Recent content by chemic_23

i've read that it's already balanced, but in some cases, a balun is needed. how do you exactly make a balun?

i was thinking of that too, but i couldn't find a 50 to 75 ohm matching transformer in our place hehe :D i designed it using the moxon calculator :D it is okay to use a 50 ohm coaxial cable for tv?

hello, good afternoon. I'm a little bit confused about the use of matching transformer. I made a 50 ohm tv antenna, and i connected it to a 50 ohm coaxial line. However, I've found out that for tv applications, 75 ohm coax should be used. my question is, if i will replace my 50 ohm coax, can i...

i've seen this transform: v(t)*e^(j*(wo)*t)<--->V(f-fo) and letting u(t)=v(t) where u(t)<--->1/(2*pi*f) +δ(f)/2 so, exp(-i*wo*t)*u(t)=1/(2*pi*(f+fo)) +δ(f+fo)/2is this correct?

Homework Statement find the Fourier transform of complex exponential multiplied to a unit step. given: v(t)=exp(-i*wo*t)*u(t) Homework Equations ∫(v(t)*exp(-i*w*t) dt) from -∞ to +∞ The Attempt at a Solution ∫([v(t)]*exp(-i*w*t) dt) from -∞ to +∞...

i've found out that its permeability is 2000.. thanks :)

so, in order to have 30mH, i need to make 613 turns? :eek:

Homework Statement hi, i just have few questions on how to make a 30mH-inductor (solenoid). I have an enameled copper wire which i will wrapped into a 7-inch rebar having 12mm diameter. In order to determine the number of turns, i made some calculations:Homework Equations L=(uAN^2)/dThe Attempt...

o, i see, sorry I've overlooked that.. thanks.. um, btw, can i use KN2222 transistor instead of 2N2222? are they the same?

hello good day, would someone kindly help me determine the part number of these 4 npn transistors here? pls help, cause my prof didn't discuss this yet.. and i don't have idea on how to calculate for the values of the transistor to determine tha part number suitable for the circuit... many...

um, I'm having a hard time understanding some terms and equations in semiconductors, particulary 2 equations and 1 term(fermi function,density of state function, and fermi level). My understanding of fermi function is somewhat the probability of an energy state to be occupied by an electron. for...

my attempt is (this is c programming) My output is really different. It gives the answer but not a detailed solution as the output above. Pls help me I really don't know how to show the long method :frown:

thank you very much :)

Homework Statement Find the taylor series of f(x)=1/(x)^(1/2) ; a=9 2. The attempt at a solution f(x) = (x)^(-1/2) f'(x) = -(1/2)*x^(-3/2) f''(x) = (1/2)*(3/2)*x^(-5/2) f'''(x) = -(1/2)*(3/2)*(5/2)*x^(-7/2) f''''(x) = (1/2)*(3/2)*(5/2)*(7/2)*x^(-11/2) f(9) =...

awww sorry hehe mistyped. it's tan45 hehe:rolleyes: i came up with this solution x=10+2t y=6+4t tan45=(6+4t)/(10+2t) (deg mode) 1=(6+4t)/(10+2t) 10+2t=6+4t t=2 substituting in (secθ)^2)(dθ/dt)=[x(dy/dt)-y(dx/dt)]/x^2 i got ((cos45)^2)/7 per sec or 1/14 per sec is this...