[HAM] Percussion & Matching Transformer

[Scott Hawthorn]

At 12:48 PM 1/10/2008, Jordan Kersten wrote:
>Does anyone know exactly what the difference between a B2 and B3 matching 
>transformer is?  I know that the B3's have some sort of a resistor that 
>has to do with percussion volume, and the B2's wouldn't have this.  Are 
>the transformers themselves the same? Can you modify a B2's transformer 
>with the percussion circuitry it needs? Or would you have to replace the 
>B2 transformer with a B3-style one?  I am converting a B2 to a B3.  I now 
>have tracked down the plate with percussion tabs, the AO-28 preamp, smooth 
>drawbars and even a newer style vibrato line box.  I have herd that they 
>have different transformers.  Can anyone comment on this?

Other than the resistor, they're the same, or close enough. You don't want 
to put that resistor in there; most folks take 'em out. It's not necessary 
for the operation of the percussion. What it does is to lower the output of 
the upper manual when percussion volume 'normal' is engaged. Nobody likes 
this effect. Don't worry about this.