Radio questions

[Tchaikovsky01]

I am building several radio projects from a kitset (Funway One if anyone has heard of it, and it's for school) and have a few questions I need to answer before I go any further. If anyone could help I would really appreciate it. The questions are:

I have two resistors of the same colour bands but they are different sizes. I suspect one is carbon fibre and the other is metal, but can I use them in the same cicuit, and can the larger of the two - metal - be wrapped around a scew to connect it without soldering? I know the other can.

My other question is about the aerials. The projects call for a ferrite rod on both the transmitter and the receiver (crystal set), can this be tuned to different bandwidths on the AM frequency by adjusting the wires? This may be a really dumb question, and if so, is there a simple way to add a tuner to the circuit? No huge diagrams full of symbols, please, as I'm a complete beginner

 

[JimB]

I have two resistors of the same colour bands but they are different sizes. I suspect one is carbon fibre and the other is metal, but can I use them in the same cicuit, and can the larger of the two - metal - be wrapped around a scew to connect it without soldering?

No such thing as a carbon fibre resistor, "carbon composition" or "carbon film" - yes. I think you probably have a carbon film resistor, carbon composition went obsolete many years ago.

A "metal" resistor, do you mean a metalfilm resistor or a metal cased resistor?
I guess a metal film. if it has wires that bend easily then yes you can bend them however you like.

The projects call for a ferrite rod on both the transmitter and the receiver (crystal set), can this be tuned to different bandwidths on the AM frequency by adjusting the wires?

"Tuned to different bandwidths" a bit of bad terminology here, I think you really mean "tuned to different frequencies".

"adjusting the wires?" Yes and no.

To make an aerial (antenna) with a ferrite rod, you wind turns of wire onto the ferrite rod and tune it with a variable capacitor connected in parallel with the coil of wire.
Adjusting the variable capacitor make the antenna resonate (respond to) different frequencies.

Does this help?

JimB

 

[Tchaikovsky01]

Reply

Yes thanks sorry about the terminology, as I stated I am a complete newbie.