[Boatanchors] 5U4 vs 5Y3

Garey Barrell k4oah at mindspring.com
Sat May 24 14:32:34 EDT 2014

Bob -

Depends upon how much DC current is drawn.  Roughly speaking, the 5U4GB is about 150 mA of DC 
current supply, and the 5Y3GT is only about half that.  All sorts of limitations/variations on 
both depending upon cap or choke input filter, DC voltage, etc.....

Tube data book covers all that stuff.  Bases are the same. 5Y3 draws LESS filament current, so 
no problem there.

But as long as the DC current drawn is less that about 80 mA you can safely sub a 5Y3 for a 5U4, 
at least long enough for test.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs

Bob Jackson wrote:
> Can a 5Y3 be subbed for a 5U4 for testing purposes?
> Bob

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