Speakerguy
Active Member
OK, so I got my new DPO3000 scope.
On DC and AC coupling, full bandwidth mode, probes shorted tip to ground clip, I get 20mv to 40mv pk-pk sinusoidal noise around 80-100MHz, all channels, all probes. It seems to vary as I move a probe around, as if acting like an antenna. If I GND couple a channel, it totally disappears, absolutely no noise.
We do have a problem with a nearby radio station or other broadcast that really messes up our channel 12 reception on cable TV (USA, NTSC). We have some regular coax feeds to some TV's and those suck, and then we have some super shielded coax in the newer part of the house and those TV's are better but still very noise picture on channel 12.
Could my channel 12 problem be the same thing the scope is seeing? I was disappointed to see this much noise on all channels, all probes unless I am GND coupled (and then it totally disappears). I might have to trek across town and plug it in and do the same test.
Any help is appreciated!
On DC and AC coupling, full bandwidth mode, probes shorted tip to ground clip, I get 20mv to 40mv pk-pk sinusoidal noise around 80-100MHz, all channels, all probes. It seems to vary as I move a probe around, as if acting like an antenna. If I GND couple a channel, it totally disappears, absolutely no noise.
We do have a problem with a nearby radio station or other broadcast that really messes up our channel 12 reception on cable TV (USA, NTSC). We have some regular coax feeds to some TV's and those suck, and then we have some super shielded coax in the newer part of the house and those TV's are better but still very noise picture on channel 12.
Could my channel 12 problem be the same thing the scope is seeing? I was disappointed to see this much noise on all channels, all probes unless I am GND coupled (and then it totally disappears). I might have to trek across town and plug it in and do the same test.
Any help is appreciated!