alanh, on Dec 26 2010, 06:27 PM, said:
I did not see your post.
Downloaded video, unless it was recorded off air first will not have any of the problems of off air interference. However the quality is usually worse anyway.
Impulse noise gets weaker as the frequency rises, so UHF such as SBS and West TV is less affected than the VHF channels. This is why the ACMA has not allocated any TV transmitters to any RF channel below channel 6.
Do you have a masthead amplifier mounted in a box below the antenna, along with a plug pack which is fed into an inserter in the antenna feed between the receiver and the wall socket?
Essentially you do not have enough signals. Another cause is corrosion in the antenna, which is common in Craigie because of the high salt level in the air. This particularly makes reception of 9, GEM and Go! unreliable in impulse interference.
Look at the antenna drawings in the link Antenna basics in the first post in this strand. Post the antenna type you have from the drawings. You should also be able to see manufacturers' pictures in the H34, and H3, H4 links in the same first post in this strand.
The best way to reduce this interference is to get an electrician to put an 100 nF capacitor across the contacts of a flasher relay or the flashing bulb.. If LEDs are being used the capacitor can be placed across the output of the controller.
From your description you either have an antenna system fault or the antenna is not sensitive enough. Do you loose signal during heavy rain?
Re the downloaded video: The downloaded video is recorded TV broadcasts. BBC 1, 2, 3 in the UK. Various stations in the US and Canada. No impulse noise at all. Ever. The video is compressed using DivX/Xvid. The quality on my 42 inch plasma is excellent. I read that UHF is used overseas whereas in Australia it's predominantly VHF. Typical that we get the bargain basement version.
As for my reception, I do not lose the signal during heavy rain. Hail is not a problem either.
The antenna is 5 years old so corrosion is not a problem. My previous antenna lasted 20 years without a problem. The only reason it was replaced was because a "high gain" antenna was installed. This did get rid of alot of the impulse noise. I do not have a masthead amplifier because the installer said that if the impulse noise was being picked up by the antenna then the amplifier will amplify the impulse noise too. I have read that on a few different websites so I accept that what the installer told me is correct.
I am on the wrong side of a hill and there are tall trees on the top of the hill. I have been told that the only way to increase signal strength is to put up a mast to get the antenna up higher. I have noticed that a few people around here have done that.
It would be helpful if you could tell me what sort of antenna you think I need. To be honest, though, as this problem only happens at Christmas I can't see that spending hundreds of dollars more is worth it.
I assume that your advice about the capacitor refers to the flashing lights on my neighbour's Christmas tree. That is not an option.
Is it possible that my neighbour's digital signal is not affected by the impulse noise from her Christmas tree lights? Her antenna is just a standard VHF/UHF antenna. The same one she has had for years. I know she has a set top box. I've seen it. Whether she uses it is another matter. She has a cathode ray TV that is at least 10 years old.
I'm just grateful I don't have one of those people who cover their houses in flashing lights for a neighbour.
Edited by Jarod63, 02 January 2011 - 12:08 AM.