05-14-2012, 01:58 PM
Codefox,
Thanks, I thought so about that "M" thing. Maybe it is from Italian "Milla" meaning "1000". I kinda saw it makes no sense and the values shoud be in 10s of Ks where they were marked as "Ms", then again, "Mega" were used for real Megohms.
No standards, no standards...darn!
I did unsolder the transformer yesterday, as the wires in the plug go directly to the primary, and there was no serialized anything there. So I was fairly sure of the Transformer being bad.
As I suspected, the primary is opened.
So I do need a new one, and I think "Oldradioparts" have some cheap options for me. One matching exactly, provided my voice coil impedance is what I think it is.
Questions:
1) The only thing is, do you think 5Watts rating is enough for a transformer? (the manual says 4.5W output).
2) Do you know by any chance the voice coil impedance of this Zenith Speaker? Or where to find it? It is 49-148 Part number from Zenith.
3) How much is DC resistance reading of the voice coil characteristic of the real impedance?
4) And, does that one turn resistance have to be counted in the voice coil impedance?
5) the field coil that should be 1kOhm reads 900 Ohm. Not sure if I should be worrying about it. What if it is a short inside the coil, then it will render the whole thing useless as a filter (will still generate the field). I think I could measure it on my L-meter, but then need to know the expected value.
Thanks, I thought so about that "M" thing. Maybe it is from Italian "Milla" meaning "1000". I kinda saw it makes no sense and the values shoud be in 10s of Ks where they were marked as "Ms", then again, "Mega" were used for real Megohms.
No standards, no standards...darn!
I did unsolder the transformer yesterday, as the wires in the plug go directly to the primary, and there was no serialized anything there. So I was fairly sure of the Transformer being bad.
As I suspected, the primary is opened.
So I do need a new one, and I think "Oldradioparts" have some cheap options for me. One matching exactly, provided my voice coil impedance is what I think it is.
Questions:
1) The only thing is, do you think 5Watts rating is enough for a transformer? (the manual says 4.5W output).
2) Do you know by any chance the voice coil impedance of this Zenith Speaker? Or where to find it? It is 49-148 Part number from Zenith.
3) How much is DC resistance reading of the voice coil characteristic of the real impedance?
4) And, does that one turn resistance have to be counted in the voice coil impedance?
5) the field coil that should be 1kOhm reads 900 Ohm. Not sure if I should be worrying about it. What if it is a short inside the coil, then it will render the whole thing useless as a filter (will still generate the field). I think I could measure it on my L-meter, but then need to know the expected value.
