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Using Two EL90’s for an ELL80E

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Forum » Valves / tubes - Semiconductors » VALVES/TUBES / SEMICONDUCTORS in RADIOMUSEUM » Using Two EL90’s for an ELL80E
           
Omer Suleimanagich
Omer Suleimanagich
 
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06.May.20 10:55
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I understand that technically an ELL80 tube is essentially two EL95 tubes feeding in to nine pins

Could two EL90 tubes substitute the EL95 tubes?

This article was edited 06.May.20 10:56 by Omer Suleimanagich .

Jacob Roschy
Jacob Roschy
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11.May.20 14:52

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Hello,

the EL90 is equivalent to the 6AQ5.

The operating plate current for the EL90 is 45 mA, while the operating plate current for the EL95 is 24 mA, i.e. the EL90 is almost twice as strong as the EL95. It may be less recommendable to downgrade the EL90 from 45 mA to 24 mA.

A much better substitute for the EL95 is the 6BM5. It can easily be matched to the operating plate current for the EL95 by varying the cathode bias resistor, probably by 270 ohms.

However the heater current should be regarded. The 6BM5 has 0.45 A, while heater current of the EL95 is only 0.2 A.
Two 6BM5s will take 0.9 A, while the ELL80 takes 0.55 A, which causes an additional load for the transformer.

Although the type 6BM5 appears to be American, the 6BM5 was actually only used in France.

Best Regards,
Jacob

Omer Suleimanagich
Omer Suleimanagich
 
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11.May.20 20:10
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Thank you for your response 

The reason for my post is , to look for alternatives that are available out there that can get a radio working again, that will not end up costing more than what the radio is worth

With the availability of LED AC 6.3 volt dial bulbs that use less current , can compensate the extra current used by the  6BM5 (hypothetically even EL90's) can be successfully used without concern to damage to the mains (power) transformer

On a different note, apart from changing the output transformer, is there a viable way to "tweek" the adapter for the ELL80 to work (using two EL90) that can give good sound and not damage the output transformer ?

 

This article was edited 11.May.20 21:15 by Omer Suleimanagich .

  
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