Freeview Reception

melipona

espresso wrote:

Did you actually read all of the article?

Of course I did!:mad:

The forward gain graph, shows how aerials designed for a specific group of frequencies have a much better gain when compared to a wideband aerial which should only be used when necessary.

And it obviously was in my case.

"Not all transmitters need receiving aerials that cover the whole UHF band. In some cases only Groups A and B, or Groups B and C/D, are used. For the former use a Group K aerial, and for the latter a Group E (see fig 1 above). These aerials can be expected to perform better than the equivalent Group W array, which covers the whole band."

Bill would be the first to tell you that each aerial installation is different and the type of antenna used should reflect that.

I only suggested a possible solution that worked for me. Soon after arriving at my new house and plugging in the Freeview box it said no signal, remade connectors and replaced cable where necessary and tried Ae amplifier got me 17 channels, but not the ones I really wanted, did some asking around, (only got 3 close neighbours), they all used sky as freeview reception was rubbish. I changed the aerial as previously stated and 70 odd channels came up, its slightly more now.

So the comment was offered in good faith and the proof is in the pudding, maybe there was another solution, but this worked. One of the neighbours has fitted a similar Ae and it works fine for them too.:beer:

Joe_Bloggs

The aerials that tend to be pointing down are the very long wideband aerials. They have to be lined up to a higher standard . They make tempting perches for Great Bustards. The wideband/masthead amplifier combination is recommended a lot by https://www.wolfbane.co.uk . Perhaps these devices will not be needed after switch over but they are needed before in many cases at present.
What hope is their for HDTV via terrestrial ? The beeb have started satellite trials.
J_B.

irnbru_2

Joe_Bloggs wrote:

What hope is their for HDTV via terrestrial ? The beeb have started satellite trials.

Every hope.

espresso

melipona wrote:

Similar thing happened to me. You need a wide band aerial to get all the free view channels, many older analouge aerials deleberiately had a narrow bandwidth to get better reception, wide band aerial available from maplin workrd for me.

Your original post above stated "You need a wide band aerial to get all the free view channels" which is what I took issue with, as it is giving incorrect advice to others who may not know better!

A wideband aerial has much less gain compared to one for a specific group as illustrated in Bill's article, which is why they should only be used when necessary. Amplifiers don't do a good job of making up for a lack of signal as they amplify the noise and unwanted frequencies as well.

melipona wrote:

I only suggested a possible solution that worked for me..

Well actually you said that you need a wideband aerial to get all of the freeview channels! It may well have worked for you but it is bad advice to state that it should be used in all situations.

A good grouped aerial will give better results unless a wideband is absolutely essential and the best quality double screened CT100 type satellite co-ax should always be used, as it rejects impulsive interference better and has a much lower loss that the old brown sub-standard co-ax.

There is no one aerial solution for all locations.

:beer:

Joe_Bloggs

@Expresso
Have you had any dealings with the Televes range ? That triple whatsit arrangement looks serious. Is it any good ?
J_B.

espresso

Joe_Bloggs wrote:

@Expresso
Have you had any dealings with the Televes range ? That triple whatsit arrangement looks serious. Is it any good ?
J_B.

No not personally. It looks to be a good idea in principle but they are big and heavy, needing a substantial pole and brackets with extra wind loading. As they are also wideband, they don't really give much advantage over a good standard grouped yagi for less overall expense.

I think that they are used as a bit of a marketing tool, by riggers who say that "you'll need one of the latest digital aerials"

:beer:

Joe_Bloggs

There has been a fair bit of DAB (Thats radio) promotion for our projected £300 million. Do people realise you likely need an efficient aerial to pointed at a transmitter receive it. Can you use it in a car ? The radio on freeview is very good. Are there DAB and terrestrial TV blackspots ? Are the 'hangers on' making it worse for the early adopters and better for the profits of bskyb and cable networks ? Contentious questions I know.
J_B. (I will not use the alleged word 'debatory'.)

oldwiring

Clearly grouped aerials give better performance, but are not some digi channels out of group and there may be changes later because certain chanels will not be available for DTT. There has been discussion on more specialist forums about varoius aspects of reception and the forthcoming change over. Some may finf these worth a look

https://www.digitalspy.co.uk

https://www.radioandtelly.co.uk

https://www.avforums.com