05-14-2012, 05:19 PM
Codefox,
Thanks, this helps. So you think the impedance is actually on the order of 4 ohms or so?
I will get it from Oldradioparts, 3 bucks is nothing compare to 30 for a new Hammond. I also think 5W is enough.
As for the field getting hot due to the shorts, here it may play differently. The current running through the field is DC in the first place, and it is pre-filtered with the first capacitor, so the pulsations are not that large. The sheer DC resistance of the field will do some filtering anyway, but the advantage due to the inductance invalidated by a short will not be there. A field with a shorted turn, plugged after a good size cap (and this one is..what...10uF or so) may never get too hot to burn due to it.
It all depends on the AC component of the voltage across the first cap, and this is what I don't know yet to estimate it.
From what Gene (Thanks Gene, it helps a lot to see the pictures) showed, his field is 833 Ohm (mine is 890 or so), so we either both have bad fields, or both are good (neither is 1K).
As for converting to PM speaker...I will put the photo of my speaker here - it is nothing short of MINT! - would be a sacrilege to throw this out due to a stupid transformer; I restored a Philco 20 speaker with fully missing cone and fully blown transformer, just to see the right speaker there. And this one is just....like new. No rust, no discoloration on the cone, no rips or even hints of rips. No, I can't
I have not recapped it yet - I am slowly sizing up the job
Thanks, this helps. So you think the impedance is actually on the order of 4 ohms or so?
I will get it from Oldradioparts, 3 bucks is nothing compare to 30 for a new Hammond. I also think 5W is enough.
As for the field getting hot due to the shorts, here it may play differently. The current running through the field is DC in the first place, and it is pre-filtered with the first capacitor, so the pulsations are not that large. The sheer DC resistance of the field will do some filtering anyway, but the advantage due to the inductance invalidated by a short will not be there. A field with a shorted turn, plugged after a good size cap (and this one is..what...10uF or so) may never get too hot to burn due to it.
It all depends on the AC component of the voltage across the first cap, and this is what I don't know yet to estimate it.
From what Gene (Thanks Gene, it helps a lot to see the pictures) showed, his field is 833 Ohm (mine is 890 or so), so we either both have bad fields, or both are good (neither is 1K).
As for converting to PM speaker...I will put the photo of my speaker here - it is nothing short of MINT! - would be a sacrilege to throw this out due to a stupid transformer; I restored a Philco 20 speaker with fully missing cone and fully blown transformer, just to see the right speaker there. And this one is just....like new. No rust, no discoloration on the cone, no rips or even hints of rips. No, I can't
I have not recapped it yet - I am slowly sizing up the job
