any good splitter/isolator suggestions

[rnewman]

Typical problem with multiple tuners is beat frequency
from tuners being tuned to near or double, etc frequencies.
Looks like hairingbone on picture.
Need to buffer/isolate/split cable signal.
(as well as shield boards from each other in pc)
Any products out there?
Thanks,
Ray

[ToxMox]

I thought herringbone patterns were from an overamplified signal.

[rnewman]

Being an very old tv repairman (back from the tube type days)
herringbone effect is the slight difference between two oscillators.
External you can see it when cable channels are the same as over the air
channels. If all the cable connections from pole to your TV is
not fully shielded and/or you are near a transmitter you can see this effect.
Most good dual tuners incorporate LNA/buffer and shielding for each tuner.
But when you start putting more than one dual card in PC there is all
kind of local oscillators running around.
WHICH just reminded me that probably my problem is more shielding
needed between boards than isolation of cable signal if my card do have
lna built in.

Of course this assumes I have a strong cable signal.
weak signals are prone to interference.

Ray

[paulbeers]

Rnewman, thank you! While I am no help in your question, I just realised my cable issue I have here with my local channels. My house is wired with RG59 (and I think low quality at that, it was already installed when I moved in of course). I have serious issues with all of my local channels, but my local Fox affililliate. I read your posts and suddenly I realised why. My other 4 locals all use the same channel on cable as they do OTA. My Fox channel is OTA 17, but on Cable it is 6. The transmitters are only about 5 or 6 miles from me (at night I can see the flashing lights from the towers). Now I know why my locals always look like crap compared to the rest of my cable channels (okay I still have crappy cable, but not nearly as bad as those 5).

[rnewman]

When my cable supplier decided to use the same channels as OTA
it was really bad on the lower channels.
Finally they had to replace ALL the cable from the pole to the cable boxes
(after trying to repair 6 times and couldn't)
VERY good double shielded cable and grounded junctions finally
cured the problem. They had to remove ch5 trap for HBO.
I always tell friends to just keep calling cable company until they get it right.
You are entitled to get a good picture at the end of the cable.
It does help to test each outlet with more than one TV (hopefully a new one)
Ray