Article View: sci.electronics
Article #20850Re: 60 Hz hum filter
From: Ihor W. Slabicky
Date: Wed, 22 Feb 1989 17:00
Date: Wed, 22 Feb 1989 17:00
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In article <2313@rayssdb.ray.com>, iws@rayssdb.ray.com (Ihor W. Slabicky) writes:
>
> Can anyone send me a schematic or info on broadband noise filters
> that will filter out 60 Hz hum on the 120VAC line? Some background:
> I use a portable stereo cassette recorder to record music off my
> receiver. When the recorder is powered from the AC line, I can hear
> lots of 60 Hz being recorded on the tape. Moving the recorder, cables,
> or power cord around tends to lessen the hum. When I record using the
> batteries, no hum. Also, when I playback, if I put the INPUT switch
> on the recorder to the MIC position, no or very little 60 Hz hum is
> heard, but when the INPUT switch is set to LINE, lots of hum. Ideas?
Well, thanks to everyone who responded. The two problems suggested are:
1 - a ground loop or faulty cables. Recommendations were to check the
cables and switch around the plugs at the wall or to other outlets.
I tried both of these, and this did not solve the problem. So...
2 - filtering capacitors going bad in the tape recorder's power supply
(AC to DC) conversion. This may be the problem. The recorder is
almost 15 years old. Before I go and take it apart, any ideas on
how to test the capacitors using a volts/ohms/DC amps meter to see
that they are bad? Any ideas on which type of capacitors to use
as replacements (obviously same or higher ufd value and same or
higher voltage value)
Thanks for your advice - Ihor
Internet: iws@rayssdb.ray.com
Usenet: {gatech, uiucdcs, decuac, sun, ukma, necntc, spdcc}!rayssd!rayssdb!iws
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!gatech!rayssd!rayssdb!iws From: iws@rayssdb.ray.com (Ihor W. Slabicky) Newsgroups: sci.electronics,rec.audio,rec.ham-radio Subject: Re: 60 Hz hum filter Summary: thanks - now what? Keywords: any ideas Message-ID: <2322@rayssdb.ray.com> Date: 22 Feb 89 17:00:33 GMT References: <2313@rayssdb.ray.com> Sender: root@rayssdb.ray.com (UNIX System Administrator @ Raytheon Company, Portsmouth RI) Organization: Raytheon Company, Portsmouth RI Lines: 30