Radio questions

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

Tchaikovsky01 said:

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?

Click to expand...

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.

Tchaikovsky01 said:

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?

Click to expand...

"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

Reply

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