10-28-2012, 03:25 PM
That is a chassis and speaker from a Philco 642 - a 1936 model designed to operate on 32 volts DC.
If you're thinking of trying to use its speaker in an AC set, forget it - the field has a DC resistance of 115 ohms, roughly 1/10 of the resistance needed in the majority of Philco sets.
The speaker is a K-29, by the way - it has a push-pull output transformer, but its primary impedance is 4000 ohms - right for the 48 tubes used in the 642, but wrong for 42 or 6F6 push-pull outputs which want to see around 5900 ohms.
If you're thinking of trying to use its speaker in an AC set, forget it - the field has a DC resistance of 115 ohms, roughly 1/10 of the resistance needed in the majority of Philco sets.
The speaker is a K-29, by the way - it has a push-pull output transformer, but its primary impedance is 4000 ohms - right for the 48 tubes used in the 642, but wrong for 42 or 6F6 push-pull outputs which want to see around 5900 ohms.
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Ron Ramirez
Ferdinand IN
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