Recent content by linear_shift

cabraham, That makes sense now, the two values Ic and ic (or Ib and ib) are separate. Ic (DC) determines the AC resistance, so the AC circuit is different (adding r_pi), than the DC circuit determining r_pi which does not see r_pi (so we don't have the "looping" r_pi calculation). Wikipedia...

Hi, In a common emitter amplifier circuit, I am considering the base-emitter junction. When you apply a base current, you get the base-emitter resistance, according to thermal_voltage/base_current. But when you get that resistance and place it in it's position in series with the emitter...

pbandjay, Thanks, that's exactly what I needed. :) I feel dumb now, it was so simple (I'm still a bit fresh on differential equations). XP I know what to do for all the QM wave equations (as well as any other wave equation) now. \o/ linear

Cyosis, I never said I was going to copy anyone, I only mean that I'm going to use the ideas in the steps being taken to solve other problems. _That_ is how I learn, not by copying.

Hi, could someone show me the steps to solve the equation d^2y/dx^2 = -ky for the solution A*exp(i*sqrt(k)*x) + B*exp(-i*sqrt(k)*x) ? I am trying to solve the time independent Schrödinger equation for a free particle, and the above question is of the same form. Wikipedia says it...

What are the equations for a phased antenna array due to: 1. Individual element gain and the number of elements 2. Aperture of the array I have been googling these for god knows how long and can't find the slightest hint, except the site Microwaves 101 (http://www.microwaves101.com/)...

I really couldn't find any technical data on the reason for disabling the AGC but is apparently generally accepted that you shouldn't use the AGC for *any* radio astronomy (link here). Also, a *yagi* for the HF band? That thing would be huge, even for the shorter HF wavelengths! I don't know of...

According to other astronomers, the AGC tries to hold the audio level constant, which is a no no in radio astronomy. Correct me if I am wrong, again, I don't know a whole lot about radio. The antenna... Well there I was planning to use what has been coined as the "phased dipole." In essence I...

I am looking at a cheap $100 shortwave radio, the Kaito KA-2100 (google it, there are a bunch of links, too many to mention), and I would like to know if disabling the AGC (automatic gain control), is possible for use as a radio telescope. Now I don't know that much about radio and electronics...

Okay, so thinner varnish, check. Thanks guys. Sorry about the weird sentence/logic construction, seems to happen everytime I post to new forums (happened on Slashdot when I posted there the first time), don't know why exactly... :$

Oh and btw, this may sound like a stupid question but does making a solenoid require *unvarnished* wire as opposed to *varnished* wire (help help the noob :P )?

Ok, cool. Not the railgun though, I'm looking more at the Gauss gun. This I could make myself. This does not have to induce much mass, however (very little it fact). Hint: its not even a gun per se, or a weapon of any sort (intentionally anyway), I'm not into that. And no its not a particle...

Okay, I guess I worded it wrong, I'm kind of reaching with a "toroid." What are you guys describing a toroidal electromagnet as? I'm thinking of it as a doughnut wound around the side with wire. Were you thinking wound on the inside or something? Now that I think about it that is ridiculous as...

Well, I am looking to make a "projectile launcher" (not really, just don't want to break the secret, I'll tell in time). Fyi, it does have poles, just not N-S up-and-down, like a bar (instead just one side of toroid to the other). Think back to the old kiddo magnet kits, I just need an...

Okay, I have been looking the web over for some toroidal (doughnut) electromagnets for a project I am working on. Any ideas on where to get some? I need about 8 to run off of 110 VAC (10A) or 12 VDC (220A). Inductive force is not important. Inner OD should be about 3 inches or so. Danke (no...