Armada M300 and RF induction from transformer.

[Guest]

Archived from groups: alt.sys.pc-clone.compaq (More info?)

I am using it to play midi files thru a sequencer programme {cakewalk}via a
sound module to an amplifier and speakers.
When using power supply there is loud RF noise. Just using internal battery
no RF noise.
Works okay with a borrowed Toshiba.
I noticed the Toshiba has a bigger transformer and maybe has an RF filter
inside.
Is there an RF filter in the Armada transformer? If not would an RF choke
solve my problem ?
Thanks for any help.

 

[Guest]

Archived from groups: alt.sys.pc-clone.compaq (More info?)

"dickydoo" <dickydoo@xtra.co.nz> wrote in
news:2iTPe.6292$iM2.622218@news.xtra.co.nz:

> I am using it to play midi files thru a sequencer programme
> {cakewalk}via a sound module to an amplifier and speakers.
> When using power supply there is loud RF noise. Just using
> internal battery no RF noise.
> Works okay with a borrowed Toshiba.
> I noticed the Toshiba has a bigger transformer and maybe has an
> RF filter inside.
> Is there an RF filter in the Armada transformer? If not would an
> RF choke solve my problem ?
> Thanks for any help.
>
The 'transformer' is in fact a switching mode power regulator. These
operate at high frequencies and produce electrical noise signals that
are both conducted and radiated.

If the noise is entering the laptop via the wire, a clip-on ferrite
suppressor may be effective, e.g.:
<http://www.maplin.co.uk/module.aspx?ModuleNo=32799&doy=27m8&QV=Y>

 

[Guest]

Archived from groups: alt.sys.pc-clone.compaq (More info?)

Dear Group,

I have a Compaq PC clone running Windows 2000 with an HL-DT-ST CDROM model
GCR-8408B. I have had no problems with it - plays CDRs and audio CDs.

As birthday present for my son, have bought (second hand) 'Battle For
Middle Earth' CD Rom, in original box - not a copy. (In fact, I have two
identical boxed sets - by mistake...)

My drive will not recognise either CDR. I have tried them in another
machines CDR which recognised each of them as the Lord of the Rings CDR. My
drive whirrs and chugs for a minute before asking for a disc to be inserted.

Any advice welcome.

TIA

 

[Guest]

Archived from groups: alt.sys.pc-clone.compaq (More info?)

"McSpreader" <invalid@hotmail.com> wrote in message
news:Xns96BF78DEC86B9McP@80.5.182.99...
> "dickydoo" <dickydoo@xtra.co.nz> wrote in
> news:2iTPe.6292$iM2.622218@news.xtra.co.nz:
>
> > I am using it to play midi files thru a sequencer programme
> > {cakewalk}via a sound module to an amplifier and speakers.
> > When using power supply there is loud RF noise. Just using
> > internal battery no RF noise.
> > Works okay with a borrowed Toshiba.
> > I noticed the Toshiba has a bigger transformer and maybe has an
> > RF filter inside.
> > Is there an RF filter in the Armada transformer? If not would an
> > RF choke solve my problem ?
> > Thanks for any help.
> >
> The 'transformer' is in fact a switching mode power regulator. These
> operate at high frequencies and produce electrical noise signals that
> are both conducted and radiated.
>
> If the noise is entering the laptop via the wire, a clip-on ferrite
> suppressor may be effective, e.g.:
> <http://www.maplin.co.uk/module.aspx?ModuleNo=32799&doy=27m8&QV=Y>
>

Thank you.

 

[Guest]

Archived from groups: alt.sys.pc-clone.compaq (More info?)

I have fitted ferrite chokes on all cables but noise still there. Could you
recommend a replacement power supply ?
"McSpreader" <invalid@hotmail.com> wrote in message
news:Xns96BF78DEC86B9McP@80.5.182.99...
> "dickydoo" <dickydoo@xtra.co.nz> wrote in
> news:2iTPe.6292$iM2.622218@news.xtra.co.nz:
>
> > I am using it to play midi files thru a sequencer programme
> > {cakewalk}via a sound module to an amplifier and speakers.
> > When using power supply there is loud RF noise. Just using
> > internal battery no RF noise.
> > Works okay with a borrowed Toshiba.
> > I noticed the Toshiba has a bigger transformer and maybe has an
> > RF filter inside.
> > Is there an RF filter in the Armada transformer? If not would an
> > RF choke solve my problem ?
> > Thanks for any help.
> >
> The 'transformer' is in fact a switching mode power regulator. These
> operate at high frequencies and produce electrical noise signals that
> are both conducted and radiated.
>
> If the noise is entering the laptop via the wire, a clip-on ferrite
> suppressor may be effective, e.g.:
> <http://www.maplin.co.uk/module.aspx?ModuleNo=32799&doy=27m8&QV=Y>
>

 

[Guest]

Archived from groups: alt.sys.pc-clone.compaq (More info?)

"dickydoo" <dickydoo@xtra.co.nz> wrote in
news:zKcQe.6524$iM2.647779@news.xtra.co.nz:

> I have fitted ferrite chokes on all cables but noise still
> there. Could you recommend a replacement power supply ?
> "McSpreader" <invalid@hotmail.com> wrote in message
> news:Xns96BF78DEC86B9McP@80.5.182.99...
>> "dickydoo" <dickydoo@xtra.co.nz> wrote in
>> news:2iTPe.6292$iM2.622218@news.xtra.co.nz:
>>
>> > I am using it to play midi files thru a sequencer programme
>> > {cakewalk}via a sound module to an amplifier and speakers.
>> > When using power supply there is loud RF noise. Just using
>> > internal battery no RF noise.
>> > Works okay with a borrowed Toshiba.
>> > I noticed the Toshiba has a bigger transformer and maybe has
>> > an RF filter inside.
>> > Is there an RF filter in the Armada transformer? If not would
>> > an RF choke solve my problem ?
>> > Thanks for any help.
>> >
>> The 'transformer' is in fact a switching mode power regulator.
>> These operate at high frequencies and produce electrical noise
>> signals that are both conducted and radiated.
>>
>> If the noise is entering the laptop via the wire, a clip-on
>> ferrite suppressor may be effective, e.g.:
>> <http://www.maplin.co.uk/module.aspx?ModuleNo=32799&doy=27m8&QV=
>> Y>
>>
A replacement PSU may do the biz. Suggest you search the web for
one, eBay is a good source. Alternatively, there are universal
laptop PSUs on the market.