Maril,
Yes, based on the facts indicated in your last post, I feel pretty confident that is what is happening -- the BAT's, with their 200kHz bandwidth, are picking up interference through the air.
The source of the interference is probably something closer to the left channel amplifier than the right, since the symptom is worse on that side.
Besides computers, other common sources of rfi in the home are:
-- Dimmer switches for lighting (either incandescent or fluorescent). If there is a dimmer switch nearby, make that your number one suspect after the computer!
-- Fluorescent lighting.
-- UPS's (uninterruptible power supplies).
-- Computer network cables.
-- VCR's, DVD players, etc. Like computers, they can generate significant noise when plugged in, even if they are turned off.
-- Possibly wireless devices like cordless phones, wifi, etc. Although they operate at far higher frequencies, they may have switching power supplies or other circuits which emit spectral components below 200kHz.
I have a portable AM radio that can receive the long-wave band (as well as short-wave and the medium wave regular AM broadcast band). You'll be interested to know that it's dial starts at 150kHz (!), well within the frequency range of what your amplifier can amplify!
Good luck!
-- Al
Yes, based on the facts indicated in your last post, I feel pretty confident that is what is happening -- the BAT's, with their 200kHz bandwidth, are picking up interference through the air.
The source of the interference is probably something closer to the left channel amplifier than the right, since the symptom is worse on that side.
Besides computers, other common sources of rfi in the home are:
-- Dimmer switches for lighting (either incandescent or fluorescent). If there is a dimmer switch nearby, make that your number one suspect after the computer!
-- Fluorescent lighting.
-- UPS's (uninterruptible power supplies).
-- Computer network cables.
-- VCR's, DVD players, etc. Like computers, they can generate significant noise when plugged in, even if they are turned off.
-- Possibly wireless devices like cordless phones, wifi, etc. Although they operate at far higher frequencies, they may have switching power supplies or other circuits which emit spectral components below 200kHz.
I have a portable AM radio that can receive the long-wave band (as well as short-wave and the medium wave regular AM broadcast band). You'll be interested to know that it's dial starts at 150kHz (!), well within the frequency range of what your amplifier can amplify!
Good luck!
-- Al