Hi!
I am trying to find a plain blue coloured Mitsumi coil for my old AM radio. Does anybody in here know the frequency of that coil? And perhaps where to find one of these?
That is not enough information to go on -Mitsumi probably made more than one type of AM radio. The more information you supply the better chance of obtaining the information you seek.
What is the model number, the year it was manufactured, can you post a photograph of the radio and the defective coil?
Is there any printing or color code on the coil?
Can you tell where, in the circuit, the coil is used?
The photos and the description you came up with make for a great start. The coil with the blue slug is almost certainly and IF transformer, but that doesn't help much. Let's see if anybody comes along with some better information.
If you mean the schematics, I have found schematics for other models close to this one. But they don't show any info on the coils. They just say the same as printed on the pcb. Which is L-3 in my case. No parts list shown.