> Hi Don:
> You can try putting ferrite doughnuts around the power lead, and all
speaker
> wires coming out of the sub box.
> This may or may not eleviate your RF problem.
> Because the sub box has the amplifier and power supply and volume controls
> all built on one skimpy unshielded circuit board, its pretty tough to keep
> RF off that thing.
> I think the reason you get RF on the speakers with the sub, and not on the
> speakers without, is because the one with the sub has a really high output
> amplifier for the sub built in...also, the amplifiers used for computer
> speakers are very very low input, which means that they will pickup, and
> amplify the slightest signal....which means any RF getting onto an input
> lead will be amplified heavily and come out the speakers....
> If its getting in at your sound card, there may well be nothing to be
done,
> that is, if the speakers are hooked up to a computer.
>
> Usually home stereo RF problems are due to long speaker leads or
unshielded
> speakers/speaker wire or unshielded RCA cables...but in the case of
> amplified computer speakers, the RF gets right into the main amplifier,
and
> that gets really hard to fix.
> I suppose you could try wrapping the main board inside the sub box with
> metal foil paper, insuring an insolator is present between the foil and
the
> circuit board...this could help to shield the board from RF...and also a
> couple ferrite chokes on the input cable coming from the computer to the
> speakers may help.
> I have a set of 5.1 computer speakers here, and they are so sensative to
rf
> that the sell phone will cause RF on them.
> Speaking of that, sell phone RFI is becoming more and more of an
> issue...digital sell phones are horribly unfiltered and cause horrible
> digital noise on allot of consumer electronics that use signal amplifiers
in
> audio circuits.
> They will even get into PC bassed recordings if poorly shielded cables are
> used anywhere in the audio line.
>
> It doesn't seem to matter how expensive a speaker system you buy for
> computers, most of them seem to be susseptible to RFI.
> 73
> Colin, V A6BKX
> ----- Original Message ----- 
> From: "Don Risavy, Jr.; NR4DR" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, April 10, 2006 7:17 PM
> Subject: R.F and Computer Power Amplified Speakers
>
>
> > Hello all,
> >
> >
> >
> > Wondered does anyone have a solution for preventing r.f from radios from
> > getting into computer amplified power speakers?
> >
> >
> >
> > I have a pair of Harmon Cardin stereo amplified power speakers with a
sub
> > woofer and have to turn the speakers completely off when using any of my
> ham
> > equipment.
> >
> >
> >
> > I'm not having this problem on another pair of stereo amplified power
> > speakers without a sub woofer.
> >
> >
> >
> > So any ideas or thoughts?
> >
> >
> >
> > Tnx cul 73 nr4dr
> >
> >
> >
> >
> >
> >
> >
> >
> >
>