RFI on the cheap:
Other suppliers are available, but I have had great success
with Mouser over the years. On page 1722 they offer some
Triad isolation with an intergral electrostatic shield.

Some of these transformers have dual primaries and can
be wired for 120V or 240V. Most of us will only need the
single primary transformers, which also cost less. Dual
windings are marked with "*". The medical units have much
lower leakage capacitance and unless you need a 500VA
transformer, I would go with the less expensive units.

*553-N48X 15VA $15.51
*553-N51X 35VA $12.00
553-N68X 50VA $11.20
553-N54MG 150VA $71.95
*553-N67A 150VA $46.98
*553-N66A 250VA $62.20
*553-N77U 100VA $25.31
Medical Applications
553-N90MD 250VA $210.38
553-N92MD 500VA 256.19

Hosfelt offers Curtis F1600CA03 RFI IEC filters.
http://www.curtisind.com/pdf/filtercatalog.pdf
http://www.hosfelt.com/en-us/dept_572.html#item_1706

I have found the addition of a 0.01uF across the output side
of the filter from hot to neutral offers somewhat higher RF
attenuation levels.

I ordered mine from Digi Key because I had a fairly large order
from them and didn't want to split an order.

http://dkc3.digikey.com/PDF/C071/1405.pdf

For a good overview of Class X and Class Y capacitors see:

http://my.execpc.com/~endlr/line-filter.html

By mounting a Curtis RFI filter in a Bud Box, mounting the
Triad isolation transformer and using a "pop in" single NEMA
15-5, or a standard NEMA 15-5 duplex outlet one can have a
very nice RFI filter that will knock most RFI down by nearly 99%.

Will included a neon pilot light with a double pole fast 1A magnetic
breaker and his unit looks like it came off an assembly line.

He was plagued by the RFI from his daughter's Dell laptop PC.
The RFI was so bad that he couldn't listen to MW stations 30 miles
away!

Be certain to size the transformer to match the load. And if you
add a fuse or breaker size it to match the load as well.


I rave on and on about the Curtis filters from Hosfelt simply because
at $0.33 each, they are a steal! CorCom and other companies make
very effective RFI fitlers. But all new RFI/EMI filters are expensive.

I use a couple Topaz Ultra-Isolation transformer in my home.
Built like a tank, and very effective with only 0.005pF (yes pF)
coupling between the primary and secondary. They are the best
isolation transformer around. But they are obscenely expensive.

Will lucked out and bought a set of 250VA for $10 each and when he
asked the flea market had 6 more that had seen better days. They
had damaged power cables and busted NEMA 15-5 duplex outlets.
He got the lot for $20!.

But in truth we compared a Topaz with Will's homebuilt unit and they
both had nearly the same level of attenuation. When you add a EMI
filter to the Topaz, it becomes the clear winner. But at upwards of
$500 each on the surplus marekt, Will's DIYS version is very
attractive.

Again this will be incorporated into a much longer and more complete
article
for Will's stopRFI page.

I am posting these in nearly a random order because I will almost
certainly be
undergoing elbow and knee surgery and we are planing on selling our
current
home and relocating. At that point my life will become rather complex
and I
don't know when I will get a chance to polish these and combine them
for
the stopRFI page.

Terry