Topband: Computer noise

[Frank Krozel]

I have an HP laptop charger that sings like mad.  Interestingly enough I have another identical one that is absolutely quiet.  Inadvertently, I do forget about that and my noise level jumps up to S-9.  Most times I remember the source LOL, 

-73-  Frank    KG9H
kg9hfrank at gmail.com




> On Nov 26, 2019, at 7:41 AM, Artek Manuals <Manuals at ArtekManuals.com> wrote:
> 
> Could be coming from the power supply? Sometimes simple clip on chokes are not enough either. I have a similar problem here on 20M I have dual (Identical) monitors . One has an irritating but not debilitating  spur on 20 the other doesn't ..If I swap the monitors the spur follows the monitor. Have tried a handful of ferrites to no avail so it is likely "radiated" IMO  and not conducted.
> 
> Grumpy Dave
> NR1DX
> 
> On 11/26/2019 6:41 AM, Rodman, David wrote:
>> A few ideas might be helpful here.  I was at the station over the weekend and found a significant amount of noise coming from one of two computers in the station.  Significant noise S5 at 1820.  One computer runs the cluster and 2m connection.  That was clean.  The other handles most of the remote chores and has about 15 USB serial devices attached.  Everything was off, except a battery operated transceiver attached to the receive antenna feed, the modem for the cable and my router.  One can definitely see that operating the computer, closing windows or plugging in USB devices causes the modulation on the signal to change, this isolating the source to the computer alone and possible connections to peripherals (they were all turned off by the way).  I did have few chokes available but attaching them to the USB wires out of the computer to their various devices made no improvement.  I could get more specific but need to leave for my office now.  Any ideas might be helpful and appreciat
>>  ed.
>> 
>> 
>> ---
>> David J Rodman MD
>> Assistant Clinical Professor
>> Department of Ophthalmology
>> SUNY/Buffalo
>> 
>> Office 716-857-8654
>> _________________
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> 
> -- 
> Dave
> Manuals at ArtekManuals.com
> www.ArtekManuals.com
> 
> 
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