My electric stove is talking to my modem, resulting in the modem
dropping its speed back or losing the connection (dial up). I can
turn any burner on high and everything works. Turn the "infinite"
control to a midpoint heat setting and the modem goes out to lunch.

The controls are primitive types with a heater and bimetallic strip
inside them (I disassembled one to fix it). The contacts appear to be
real silver.

The only place the modem and stove come together is at the CB panel
they have independent circuits up to that point.

Modem line is 40 feet of UTP cat 5 up to the phone connection box.
(added the twisted pair in an attempt to fix the problem) The lines
are 10 feet apart everywhere except the CB panel.

Phone box and power share the same earth ground. I lifted the power
connection and saw no unbalance ( 0 VAC) between ground and neutral
with the stove cycling.

Any burner on the stove causes the problem. The small one is 600
watts the oven 2,000 watts. 240 VAC to the stove 120 to the outlets.

If I turn my stereo on (same circuit as modem and computer) and crank
the volume to uncomfortable levels (unless of course I've had a few
home brews) the problem goes away (and no my perception isn't at fault
.. . . but, truth speaking, in that condition most problems do go
away)

Stereo PA has a very stiff power supply 100 joules with HF bypass
photo flash caps and polystyrene layered caps. Problem only goes away
with bass turned up and continuous music source, or large bass
transients. (floor shaking, teeth rattling, bass)

So far I've added twisted pair to the phone connection (40 feet), a
toroid to the (external) modem's wall wart transformer, and a toroid
to the phone lines - in all cases for common mode rejection - not
around each line.

Interested in hearing from people who have solved this problem, or
just anyone with an idea of what to try next. Stove is easy to get
to, computer 120 VAC easy to access, power panel less so.

Short of staying inebriated and playing the "Sheffield Drum Record"
or "Lisztronique" over and over . . . (I'm willing, but my wife has a
problem with that approach)