Pros and cons of cable cards?

[kd0bcl]

I should try for a signal strength greater than 0dB (as measured by the Ceton) to eliminate this problem? .

Not at all, if the ceton is reporting 0db with good snr <33db for most systems, 35+ preferred, that should be perfect. That is what mine runs and the tiling on copy once is there. I have played around with sigs from -5 to +20. makes no difference.

All I was saying is that the reported values from the ceton are actually lower then the rf power that is actually measured at cable input. If you were to put a signal meter on your outlet you would have a reading of about 7-9 dbmv on that frequency that the ceton reports 0db.

The reported levels by the ceton in my experience are spot on if you account for this extra internal loss. The 0dBmv on the diag page is exactly what you want to strive for, also making sure that is is balanced "tilt." You do not want a ch on freq 111mhz to be a +12 and a channel on 747mhz to be 0. This can be tougher to achieve and depends on the tap outside to be balanced properly to start.

Again it sounds like you have a "ceton" issue and not a signal issue. I have not bothered with it much lately since my only copy flags are on our premiums (hbo) in my case. Since this is the only issue I have, and others have it too I am just waiting. I have been reading here and on dsl reports if some magic firmware will fix it. I have stopped experimenting on my system however, I just want to sit and watch TV

Peter

[richard1980]

The InfiniTV has a built-in amplifier that corrects the signal loss associated with splitting the signal 4 ways. The only signal loss you should see from the coax cable to the tuner would be the signal loss associated with the connectors, which is not enough to even worry with. So basically if you read 0 dB at the tuner, you should read 0-1 dB at the cable.

[kd0bcl]

The InfiniTV has a built-in amplifier that corrects the signal loss associated with splitting the signal 4 ways. The only signal loss you should see from the coax cable to the tuner would be the signal loss associated with the connectors, which is not enough to even worry with. So basically if you read 0 dB at the tuner, you should read 0-1 dB at the cable.

Have you confirmed this? My own and the 3 others I have seen this does not appear to be the case? All 4 that I have checked were internal pcie boards and they all had about 7-8 db loss reported vs actual measured rf signal.

Perhaps some do have some sort of auto gain control or active splitter inside, but I have not seen it.

[WhatHappend]

I also don't believe the Ceton tuner has any internal amplification. I saw that posted before (maybe by Eric), but all my tests also show a loss of at least 7dBm according to the RF level presented on the Ceton page.

I wonder if whom ever posted that was confused by each tuner instances AGC amp? All tuners have internal AGC amps and the the amount of AGC gain needed is usually read for software/firmware to determine the input signal level. This is different to a wide frequency amplifier of say 10dBm to prior to the internal splitter to compensate for the splitting loses.

[richard1980]

I just assumed erkotz knew what he was talking about:

The InfiniTV amplifies the signal, so there is not a 7dB loss to each tuner
The InfiniTV does use an active internal splitter

Are you sure you are measuring the same frequency at the tuner and on the line?

[kd0bcl]

It sure sounds like he is saying it does, but all I know is that when I tune any particular frequency and read the diagnostic page I get a value of approx 7db less than what my signal level meter reads on the same qam frequency. I know the meter is accurate as it has recently been calibrated and I use it for field use daily. (JDSU DSAM 3300)

The end of the day it does not really matter, whatever is in the card is not disrupting MER/SNR, so it is easy to overcome with properly managing the incoming signal.

Perhaps he was talking about the AGC amp that is associated with each tuner, but from the two links posted it does not sound like it.

Maybe erkotz will chime in.