>? ? The 8 Henry filter choke with an oil filled .1mFd in parallel then an oil
>filled 20mFd cap to
> ground is a tuned filter, tuned to 120 Hz.? If you truly have 60 Hz hum, you
> have a diode open in
> one of the arms of the bridge rectifier.? ? If you truly have 120 Hz hum, you
> have a "detuned
> filter" possibly the oil filled 20mFd cap has changed value.? Check the
> values of both caps first.
>? ? With this, like all power supplies the HUM sounds greater with a higher
>current draw, from the
> supply.
## if the 20 uf filter cap dropped a bit in value.. that will NOT de-tune
the 8 henry filter choke.
## The .1 uf in parallel with the 8 h choke is the tuned choke. Now if the
.1 uf resonating cap
changed value, the choke is now de tuned.
Jim VE7RF
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