Xref: utzoo sci.electronics:5323 rec.audio:11072 rec.ham-radio:8934
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!pasteur!cad.Berkeley.EDU!moto
From: moto@cad.Berkeley.EDU (EDIF Committee)
Newsgroups: sci.electronics,rec.audio,rec.ham-radio
Subject: Re: 60 Hz hum filter
Summary: REPLACE THEM ALL!
Keywords: any ideas
Message-ID: <10274@pasteur.Berkeley.EDU>
Date: 23 Feb 89 20:16:59 GMT
References: <2313@rayssdb.ray.com> <2322@rayssdb.ray.com>
Sender: news@pasteur.Berkeley.EDU
Reply-To: moto@cad.Berkeley.EDU.UUCP (EDIF Committee)
Organization: University of California, Berkeley
Lines: 25

In article <2322@rayssdb.ray.com> iws@rayssdb.ray.com (Ihor W. Slabicky) writes:

>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)

If the recorder is that old (and especially if it hasn't been used much),
then the electrolytic cap. are probably dried out. It is often possible to
"re-form" the barrier, but for the price of new caps. at this voltage I would
simply replace every single one. Just the electrolytics (polarized) ones! The
others should be ok unless physically damaged somewhow.

The same or higer volt/ufd is fine, but try to stay within about +20%, since
the actual capacitance will vary some with too low a voltage and too high a
capacitance (e.g. 100X) can give you problems with leakage.

Be careful with over heating the PC board and good luck!
Mike Waters    AA4MW/7                  *
Motorola CAD Group                      *    Witty remark goes *HERE*
Mesa, AZ   ...!sun!sunburn!dover!waters *
          OR   moto@cad.Berkley.EDU     *