Xref: utzoo rec.video:7026 sci.electronics:6884
Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!usc!apple!bionet!ames!amdahl!pacbell!ditka!qiclab!sopwith!snoopy
From: snoopy@sopwith.UUCP (Snoopy)
Newsgroups: rec.video,sci.electronics
Subject: strange audio problem
Message-ID: <242@sopwith.UUCP>
Date: 10 Jul 89 05:47:49 GMT
Reply-To: snoopy@sopwith.UUCP (Snoopy)
Followup-To: rec.video
Organization: The Daisy Hill Puppy Farm
Lines: 39


A friend of mine has a ~5 year old VHS vcr, (RCA?) 2 head, linear audio,
and a 19" (Sanyo?) color tv.  When playing a tape, strange uneven, squeely
noises often occur.  This does not happen when using the VCR with other
televisions, it does not happen when the tv is receiving off an antenna
(either with the vcr 'off' or when using the vcr's tuner and re-modulating
to channel 3).  It does not happen if the tv's volume control is turned down
and the audio output jack of the vcr is input to a stereo.  It happens both
with pre-recorded tapes and with tapes recorded on this vcr.

I cleaned the heads, capstans, etc. and unplugged a bunch of the internal
connectors and reseated them.  No improvement.  I tried moving the vcr
physically with respect to the tv within the limits of the ~3' coax, in
case there is an emi problem.  Didn't help.  I tried intentionally
mistuning the tv, but couldn't get a similar noise.

I haven't tried using a longer cable to allow moving the vcr farther away,
or dragging my betamax over and trying it with her tv.

The noise is pretty bizzare, it is *not* 60Hz hum, or ~15kHz flyback, or
hiss.  I'm guessing it varies in both amplitude and frequency.  Freq is
probably in the few-hundred Hz range.  (My 'scope is in the shop or I'd
look at it.)  There is a definite randomness to it.

Supposedly it didn't used to do this, and has gradually been getting worse.

My solution would be to run a coax from the vcr to the stereo, but this
would be difficult to do in her living room without violating aesthetics.

Ideas on what might cause this noise?  And why only one tv of three picks it
up?

    _____     						  .-----.
   /_____\    Snoopy					./  RIP	 \.
  /_______\   qiclab!sopwith!snoopy			|  	  |
    |___|     parsely!sopwith!snoopy			| tekecs  |
    |___|     sun!nosun!illian!sopwith!snoopy		|_________|

		"I *was* the next man!"  -Indy