which wouldn't be low frequency.

Wouldn't that depend on your definition of "low frequency"? My AM radio
is low frequency

My frequency of urination is high. ^_^

TDD

You must be drinking Bud.

The Daring Dufas wrote:

My frequency of urination is high. ^_^


But it has a very short wavelength! ;-)

"Ken S. Tucker" wrote:

Michael A. Terrell wrote:
Jim Wilkins wrote:
"Michael A. Terrell" wrote in message
m...

That Bethany VOA site is now a stinking golf course.
It went the way of the American values it promoted.


It should have been turned into a museum. That site had a huge impact
on W.W. II It went from an empty pasture, to the most up to date Short
Wave Radio transmitter site in a very short period. It fed news & music
to the world, and was a huge boost to morale.

Switched wires radiate as per &E/&t (Maxwell's Eqns).
It's called sparks, and can nearly radiate all over the
radio+ spectrum.


Then the item is defective. It should have a snubber to reducew the
arcing.

"tm" fired this volley in
:

So? You don't need a per cycle control. On-off every minute would be
fine. Or % of a minute.

Yep. In that case, a simple self-heating bi-metal strip switch would do
it.

WOW! What an IDEA! Wait...

LLoyd

"Michael A. Terrell" fired this volley in
m:

Then the item is defective.

Likely as not, yes -- but the design, not the "item". Made of Chinalloy in
China.

LLoyd

On 11/10/2012 2:19 PM, tm wrote:

"The Daring Dufas" wrote in message
...
On 11/9/2012 9:58 PM, tm wrote:

"Michael A. Terrell" wrote in message
...

tm wrote:

"Michael A. Terrell" wrote in message
m...

micky wrote:

Really older blankets might have a problem with low frequency
radiation.


Very doubtful, considering that one cycle is 5000000 meters long.
That's 5,000 Kilometers or about 3106 miles. How big is that
blanket?

Well, if it has a poorly designed triac controller, it may radiate
RFI.


Which wouldn't be low frequency.

Wouldn't that depend on your definition of "low frequency"? My AM radio
is low frequency

My frequency of urination is high. ^_^

TDD

You must be drinking Bud.

I've actually never consumed an alcoholic beverage in my life. I've
never had a beer, a shot of whiskey or even a glass of wine. Most
folks call me a liar but those who know me personally know my lack
of a taste for alcohol is true and that it has nothing to do with
religion. One of my blood pressure meds causes me to pee like Niagara
Falls. Plus, the caffeine in Diet Dew puts kidneys into overdrive. A
feller has to watch his figure, that's why I drink diet soft drinks. ^_^

TDD

On 11/10/2012 2:25 PM, Michael A. Terrell wrote:

The Daring Dufas wrote:

My frequency of urination is high. ^_^


But it has a very short wavelength! ;-)


I've never been ashamed of my 1/4 wave whip. ^_^

TDD

The Daring Dufas wrote:

On 11/10/2012 2:25 PM, Michael A. Terrell wrote:
?
? The Daring Dufas wrote:
??
?? My frequency of urination is high. ^_^
?
?
? But it has a very short wavelength! ;-)
?

I've never been ashamed of my 1/4 wave whip. ^_^


You said it was a folded dipole! ;-)

On 11/10/2012 11:20 PM, Michael A. Terrell wrote:

The Daring Dufas wrote:

On 11/10/2012 2:25 PM, Michael A. Terrell wrote:
?
? The Daring Dufas wrote:
??
?? My frequency of urination is high. ^_^
?
?
? But it has a very short wavelength! ;-)
?

I've never been ashamed of my 1/4 wave whip. ^_^


You said it was a folded dipole! ;-)


Well, there is that Slinky antenna. ^_^

TDD

The Daring Dufas wrote:

On 11/10/2012 11:20 PM, Michael A. Terrell wrote:
?
? The Daring Dufas wrote:
??
?? On 11/10/2012 2:25 PM, Michael A. Terrell wrote:
?? ?
?? ? The Daring Dufas wrote:
?? ??
?? ?? My frequency of urination is high. ^_^
?? ?
?? ?
?? ? But it has a very short wavelength! ;-)
?? ?
??
?? I've never been ashamed of my 1/4 wave whip. ^_^
?
?
? You said it was a folded dipole! ;-)
?

Well, there is that Slinky antenna. ^_^


New Slinkies are plastic.

On Sat, 10 Nov 2012 13:42:17 -0500, wrote:

On Sat, 10 Nov 2012 00:06:51 -0500, micky
wrote:

On Fri, 09 Nov 2012 22:06:23 -0500, wrote:



What he NEEDS is a 12 volt blankie.

I didn't know thtey had such things, but
http://www.amazon.com/Heated-Fleece-.../dp/B000V8QVX6
http://www.walmart.com/ip/Maxsa-Comf...-Blue/10756183

Onlly 25 dollars for each.

My baby brother has been a long

They let babies drive trucks!

He turned 45 a couple weeks after the crash

I'm not surprised. A near death experience makes someone grow old
fast. Although 44 years in a couple weeks is remarkable.

distance trucker across north america, from Alaska to Florida - and
has 12 volt mattress warmer and 12 volt electric blanket for YEARS.

Lost 'em both when he rolled the truck last year. Bust his neck too,
but he's back on the road - doing mostly short haul flatland driving
hauling crude - less than 2 years after the crash.

Glad he's doing so well

Yea, he's only got less than 30 degrees total lateral movement, and
by the end od a day his neck is sore - but with convex mirrors on the
truck he's OK as long as he's carefull. Guess they figured it was
better to let him drive again than to try to retrain him for something
else.
Darn good driver. Other than being struck by lighning, a herd of
antelope, and about a hundred separate deer his record was very good
till he ditched and barrel rolled just west of Calgary 2 years ago May
24. Not sure how many million miles he and his little dog CB have
under thair belt - CB is 16 now and was on the road with him from the
time he was a pup antill about 6 months before the accident. (Jack
Russel /???? cross)

Good for them.

On Sat, 10 Nov 2012 06:41:13 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"tm" fired this volley in news:k7kogp$92f$1
:

t's best when they switch on the zero crossings.

It can't be a "duty cycle controller", and switch _only_ on the zero
crossings.

Nonsense. Just cycle skip. It's only heat. Pulse width modulation
averaging across seconds is just fine.

When a device only turns on and off at the AC zero crossings, we call it
a "wire".

Wrong.

On Sun, 11 Nov 2012 00:20:19 -0500, "Michael A. Terrell"
wrote:


The Daring Dufas wrote:

On 11/10/2012 2:25 PM, Michael A. Terrell wrote:
?
? The Daring Dufas wrote:
??
?? My frequency of urination is high. ^_^
?
?
? But it has a very short wavelength! ;-)
?

I've never been ashamed of my 1/4 wave whip. ^_^


You said it was a folded dipole! ;-)

I thought he said it was a rubber ducky.

z fired this volley in
:

Nonsense. Just cycle skip. It's only heat. Pulse width modulation
averaging across seconds is just fine.


If you'd take the time to read the thread before making a knee-jerk
response, you'd note that I dealt with that in an immediate follow-up to
the one you responded. I just hit "send now" before writing everything I
meant to. (but -did- follow up to address your exact contention)

I'm not in the 'nonsense' business concerning electronics -- having made
it my profession for over 40 years.

Do you make "gut" decisions when trouble-shooting, and just swap
suspected parts, or do you thoroughly examine the symptoms first? The
first, we used to call "tube caddies" in the old TV days. The latter, we
called "technicians".

LLoyd

On Mon, 12 Nov 2012 12:05:40 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

fired this volley in
:

Nonsense. Just cycle skip. It's only heat. Pulse width modulation
averaging across seconds is just fine.


If you'd take the time to read the thread before making a knee-jerk
response, you'd note that I dealt with that in an immediate follow-up to
the one you responded. I just hit "send now" before writing everything I
meant to. (but -did- follow up to address your exact contention)

Sometimes, sometimes not. It often depends on what's in my view at the
time. Errors this glaring do deserve a response. It was a *DUMB*
statement. I actually didn't notice that I was in SED. It was *that*
dumb.

I'm not in the 'nonsense' business concerning electronics -- having made
it my profession for over 40 years.

Apparently you are in the nonsense business, and have been for forty
years. You pulled a real boner on this one. Defending it, such as
you are trying, is worse.

Do you make "gut" decisions when trouble-shooting, and just swap
suspected parts, or do you thoroughly examine the symptoms first? The
first, we used to call "tube caddies" in the old TV days. The latter, we
called "technicians".

Have you stepped in it this deep every day of your forty years? Not
that any of this has anything to do with your absurd statements.

z wrote:

On Sun, 11 Nov 2012 00:20:19 -0500, "Michael A. Terrell"
wrote:


The Daring Dufas wrote:

On 11/10/2012 2:25 PM, Michael A. Terrell wrote:
?
? The Daring Dufas wrote:
??
?? My frequency of urination is high. ^_^
?
?
? But it has a very short wavelength! ;-)
?

I've never been ashamed of my 1/4 wave whip. ^_^


You said it was a folded dipole! ;-)

I thought he said it was a rubber ducky.


He flushed that down the toilet. ;-)

On 11/12/2012 9:34 AM, z wrote:
On Sun, 11 Nov 2012 00:20:19 -0500, "Michael A. Terrell"
wrote:


The Daring Dufas wrote:

On 11/10/2012 2:25 PM, Michael A. Terrell wrote:
?
? The Daring Dufas wrote:
??
?? My frequency of urination is high. ^_^
?
?
? But it has a very short wavelength! ;-)
?

I've never been ashamed of my 1/4 wave whip. ^_^


You said it was a folded dipole! ;-)

I thought he said it was a rubber ducky.


The darn thing kept floating off whenever I went swimming. O_o

TDD

Parabolic heater:

Personal heater, because beam is so narrow.

Problem for me: the air within the beam gets warm
enough for the relative humidity to go down to what
seems like zero, and you're breathing it.

REALLY dries out the nasal passages, so much that
it can hurt. For me, anyway.

Much prefer OLD Markel heater, with only the front
element on.

(Amazon reviews say that today's Markel heaters are
for ****, crappy wiring inside, cheap construction.
Although outer shell, reviews say, looks and feels
like the old ones. Do read the reviews before
buying one.)


David

In article ,
whoyakidding wrote:
On Sat, 10 Nov 2012 02:48:29 -0500, "Existential Angst"
wrote:


My hot-wired blanket now works, and as far as the risk of fire goes, even at
full blast, it's got a long long way to go before ignition... heh, famous
last words, eh?? LOL

It sounds like you're on a parallel path to what I have in my
motorhome. It had 2 tired deep cycle batteries which I replaced and
added a third. If I remember right I have about 1kwh capacity to 50%.
I bought a 1000W true sine inverter on sale for $150. Now I have more
battery capacity for running the furnace heavily overnight when dry
camping in cold temperatures. And I don't have to use the generator
nearly so often. Even the inverter microwave is OK at half power.

In my rig the bedroom is at the back. It stays cool when the rest of
the coach is toasty. I've considered getting an electric blanket and
running it off the inverter and then turning down the furnace
thermostat overnight. I should break even on the battery use and come
out ahead on propane. One wrinkle is that the furnace has an outlet
into the holding tank compartment. If I run the furnace too little in
below freezing temperatures then I'd have to worry about the dump
valves freezing. I've traveled in the off season and my record so far
for being comfortable is 14 degrees Fahrenheit. Man the RV crowd
really thins out when it gets cold. If I get a chance to
experiment further I'll report here.

Valve freezing shut.

Do they still make low-wattage electric tape-warmers to wrap around pipes,
like in a garage? Maybe that would help.

David

In article ,
The Daring Dufas wrote:
feller has to watch his figure, that's why I drink diet soft drinks. ^_^

TDD

Do you know how much SUGAR (or worse) is in a soft drink?

Likewise caffein.

I used to drink coke like it was water. For years.

Who knows what it did to my innards...

David

In article ,
Michael A. Terrell wrote:

micky wrote:

On Fri, 09 Nov 2012 22:18:39 -0500, "Michael A. Terrell"
wrote:

....
I don't think so. And if that were the case, then a
radio transmitter broadcasting at 600 KHz would require an antenna
that was a third of a mile long.


No, it doesn't. AM BC band broadcast antennas are not a full
wavelength, and the aren't resonant at the transmit frequency.


Please say more about that. Thanks!


They all
use use L/C networks to make the tower work at the allocated frequency.

What, some kind of impedance matching?


Some ATU are as large as the AM transmitter when the tower is difficult
to configure.

ATU -- what's that?


Thanks!

David


PS: And if you feel like writing a bunch, give us all a tutorial!

David Combs wrote:

In article ,
The Daring Dufas wrote:
feller has to watch his figure, that's why I drink diet soft drinks. ^_^

TDD

Do you know how much SUGAR (or worse) is in a soft drink?

Likewise caffein.


Caffeine isn't all bad. It's a natural diuretic.

It sounds like you're on a parallel path to what I have in my
motorhome. It had 2 tired deep cycle batteries which I replaced and
added a third. If I remember right I have about 1kwh capacity to 50%.
I bought a 1000W true sine inverter on sale for $150. Now I have more
battery capacity for running the furnace heavily overnight when dry
camping in cold temperatures. And I don't have to use the generator
nearly so often. Even the inverter microwave is OK at half power.

When my two twelve volt batteries died, I got two mondo six volts and wired
them in series. They lasted a lot longer than the two twelves, and I would
suggest it to anyone who is at a stage of buying two new twelve volt
batteries for their MH or TT. I can't explain the math, but it does give
you more amp hours. Costs about the same. Sure made a big difference in
our coach on how long the batteries would last between charges, and
intensity of lights.

Steve

David Combs wrote:

In article ,
Michael A. Terrell wrote:

micky wrote:

On Fri, 09 Nov 2012 22:18:39 -0500, "Michael A. Terrell"
wrote:

...
I don't think so. And if that were the case, then a
radio transmitter broadcasting at 600 KHz would require an antenna
that was a third of a mile long.


No, it doesn't. AM BC band broadcast antennas are not a full
wavelength, and the aren't resonant at the transmit frequency.

Please say more about that. Thanks!


Early radio stated the wavelength in meters, rather than frequency so
it was rather obvious The wavelength at 600 KHz is 300,000,000/600,000
or 500 meters (1640 feet)


60 Hz is 5,000,000 meters for one cycle in free space. Roughly
16400000 feet, or 3106 miles. That means that you aren't going to have
much AC power radiated in a few feet of conductors. For instance, if
there is 20 feet of heating element, it is roughly 20/16,400,000 or
1.2195e-6 of a wavelength


http://www.csgnetwork.com/freqwavelengthcalc.html is one of many free
Javascript based wavelength calculators you can play with.


They all use use L/C networks to make the tower work at the
allocated frequency.

What, some kind of impedance matching?


Yes, and every installation is a custom design.


Some ATU are as large as the AM transmitter when the tower is
difficult to configure.

ATU -- what's that?


ATU= 'Antenna Tuning Unit'. In AM broadcast, it is a custom
impedance matching network designed to match the antenna to the
transmitter's output impedance of 50 Ohms. They have to handle the
transmitters full rated power, and be fairly tolerant of lightning
induced flash over conditions.


The old Voice Of America transmitter farm at Bethany Ohio had huge
underground vaults for the antenna switches, and remote tuned ATUs. Of
course, they could put out up to 500 KW at any frequency from 1.5 to 30
MHz into the directional array to target any point on earth. The WLW
site a few miles away could do 500 KW, but since it was designed for a
single frequency it was much smaller. Both of those sites date back to
the early days of radio, and the VOA site is now a golf course.

"David Combs" wrote in message
...
In article ,
Michael A. Terrell wrote:
micky wrote:
On Fri, 09 Nov 2012 22:18:39 -0500, "Michael A. Terrell"
wrote:

...
I don't think so. And if that were the case, then a
radio transmitter broadcasting at 600 KHz would require an antenna
that was a third of a mile long.

No, it doesn't. AM BC band broadcast antennas are not a full
wavelength, and the aren't resonant at the transmit frequency.

Please say more about that. Thanks!

AM radios use a ferrite cored coil antenna that picks up the magnetic
component of the RF wave, so they don't have to be sized to the
wavelength like FM and TV antennas.
http://www.radio-electronics.com/inf...od_antenna.php

I built an audio-band VLF radio receiver as a kid with a large folding
air-core coil antenna made from a scrapped TV yoke.
http://en.wikipedia.org/wiki/Dawn_ch...lectromagnetic)
I had to hike it far from the roads to reduce 60Hz hum from power
lines.

They all
use use L/C networks to make the tower work at the allocated
frequency.

What, some kind of impedance matching?

The antenna should look like a pure resistance that absorbs (and
radiates) the incoming signal completely. SWR or Standing Wave Ratio
is an indication of how far out it is.
http://en.wikipedia.org/wiki/Standing_wave_ratio

It's difficult to write a simple, intuitive but accurate explanation
of this stuff. Thus I practice. The principles of AC circuits do not
relate to everyday experience. I was surprised by how well the
mathematics of the "imaginary" square root of -1 describe inductive
and capacitive circuits.

Some ATU are as large as the AM transmitter when the tower is
difficult
to configure.

ATU -- what's that?
Thanks!
David
PS: And if you feel like writing a bunch, give us all a tutorial!

On Fri, 4 Jan 2013 21:21:32 -0700, "Steve B" wrote:


When my two twelve volt batteries died, I got two mondo six volts and wired
them in series. They lasted a lot longer than the two twelves, and I would
suggest it to anyone who

.... is dumb enough to take clueless advice.

is at a stage of buying two new twelve volt
batteries for their MH or TT. I can't explain the math

No ****?

, but it does give
you more amp hours. Costs about the same. Sure made a big difference in
our coach on how long the batteries would last between charges, and
intensity of lights.

Steve

LOL

"David Combs" wrote in message
...
In article ,
The Daring Dufas wrote:
feller has to watch his figure, that's why I drink diet soft drinks. ^_^

TDD

Do you know how much SUGAR (or worse) is in a soft drink?

Likewise caffein.


There is no sugar in most soft drinks. It is all that corn surp subistute.
A new study just out says that the high frutose (however you spell it) does
not cut off parts of the brain like the pure sugar does so you keep eating
and gitting fatter.

The artifical sweetner is even worse for what some of them can do to your
brain.

Idid not know all of this, but never drank many soft drinks. Mostly tea
sweetened with sugar.

In article ,
David Combs wrote:

No, it doesn't. AM BC band broadcast antennas are not a full
wavelength, and the aren't resonant at the transmit frequency.


Please say more about that. Thanks!


They all
use use L/C networks to make the tower work at the allocated frequency.

What, some kind of impedance matching?

Yup. It's an impedance match / transformation arrangement, which
matches the impedance of the antenna (often far off resonance in these
cases) to the impedance of the transmission line.

Although the antenna by itself is not resonant, the antenna + matching
circuit is.

Some ATU are as large as the AM transmitter when the tower is difficult
to configure.

ATU -- what's that?

Antenna Tuning Unit. A big impedance L/C impedance matcher.

PS: And if you feel like writing a bunch, give us all a tutorial!

If you're really interested in this topic, may I suggest looking
through Laport's classic text from the 1950s, "Radio Antenna
Engineering"? Lots of information, and some very nice photos of long-
and medium-wave antenna setups (military and commercial).

Although original copies are few and far between (and rather
expensive) these days, the book's copyright expired a few years ago
and it reverted to the public domain. I scanned it, and you can
download a copy at no charge.

http://snulbug.mtview.ca.us/books/Ra...naEngineering/
http://www.lulu.com/shop/edmund-lapo...-17560294.html

If you decide you want a printed copy,

http://www.lulu.com/shop/edmund-lapo...ct-188778.html

Lulu sells it for the cost of printing and shipping... I set the
"author's commission" to zero, so they don't charge a royalty or take
a percentage of it.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Sat, 05 Jan 2013 07:31:24 -0800, whoyakidding's ghost
wrote:

On Fri, 4 Jan 2013 21:21:32 -0700, "Steve B" wrote:


When my two twelve volt batteries died, I got two mondo six volts and wired
them in series. They lasted a lot longer than the two twelves, and I would
suggest it to anyone who

... is dumb enough to take clueless advice.

is at a stage of buying two new twelve volt
batteries for their MH or TT. I can't explain the math

No ****?

, but it does give
you more amp hours. Costs about the same. Sure made a big difference in
our coach on how long the batteries would last between charges, and
intensity of lights.

Steve

LOL
Just so happens he is right - even if not for the right reasons. MUCH
better to increase voltage by connecting in series that to increase
amps by connecting in parallel. A "battery" by definition, is a
series of cells connected in series. Parallel connection of cells is
much more likely to run into problems down the line.

"Dave Platt" wrote in message
...
...
.I scanned it, and you can
download a copy at no charge.


Done, in an hour and a half on dialup, and thank you VERY much!
jsw

On Sat, 05 Jan 2013 13:46:52 -0500, wrote:

On Sat, 05 Jan 2013 07:31:24 -0800, whoyakidding's ghost
wrote:

On Fri, 4 Jan 2013 21:21:32 -0700, "Steve B" wrote:


When my two twelve volt batteries died, I got two mondo six volts and wired
them in series. They lasted a lot longer than the two twelves, and I would
suggest it to anyone who

... is dumb enough to take clueless advice.

is at a stage of buying two new twelve volt
batteries for their MH or TT. I can't explain the math

No ****?

, but it does give
you more amp hours. Costs about the same. Sure made a big difference in
our coach on how long the batteries would last between charges, and
intensity of lights.

Steve

LOL

Just so happens he is right

I'm right, period.

SteveB is a blatant racist. Racism is rooted in ignorance, and that
ignorance manifests in many ways such as giving advice on subjects he
doesn't have a clue about.

Apparently you're the type who tolerates racists and thinks that being
kind to them makes sense and that ridiculing them is mean. But if you
want to help him then for ****s sake at least correct the dumbest part
of his misconceptions.

MUCH
better to increase voltage by connecting in series that to increase
amps by connecting in parallel. A "battery" by definition, is a
series of cells connected in series.

The simple story here is that in the motorhome case he's talking
about, and considering equally priced series or parallel arrangements,
the battery _capacity will be the same_ which is something you failed
to note.

Parallel connection of cells is
much more likely to run into problems down the line.

In FACT it's highly UNlikely that two batteries in parallel will "run
into problems down the line" if properly maintained, as proven by
thousands of successful dual battery installations.

No matter series or parallel or anything else, motorhome battery
problems are most likely to be caused by inexperienced owners who tend
to run the bank down too low and fail to regularly charge it fully.
The last part largely because they don't even know the definition of
fully charged, or how to tell when it's been attained.

In my own motorhome I did 12V in parallel because I could get the best
deal on that from Costco, and because I wanted to expand the string to
all there was room for, which was 3 units.