does freeview DVB-S get rain fade?

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bok007

76 posts

Master Geek

# 21090 15-Apr-2008 15:36

Hi
After getting lots of rain fade on sky today, I am wondering if freeview DVB-S is as susceptible as sky?
could be a good reason to go freeview??
Thanks!

openmedia

2118 posts

Uber Geek

Trusted

# 123696 15-Apr-2008 15:56

SInce the move to Optus D1 the chance of rainfade on Sky should be close to zero, so I'd have your disk alignment looked at.

If you have an issue with Sky you will have the same problems with freeview given that they share a satellite and run at similar power.

Generally known online as OpenMedia, now working for Red Hat APAC a Technology Evangelist and Product Manager. Still playing with MythTV and digital media on the side.

bok007

76 posts

Master Geek

# 123699 15-Apr-2008 16:02

Thanks Steve
I thought that was the case - It was really heavy rain today though eh!

allstarnz

1693 posts

Uber Geek

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# 123703 15-Apr-2008 16:04

it shouldn't make a difference of Sky or Freeview, they both use the same technology, just Sky is encypted.

It depends on the dish more than anything. The larger the dish, the less susceptible to rainfade it is.

talsemgeest

75 posts

Master Geek

# 123709 15-Apr-2008 16:25

Ihave a relatively newly installed sky dish and we still get rain fade, even though it's not supposed to happen...

bok007

76 posts

Master Geek

# 123716 15-Apr-2008 16:41

I had heard it depends on the transponder frequencies,
that happened to have the same wavelength as drops of rain!

mcraenz

1091 posts

Uber Geek

# 123720 15-Apr-2008 17:07

talsemgeest: Ihave a relatively newly installed sky dish and we still get rain fade, even though it's not supposed to happen...

just because it's new doesn't mean it was aligned properly in the first place. You may want to get sky to redo it

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talsemgeest

75 posts

Master Geek

# 123721 15-Apr-2008 17:10

Yeah, thats what I'm thinking. Or maybe I should just do it myself. (Sorry to be off topic)

paradoxsm

3000 posts

Uber Geek

Trusted

# 123761 15-Apr-2008 18:52

It also depends how accurate they got the alignment when they installed the dish. Possibly the area of the country you are in might have a factor too. I one had a diagram on how it was all aimed from the downlinks but seem to have lost it.

I have a new dish with dual LNB and have not had any issues though it may still occur.

In short. yes, Freeview is susceptible to rainfade though it shoulld be very rare.

Fraktul

836 posts

Ultimate Geek

Trusted

# 123765 15-Apr-2008 19:06

bok007: I had heard it depends on the transponder frequencies,
that happened to have the same wavelength as drops of rain!

Three seperate issues, resonance in the intervening material, wavelenght compared to the size of the intervening object(s) and size and positioning of the intervening object within the fresnel zone.

CYaBro

3169 posts

Uber Geek

Subscriber

# 123870 15-Apr-2008 23:04

I have been using Freeview DVB-S since it was launched.
Only once had a rain fade type problem - Picture got all pixelated and broke up for about 15 mins but that was during a really really heavy rain shower.

cyril7

6964 posts

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Subscriber

# 123990 16-Apr-2008 11:59

Since D1 tookup duty I have only seen rain fade when the noise on the roof was so loud I couldnt here the TV anyway.

Actually if the weather front is moving from the northwest you often see the rain fade before the front/heavy weather arrives.

Regardless with a correctly aligned 65cm dish and the current levels off D1 (which is the same for sky and freeview) you should only experience rainfade under the most heavy of downpours.

Cyril

kiwisat

147 posts

Master Geek

# 124291 17-Apr-2008 09:28

CYaBro: I have been using Freeview DVB-S since it was launched.
Only once had a rain fade type problem - Picture got all pixelated and broke up for about 15 mins but that was during a really really heavy rain shower.

Often the skew of the LNB is overlooked because of the strong signal from D1. Try picking up SCTV on D1 vertical, and if necessary adjust the LNB for maximum signal strength. Then all the H pol transponders will be receiving maximum signal from the dish.
I currently install Freeview using a very accurate 45 cm dish and because of its wide beam width, can receive acceptable signals
over a degree or more either way, but a final tweek on SCTV (TP 12635V, SR 5090, PIDs 0609,0610,0609) gets all the ducks in a row.
If you have Sky box in the loop, you must pull it's plug or it will power the LNB for H pol and you won't get Vertical signal.

Be aware that you won't always see colour bars on SCTV but the transponder will still be active.