anthony stokes

In recent days on my 1.1m dish 30km east of London I have found Hotbird 2
and 3 transponders to be generally much more weakly received than broadcasts
from the other Hotbird satellites at 13 East. No amount of longitudinal
variation of my dish improves the reception which remains rather weak
compared to the Hotbird 6 and 7A transmissions.

Is this a real effect which has been noticed by others near London ?

My dish elevation has not slipped and there is no new tree growth in the
signal path: so I wonder whether there has been some small seasonal
reduction in the power output or change of accuracy in direction-pointing of
the beams from two of the Hotbirds ?

Anthony

charles ellson

Is it HotBird 2/3 channels which are dodgy or is there also a bias
against horizontal or vertical channels ? If the latter then the LNB
skew might be slightly off, if the former (to a significant extent)
then possibly the dish is off-beam from the centre of the HotBird
group.
--
_______
+---------------------------------------------------+ |\\ //|
| Charles Ellson: charles@e11son.demon.co.uk | | \\ // |
+---------------------------------------------------+ | > < |
| // \\ |
Alba gu brath |//___\\|

anthony stokes

Thanks for the suggestions, but it seems not a polarisation issue: - and
since the weakened strength of Hotbirds 2 & 3 here is throughout both day
and night it does not seem due to the two satellites having drifted further
away from the equator.
No longitude variation of my antenna appears to bring up these transmissions
any stronger than ( for example ) the Nilesat vertical channels - which are
barely OK in fine weather but lost when raindrops settle on the LNBF.

I was wondering whether any other viewers / listeners near London have
observed a similar reduction in Hotbirds 2 & 3 as compared with 6 & 7A (
which possibly are maintaining slightly higher ERP being nearer the start of
their expected lifetimes )

Ant.

anthony stokes

Reverting to a SYNTEC 2000 0.3db LNBF instead of the Titanium 0.2db
universal single LNB has brought all Hotbirds transponders back to usual
strength and quality here; although I remain unable to explain how the
Titanium LNB could malfunction in such a way.

Ant.

charles ellson

If the fault is electrical then you've probably had it but it might
also be mechanical, possibly as simple as the amount of
in/out/rotation adjustments of the LNB in the clamp or a boom which is
slightly out of position. If the dish is mounted somewhere that you
can safely see/watch a signal meter while you jiggle around the LNB
(or gently prod the dish and boom with finger pressure) then you might
be able to improve things or, if that makes no difference,
conclusively condemn the Titanium LNB.
--
_______
+---------------------------------------------------+ |\\ //|
| Charles Ellson: charles@e11son.demon.co.uk | | \\ // |
+---------------------------------------------------+ | > < |
| // \\ |
Alba gu brath |//___\\|