Hi all ,

I had a pair of cute little SE OPT's , just enough
for a PCL82 / 16A8 SE amp I think .
Pri. it has a tap for 3k5 and 7k so if my calc's are
right I'll have a UL tap at 25% if I use the pri.
"upside down" ??
There's just one wire the " 0 " and the " 7k " and
two to the " 3k5 " tap , so the " 3k5 " should be
a tap somewhere on the " 0 - 7k " winding .

I think I'e got it right , but .....
And if so there might be n00bs here who can
learn something from it ??

Ronald .

Hi Ronald,

There's just one wire the " 0 " and the " 7k " and
two to the " 3k5 " tap , so the " 3k5 " should be
a tap somewhere on the " 0 - 7k " winding .

If you are not sure, you can operate the OPT backwards using
AC of a few volts and just measure from tap to tap at the
supposed primaries.

Dont?forget you get a winding (!) ratio readout this way :-)

Tom

Hey Tom ,

There's just one wire the " 0 " and the " 7k " and
two to the " 3k5 " tap , so the " 3k5 " should be
a tap somewhere on the " 0 - 7k " winding .

If you are not sure, you can operate the OPT backwards using
AC of a few volts and just measure from tap to tap at the
supposed primaries.

The 3k5 and 7k are printed on the OPT so there's no need
to test and re-calculate I think ;-))

Dont?forget you get a winding (!) ratio readout this way :-)

Isn't that what I need for the UL tap ??
I thought Ug2 = x % of Ua (ac / signal)

And somehow I don't like to calculate with turnratio's and
squares , so I asume a load and use P-in = P-out and Ohms law .
That way you'll see better what you're doing I think .

Anyway , thanks ,

Ronald .