Help with an old circuit diagram, please?
Well, I'm getting closer to my project. The bulk of the device is to be based around an old transistor radio. I've got hold of one (a Phillips D1018/05, if it helps).
Wonderfully, I opened the radio to find it has the circuit diagram stuck inside the back cover.
Unfortunately, it's only half an inch high, so, I've scanned it.
Now, I have a problem:
The directions I am working with are vague:
Try removing the Ferrite tuning coil and then replacing it with (another detecting component which I have, but if I name it the surprise will be lost) with a 12mH inductor connected in parralel.
Spelling aside, I was happy with this, until I opened the radio and found that the antenna has four wires connected to it.
So, I need a few answers:
- In the circuit diagram, which part is the ferrite tuning coil / antenna? I think it's part of the bottom-left corner of the diagram, but I need to confirm this.
- The four wires all disappear through the same hole, but one is stained blue and one red - which ones should I be dealing with?
- The component I am replacing the coil with is polarity-sensitive. The vendor was very careful to indicate the negative electrode - which way round should I connect it? I think I need to connect the negative of the component towards the bottom lead of the circuit diagram, but I want to make sure before I kill the component.
(If there's anything I've forgotten to ask / say, please let me know that as well. I'd rather not reveal the nature of the final project; it's not for a contest, but there's nothing like it on the site yet. If useful advice depends on knowing what the component is, then I will reveal it, but I'd prefer not to spoil the big unveiling.)