Rewards (??!!?) of Minimizing Eddy Current Losses

[David Schwab]

I saw that and that was puzzling (since that post does appear to come from a human). Maybe the first one (with addition of the female face pic) is "real" to "get past the defences"? And also, I don't understand where the payoff is (there is usually a spam link somewhere in the sig or profile)--unless early post links have been disabled or something. The bot replies seem to be typically written with a vagueness where well-meaning responders reply or seem to end up thinking of the oddliness as "innocent newbie confusion" and don't notice the spam links (which survive in the posts and/or sig/profile, etc.).

I don't think it's a spammer. As you said, there was no spamming going on. Also her join date was October, so if it was a spammer we would know by now.

She's certainly welcome to come back and say hello. We are making accusations based on nothing just because it's a female. I don't think we would have done that without the photo.

[dai h.]

for me, I don't it looks odd *just because* the poster is "female" (there isn't anything wrong with a female being interested in PUs, musical instrument related activities, engineering, astronaut(-ing--I know, no such word), etc.), but more a combination of things and previous (apparent) spambot characteristics. And someone else (who appears to be an actual different person) seems to be using the same moniker (on facebook or twitter or whereever I saw), so makes me wonder if fake signup monikers are being automatically harvested or something.

[Chuck H]

for me, I don't it looks odd *just because* the poster is "female"

No. There's nothing wrong with a girl guitar player being interested in the inner working of their gear. But it IS absolutely unusual. I went ahead and replied on her/his/it's thread, but I wouldn't go PMing if you know what I mean. I'm still a bit skeptical.

so makes me wonder if fake signup monikers are being automatically harvested or something.

+1
Could be all that is needed is for a couple of members to get too directly involved and some viral wormy trojan opens the belly of the big horse and creeps out.

[Joe Gwinn]

You will notice that her pupils line up with the corners of her mouth, so I don't think they were enlarged. Makeup will do wonders for the size of the eyes.

(I come from a family of artists so you learn this stuff at some point)

Despite the makeup, it looked odd to me, which started me thinking. I have to assume that most artists know the proportions, and so can make something look right if they choose to.

I have seen lots of advertising photos where the pupils have been enlarged to make the model look more alluring (more interested in the viewer, to be precise), and the doe-eyed look is basically that the eyes are larger (like with babies). Japanese Manga comics take this to extreme.

But the filename of the picture may provide a clue: "avatar31773_1.gif".

[Chuck H]

Funny to me is how she/he/it seems to have joined all kinds of discussion groups lately. Trucks, music electronics, cruise line chat and another I can't remember now. See below... Apparently she's married. ?!?

Carnival Cruise Lines - Live TV Onboard? - Cruise Critic Message Boards

[FunkyKikuchiyo]

She's certainly welcome to come back and say hello. We are making accusations based on nothing just because it's a female. I don't think we would have done that without the photo.

Dude, I've worked in a few music stores. Nothing freaks out the guys there more than a girl walking through the door.

It is unusual and very rare. Girls stay away from gear heads like crazy. The musicians out there who are women let their male friends do the shopping for them. Women are better at focusing on just the music, and gear nuts tend to irritate their shopping habits. I eventually learned a sales style that worked across the board, but it took me some time.

Don't believe that we're a bunch of dorks, you say? Well, David DID post a technical drawing proving the placement of her eyes was valid (no offense David).....

[Chuck H]

Don't believe that we're a bunch of dorks, you say? Well, David DID post a technical drawing proving the placement of her eyes was valid (no offense David).....

LOL

Milk came out of my nose!!!

I wasn't even drinking milk?!?

[dai h.]

Funny to me is how she/he/it seems to have joined all kinds of discussion groups lately. Trucks, music electronics, cruise line chat and another I can't remember now. See below... Apparently she's married. ?!?

Carnival Cruise Lines - Live TV Onboard? - Cruise Critic Message Boards

lol... SHE has a wife (!?).

(hmm... the same text/query shows up elsewhere:

Carnival Cruise Lines – Live TV Onboard? | Deluxe Cruise Vacation

Carnival Cruise Lines - Live TV Onboard? -VOS Poeme Answers.

some sort of scheme to obtain (real and varied) responses to make the first one appear more genuine to search engine software? )

[David Schwab]

But the filename of the picture may provide a clue: "avatar31773_1.gif".

They are all named like that. Mine is "avatar11_1.gif"

[David Schwab]

lol... SHE has a wife (!?).

She might... that's not uncommon these days, or it could be the husband writing that.

However, I notice if you do a search for "Jessica1988", you come upon several different profiles, like these:

http://www.supernova.com/Jessica1988

http://www.pof.com/member21680751.htm

http://twitter.com/jessica1988

http://www.interpals.net/Jessica1988

http://weight-loss.fitness.com/u/21622/jessica1988

http://www.kongregate.com/accounts/Jessica1988

And so on.

But here's ours:

http://forums.babypips.com/members/jessica1988.html

[FunkyKikuchiyo]

I just did a quick search out of curiosity - over a dozen message forums without having to dig very deep, all using the same engine, all joined during October or November, and all with short strange messages. Also, she likes mastiffs and is a body builder.

In one she cites an age that wouldn't correspond with 1988 being a birth year.

Found some where she is banned.

This one is almost exactly the same as the amp shopping thread: What do you think about my budget for a b5 vw passat?

Not spam per se, but definitely weird.

Or, are we the weird ones?

In any case, this was a great thread before the distraction...

[David Schwab]

This one is almost exactly the same as the amp shopping thread: What do you think about my budget for a b5 vw passat?

If you search for images under her user name, you see lots of Passat forum pictures, but I didn't find any with her name. Odd.

I still don't think it's out of the ordinary. If you were to search for a screen name I have been using since about 1996, you will find many many posts. lol

Well back to the thread.

[dai h.]

oops...sorry for bumping the thread off course...

back to regularly scheduled programming

[Joe Gwinn]

They are all named like that. Mine is "avatar11_1.gif"

Yes. I noticed that later.

[Mike Sulzer]

Hi Bob,

The losses due to eddy currents go in parallel, not series. So you can think of it as kind of like loading the circuit down with a smaller value volume pot. It lowers the height of the peak and broadens it.

It is really more complicated than that, though. It is not a pure resistive load because this resistance has an inductor in series with it. And it is not a simple resistor, either, since its value is increasing with something like the square root of frequency.

There is a complicated effect on the frequency response. Steel core pickups, such as humbuckers, generally show a dip in the frequency response in the middle. That takes a fairly low value of resistance, that is, a big loss due to eddy currents. The impedance in parallel due to the eddy currents rises with frequency, but it still has a significant effect at the peak; no surprise since the impedance of the pickup maximizes there, and so it is not so hard to load it down.

This complicated frequency response should have a characteristic sound. By this, I do not just mean a change in the Q because there would still be some differences even if you adjust the Q to be the same (in an eddy current free pickup) by loading it with a resistor.

Folks -

So, I made 2 versions of these sidewinders I've been working on, quite similar except that one used a laminated core and one a solid core. Measured inductances and ac resistances (with the Extech) were quite similar at 120hz, divergent (as expected) at 1k.

The irony is that the laminated core device is SO sensitive to cable capacitance! The solid core displays a much more gentle effect in these tests.

It doesn't seem to be just that "there's more up there to hear." I suppose these eddy current effects appear as resistance in series with the reactive elements, and this laminated thing just has a higher Q. (Is this true?)

Anyway, it's so extreme that I'm actually hesitant about sending these laminated things out into the world, and I'm not fond of onboard buffers...

Bob Palmieri