Thanks for all you wrote. Someone said the problem is that Comcast doesn't
ground their cables correctly. i did raise the volume and that would be fine
if I was recording a movie with all kinds of explosions. but htat is not
what I want to record. And I don't have a portable recorder. I do have a
VDR/DVD recorder hooked in to that TV so I guess I am goingn to have to
figure out how to record with DVD. So far I have taped with tapes but either
the tapes are wearing outor the recorder is. I would then disconnect the
cable and hook cables to the RCA jacks and run from the recorder to my PC.
so it took twice as long to record something on my PC. I was hoping to
delete the middle man and save half the time.
I think to finish the DVD recording I would have to have sighted help to go
through the menus or I could rip them onto my PC.
Dean
-----Original Message-----
From: Steve Jacobson
Sent: Wednesday, March 19, 2014 4:18 PM
To: PC Audio Discussion List
Subject: Re: Hum from Cable
This is probably stating the obvious, but be sure to turn up the volume some
on your TV to overcome any residual
hum that is a part of the TV's circuitry. If you run your headphones at
relatively low volume, you may not hear
the hum, but when that same signal is fed through another amplifier and
played back at a higher volume, hum can
become evident. However, that would be too easy a fix.
Also check where your cable is routed. Sometimes if a cable is too close to
another power supply, even an AC
adapter, hum can be introduced.
Finally, the cause is most likely the hardest to fix, that being a ground
loop. This is especially likely if your
TV is connected to cable TV. It can be further complicated if your computer
is connected to a network through an
ethernet connection as well. Try disconnecting the cable from your TV while
it is on to see if the hum goes away,
realizing, of course, this isn't a viable solution. If the hum does go
away, you probably have a groundloop. We
tend to think that "ground" is "ground" and this just isn't the case. When
devices are connected to ground
through multiple paths that take different routes, those paths can
themselves create what amounts to one turn on a
large coil that can pick up hum. Sometimes to correct such a problem you
have to actually disconnect a device
from ground or isolate devices. Let's take a quick possible example. Let's
say that your computer is connected
to internet by being plugged into a router that is connected to a cable
modem. In addition to normal grounds,
there is a ground on the ethernet cable that connects back to the ground of
your router, that connects to the
ground on your cable modem that connects to the ground or outer shield of
the coaxial cable that goes to a
splitter where the cable splits and goes to your tv. Now, the ground on
your tv is connected to the audio ground
on your patch cord which connects to the audio ground on your desktop which
is connected to your desktops ground.
We have just described a path that makes a long trip that can be described
as a loop. If disconnecting the cable
from your TV gets rid of the hum, there are filters that can be placed
between a TV and a cable that allows the
cable's shield to act as a ground for radio and TV signals but not for AC.
This would then break this particular
loop. Unfortunately, there are other interactions that can cause ground
loops so figuring out how to avoid them
is a pain.
Of course, if you were able to connect your TV to your desktop using
bluetooth, there would be no physical
connection. This can be done in a number of ways, but the bluetooth sound
might be lower quality. You also might
consider recording on aa portable audio recorder and then transferring the
results to your computer. In the end,
you should be able to record directly on your desktop, but depending upon
other factors, the hum may not be so
easy to eliminate. Maybe, though, you'll be lucky, and turning up the TV's
volume a little will clear up
everything!
Best regards,
Steve Jacobson
On Wed, 19 Mar 2014 14:17:09 -0400, Dean Masters wrote:
Yes it is to a desktop. All outlets are the three prong type which means
they should be grounded.
Dean
-----Original Message-----
From: Joe Paton
Sent: Wednesday, March 19, 2014 4:15 AM
To: PC Audio Discussion List
Subject: Re: Hum from Cable
Hi,
are you connecting to a desktop computer?
You might try grounding your machine if this is the case.
Joe
On Tue, 18 Mar 2014 21:52:03 -0400
Dean Masters <dwmaster...@gmail.com> wrote:
I am wanting to run a patch cord from the headphone jack on my TV to my PC
to record some shows but there is a hum. I have Comcast cable. The patch
cord is actuallly two cords with male plugs on both ends and a connector
with two female plugs.
When I put headpohones in the jack there is no hum.
Is there something I can do to get rid of the hum?
Thanks,
Dean
--
Joe Paton <j...@vi-ability.demon.co.uk>
