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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Alarms, Phones, Aerials, CCTV & Datacomms >> aerial masthead problem ? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1198017408 Message started by supra59 on Dec 18^th, 2007, 10:36pm

Title: aerial masthead problem ?
Post by supra59 on Dec 18^th, 2007, 10:36pm

Hi hope you can help, i have just fitted a new aerial and masthead and tranny, all bbc itv etc chan five are great i get a perfect picture, but when i put it all thought my two satalite boxes using the rf in and out when i tune my tele to pic up both my sat boxes the picture is crap not bbc etc sky pictures then if i pull the areial out my sky picture becomes good again. it should be simple i think but this one as got me i know i can use the scart leads which by the way does work fine, but i send the picture into each bedroom through a digital splitter using the rf i have tryed iliminating problem by just using one tv without the splitter still the same problem so if you tv aerial guys have any ideas i would love to know. thanks Supra

Title: Re: aerial masthead problem ?
Post by Twobarrows on Dec 20^th, 2007, 12:14pm

Not 100% sure of your situation, but have you changed the channels on one of the Sat boxes ? You cannot mux both together as they will both be on the same channel by default & interfere, so you need to change one.
Hope this helps..........

Title: Re: aerial masthead problem ?
Post by Lectrician on Dec 20^th, 2007, 7:58pm

The RF out channel of one or both of the sat boxes may be too close to that of bbc1, bbc2, itv, ch4, ch5.....

What transmitter are you on? You can find what RF channels are being used for the channels, and then put your sat RF outs on different channels.

Title: Re: aerial masthead problem ?
Post by Twobarrows on Dec 21^st, 2007, 8:25am

Yopu can get a guide to installing home TV / Sat from Satcure, it's very helpful , especially in the area of selecting channel numbers (which is not as simple as you might imagine).

Title: Re: aerial masthead problem ?
Post by supra59 on Dec 21^st, 2007, 3:47pm

hi guys thanks for the comments, both boxes are set to different freq even get the same with just the one box attached
all was well till i fitted the new aerial , my old aerial was just a normal aerial no masthead boaster so im confident its something with that it could even be ive got a faulty one, but with not ever fitting one before thought if i asked maybe there was an easy fix to the problem but thanks anyway please keep thinking guys cos its really doing my shed in lol thanks again Supra

Title: Re: aerial masthead problem ?
Post by Lectrician on Dec 21^st, 2007, 6:02pm

Your new aerial may be recieving distant transmitters aswell as local ones, with the distant transmissions being on or near the frequency of the satalite recievers you are using.

Title: Re: aerial masthead problem ?
Post by CWatters on Dec 21^st, 2007, 7:49pm

It's possible to have too strong a signal.

What's your postcode?

Title: Re: aerial masthead problem ?
Post by supra59 on Dec 21^st, 2007, 8:03pm

hi guys m43 manchester
so how do i stop it if its that any ideas thanks i will try setting sly on a different freq what do you think ?
thanks

Title: Re: aerial masthead problem ?
Post by CWatters on Dec 21^st, 2007, 8:54pm

This site is good for checking what aerial you need...

http://www.wolfbane.com/cgi-bin/tvd.exe?DX=L&HT=10&OS=m43

Try entering you full post code. If you just enter M43 it says...

There is a choice of transmitters and the aerial recommended is different depending on which one your should point at.

Winter Hill = Group CD, Horizontal polarisation
Saddleworth = Group B Vertical polarization.

Both Amplified extra high gain types. If your new aerial is a wideband that might be part of the problem. It could be picking up the other transmitter. (EDIT: A Group B aerial just covers part of the TV band but that doesn't mean fewer channels - all the digital channels on the Saddleworth transmitter are within the group B part of the TV band)

Check the polarization is right (elements vertical or horizontal).

Check the UHF output frequency on the sky box isn't similar to one of the multiplexes from the other local transmitter (or the analog channels).

Try plotting your position and the transmitters on a map. See if your aerial is pointing at both because of the way they line up.

Repeat the postcode lookup with it set to Distant at the top. Plot those transmitters as well and see if you are pointing at one of them as well as the correct local transmitter.

Title: Re: aerial masthead problem ?
Post by CWatters on Dec 21^st, 2007, 9:02pm

Note that if you want to get both digital and analog you also have to look here for the analog recommendation which might be different and if so design a compromise..

http://www.wolfbane.com/cgi-bin/tva.exe?DX=L&OS=M43&HT=10

Title: Re: aerial masthead problem ?
Post by CWatters on Dec 21^st, 2007, 9:11pm

Perhaps I'm making it sound hard? Basically three steps:

Check right aerial pointed at right transmitter.
Check what other transmitters and frequencies it might be picking up
Retune the sky box to avoid those.

Title: Re: aerial masthead problem ?
Post by supra59 on Dec 21^st, 2007, 9:36pm

thanks for all your help i will try all that see how we go bloody hell i thought an aerial was an aerial end of lol more to it than i thought thanks again sups