Digital Tv (bit NB) again!

[mjf]

Dammit - the first one disappeared.

Can anyone help / advise?

I have a power TV aerial that used to give a ghost effect on all terresial stations.

The digital box connected to the same aerial source give now gives excellent results on the many new channels this system provides.......except ITV1 (ch3) which often 'freezes' normally at crunch moments, annoyingly. I do not mind missing Corrie but like to watch / video G Prix so need it for Monaco this w/e.

Co-incidentally my cable at home gives excellent pictures except ITV which is fuzzy when compared to the other channels.

Is the ITV signal duff in S Eng. Do others have a similar problem in Solent area and.....what can I do to get better ITV reception pls?

Anyone Help?


Thanks

Michael

<hr width=100% size=1>

 

[mainshiptom]

When on itv press menu and signal information!

There could be a few things wrong?

Strength of signal?
Amount of errors received?

May just tune the aerial to this channel i.e. turn the aerial until you get the best reception?


<hr width=100% size=1>

 

[mjf]

Cannot as its like a flat plate and sites high on the radar arch.

Will try the signal strength info thou - stupid I should have thought of that myself.

Michael

<hr width=100% size=1>

 

[mainshiptom]

OK then, turn the boat around ?

Tom

<hr width=100% size=1>

 

[Wiggo]

Don't be daft, he needs to get the thing higher up. Have the boat craned out and chocked off on very high blocks.

<hr width=100% size=1><A target="_blank" HREF=http://homepage.ntlworld.com/graham.wignall/boats/eulimene600x800.jpg>The old and the new</A>

 

[mjf]

jez, the boat swings round automatically at anchor so that bits solved.

The aerial has to be 12/15 ft above the water - maybe a sat dome is needed?

Michael

<hr width=100% size=1>

 

[mainshiptom]

or move ?

<hr width=100% size=1>

 

[Wiggo]

Seriously, I don't think there's much you can do about it. Ours does the same thing, but then again, in bad weather so does the Sky system at home. If the data has too many errors, the picture freezes for a second while it catches up with itself.

If it's really bad, try replacing the cable between the aerial and the amplifier - it should be proper 75Ohm, not regular 50Ohm TV coax, and every extra joint in it halves the available signal. Also make sure you have a decent lead from the amplifier box to the digibox.

<hr width=100% size=1><A target="_blank" HREF=http://homepage.ntlworld.com/graham.wignall/boats/eulimene600x800.jpg>The old and the new</A>

 

[amf]

General problem in marinas with all those yacht masts. Ghosting on analog reception means errors on digital reception. For some reason ITV always seems to suffer more than others (you will probably notice a worse picture on ITV on analog - maybe it is transmitted with less power?

Do you have a gain control on your aerial? if so you could try turning this up (or down) to see if it makes any difference.

Andrew

<hr width=100% size=1>

 

[mjf]

I think the gain is a on/off thing at the base of the aerial box. Will try it off.

Also noted the cable dia - Thanks.

Why only ITV though - is their frequency so different or, like I said, power not enough puff?

Michael

<hr width=100% size=1>

 

[itsonlymoney]

Read a magazine (if the darned thing has turned up yet from subscription) drink, smoke and be merry. You can always catch up on Emmerdale etc. when you get home /forums/images/icons/laugh.gif
Ian

<hr width=100% size=1>Play the best game you can with the cards you've been dealt ! ! !

 

[andyball]

We get the same (well, not as bad) with ch5....great except at low water.

Experimented a bit, since signal strength 63% according to telly, but quality meter low at time in question.

Presumed higher = better, so before getting a stainless mast made or laying out for a glomex base & extension I knocked something up out of an old deck-brush some broken nhs crutches.

2' of extra height actually made it worse !....& no, it wasn't wobbling around up there.The strength was imprived to 60% , but quality actually worse.

Found that with new aerial (fitted before the above messing around- a status 315 saucer type with pre-amp inside) it works better in the following circ's

a: if I hold it up high (not practical, but instructive, since the same position on a pole is not as good)

b: rather better on a s/steel table on the raised aft-deck

c: best of all (so far...experiments continue as/when low springs are here) lower than all above but on the steel cabin roof.


Concluded that some sort of ground plane works best with our aerial...seemingly the bigger the better

Other faint possibility for you is that box picked up another weaker transmitter when first set up & is using this for itv, rather than the iow one.....check in system/channel/whatever that the uhf channel matches those here:

http://www.bbc.co.uk/reception/tv_transmitters/tv_digit_full.shtml (you want rowridge & mux 2)

also http://www.dtg.org.uk/retailer/dtt_channels.htm

shows which channels are on which mux....the 64qam mux's are usuaully the ones that people have trouble with in marginal areas/installations; they squeeze more channels in on the same mux & sometimes it's noticeable..seems they tried to force them to change to qam16(less channles per mux) but someone concluded that it was only a few people who noticed, so it didn't really matter.


some useful info here

ps: they're all transmitted with the same power, as long as from rowridge.

possible for greater/lesser space to be given to a channel in the mux , though- surely the bbc wouldn't stoop so low?

we also replaced boaty small bore 75ohm cable with satellite grade from tlc (double shielded & lower losses), but difference wasn't startling, cheap enough though, at 19p/m vat.


<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by andyball on 20/05/2004 16:18 (server time).</FONT></P>

 

[mjf]

many thanks for all the tips - I am determined to get it working properly.

Clearly Wx has something to do with the reception which frankly surprises me these days.

Michael

<hr width=100% size=1>