Home |
Search |
Today's Posts |
#11
![]() |
|||
|
|||
![]()
The most simple example of a constant-resistance network is a capacitor
in series with a resistor, both in parallel with an inductor in series with a resistor. When all 4 components have the same value in ohms (R) then the input resistance is a constant resistance R from DC to infinity. ---- Reg, G4FGQ Since the reactive components change reactance with frequency, Reg's network may be a little hard to realize in practice. Try making the inductance equal to R^2*C Reg. You might have better luck. You also might want to review Everitt's take on this subject, starting on page 284 of the second edition of his book, _Communication Engineering_. His ideas are quite enlightening. 73, Tom Donaly, KA6RUH ========================================= Tom, sorry to be so disappointing. My Little formula for calculating L and C for the constant resistance network is quite correct. When designing constant-resistance networks it is convenient to have a design-frequency. It can be the frequency at which I said Xc = Xl = R ohms. So we can now calculate both L and C without prior knowledge of either of them. After a little arithmetic it will be quite enlightening to discover , as you say, that L = C*R^2, but which is a less-convenient starting point. In addition to a design frequency there can also be a design time constant. --- Reg, G4FGQ |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
lining up microwave antenna's | Antenna | |||
Flagpole antennas | Antenna | |||
HF Mobile Antenna Comparisons | Antenna |