Herringbone distortion on screen

[JAT]

Hi folks,
I'm having a problem with my video recorder. Whenever I switch to
any channel on my TV the picture is perfect. However when I switch to
channel 0 which I use for video playback there is interference on the screen
in the form of what I can only describe as a herringbone pattern. I've went
back to basics and set everything up again from scratch but it has made no
difference. What I can't understand is this, the lead from the outside
aerial goes into the video recorder, and the TV then receives it's feed from
the video recorder via another lead. This means surely that there is nothing
wrong with my aerial, otherwise I wouldn't be getting a perfect picture on
my TV. Since we can therefore assume that the aerial is OK and is delivering
a good signal to the video, does the problem lie within the video? If that
is the case how can the signal pass through the video and provide a perfect
picture on the TV when viewing the channels direct rather than through
channel 0 the playback channel? I've tried tuning another empty channel to
act as the playback channel but the effect is the same. Any ideas what I can
try here? Any help appreciated.

Alex

 

[Art]

Please supply the Make, Model, and Chassis number of the Tele and the make
and model of the VCR. That way we may give you a more totally informed
guess. At this point WE have no idea other than you may have some problem in
the tele or vcr.

 

[JAT]

The TV is a Hitachi C2114T and the VCR is a Mitsubishi HS-740V(B). Hope that
helps.

Alex

 

[Barney]

It may be that the frequency of the carrier signal comung out of the VCR is
a close to one of your TV channel frequencies -- and there is some crosstalk
going on. You need to detune your VCR slightly -- there is normally a screw
adjustment at the back of the VCR to enable you to do this. After you have
done this you will have to adjust the channel on the TV that you use for VCR
playback accordingly.

 

[Graham]

Firstly, herringbone patterning is a good choice of words because that's
exactly the correct phrase for this kind of interference.

While the VCR is playing a tape pull out the aerial from the VCR. Is the
picture clear now?

Assuming it is, it means that the RF channel your VCR is set to is the same
as, or adjacent to a broadcast channel coming down your aerial. This may be
from a different transmitter from the one you normally receive.

You say you tried a different channel (programme) number other than 0, but
what you didn't do is change the RF channel your VCR is outputting.

With very old VCR.s this was done with a screwdriver adjustment in the back
of the machine, nowadays you will have to look through the installation
menus or RTFM.

As you are in the UK, all of the preceding is in one sense irrelevant.
Is your TV and VCR equipped with SCART sockets?
If so why don't you use them?
For one thing if your equipment is stereo you wont get stereo playback when
connected via the aerial socket of the TV, as no VHS machine outputs a NICAM
signal when playing back.

Also, in many cases, when you hit play button the TV will automatically
switch to the SCART source.





--
Graham.



%Profound_observation%

 

[JAT]

One set of scart leads being bought next week. Thanks Graham.

Alex

 

[JAT]

I'll give that a try over the weekend Barney, and if it doesn't work I'll
try the scart leads as Graham suggested. Many thanks.

Alex