Transformer Hum 1U pkg.

[jh]

>JH. could you be more specific. Do you mean transormers (flat) like the >Signal
>Transformer "Flathead"? These have a (QUOTE) "semi-toroidal" construction >that
>minimizes radiated magnetic fields. Doesn't work ??? or is the transformer you
>were referring to a different core (like an E-I)?

Don't know about "semi toroidal" ones. What I mean are these flat blue ones
that look like a brick and are soldered directly to the PCB.

>It might be that the problem with the small single rack transfromer is that
>the core is so small that the flux density is right in the edge of saturation,
>and so magnetic leakage.... ???

Yes, probably. And a bad form factor might cause the fileld to leave the
core more than it should as well.


>(SOT)
>Real toroids rule. I power my studio with a 1200VA 120pri/120VCT secondary >in
>the "balanced power" mode... hot and neutral are 60VAC from earth ground. >The
>center tap goes to earth ground (ROD). No hum problems... but I have good
>grounding practice anyway. Most of the benefit is probably from the real earth
>ground, and second from the balanced hot/neutral currents. It cost about >$200
>to get the custom wound, shielded, vaccuum impregnated Xfmr. And to this >day,
>years later.... The Xfmr rep. still calls me to see if I need another ;-)
>Harry
>

Sounds good. Never tried it myself. This big one, is it completely quiet then ?
Of do you have to put it into a different room ?
Hmm, 1200VA wouldn't be enough for my little studio (;->).

JH.