Osc Coil/ Tunning Coil or simply inductors

Hi all

i am newly involved in RF electronics, have some confusion regarding inductors/coils. i want help in clearing the following concepts:

1. If in tank circuit inductor (hand made or purchased from market) is connected to the oscillator input of chip then is it called oscillator coil or is it called by any other name xx coil ?

2. Is there any characteristic that separate tuning coil from osc coil?

3. Is tuning coil a pick up coil that acts as antenna and osc coil does not pick signals but provide required resonance?

4. can i use tune-able/plastic molded inductor(i don't know it's osc coil or else) either in tank circuit for oscillator input and also in Rf front end for tuning purpose.
Can same coil be used for different tasks

Masood

what ever name it is, it is an inductor.

They are all the same thing, it is how you use it that decides what name it has.
All conductors have inductance, it is an electrical property of anything carrying a current and creating a magnetic field. In most electronic applications the conductor is just a wire and it is often made into a coil. Winding it into a coil reduces it's physical size and also concentrates it's magnetic field in a smaller area and increases it inductance. Adding a core inside the coil, which may be fixed or adjustable, also alters it's inductance. Cores made with iron, which may be solid metal or ferrite (powdered iron & ceramic mix) have the property of increasing the inductance and cores made from brass do the opposite, they reduce inductance.
All coils pick up signals and also radiate them, that is why you sometimes see them in a metal screened case, it blocks signals from entering and leaving.

"tank" coils were coils connected to the anode circuit of a valve amplifier. They were always used in the output circuits of ALL high power valve transmitters, so tank coils tend to be big, able to deal with real power (up to 500 kWs !!). Now oscillator coils don't have to deal with any real power at all, but there construction should be such that they are very stable, so a change in temperature does not change their inductance and hence oscillator tuning.
Frank

Hi All,
Thanks for all your replies they are really helpful. I ma currently facing problem in implementing FM radio with TA2003 radio ic.
I have connected all the components for TA2003 FM mode but it seems that i am unable to tune any station(FM band coil and gang capacitor). I have connected all components over breadboard (TA2003 and all required Rs & Cs) except tank circuit which is soldered in separate wire-board, i thought that tank is most sensitive part so i put that on separate wire-board but still unable to Pick any station. Any ideas what has gone wrong? has any one used this chip over breadboard.(can we use the chip for 8-108 MHz FM band over bread board, remember that Tank circuit is separately soldered on the wire-board that would handle 88-108 MHz signals)

Masood

The wiring around the tuned circuits has to be as short as possible. Consider the length of wire used to make the tuning coil, any additional length from your connecting wires is like additional length wound around the coil.
Also make sure you have both GND pins connected and the supply decoupling capacitor is as close to pin 3 (VCC) and GND as possible.