smcka, on Oct 8 2011, 04:07 PM, said:
I've bought a Poletec LP35 for use in Galston - Light blue area. We cannot get 1, 7Mate and Gem (so seems to be all the 'secondary' channels); at best we get audio but no picture. We have a Tivo unit into an old clunker telly, but this all worked OK with the old 15+ antenna. The current antenna is pointed roughly towards Atratmon.
I've kept the Kingray masthead amp off the old antenna. Unsure of power, etc as I installed this myself.
We have a thunderstorm in Sydney and we are getting severe disruption and outages (and I am trying to watch Bathurst).
Apart from the obvious of getting in a antenna guy, what recommendations could you suggest? Just a bot over not being able to get what I think we should.
Not receiving the HD channels but the SD channels are OK, suggests you only have an SD tuner.
If you needed an amp previously for reliable digital reception, you may still require one, or you may not,.... it all depends on the signal strength and more importantly, the signal quality arriving at the antenna.
Pointing an antenna 'roughly' at a transmitter in difficult reception areas is usually not sufficient. You need accurate alignment and mounting the antenna in the optimum signal location, as even just a few centimetres difference in any direction, including up/down can make a huge difference.
Different antennas perform differently, so replacing an antenna in the identical position with a different type of antenna doesn't necessarily mean reception will be the same or better than previously.
What can you do without getting an antenna guy in?.... not a lot, unless you have a digital signal instrument which can measure DCP, pre-viterbi BER, MER and NM. (and of course understanding it all and applying the information to determine any issues and how to correct them).
Check all your connections and cabling. If you have fitted an F connector, ensure there are no stray strands of braid or foil shorting on the centre conductor.
A good installer will perferm a signal site survey, all over your roof, at different heights (and even other places on your property if suitable signal levels are not found on the roof) with different antennas, to determine which antenna and mounting location provides the best result.
Without performing a site survey with accurate instrumentation, all you can do is experiment and you may never find that magical 'sweet spot' which provides reliable digital reception.
As for lightning... even with excellent signals, lightning can cause interference, but the poorer the signals, the greater the effect the lightning will have on reception.
Having said all that, if it all worked OK previously, then it can again.
It may be something as simple as a crook connection.