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Thread ID: 49101 2004-09-10 05:09:00 OT TV Aerial Chris Randal (521) Press F1
Post ID Timestamp Content User
270911 2004-09-12 04:50:00 And if you want to know if a 300 ohm ribbon dipole will work into your 75 ohm tv socket, put a piece of wet string on the center terminal of the tv socket - if it works ok, yh wet string can be replaced with a ribbon dipole, or a rabbit ears. All are evil things that pick up almost omnidirectionaly, but are adequate where you have a good strong signal almost entirely direct from the transmitter. (Not too many reflections from whatever.) R2x1 (4628)
270912 2004-09-12 05:09:00 doesn't the wet string dry out,

this reminds me once how Channel 2 station TV1 in Auckland would be poor reception in summer, a quick solution until the bolts on the aerial were replaced was to water the aerial with the garden hose every 30 minute.
Earnie Moore (5918)
270913 2004-09-12 06:15:00 Personally i dont think money was a factor at all, it was bad consulting and ignorant advise that stalled this project,
Between four and six digital channels can fit in the transmission spectrum of one Analogue channel.
These Extra freqencies auctioned off would have easily covered initial costs.
Moneys generated thru new sales of Digital TVS and decoders would have boosted local economy and programs from established DTV broadcasters would have given us some spectacular choices.
skinnerjack (4296)
270914 2004-09-12 08:38:00 >Personally i dont think money was a factor at all, it was bad consulting and ignorant advise that stalled this project,
Between four and six digital channels can fit in the transmission spectrum of one Analogue channel.

not quite. the limited effective range means more transmitters need to be installed which would use up a lot of the extra channels and the cost would be huge. anything just out of line of site will require its own transmitter. for eg locally here we would have to have several transmitters just to cover the same aera that 1 analogue transmitter covers simply due to the amount of hills around here.
tweak'e (174)
270915 2004-09-12 09:22:00 Thanks Billy T and Godfather.

It is definitely the VHF channel that is the problem from where we are in Manurewa (Ch 1)

The others (all on UHF) are fine.

The outdoor aerial is one of what appears the original Sky aerials - sort of X shape directors and /\ shape reflectors. Could that be the problem?

Thanks folks
Chris Randal (521)
270916 2004-09-12 10:36:00 You describe a UHF antenna.

A VHF antenna is BIG. 6 feet or more across.

There is a law of physics that determines the required size, related to the frequency. VHF is lower in frequency, needed larger aerial size.

You will never get good TV reception of VHF channels (1 - 11) on a UHF only antenna. Thats why indoor aerials work a bit better on UHF channels, they better approximate the size.

An indoor antenna for Channel 1 would not leave space for you in the same room ... as an example.
godfather (25)
270917 2004-09-12 11:10:00 >The outdoor aerial is one of what appears the original Sky aerials - sort >of X shape directors and /\ shape reflectors. Could that be the problem?

Well, that's definitely your problem Chris, you have a UHF antenna that has inadequate capture area for VHF signals. If you could persuade your landlord to let you put up your own antenna (or pay for one to be put up for him if he's that fussy about what goes on his roof) then your reception will improve out of sight!

If not, there is little option but to use rabbit ears, but their effectiveness will depend heavily on where your home is located. If you are on the northern side of town with a clear view across to the Waitakeres you might have some hope, but if you can't see the Waitakeres then reception will not be very good at all.

Cheers

Billy 8-{)
Billy T (70)
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