Digital TV and Weather

[Ext User(Al Foyle)]

Any of you guys experience reception problems during wet weather on
digital? Recently, we have. Mainly TEN Victoria and WIN, though. Analog
reception is fine during crap weather.

[Ext User(darryl)]

In article <445fa86d.00004505.bm008@yahoo.com.au>,
Al Foyle <al_foyle@yahoo.com.au> wrote:

> Any of you guys experience reception problems during wet weather on
> digital? Recently, we have. Mainly TEN Victoria and WIN, though. Analog
> reception is fine during crap weather.

Remind me, what is wet weather? It no longer rains in Sydney. I just
wish it would even at the expense of reception.

[Ext User(Derek)]

"Al Foyle" <al_foyle@yahoo.com.au> wrote in message
news:445fa86d.00004505.bm008@yahoo.com.au...
> Any of you guys experience reception problems during wet weather on
> digital? Recently, we have. Mainly TEN Victoria and WIN, though. Analog
> reception is fine during crap weather.
>
Rain reflects radio waves causing multipathing. On analog this shows up as
ghosting.
Digital is able to cancel out multipath up to a point, then it breaks up.
What transmitter site are you watching?
Do you know the GI settings of the digital channels you watch?

Derek.

[Ext User(Al Foyle)]

darryl wrote:

> Remind me, what is wet weather? It no longer rains in Sydney. I just
> wish it would even at the expense of reception.

Silly question. Sorry. It's just that we got our annual rainy day on the
weekend, and the reception was woeful. Pops and crackles, frozen
pictures, sometimes muted audio, etc.

I wonder how much it has to do with the receiver as it does with the
antenna. You see, in the family room I have a DSE branded unit connected
to a normal external antenna. In either analog or digital the reception
is perfect. In the lounge, however, I have a set of rabbit ears cable
tied to a mike stand. It's connected to a Kross (Safeway special)
receiver. It's fairly sensitive to orientation, but generally, while the
analog reception is crap, the digital is fine, unless I move the
antenna, of course.

However, on Sunday, neither were that fine at all. Mostly TEN Vic and
Prime were the worst affected.

Of course, for a one-day-a-year event, it shouldn't really matter. I'm
just concerned just in case it decides to rain again some time in the
future...

:-)

[Ext User(PeteR)]

"Al Foyle" <al_foyle@yahoo.com.au> wrote in message
news:446010a4.000065ae.bm000@yahoo.com.au...
> darryl wrote:
>
> > Remind me, what is wet weather? It no longer rains in Sydney. I just
> > wish it would even at the expense of reception.
>
> Silly question. Sorry. It's just that we got our annual rainy day on the
> weekend, and the reception was woeful. Pops and crackles, frozen
> pictures, sometimes muted audio, etc.
>
> I wonder how much it has to do with the receiver as it does with the
> antenna. You see, in the family room I have a DSE branded unit connected
> to a normal external antenna. In either analog or digital the reception
> is perfect. In the lounge, however, I have a set of rabbit ears cable
> tied to a mike stand. It's connected to a Kross (Safeway special)
> receiver. It's fairly sensitive to orientation, but generally, while the
> analog reception is crap, the digital is fine, unless I move the
> antenna, of course.
>
> However, on Sunday, neither were that fine at all. Mostly TEN Vic and
> Prime were the worst affected.
>
> Of course, for a one-day-a-year event, it shouldn't really matter. I'm
> just concerned just in case it decides to rain again some time in the
> future...
>
Rain absorbs radio signals, particularly on the UHF channels which will
cause your digital tuner to drop out if you have a weak signal to start
with. You don't say whether you are watching TEN Victoria on a VHF or UHF
channel, that would be useful information.
It's unlikely that rain causes multipathing as mutipathing is normally
caused by the signal being reflected off solid objects such as walls,
buildings and hills. When the signal bounces of a solid object the result is
a delayed second signal arriving (in time) later than the main signal. This
results in ghosts in analogue television and/or wave phase cancellation that
can cause digital tuners to drop out.
If you can, ditch the rabbit ears and get a decent external antenna
installed. Rabbit ears rarely give good consistent reception on all
channels.

PeteR

[Ext User(Al Foyle)]

Derek said....

> Rain reflects radio waves causing multipathing. On analog this shows up
> as ghosting.

Didn't see any ghosting on analog at the time.

> Digital is able to cancel out multipath up to a point, then it breaks up.
> What transmitter site are you watching?

Mt. Tassie, Gippsland. Ten Vic, WIN, Prime, ABC, etc.

> Do you know the GI settings of the digital channels you watch?

No. But hopefully they're low GI. I'm on a diet. [1]











[1] Or in other words - what does "GI" mean?

[Ext User(Al Foyle)]

PeteR wrote:

> Rain absorbs radio signals, particularly on the UHF channels which will
> cause your digital tuner to drop out if you have a weak signal to start
> with. You don't say whether you are watching TEN Victoria on a VHF or UHF
> channel, that would be useful information.

Sorry. It's all UHF around here. Has been since the early 90s when we
started receiving more regional network services. As far as I'm aware,
this is the case across Victoria apart from MEL.

> If you can, ditch the rabbit ears and get a decent external antenna
> installed. Rabbit ears rarely give good consistent reception on all
> channels.

It's something that's "on the books". However, the same thing is
occuring on the receiver in the family room which has line of sight to
the transmitters on Mt. Tassie, which are about 20 km away, as the crow
flies. When it was happening the other night, I ended up flicking back
over to the analog channels which were coming in clear as a bell.

[Ext User(PeteR)]

"Al Foyle" <al_foyle@yahoo.com.au> wrote in message
news:44615de0.000074d6.bm004@yahoo.com.au...
> PeteR wrote:
>
> > Rain absorbs radio signals, particularly on the UHF channels which will
> > cause your digital tuner to drop out if you have a weak signal to start
> > with. You don't say whether you are watching TEN Victoria on a VHF or
UHF
> > channel, that would be useful information.
>
> Sorry. It's all UHF around here. Has been since the early 90s when we
> started receiving more regional network services. As far as I'm aware,
> this is the case across Victoria apart from MEL.
>
> > If you can, ditch the rabbit ears and get a decent external antenna
> > installed. Rabbit ears rarely give good consistent reception on all
> > channels.
>
> It's something that's "on the books". However, the same thing is
> occuring on the receiver in the family room which has line of sight to
> the transmitters on Mt. Tassie, which are about 20 km away, as the crow
> flies. When it was happening the other night, I ended up flicking back
> over to the analog channels which were coming in clear as a bell.
>
Poor old GLV. When it started up in the late fifties it was GLV10. When ATV0
in Melbourne changed to channel 10 in the 70's GLV was moved to channel 8 to
make way for it (Reg Ansett owned ATV0/10 then and he was the equivalent to
Kerry Packer at the time). Now GLV and the rest in the Latrobe Valley are
all on UHF just to keep Melbourne happy. Will it ever stop? ;>)
[End of rant]

Even at 20KM line of site to the transmitter, rabbit ears on UHF are very
iffy in digital. I'd be putting a UHF yagi antenna on the roof and splitting
it to the two receivers, maybe with a head amp if necessary.

PeteR