More aerial help needed

TheDriver

Hi Folks,
Tried my aerials in attic last night, 1 grid with 10db amplifier (philex). Can get 4 irish and 4 british but some shadows on 2 rte, perfect tv3 and tg4 and very watchable british (i.e. just slightly below digital quality, light snow). Should I get a more powerful amp (maybe a televes) or a 2nd aerial as the shadows kinda go when i twist it a bit yet the rest of the channels go bad. Also was thinking of VHF for 2 rtes, can I use an amp after dilpexing uhf and vhf aerials if the amp is for uhf? No idea what the channels numbers are, in Bandon.

Ulsterman 1690

Its possible that you need a third aerial for RTE.

In many parts of Ireland (not sure about Bandon) RTE is on VHF and TV3/TG4 are on UHF

"ghosting" is the technical term for the "shadows". Its caused by signals bouncing off objects and being picked up on your aerial several times a more powerful amplifier wont help as it will just boost the "ghost" signals as well as the wanted one

TheDriver

I'm extremely puzzled, played around with aerial more and can get perfect RTE1 on VHF tuner and not great on UHF tuner even though my aerial is TRIAX grid. RTE 2 is alright in VHF. Should I get the VHF aerial, other channels are grand. Do I get a booster for UHF only and does it allow VHF pass through?

Darby OGill

I am trying to solve a problem I have only with RTE 2. (VHF signal from Kippure, direct line of sight).

There is a permanent "bleed" on dark grays/blacks/clouds etc. on screen. It's not a shadow in the sense of a second, similar image, just more of an actual shadow!! It does not happen on any other channel, only RTE2, and has been going on forever. Aerial was replaced last year, same problem. Any ideas?

Antenna

Ulsterman 1690 wrote:

In many parts of Ireland (not sure about Bandon) RTE is on VHF and TV3/TG4 are on UHF
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As I said already (in the other thread which Driver had started) Bandon has a RTE relay that transmits RTE1,2, TG4 (Group B UHF) but where Driver is living sounds like an area of good reception from Mullaghanish (as he has perfect TV3 which could only be coming from there) - so he might be better off getting a VHF aerial for RTE1,2 from Mullaghanish.

(Its better to avoid receiving from relays if a good signal can be got from a main transmitter instead as you will suffer from much less 'outages' due to power cuts at relay site etc)

Sounds like he is currently receiving TG4 and TV3 from Mullaghanish (group A - low UHF) and the "deflector" (AFAIK group C/D - high UHF) satisfactorarly on the same wideband aerial as these signals are same polarisation and from roughly the same direction where he is. The local relay for RTE1,2, TG4 is in group B and from another direction - so the existing wideband UHF aerial will not receive that properly if its aimed to the "deflector".

Get a VHF aerial and instead of Philex use a televes wideband UHF masthead amp with passive VHF combine, that should be OK
like this:
http://www.televes.es/hojastecnicas/103784.pdf

TheDriver

Thanks Antenna for all the advice. Is there any particular type of VHF aerial or are they all the same, will try Dwyers tomorrow for one. Do they stock the 103784 and any idea how much?
I'm still puzzled why I can get great RTE1 on VHF tuner from my UHF aerial!

Antenna

I suspect you don't want to spend very much - the Goldy coloured Yagi is the cheapest VHF band 3 they have.

byte

There are various sizes of VHF aerials, same as UHF. But I'd say a 4/5 element VHF would do the trick. Maybe check the nearest outdoor rig and see how many elements it has. A 4 or 5 element should be in the region of 15 to 25 euro.

As for mast head amp, I suggest the Triax 25W-1W amp, which has 25dB gain on UHF. The Televes mentioned by Antenna is a good amp, but if you already have a good UHF signal with a 10dB amp, I think 31dB amp is too much and could lead to cross modulations.

As for receiving VHF on a grid, it can be possible alright, but very hit and miss. And as you've said, one channel only works fine, the other doesn't.

Ulsterman 1690

I'm still puzzled why I can get great RTE1 on VHF tuner from my UHF aerial!

The RTE1 signal in your area must be fairly strong

But youll still probably get a better picture on a proper aerial

TheDriver

Will try to pick up the aerial and booster today, some neighbours have a 7 element VHF aerial, others just have UHF. I am doing loft. The picture with 10db is still bit snowy for the British channels so might try the 31db. Thanks for all the help, will report back when the job is done.