bizarre ribbon mic transformer question

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dissection of the rm700 transformer
sec: 985 turns 4,01H 94 dcr wire diameter 0,1mm
pri: 19 turns wire diameter 2x0,4mm

normal_7%7E0.jpg




enjoy,
-max
 
[quote author="ioaudio"]dissection of the rm700 transformer
sec: 985 turns 4,01H 94 dcr wire diameter 0,1mm
pri: 19 turns wire diameter 2x0,4mm
[/quote]

Thanks, interesting. So it's a simple pri sec job with the slight twist of a twin wire primary. Roughly 1:50 makes sense because the output impedance is roughly 400 ohms.

The (usual) RB-500 is a bit more elaborate. Dual bobbin, each wound pri sec pri. The two primaries are in parallel, the two bobbins primaries as well as secondaries, are wired in series. Gives roughly 1:25. DC on the secondary is something like 30 ohms. Noisewise the stock tranny isn't bad.
 
make sure you bring the pri leads out together, since only 19 turns, you can get weird things happening if for instance, one lead came out on one side, and the other lead 180 opposite.
this is if you rebuild, of course.

good stuff! any thing with the beyer technique of snapping the bobbin over a fixed core?
 
thanks andreas - did you measure inductance/wire sizes?

cj, no spinning bobbin, normal ei cores, soft wax.

here´s the link of the rest of the pics again
http://twin-x.com/groupdiy/thumbnails.php?album=178
 
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