"RJH"
Phil Allison wrote:


** The resistance of the primary winding of a mains transformer is
characteristic of its VA (or power) rating. Small transformers have high
values and large ones low values.

I hunched the toroidal tranny in your amp was about 200VA rating -
which
corresponds to 8 to 12 ohms primary resistance.

20 ohms corresponds to a 120VA tranny, 100 ohms to a 35VA one.

These figures are for 240VAC rated transformers, 120VAC ones have about
1/4
the resistance value for the same VA.


Ah, thanks very much, good to know. New fuse (1.6A) and the amp's
working - measures 7 ohms.


** Ah - a 7ohm primary toroidal is normally rated at 225VA for 240V
operation.

The inrush surge will be around 40 amps peak, single cycle, worst case.

That is an awfully large surge for a 1.6A fuse to tolerate.

Better have a few spares on hand ....



..... Phil