TV reception problem

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Rickles

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#815955 11-May-2013 21:14

Thanks for that ... I'll be sure to check the mounting and/or bracket. The current one looks as though it's just screwed to the existing arm, but once it stops raining I'll take a closer look.

R.

grant_k

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#815959 11-May-2013 21:44

Rickles: Thanks for that ... I'll be sure to check the mounting and/or bracket. The current one looks as though it's just screwed to the existing arm, but once it stops raining I'll take a closer look.

Yes, that's right. Just unscrew it and replace with the new one.

Rickles

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#816511 13-May-2013 09:30

Before spending money on a new LNB ...

Last night started recording a Prime program at 9:30pm. All fine until 16 minutes in and then the distortion started. I shut down the recording program, which also turned off the receiver card, and then restarted it ... no problems for the remaining 40-plus minutes of the broadcast!!

I'll at least take out, clean and reseat the PCI card, and also check cable connections both computer and dish, but not sure if this behaviour points to card or LNB failures.

Best guess is that if card, then it would fall over pretty consistently, but then I'd think the LNB would do same?

R.

grant_k

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#816535 13-May-2013 10:12

The fault that occurs with the Sharp Dual-throat LNBs as they get older is LO drift. In my case, I found that MySky could still lock on to some of the channels during sunny days, whereas my Vu+ Duo wouldn't. Then as it got worse, some channels wouldn't work on MySky either. The amount of drift is temperature and voltage dependent, so there are all sorts of variables going on. Eventually, it will crap out completely, as have thousands of those particular LNBs, all around the country.

Because you have previously experienced similar problems when using a decoder provided by Sky, my money would be on the LNB being at fault, rather than your PCI card. In any case, it doesn't cost a lot to replace the LNB, and in my case, reception improved out of sight, so I wondered why I had persevered so long, looking at other options. In my case, I replaced the mainboard and power supply in my receiver, all to no avail.

Rickles

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#816546 13-May-2013 10:33

Thanks Grant.

Rickles

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#822900 21-May-2013 12:22

UPDATE: Got on the roof and checked dish and LNB mountings ... all rock solid, no signs of movement.

Wiggled the cable and found it was very taut between the LNB entry and where it ran along the guttering. Pulled a little slack and turned the rubber boot a few times whilst dirt and dust dropped out ... may have tightened the screw at same time.

Since then (5 days ago) all transmissions have been fault free, including random recordings, switching channels and times etc.

Maybe just a loose connection afterall? Might now pull boot off, undo cable and spray and clean fitting, then ensure done up tight again .... maybe a little CRC and/or Vaseline to waterproof it? Same on outside of rubber boot.

R.

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grant_k

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#822913 21-May-2013 12:41

Rickles: Maybe just a loose connection afterall? Might now pull boot off, undo cable and spray and clean fitting, then ensure done up tight again .... maybe a little CRC and/or Vaseline to waterproof it? Same on outside of rubber boot.

It's possible that there was some corrosion on the centre pin, or the screw thread which connects the outer sheath of the coax. In which case, rotating it back and forth a few times would clear it.

Definitely DON'T spray CRC inside the connector or you will cause an impedance mismatch. IF signals in the 1-2GHz range rely on a matched termination at both ends of the cable to avoid SWR problems. If you have an impedance mismatch due to CRC, you may find that some channels drop out altogether.

The best idea would be to pull the boot off, and undo the connector, make sure all is clean and dry inside, and put it back together. Vaseline, being petroleum-based will attack the rubber boot, so that isn't a great idea either. The pros use PIB self-amalgamating tape for jobs like this, but normally the rubber boot is sufficient for LNB connections. If you're worried about it, you can buy self-amalgamating tape from MasterTrade, JA Russell etc.

Rickles

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#822920 21-May-2013 12:52

Thanks again Grant ... all good advice.

R.

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