Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!decwrl!wuarchive!uunet!keinstr!chaplin
From: chaplin@keinstr.uucp (chaplin)
Newsgroups: sci.electronics
Subject: Re: AM Reception
Message-ID: <1991May9.163507.406@keinstr.uucp>
Date: 9 May 91 16:35:07 GMT
References: <1991May2.113020.17346@nntp-server.caltech.edu> <809@newave.UUCP> <1991May7.191543.15285@mccc.edu>
Organization: Keithley Instruments, Cleveland, Ohio
Lines: 33

In article <1991May7.191543.15285@mccc.edu> pjh@mccc.edu (Pete Holsberg) writes:
>AM reception of distant stations with the engine running is
>horrible!  More static than ....!  This never occurred with the Toyota radio.
>
>Radio man says that even his $1000 Blaupunkt has the same AM front end
>(I guess he means front end design?) as the more moderately priced Sony,
>and that the Toyota radio is one in a million.
>
>How can I tell if he's right or not?  Is there a reasonable solution to
>getting her a tape player and decent AM reception?
>
>Thanks,
>Pete
>-- 
>Prof. Peter J. Holsberg      Mercer County Community College
>Voice: 609-586-4800          Engineering Technology, Computers and Math
>UUCP:...!princeton!mccc!pjh  1200 Old Trenton Road, Trenton, NJ 08690
>Internet: pjh@mccc.edu	     Trenton Computer Festival -- 4/20-21/91

I'm just guessing that the characteristic of the static varies with the
engine speed, right?  If that's true, the source of the static is
probably noise on the power supply.  The Toyota radio probably had
better power supply noise rejection.  Since you can't increase the
noise rejection of the Sony radio, about all you can do is to filter
the noise out of the power supply.  Also make sure there is a *good*
ground connection between the radio and the battery's negative
terminal.  This is usually in the wiring harness, but it can't hurt to
ground the case of the radio directly to the metal chassis of the car.
-- 
Roger Chaplin / Instruments Division Engineering / uunet!keinstr!chaplin
CI$: 76307,3506 / voice: (216) 498-2815 / FAX: (216) 248-6168
"In the last analysis the customer is the independent auditor.  In the
merciless light of real use, every flaw will show." - Frederick P. Brooks, Jr.