Certain groups of channels gone

TheDriver

I have a dish from the last owners on the house. my main humax box is loosing channels from the following:
10964H
10773H
10891H
11307H
10714H

But they are working fine on the feed to a different TV.
Is it a box issue or an LNB issue. The channels do come back on periodically on the affected tv

brightspark

Try switching the cables around at the LNB.

It could be water damaged cable preventing sufficient voltage switching the LNB, if the problem moves to the other TV it's the LNB. (You will need to identify which cable is feeding which box of course)

If it doesn't move it could be either the cable or box.

Swapping boxes around might be an idea to try first if access to the dish is difficult.

A higher voltage is required to enable the H, so a bad cable can cause problems.

From http://www.satcure.co.uk/tech/lnb.htm


A modern "Universal" LNB requires a 22 kHz signal at 0.5v p-p to switch its Local Oscillator to 10.6 GHz ("high band"). Otherwise it uses its 9.75 GHz oscillator.

Polarisation switching is controlled by DC voltage supplied by the receiver. 12.5v to 14.5v gives vertical and 15.5 to 18v gives horizontal polarisation. A higher voltage than that can damage the LNB (although I have run it up to 24 volts, briefly, without damage). A voltage that is too low will prevent the LNB from working correctly.

TheDriver

Thanks, will try. I should add that sometimes there is a signal for these particular channels but it is pixelating and most other times its 90% signal strength and quality. Other tv is fine at these times.

Atlantic Dawn

Had a similar problem myself and turned out the cable going in to LNB for that box had loosened, quick tighten up and was good as new.