Fred McKenzie wrote:
wonder what is the difference between enam. cu wire and magnet wire

Jan-Martin-

To the best of my knowlege, the only difference is that you could use other
kinds of insulation on wire to be used for magnets. In other words, enameled
copper wire is one type of magnet wire. Other insulating materials such as
cloth, fiberglass and asbestos have been used.

I got started in electronics by tearing up discarded radios for their parts.
Radios from the 1930s and 1940s had speakers that used an electromagnet instead
of the permanent magnet used in most of today's speakers. In additon to
providing the speaker's magnetic field, the electromagnet acted as a filter
choke inductor for the radio's power supply. Those old speakers were a good
source of enameled copper wire.

73, Fred, K4DII

Also old tv focus coils and deflection yokes.
I've also torn up old transformers to rewind them
and saved the wire.
I've made a few filter chokes out of old filament transformers.
I pull out the E I core pieces, unwind the secondary, and add more
wire to the primary. Then I reassemble the core, with all the E pieces
going the same way (single air gap since a choke see mostly DC).
Radio Shack filament transformers are wound on a plastic bobbin which
makes the job easier. I've gotten about 7-8 henrys out of these,
good filter chokes for tube equipment.