[Ham-Computers] Re Ground Loop Potential

[Philip]

Duane.

I know that you run that big "Alpha Amp" when doing the nets.  Maybe RF from 
your Ham set-up is entering the moo by way of the speaker leads and causing 
some latent damage.  The actual total failure wouldn't necessarily have to 
occur at the moment that you're transmitting, just latent damage that causes 
the failure later down the road.  It would be very easy for RF to ride into 
the speaker system via the power line then into the moo AF output jack.  If 
that's the case, putting a few ferrites on the speaker lead or wrapping the 
speaker lead a few turns through a ferrite toroid might cure the problem!

Phil, KO6BB
OTR Quote:
"Never Steal A Butcher's Wife"

----- Original Message ----- 

>
> Hi All,
>
> This Compaq business machine model 5100 continues to destroy the 
> integrated
> sound chip on the mother board. The last MB replacement lasted 17 days!
> Thus far, none of the "technicians" dispatched here on site seemed to have
> a clue about measuring the resistance between the sound output jack and 
> the
> external amplified system.
>
> The external speakers are by Lab Tech, no woof woof, just one with the
> amplifier and the other slave speaker. The main unit has on/off, volume,
> bass, treble and headphone jack. I paid $80 for them about eight years ago
> and they perform well enough.
>
> For some unknown reason the sound chip suddenly fails. Since I only use
> this super computer for e-mail, with firewall and anti-virus software kept
> current, it gets little use. I do not surf with it. There is much I could
> do with it, "if" it were reliable!
>
> I use a dialup connection. I use MSIE and Outlook Express version 6.0 The
> OS is Windows XP Home Edition.
>
> I have a UPC and two surge protectors before it! The system, including
> monitor and speakers, run off the battery of the UPC. Thus I should not be
> getting voltage spikes etc.
>
> Could this failure be caused by a ground loop existing between the sound
> chip and the external powered speakers?
>
> Gentlemen, I am desperate! This is a fabulous system, but useless to me as
> is. I am sick of repair people showing up, replacing the MB and saying "it
> is cured!". Something is wrong somewhere and they are not finding the guy
> with the gun shooting my sound chip! I need suggestions, I need solutions.
> Ideas?
>
> Thank you.
>
> Duane Fischer, W8DBF
> dfischer at usol.com
>
> P.S. I am on emergency backup laptop for e-mail.
>
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