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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 16th Oct 2018, 11:38 am   #1
Neil Purling
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Default Field Coil Speaker

Are field coil speakers manufactured today?
The defective speaker got tossed in a clear-out. It was defective.
I believe that it was of 5" diameter.
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Old 16th Oct 2018, 8:37 pm   #2
ukcol
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Default Re: Field Coil Speaker

Hi Neil,

Field energized speakers become obsolete many decades ago, the improvement in magnet materials for permanent magnet speakers being responsible.

If you want your set to be original you will have to source a speaker from a scrap set. Otherwise you can use a PM loudspeaker and fit a smoothing choke in place of the field coil.
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Old 17th Oct 2018, 5:16 pm   #3
Studio263
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Default Re: Field Coil Speaker

Quote:
Originally Posted by Neil Purling View Post
Are field coil speakers manufactured today?
Bizarrely yes! I was shown a huge pair of new 'Focal' speakers the other day that despite being intended for domestic use almost reached the ceiling of the room that they were in, with the other dimensions almost to scale. A 'special feature' was than the woofers were electrically magnetised, which made me laugh. Goodness knows what the reason was, something else to fiddle with?

Needless to say this was being offered as the latest thing, not something from the 1930s which had become unnecessary decades ago. They cost úsilly as well, so I won't be buying a pair.
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Old 27th Oct 2018, 8:46 am   #4
Neil Purling
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Default Re: Field Coil Speaker

I was thinking of a 5" field coil speaker & the chassis that needs it has little room for a choke, unless it was very small. It depends on how many Henries value the OE field coil was & the HT current drawn through it. Probably why a field-coil speaker was used, even in a 1939-40 radio.

I shouldn't have thrown out the defective speaker obviously. Someone on this Forum might have been able to help getting it re-coned. You know how 'crispy' very old paper gets.

Last edited by Neil Purling; 27th Oct 2018 at 8:54 am.
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