Hi, I can confirm that adding an antenna amplifier (even for a cable setup) can dramatically increase the quality of certain channels.
BBC1 and BBC2 were pretty awful on my setup until I added an amplifier; before that I was pretty convinced that the noise I was seeing was produced by my MythTV box itself: only 3 or 4 channels had a fairly repetitive pattern of visible distortion, even CPU activity was somehow visible in the noise pattern... After adding an antenna amplifier image quality increased beyond expectation.... (of course no guarantee that this will happen for you too. Just my experience that might help you....) Regards, Stanley. > I would try using an antenna amplifier, as the inputs of some cards are > not very sensitive. > > Michael Ellis wrote: >> Hi folks. >> >> I am troubleshooting a noisy picture coming from the upper channels >> on my PVR 500. An MPEG2 file which illustrates this is available at >> this url: >> http://www.ellissoftworks.com/noisy-pvr500.mpg >> >> This test file was captured by executing the following commands: >> $ ivtv-tune -c 62 /dev/video0 >> $ cat /dev/video0 > noisy-pvr500.mpg >> >> At first, I assumed I had a noisy cable configuration. So, I >> replaced the cable connecting my PVR500 to the wall, and the problem >> persisted. Following that, I connected the cable directly to the >> TV's built-in tuner, and I found that the image was fine when >> acquiring it via the TV's tuner, but using the same cabling, the >> PVR500 delivered the noisy image. >> >> The first few channels (2-13 or so) are perfect, and channels from >> 13-40 or a little noisy. Above that, you get results such as the >> example I provided above (that one's channel 62). >> >> It's worth mentioning that this has not been a problem in the past >> (prior to last month, I was using IVTV 0.6.4). So, I reverted to >> 0.6.4, but that did not correct the issue either. >> >> My configuration information appears below. Any suggestions as to >> what I might try? Could this be a hardware problem? >> >> Thanks for your thoughts. >> -Mike Ellis >> >> >> >> Linux video capture interface: v1.00 >> ivtv: ==================== START INIT IVTV ==================== >> ivtv: version 0.6.7 (tagged release) loading >> ivtv: Linux version: 2.6.16-gentoo-r13 SMP gcc-3.4 >> ivtv: In case of problems please include the debug info between >> ivtv: the START INIT IVTV and END INIT IVTV lines, along with >> ivtv: any module options, when mailing the ivtv-users mailinglist. >> ivtv0: Autodetected Hauppauge WinTV PVR-150 card (cx23416 based) >> ACPI: PCI Interrupt Link [APC1] enabled at IRQ 16 >> GSI 20 sharing vector 0x32 and IRQ 20 >> ACPI: PCI Interrupt 0000:05:08.0[A] -> Link [APC1] -> GSI 16 (level, >> low) -> IRQ 50 >> ivtv0: Unreasonably low latency timer, setting to 64 (was 32) >> tveeprom 0-0050: Hauppauge model 23552, rev E587, serial# 8382698 >> tveeprom 0-0050: tuner model is Samsung TCPN 2121P30A (idx 87, type 70) >> tveeprom 0-0050: TV standards NTSC(M) (eeprom 0x08) >> tveeprom 0-0050: second tuner model is Philips TEA5768HL FM Radio >> (idx 101, type 62) >> tveeprom 0-0050: audio processor is CX25843 (idx 37) >> tveeprom 0-0050: decoder processor is CX25843 (idx 30) >> tveeprom 0-0050: has radio, has no IR remote >> ivtv0: This is the first unit of a PVR500 >> tuner 0-0060: TEA5767 detected. >> tuner 0-0060: chip found @ 0xc0 (ivtv i2c driver #0) >> tuner 0-0060: type set to 62 (Philips TEA5767HN FM Radio) >> tuner 0-0061: chip found @ 0xc2 (ivtv i2c driver #0) >> cx25840 0-0044: cx25843-23 found @ 0x88 (ivtv i2c driver #0) >> cx25840 0-0044: loaded v4l-cx25840.fw firmware (16382 bytes) >> wm8775 0-001b: chip found @ 0x36 (ivtv i2c driver #0) >> ivtv0: loaded v4l-cx2341x-enc.fw firmware (376836 bytes) >> ivtv0: Encoder revision: 0x02060039 >> ivtv0: Allocate DMA encoder MPEG stream: 128 x 32768 buffers (4096KB >> total) >> ivtv0: Allocate DMA encoder YUV stream: 194 x 10800 buffers (2048KB >> total) >> ivtv0: Allocate DMA encoder VBI stream: 120 x 17472 buffers (2048KB >> total) >> ivtv0: Allocate DMA encoder PCM audio stream: 455 x 4608 buffers >> (2048KB total) >> ivtv0: Create encoder radio stream >> tuner 0-0061: type set to 70 (Samsung TCPN 2121P30A) >> ivtv0: Initialized WinTV PVR 500 (unit #1), card #0 >> ivtv: ====================== NEXT CARD ====================== >> ivtv1: Autodetected Hauppauge WinTV PVR-150 card (cx23416 based) >> ACPI: PCI Interrupt Link [APC2] enabled at IRQ 17 >> GSI 21 sharing vector 0x3A and IRQ 21 >> ACPI: PCI Interrupt 0000:05:09.0[A] -> Link [APC2] -> GSI 17 (level, >> low) -> IRQ 58 >> ivtv1: Unreasonably low latency timer, setting to 64 (was 32) >> tuner 1-0061: chip found @ 0xc2 (ivtv i2c driver #1) >> cx25840 1-0044: cx25843-23 found @ 0x88 (ivtv i2c driver #1) >> cx25840 1-0044: loaded v4l-cx25840.fw firmware (16382 bytes) >> wm8775 1-001b: chip found @ 0x36 (ivtv i2c driver #1) >> tveeprom 1-0050: Hauppauge model 23552, rev E587, serial# 8382698 >> tveeprom 1-0050: tuner model is Samsung TCPN 2121P30A (idx 87, type 70) >> tveeprom 1-0050: TV standards NTSC(M) (eeprom 0x08) >> tveeprom 1-0050: second tuner model is Philips TEA5768HL FM Radio >> (idx 101, type 62) >> tveeprom 1-0050: audio processor is CX25843 (idx 37) >> tveeprom 1-0050: decoder processor is CX25843 (idx 30) >> tveeprom 1-0050: has radio, has no IR remote >> ivtv1: This is the second unit of a PVR500 >> ivtv1: Correcting tveeprom data: no radio present on second unit >> ivtv1: loaded v4l-cx2341x-enc.fw firmware (376836 bytes) >> ivtv1: Encoder revision: 0x02060039 >> ivtv1: Allocate DMA encoder MPEG stream: 128 x 32768 buffers (4096KB >> total) >> ivtv1: Allocate DMA encoder YUV stream: 194 x 10800 buffers (2048KB >> total) >> ivtv1: Allocate DMA encoder VBI stream: 120 x 17472 buffers (2048KB >> total) >> ivtv1: Allocate DMA encoder PCM audio stream: 455 x 4608 buffers >> (2048KB total) >> tuner 1-0061: type set to 70 (Samsung TCPN 2121P30A) >> eth0: no IPv6 routers present >> ivtv1: Initialized WinTV PVR 500 (unit #2), card #1 >> ivtv: ==================== END INIT IVTV ==================== >> >> >> ========================= >> Michael F. Ellis >> President >> Ellis Softworks Inc. >> ---------- >> Phone: (941) 713-0361 >> Email: [EMAIL PROTECTED] >> Web: http://www.ellissoftworks.com >> >> >> >> _______________________________________________ >> ivtv-users mailing list >> [email protected] >> http://ivtvdriver.org/mailman/listinfo/ivtv-users >> > > > _______________________________________________ > ivtv-users mailing list > [email protected] > http://ivtvdriver.org/mailman/listinfo/ivtv-users > _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
