10-12-2010, 05:10 AM
My calculations were wrong. Actual measurement shows 100mA of current through the tweeter field coil (item N172).
The current through big speaker's field coil is 57mA. The current through transformer N152 is 42mA. This corresponds to current through 6F6 audio driver (plate current of 6F6 is 35mA). So, 57+42=appr.100mA... Looks like ALL IS CORRECT, and dissipation in tweeter field is 0,1A*0,1A*670Ohm = 6,7W.
Why on earth then other owners of 38-690 say, that the tweeters should not be hot and have the same temperature???
The current through big speaker's field coil is 57mA. The current through transformer N152 is 42mA. This corresponds to current through 6F6 audio driver (plate current of 6F6 is 35mA). So, 57+42=appr.100mA... Looks like ALL IS CORRECT, and dissipation in tweeter field is 0,1A*0,1A*670Ohm = 6,7W.
Why on earth then other owners of 38-690 say, that the tweeters should not be hot and have the same temperature???
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