Superhub : Power levels too high?

[Sephiroth]

If you get a chance, it's worth tracing your cable back to its source inside the block to see if that's a rats' nest. If it is, anything can happen. You's see splitters on splitters and JB can tell you what that means. On the other hand, it might be perfectly OK.

The cable to the block will come from a street cabinet, prolly sitting in the sun. That would account for the power level fall and if I'm right, it'll rise again this evening. Keep us posted.

[scaseman]

The power actually dropped slightly after dark.

[Sephiroth]

So there's a highly local situation, it seems; like in the block. As I said it'll be worth tracing your coax to see what state the block's box is in.

[scaseman]

I fitted a 10Db Forward Path Attenuator and now get the following. Are these power levels still ok.

Downstream Channels
Lock Status Channel ID Frequency Modulation Rx Power SNR Pre RS Errors Post RS Errors
Locked 43 315000000 Hz QAM256 -4.3 dBmV 41.4 dB 98 0
Locked 40 291000000 Hz QAM256 -3.4 dBmV 41.4 dB 22 0
Locked 41 299000000 Hz QAM256 -3.6 dBmV 41.8 dB 40 0
Locked 42 307000000 Hz QAM256 -4.1 dBmV 41.8 dB 46 0
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Upstream Channels
Lock Status Channel ID Frequency Modulation Tx Power Mode Channel Bandwidth Symbol Rate
Locked 1 35800000 Hz ATDMA 40.5 dBmV 16QAM 6400000 20480 Kbits/sec
Unlocked 0 0 Hz Unknown 0.0 dBmV Unknown Unknown 0 Kbits/sec
Unlocked 0 0 Hz Unknown 0.0 dBmV Unknown Unknown 0 Kbits/sec
Unlocked 0 0 Hz Unknown 0.0 dBmV Unknown Unknown 0 Kbits/sec

[Sephiroth]

Those levels are OK. Does it perform OK now?

[jb66]

So you've got a powered booster to amplify the signal then a attenuator to lower it? Just be done with the amplifier

[sollp]

Originally Posted by scaseman

I fitted a 10Db Forward Path Attenuator and now get the following. Are these power levels still ok.

Downstream Channels
Lock Status Channel ID Frequency Modulation Rx Power SNR Pre RS Errors Post RS Errors
Locked 43 315000000 Hz QAM256 -4.3 dBmV 41.4 dB 98 0
Locked 40 291000000 Hz QAM256 -3.4 dBmV 41.4 dB 22 0
Locked 41 299000000 Hz QAM256 -3.6 dBmV 41.8 dB 40 0
Locked 42 307000000 Hz QAM256 -4.1 dBmV 41.8 dB 46 0
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Unlocked Unknown 0 Hz Unknown 0.0 dBmV 0.0 dB Unknown Unknown
Upstream Channels
Lock Status Channel ID Frequency Modulation Tx Power Mode Channel Bandwidth Symbol Rate
Locked 1 35800000 Hz ATDMA 40.5 dBmV 16QAM 6400000 20480 Kbits/sec
Unlocked 0 0 Hz Unknown 0.0 dBmV Unknown Unknown 0 Kbits/sec
Unlocked 0 0 Hz Unknown 0.0 dBmV Unknown Unknown 0 Kbits/sec
Unlocked 0 0 Hz Unknown 0.0 dBmV Unknown Unknown 0 Kbits/sec

Even though the recieve levels are better the upstream TX Power should not have been attenuated, so something is still not quite right. After having another look, you were originally locked onto 27.40mhz but since the levels have been adjusted and HDU fitted it's now locked onto 38.50mhz with a 5dB variance so could well be incorrect return levels in the network?

[qasdfdsaq]

Higher frequencies don't travel as far.

[scaseman]

So you've got a powered booster to amplify the signal then a attenuator to lower it? Just be done with the amplifier

It's nice to know that people on this forum are so helpful.
If I turn that off I lose my TV. I could always remove the attenuator. I suspect it does not help much either way. The only problem that seems to occur is worse ping and jitter but that has been more of a problem for a couple of weeks.

[jb66]

yes if its off the tv goes off but if its replaced with a splitter it would be fine

[scaseman]

So you've got a powered booster to amplify the signal then a attenuator to lower it? Just be done with the amplifier

The amplifier was fitted because my TV signals were a bit low and I was losing HD channels especially in the evening.

[sollp]

Originally Posted by qasdfdsaq

Higher frequencies don't travel as far.

Higher Frequencies attenuate more depending on cable type and the length of the cable, at 30mhz RG6 Loses 3.84dB @100m, so the difference between 27mhz and 38mhz would be small, say 0.50db if that, not 5dB.