[ucodegen]

[quote=spdrun]They were (AFAIK) high enough to only be reachable by non-man-portable long-range SAMs. i.e. truck-mounted or fixed SAM sites. The most recent transport shot down was above 20,000 ft when hit.

Flying through airspace where SAMs capable of reaching to your cruising altitude are in active use doesn’t strike me as a terribly bright idea. But hey, if you want to try it, it’s your life :)[/quote]Can’t get into classified info here.. but the transports were shot down by shoulder mount/manpacks. They were also turbo-props. That means they weren’t above 20,000 ft. AN-26 will do 24,000 – unloaded(maxed out). Shoulder launch have a max altitude of ummm.. lets say peaking at about 12,000 feet vertical (note that this is vertical which is different than circular range). They have to be in range to get an IR lock (photosensor, which means visible range of emitter). Commercials cruise at 35,000 feet.

The system that shot the commercial AC down is not a cheap nor simple system. It is part of a Theater Air Defense System, which means — how they hell did the rebels get a hold of one of those. I suspect this is the first use of one of these by the rebels. All of the other shoot-downs were by shoulder mounts. I suspect the person was trigger happy and didn’t think about the altitude the aircraft was flying at (got to learn to characterize your aircraft before killing it – definitely don’t want to light up something holding a HARM). This system can be built up with multiple radars and launchers to be ‘interlinked’ to extend its range. — I do wonder it is using the launch control software I have come across.

ref including info on other Ukraine shoot-downs:
http://www.businessinsider.com/ukraine-separatists-have-shot-down-multiple-aircraft-over-the-past-month-2014-7

[ucodegen]

[quote=spdrun]I wasn’t speaking to dissimilar metal corrosion, only to corrosion due to the pipes being used as ground. It shouldn’t be significant since current flowing through ground is normally zero (and A.C., not D.C. if there is one).[/quote]Under normal conditions that is true. Interesting factoid is that under strain/earthquake conditions.. quartz can generate significant voltages.

BTW, My response with respect to galvanic action was due to this statement:
[quote=spdrun]

I think that when the pipes became copper, things change. You can cause current based copper erosion from galvanic action.

Practically, it should be a non-issue since ground shouldn’t have (significant) current flowing through it under normal operating conditions. Yeah, I know some timers and things like that can use it as a return path, but it’s rare.[/quote]
It is an issue because copper vs. cast-iron or steel forms a battery. Most mains are cast iron or galvanized steel. Newer houses are copper. Newer water main replacement pieces may be PVC(green). Wet or damp soil forms free ions from different types of ‘salts’ (Salts can be things like copper-chloride, not just sodium-chloride). These ions complete the circuit for the ‘dissimilar metal’ battery. Because the dissimilar metals form a battery, they also form the needed current (Current is actually the result of their corrosion). They just need an ion path for the return current. Water that is not pure/distilled water can also complete an electrical circuit. Purity in water can be measured in some extent, but the water’s willingness to carry electricity. If it will not carry electricity, it is pure – ion free. There is also research and experimentation on ships in salt water using voltage generators to oppose the current produced by corroding steel, and thereby stop shipboard corrosion.

[quote=spdrun]
OTOH, using piping as neutral return would probably yield amusing results.[/quote]
If you saw the posts between myself and Blogstar, piping was once used as neutral/ground on old AC systems(Alternating Current that is, not Air Conditioning). Don’t really need a return for AC, just a large capacitance sink. These old systems were all galvanized steel/cast iron, no copper. They used the mains as part of the ground-plane.

[quote=spdrun]BTW – I’ve seen the videos of people being hooked up to work on H.T. lines from a helicopter — that takes some serious cojones! Thanks for mentioning that again. And you’re basically right about everything electrical you’ve posted here — are you an EE?[/quote]Yep. EECE/UCSD/Revelle oldtimer. I put myself through college building houses.

[ucodegen]

[quote=spdrun]

I think that when the pipes became copper, things change. You can cause current based copper erosion from galvanic action.

Practically, it should be a non-issue since ground shouldn’t have (significant) current flowing through it under normal operating conditions. Yeah, I know some timers and things like that can use it as a return path, but it’s rare.[/quote]It is actually quite significant. I know of more than one house where the copper plumbing had to be redone because of the interaction between galvanized steel and copper. It acts like a battery. Direct connection between the two can help create a closed path/short. The two metals adjacent to each other act like aluminum vs silver in an acid. Normally zinc acts as sacrificial in such a reaction, but the zinc is just a ‘coating’, which erodes quickly. With normal galvanized pipe, the zinc starts reacting to protect the steel. It will swell and close scratches. The problem is that there is a second path through the copper. This is why ‘mixing’ pipe types can have unexpected results. Generally when doing copper to galvanized connections, you want an insulator pipe segment in between. It is even in California plumbing code.
http://homeguides.sfgate.com/connect-copper-galvanized-plumbing-20916.html

Remember, you are dealing with the galvanic action occurring over years.. not minutes, and that soil is used to create ‘neutral’ and ‘ground’ for AC supply.

[ucodegen]

[quote=Blogstar]
I never had to do anything too complicated, one , or later on, two standard ground rods with wire sized to the service , it was legal to bend a piece of rebar up through the foundation and into the wall cavity with an inspection hole. Also a shallow trench with bare copper wire I think 20 feet of wire buried only 18 or 24 inches nothing crazy. Nobody I know did it that last way though. Good with rock below I guess.[/quote]
The amount of rod sunk or buried wire also depended upon service size. I heard of the shallow trench, but at 20 feet, it may be the old 60amp service or smaller. I think complication comes in with odd soils (dry, non-conductive). I think the other reason why shallow 20foot trench is avoided, is that it can create a differential voltage at the soil surface. I have also heard of a long rock drill being used to go into rock, cementing the rod into the rock. I think there were also restrictions on the type of rock (quartz is a good insulator).

[ucodegen]

[quote=spdrun]ucodegen —
As to double insulation, you’re talking about a device with a plastic case and with insulated connections inside. Coming in contact with a hot is extremely unlikely, so a ground isn’t needed.[/quote]Thats part of it, but remember my note about the ‘ground’ wire’s use for removing static electricity. The insulated chassis prevents movement of static electricity towards the user.

[quote=spdrun]Why do you get a shock when coming in contact with a 120V hot whilst wearing rubber shoes? The amount of current required to shock is very small, and no insulator is 100% perfect. Capacitative effects might also play a role. But I suspect it’s more the former than the latter.[/quote]Capacitive/Inductive relations play the entire role with AC. That is why there is NO return wire on high tension lines. The driven ground rods act as an immense capacitive sink. The amount of current resulting from the human to 120V hot line is not small. It is easily enough to stop the heart and can cause skin burns. Humans are a larger capacitance sink than a bird (over 100lbs vs just ounces). Take a look at videos of people servicing high voltage lines by helicopter. That arc that is generated is not a low voltage, low current arc. To keep safe, the people doing the service are in silver mesh suits (Gaussian shield) that are very conductive.

[ucodegen]

[quote=Blogstar]With some older houses, grounding to a water pipe was code. after pvc repairs became common that changed. Now the ground rod is used and the water pipes are grounded to that , cold near the house main and the hot water pipe is bonded to cold at the water heater. Thats with copper pipe , with plastic different story.[/quote]That must be really old code. It is probably during the time when everything was galvanized and the watermain was cast iron.. metal connecting everything. I think that when the pipes became copper, things change. You can cause current based copper erosion from galvanic action.

[quote=Blogstar]I believe now, that two ground rods sunk or buried 5′-6′ apart , connected to a continuous solid wire, or a stranded wire in conduit, are required for service mains. Some jurisdictions allow one rod with special testing.[/quote]One house I built, it was 15 feet deep (about 1976). The 5 feet apart sounds familiar. It depends upon how much soil moisture exists. A company I worked in had a hole in the foundation where the grounding rods were driven, more than 5 of them, oriented outwards from center. The hole was to allow inspection of the electrical connections.

[ucodegen]

[quote=spdrun]
As far as grounding, the power company equipment doesn’t care whether it’s putting 10A through a load or an additional 50mA through a human body. The grounding is there so the latter situation is less likely to arise. If a hot wire shorts to the case, breaker will trip vs making the case hot. If breaker doesn’t trip, the case will still be grounded. GFCI makes the latter situation EVEN less likely to arise.[/quote]
Explain double insulation… ie. products without the third wire; like todays drills etc.

[quote=spdrun]H->LOAD->N->human->ground — the neutral/grounded side would be connected to hot through the load, but not tied to ground (0V). Since the load generally has a lower impedance than the human body, you’d have close to 120V across any grounded human that is unfortunate enough to touch the casing.[/quote]
Please explain why you receive a shock when you just touch the hot wire on a single phase 120v supply, even if you are wearing rubber soled shoes and are not connected to any ground or neutral? Do you know what the internal resistance of the human body is? Did you measure with needles or on dry skin? The human body is highly conductive, the skin isn’t.

[quote=spdrun]Separating neutral and ground at the main breaker box is done for LIFE SAFETY, not for the power company’s safety.[/quote]Not completely accurate. The neutral and ground are REDUNDANT paths. Neutral is the return path(of sorts) and ground is the safety path. Take a look at power lines (high voltage transmission lines). Identify the ‘neutral’ or ‘ground’ wire. You will find that there are none. So where is the ground wire? On a two or three phase supply, it is effectively the ‘center-tap’ and it is also tied to a copper rod driven into the ground (up to 25 feet sometimes). When setting up a house, it is important to ‘balance’ current draw or load between the two phases on a house supply, else you will have a ‘noisy’ or poor ground. If you have a chance to see the wires coming in through the meter, you will see two ‘bus’ bars. These are not supply and ground. They are BOTH hot. They differ by phase (they are 180 degrees out of phase). This is how it is possible to get the 240 volts for electric ranges, ovens and dryers. The power is taken by going across the phases instead of to ‘neutral’. Home breakers are ALWAYS placed on the ‘hot’ side. That is because almost full power can be sunk straight to ground (partially explained by the answer to one of my questions above).

If you have one of the older houses supplied by power from wires mounted above ground, you will generally see 2 black wires wrapped around a silver bare wire. The black wires are the two 120v phases, the silver wire is the ground or neutral ‘tie’ that will join the ground/neutral of the house to the neutral that is sunk with the transformer. You will generally see two wires tied to insulators on top, not 3 (because there is no ‘return’ neutral wire back to the power plant). When a house power service is installed, a copper rod is sunk (driven) into the ground near the breaker box. On old houses, you could find often find it. With newer houses, it is harder to find – but it is there just the same. The neutral and ground that you have in the house are tied to the same point near the breaker box. The required wire gauges are different though. In general, ‘ground’ is intended to divert ‘static’ electricity generated by rapidly moving insulators, air moving across isolated conductors, or similar static sources (triboelectric effect).

GFCIs work by comparing the current between the ‘hot’ wire and neutral (they don’t look at ground wires). The currents have to be the same. If they aren’t, then current is ‘leaking’ from the correct path and a GFCI will trip. GFCIs don’t care about the total current going through them.

Standard breakers sit ONLY on the hot wire, and measure current coming from the mains and going to… wherever it is going. They don’t care where the current is being sunk. They care only about the total current and are there to protect the wiring (sized to the gauge of the wire being used on that circuit).

NOTE: GFCIs and Breakers DON’T have the same function.

[ucodegen]

[quote=scaredyclassic]Ah forget It. Maybe I suck.[/quote]
Looks like the medication just kicked in..☺

[ucodegen]

But after the first few weeks, Stretton allegedly retreated to her room, saying she suffered from chronic obstructive pulmonary disease, and refused to perform her duties while remaining in the home.

How many weeks? If I am not mistaken, it take either 30 or 60 days to establish ‘residency’ status in the eyes of the law. She could have been summarily thrown out until she hit the residency establishment limit.

[ucodegen]

I would be careful of Samsung, Casio, and to some extent Fujifilm. The sensors tend to generate washed out photos. What resolution are you going to be ‘presenting’ the photos at, or printing at (pixel x pixel or inch by inch for print). What the needed quality of the final product will determine what you want to look at.

Many of the point and shoots do not have a flash that will ‘throw’ very far. You can augment that by using a remote flash set for flash trigger (triggers when it sees the camera’s flash go off). Most of the point an shoots will also have poor low light response – even though they may claim low light(images start to get grainy in low light).

Good names to look for are Canon, Sony, Nikon.

I have a Nikon Coolpix S9500. It works pretty well, though focusing in low light can be a problem. It also has a pretty good zoom (550mm equiv) and has a 24mm equiv wide. It does overcompress some images, particularly those with a lot of detail… but I am also known as a pixel peeper(picky and look down to pixels to eval shot). Sony also makes a similar model that I think may actually be better. The Coolpix S9500 is no longer made, and seems to be replaced by a Nikon Coolpix S9700 (from my recollection).

To look for camera evals – you can look at http://www.dpreview.com

[ucodegen]

[quote=SK in CV]
Beats owns a subscription streaming business similar to spotify.[/quote]Still not enough to justify $3bil. iTunes has a streaming service too – iTunes radio. That’s why I’m still scratching my head on this one.

[ucodegen]

[quote=spdrun]

The other real problem with your position is that to have an effective military, they must follow orders.

Short of an actual severe national emergency like WW II, do we actually want an effective military?[/quote]I think yes. But I think we also need to make sure we hold those we elect to high standards and be open on our discussions of international politics, whether or not force is required, what are the real consequences down the line should we avoid getting involved etc. Too much has been done by stupid sound bites these days. It is easier to make an inflammatory statement than to build a reasoned position and argument.

I don’t think the military is the answer to all situations, but it the military force should be significant enough to give pause to the Kim Jung Il and other puffed up suited dictators – even with all of their self delusions. Too many countries seem to see that military force should be the first not last approach.

[ucodegen]

[quote=joec]Isn’t military service or defending the US a requirement of being a US citizen?[/quote] Its a bit more nuanced than that.

[quote=joec]The problem with a lot of these foreign military campaigns is that people see it as serving certain special interests or political parties (oil, etc).[/quote]Some of that blame can be laid on our own Main-Stream-Media. Some of that can be laid on poor focus. Some of that can be laid on jingoism that the BushII initiated action used. “Shock and Awe – how corny. They ended up burning a resource that would have identified all of Saddam Hussein’s closest, underground supporters were. I could go on with how that was all F**Ked up..

[quote=joec]Looking at Iraq now and what’s going on, I wonder if the US is going to start taking a back seat to a lot of these foreign campaigns since no one wants to see US boots on the ground. Without troops on the ground, you can’t really hold or maintain territory, or really build allies for intelligence/etc…[/quote]I think they are going to take the approach of ‘remote’ or a ‘button press’ war.

[quote=joec]Longer term, for the terrorists, it looks like they will slowly gather strength since no International power looks to have the will to do anything to send troops in a foreign hostile country. I wonder if this is just the start of a cold/contain war where terrorists start slowly building up strength…and is normal for a while.[/quote]Could be. Looks ok to the politicians, but eventually you will have to deal with the increased internal pressure. I think the best approach if this continues is to bring a strike team in with oil well professionals and deep-plug all the wells that we fixed when over there. Use Carbide and Epoxy mix so that it will tear up drill-heads. Then just walk away. Let them fight over that stupid piece of sand. They have not comp’d us for fixing the wells that Saddam destroyed, new military equipment that they are just abandoning and running away from etc.

[quote=joec]I heard Iraq lost near 1.3 billion in military equipment that the ISIS group has now including hundreds of tanks, a couple helicopters, thousands of rounds of ammunition.[/quote]Something like that. They elected a totally incompetant Shiite, (wanted to drop that extra i) who filled their military command with nepotistic drones who don’t know how to even fight a simple skirmish. The ISIS groups tactics are very simple and they are taking a simple path. A little guerrilla tactics along the road they are using will bring them to a screeching halt.. but now it may even be a little to late for that. It looks like current Iraq military command is planning to fight them IN Baghdad. Dumb. They need to push the battle towards the insurgents and get it away from the populace that can be harmed.

[ucodegen]

[quote=scaredyclassic]

the military is just following orders, in other words, so everyone is off the hook?[/quote]
I wouldn’t expect a strawman argument from you.. how do you get from Military to everyone off the hook? Classic strawman. Does not follow. For the military to do its job, it has to follow orders. You can’t have anarchy in command when in the middle of a military operation. I clearly stated; take a look at who we choose as Commander in Chief and Congress. If we don’t like how they are acting, take a long hard look at who we elect. The finger points back to us!!! We can’t blame anyone else, whether you would like to or not!

More strawmans:

is there any point where we say, siniing up for tthe US military is like signing up for an illegal whaling expedition?

is there any point where a guy signing up for this is not signing up honorably to serve his country, but is signing up knowing we are doing bad crap?

NOTE: Being in the miliary means you are going to have to do bad, nasty crap. War and miliary operations ARE nasty. The whole purpose is to avoid war and not make it ‘sanitary’. Military options should always be considered the last recourse, not the first. If it is sanitary, easily done by pushing buttons thousands of miles away, those commanding the operations will cease to regard the real consequences of that button press.

[quote=scaredyclassic]
putting your life on the line is irrelevant.
[/quote] That statement is true if you have never had to put your life on the line, never see your family again, relatives again.. have no children etc. A very immature and juvenile statement.

[quote=scaredyclassic]
if you volunteer for a corrupt private rorganization, even if it’s risky and you could die in the work, say an illegal whaling ship expedition, we don’t say, wow, taking risks, putting your life on the line, catching whales, making money……we say, why are you volunteering for a whaling experdition in vioaltion of international law? why are you involved in this mess. what in the hell was going through your mind when you volunteered for an obviously evil venture?[/quote]Man are you going for strawman arguments; they just keep coming. First and foremost: THE MILITARY DID NOT GENERATE THEIR OWN ORDERS!!! It came from the Commander in Chief. So that leaves the uncomfortable question: “Who put the Commander in Chief in charge or in his/her current position?” What would have happened if all of those people who put him in charge, stood up with one voice and said “STOP”?

[quote=scaredyclassic]is there any point where we say, siniing up for tthe US military is like signing up for an illegal whaling expedition?

is there any point where a guy signing up for this is not signing up honorably to serve his country, but is signing up knowing we are doing bad crap?[/quote]
So what happens when we actually need the military? How do you get 2 to 10 years of experience built up? You can’t do that on a moments notice.

[quote=scaredyclassic]
is it ever OK for a regular citizen to say to say, NO, not in my name, no thank you, do not serve me, i do not want your service, in this way. I would prefer you NOT serve me whale meat, or back the military. youdo not have to follow these orders if you do not VOLUNTEER in the first place…

. I would prefer you not Volunteer to put your lfie on the line for a corrupt military industrial world whaling death expedition. iw ould prefer you fight for a better country here…[/quote]You really need to avoid strawman arguments. It corrupts what ever valid points you may have by taking ridiculously extreme positions to try to demonstrate your point. The real problem here is that the Military/Commander In Chief/Congress have to be responsible to more that just your sole opinion. The other real problem with your position is that to have an effective military, they must follow orders. Arguing over command on the battlefield invites only one thing.. your own death.

[ucodegen]

[quote=SK in CV]
I think they bought it for the streaming. Product is no better than upper end crap.[/quote]

Streaming what? There is a lot of prior art on streaming audio.. so no moat there. The only thing I can think of is the association of ‘Dr Dre’ with ‘Beats Audio’, as well as the ‘cool’ business name ‘Beats’..

[Author]

Posts