I don't really know what I'm talking about !
Scott
reception area for analogue TV. There is a local relay, which does
not carry digital services. I invested in an aerial upgrade using a
Group E aerial, which is the right one. I seem to have fairly high
signal strengh on each multiplex.
Periodically, I get picture freezes (which usually recover) and
sounds like a metal object hitting a pipe. This seems to be worse on
the 64QAM channels (though C4 is not too bad).
I don't know if this is likely to be -
- impulsive coming from an applicance inside the flat (fridge?)
- impulsive coming from outside (though the aerial seems to be far too
high for vehicle electrics)
- multipath reflected signals due to high buildings between here and
the transmitter
- interference from stronger analogue channels
- aerial moving in the wind
- weather conditions
- lack of software upgrades
Is there any way of identifying the most likely cause?
I've seen a suggestion to fit an attenuator to cut the analogue
signal, but this does not seem to make much difference.
I see there are quite a few new boxes (including a new Philips).
These seem to offer faster channel changes and better graphics, but
will they improve the basic picture and sound?
Any advice gratefully received (as is the TV signal).
Scott
Tony Walton
>
> Periodically, I get picture freezes (which usually recover) and
> sounds like a metal object hitting a pipe.
That's a good description of what I used to get on my old Philips DTX6370!
When you upgraded the aerial did you also upgrade the downlead? Mine
was definitely due to impulse interference from outside - poorly
suppressed vehicle ignition systems mainly - and was cured almost
completely by an aerial upgrade which included a shiny new downlead
(CT-100 cable, is it? Help me out, Bill!). "Almost completely" means
"from 15-20 metal objects hitting pipes per night to maybe one every
couple of months if I was unlucky".
--
Tony
Bill
Delighted, old bean.
CT100
QC100
QF100
HF109.
Look for copper foil on copper brail. Don't use silver foil type except for
very undemanding or budget applications.
Bill
Dave Fawthrop
They actually *make* co-axial cable with silver foil?
Must be a bit pricy ;-)
mike ring
news:20cuc0ps0o0cpu04b...@4ax.com:
>
>
> Periodically, I get picture freezes (which usually recover) and
> sounds like a metal object hitting a pipe. This seems to be worse on
> the 64QAM channels (though C4 is not too bad).
>
I had exactly the same symptoms from my old philips, and also from the
Daewoo decoder/VCR.
But the Goodmans GDB4 from Smiffs at 50 squid seems rock solid.
ISTM that electrical impulsive interference is more important than I had
thought, and protection should be part of a boxes specification; perhaps
this group should seek further information on models on sale?
Assuming mains, aerial etc borne noise can't be totally eliminated in this
electrically noisy environment, it should be catered for in design.
(Then you could buy a box that would behave from it's specs)
mike
Anthony Stokes
"Dave Fawthrop" wrote in message
> | Look for copper foil on copper braid. Don't use silver foil type except
for
> | very undemanding or budget applications.
>
> They actually *make* co-axial cable with silver foil?
> Must be a bit pricy ;-)
Hmm, I suppose if it was silver foil the spec might be better than the
copper-over-copper types of cable ( thinking of the silver or rhodium plated
copper wire used in some radio frequency circuitry ) - but I guess the
silver ( i.e. Aluminium ) foil types of cable are generally not usually as
good as the copper foil + copper braiding types ~ though I have had no
trouble using an entire 100 metre drum of very obviously aluminium outer
conductor cable connecting the IF output frequencies of a Ku band LNBF to a
set-top digital FTA receiver.
Ant
Bill
>Must be a bit pricy ;-)
OK, it was shorthand. Usually the foil is in fact clear plastic mylar sprayed
with about a micron of some conductive substance. Sometimes though it is
actually aluminium. In any case it is crap.
Bill
Tony Walton
Mine seems to be aluminium with a layer of some sort of laquer (I found
a lump of spare cable in the cupboard under the stairs, took a bit of
the foil and put a match to it). Not surprising it's cheapy stuff - the
installation was one of those OnDigital £40 upgrades. Seems to do the
job, though.
--
Tony
Bill
>a lump of spare cable in the cupboard under the stairs, took a bit of
>the foil and put a match to it). Not surprising it's cheapy stuff - the
>installation was one of those OnDigital £40 upgrades. Seems to do the
>job, though.
>
>--
>Tony
>
mysteriously appeared on Satcure's site (!) I've tried to put some sort of
vague values on the difference between the different types of cable. There are
so many makes though that you can't establish hard and fast values. I just find
it easier to stick to a few tried and trusted copper on copper cables.
Bill