merging 2 aerial streams without interference
 

I wonder if anyone can help me. I live in cardiff and my local transmitter
is Wenvoe. I get perfect analogue and digital reception from there. However
I am fed up of all the regional wales opt outs particularly BBC 2W digital.
and the lack of QVC on the wenvoe transmiter. I erected a 32 element aerial
and pointed at the Mendip transmitter - i Get perfect reception on that too.
But when I merge the two feeds together through a simple "y" merge/splitter
box I get terrible interference, particularly on analogue channel 5 and 4
and slightly less on the English ITV and BBC, and Mendip digital reception
is hopeless and QVC is not picked up at all. Transmissions both analogue
and digital remains ok on Wenvoe, Anybody suggest a fix?

You could bugger about attenuating the Wenvoe, but really you need channel
filter/levellers for both transmitters. £200 should cover it.

Bill
http://www.wrightsaerials.tv/index.html

In article , john whale
wrote:
I wonder if anyone can help me. I live in cardiff and my local
transmitter is Wenvoe. I get perfect analogue and digital reception from
there. However I am fed up of all the regional wales opt outs
particularly BBC 2W digital. and the lack of QVC on the wenvoe
transmiter. I erected a 32 element aerial and pointed at the Mendip
transmitter - i Get perfect reception on that too. But when I merge the
two feeds together through a simple "y" merge/splitter box I get
terrible interference, particularly on analogue channel 5 and 4 and
slightly less on the English ITV and BBC, and Mendip digital reception
is hopeless and QVC is not picked up at all. Transmissions both
analogue and digital remains ok on Wenvoe, Anybody suggest a fix?

As Bill has indicated, a 'proper' fix for this may be costly. However you
could try slightly altering the length of one of the antenna leads before
it enters the y-combiner. This will change the relative phases of the
signals from the two antennas, and *might* give a better result.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
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Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In message , john whale
writes
I wonder if anyone can help me. I live in cardiff and my local transmitter
is Wenvoe. I get perfect analogue and digital reception from there. However
I am fed up of all the regional wales opt outs particularly BBC 2W digital.
and the lack of QVC on the wenvoe transmiter. I erected a 32 element aerial
and pointed at the Mendip transmitter - i Get perfect reception on that too.
But when I merge the two feeds together through a simple "y" merge/splitter
box I get terrible interference, particularly on analogue channel 5 and 4
and slightly less on the English ITV and BBC, and Mendip digital reception
is hopeless and QVC is not picked up at all. Transmissions both analogue
and digital remains ok on Wenvoe, Anybody suggest a fix?

I don't myself know the channels groups involved. But if the channel
groups do differ, then you could get a tuned combiner. It has tuned
circuits for the two inputs before it merges them.

Otherwise, it may be worth trying feeding each aerial into an amplifier
before merging them. That way you avoid disturbing one or both aerials
by the way that your downleads connect their elements together.
Depending on the amplifier designs, you might just also need an
attenuated Y so that the amplifier outputs do not disturb each other.

Regards
--
Dave English,
Client Software Development, Thus PLC,
Dorking Business Park, DORKING, Surrey, UK. RH4 1HJ
http://www.thus.net

Thanks for that, think i will try attenuator first 200 pound is a lot to
pay - do ijust attenuate wenvoe , or mendip as well or even the combined
feed? BTW have you got a link to a supplier for
"Bill" wrote in message
...
You could bugger about attenuating the Wenvoe, but really you need channel
channel filter/leveller?

filter/levellers for both transmitters. £200 should cover it.

Bill
http://www.wrightsaerials.tv/index.html

"john whale" wrote in message
...
I wonder if anyone can help me. I live in cardiff and my local
transmitter
is Wenvoe. I get perfect analogue and digital reception from there.
However
I am fed up of all the regional wales opt outs particularly BBC 2W
digital.
and the lack of QVC on the wenvoe transmiter. I erected a 32 element
aerial
and pointed at the Mendip transmitter - i Get perfect reception on that
too.
But when I merge the two feeds together through a simple "y"
merge/splitter
box I get terrible interference, particularly on analogue channel 5 and 4
and slightly less on the English ITV and BBC, and Mendip digital reception
is hopeless and QVC is not picked up at all. Transmissions both analogue
and digital remains ok on Wenvoe, Anybody suggest a fix?

What about a second digibox for Mendip? Leave your current setup as it is
and only feed Mendip into the digibox. That should give you everything you
already have plus the stuff you want without interference. Or have I just
gone mad?

What about a second digibox for Mendip?

Why didn't I think of that? Brilliant idea. Now that DTT boxes are so cheap all
sorts of things become possible.

Bill
http://www.wrightsaerials.tv/index.html

On Mon, 1 Mar 2004 11:55:29 -0000, "Dave"
wrote:


What about a second digibox for Mendip? Leave your current setup as it is
and only feed Mendip into the digibox. That should give you everything you
already have plus the stuff you want without interference. Or have I just
gone mad?

It'd need to be one with a different remote code to the current box
though...

Colin

On Mon, 1 Mar 2004 02:17:44 -0000, "john whale"
wrote:

I wonder if anyone can help me. I live in cardiff and my local transmitter
is Wenvoe. I get perfect analogue and digital reception from there. However
I am fed up of all the regional wales opt outs particularly BBC 2W digital.
and the lack of QVC on the wenvoe transmiter. I erected a 32 element aerial
and pointed at the Mendip transmitter - i Get perfect reception on that too.
But when I merge the two feeds together through a simple "y" merge/splitter
box I get terrible interference, particularly on analogue channel 5 and 4
and slightly less on the English ITV and BBC, and Mendip digital reception
is hopeless and QVC is not picked up at all. Transmissions both analogue
and digital remains ok on Wenvoe, Anybody suggest a fix?


What channels do you rx from Wenvoe that you don't rx from Mendip and
wish to keep?
--
Cheers

Peter

Remove the INVALID to reply

"Peter" wrote in message
...
On Mon, 1 Mar 2004 02:17:44 -0000, "john whale"
wrote:

I wonder if anyone can help me. I live in cardiff and my local
transmitter
is Wenvoe. I get perfect analogue and digital reception from there.
However
I am fed up of all the regional wales opt outs particularly BBC 2W
digital.
and the lack of QVC on the wenvoe transmiter. I erected a 32 element
aerial
and pointed at the Mendip transmitter - i Get perfect reception on that
too.
But when I merge the two feeds together through a simple "y"
merge/splitter
box I get terrible interference, particularly on analogue channel 5 and 4
and slightly less on the English ITV and BBC, and Mendip digital
reception
is hopeless and QVC is not picked up at all. Transmissions both analogue
and digital remains ok on Wenvoe, Anybody suggest a fix?


What channels do you rx from Wenvoe that you don't rx from Mendip and
wish to keep?
--
Cheers

Peter

Remove the INVALID to reply

Its more the other way around, Wenvoe broadcasts BBC1 Wales and BBC2 Wales
which has regional opt outs which differ quite a lot from natianal BBC1 &
BBC2. Wenvoe also broadcasts Welsh language channel S4C instead of QVC,