TBS 6981 High Frequecy Horizontal Issue - Distributed System

[antthomas]

Hi,

I have a TBS 6981 card and I've been having issues watching High Frequency Horizontal polarisation channels.

I live in an apartment block that has a distributed satellite system.

Things I have tested and can confirm:

L/V, L/H and H/V channels all work fine all the time.
The card works fine when directly connected to an LNB.
The card can sometimes tune the H/H channels but often can't and if it does it will lose signal at some point.
A generic STB works fine on all 4 bands.
When I looped the TBS 6981 through a generic STB and tuned the STB to a H/H channel the TBS 6981 card can tune H/H channels fine. If I turn the box off the H/H signal disappears but all other channels work (L/V, L/H, H/V).
I have tried both Tuner A and B.
The extra power connector is connected. (I have tried with and without and it makes no difference)

It seems there is an issue with the 18V 22kHz signal.

Has anyone else seen this before?