pjh@mccc.edu (Pete Holsberg) (05/08/91)
My wife's 87 Toyota Camry LE has a nice AM/FM/Stereo radio, but no tape
player. She recently decided that she needed a tape player, and a local
radio shop put a Sony ("best in the shop") AM/FM/Stereo/Tape radio in
her car. 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 -- 4/20-21/91chaplin@keinstr.uucp (chaplin) (05/09/91)
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.
pjh@mccc.edu (Pete Holsberg) (05/13/91)
In article <1991May9.163507.406@keinstr.uucp> chaplin@keinstr.uucp (chaplin) writes: =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? = =I'm just guessing that the characteristic of the static varies with the =engine speed, right? Sometimes. Mostly, it's just fairly loud static, almost like the whitenoise generators that are used to prevent eavesdropping. 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/??-??/92
mcovingt@athena.cs.uga.edu (Michael A. Covington) (05/19/91)
To get good AM reception in a car... (1) use all the standard anti-noise techniques described in The ARRL Handbook for the Radio Amateur. An RF choke in the 12-volt power supply lead for the radio can sometimes work wonders. Also, there are things that can be done to make the engine and the other electrical components less noisy. (2) Most car radios are very good on AM. The exception might be some that are designed for good sound quality rather than narrow bandwidth and good sensitivity. The real problem is that you are trying to use an AM radio in a place where there is a powerful RFI source (the engine) and a *highly* unsuitable antenna (a whip that is about 1/300 wavelength, ideal would be 1/4 wavelength). Ask in rec.radio.shortwave. There are people who successfully use shortwave radios in their cars. They have the same problems as with ordinary AM, but to a greater extent. They probably have some rather good solutions, or at least, they can tell you the state of the art. -- ------------------------------------------------------- Michael A. Covington | Artificial Intelligence Programs The University of Georgia | Athens, GA 30602 U.S.A. -------------------------------------------------------