Aerial Installation Query

[rjm2k]

My property has always suffered from bad reception, I believe mostly due to the aerial being loft mounted. In order to finally sort this I used an installer who was recommended to me to put up an external aerial. Some of the things I was told don't ring true so I thought I'd double check things.

The installer put up a high gain Master plug Aero16-mp Aerial (which he kept saying was really really good as it was gold! and you can't buy in the shops which I know is wrong as b&q sell them), the aerial comes with the boom split into 2, you bolt the 2 parts together to make the full length. The installer didn't connect the boom extension (saying that it isn't needed and makes the aerial too heavy for the post it's mounted on, it would need a 3/4inch steel post for the extension), he even binned the extension (which I have retrieved). The installation instructions which I retrieved from the bin has no mention of only using half of the boom length under any circumstances.

The reception is better than it was on the loft aerial, though analogue is snowy and some digital channels break up. He said he wasn't worried about analogue as it was being switched off soon and the digital channels were operating on half power at the moment so that would improve later!

My humax shows quality as 100% and strength as 60% (at least on one channel I didn't check all), the feed is split by an unpowered wideband splitter he put in the loft to support 3 tvs. He told me that one of the cables feeding one of the tvs was poor quality because it wasn't double screened (i'd never had problems with it and even he agreed that if it works then fine). I noticed that he had cut off the loft end of this cable and spliced another bit of cable onto it which had an f connector on, I was a bit suspicias about this as he hid the join between the cables under the loft insulation, I only realised something was strange because the "cheap" cable was white but there were no white cables going into the splitter.

I checked on a website which said that in my area I should fit an amplified high gain aerial.

I'm 15 miles away from my transmitter and wondering if I would be better off going up and fitting the extension myself plus making sure it's alligned. Since the signal strength is low, I can only assume that if adding the extra bit of boom increases the strength (which is what he said but also said it would be too powerful) would improve the strength going to each tv?

I assume the snowy analogue is wrong and the aerial may need alligning?

 

[ericmark]

As the boom becomes longer and one adds more elements so the spacing alters so can't see how one can expect half an aerial to work anywhere near as good as a full aerial with same amount of elements as the half one.

As to gold plated plugs these are specially designed to extract more money from the client and seems they work well!

I transmit and not a single gold plated plug or socket.

Sorry to say it is the same in this area with aerial fitters being more known for their ability to work at height than expertise. I had one complaining to me how customer wanted him to stack aerials for higher gain and how he had to explain that would not work.

Not sure how my friends aerials work with 9 pointed at moon for earth moon earth contacts but could not see point in arguing with him.

He was likely right that with such a wide band it would not have worked too well with all programs but woman only wanted to watch S4C all other programs were near the same English and Welsh.

15 miles is considered as quite close and really you should pick up signals on wet bit of string being so close. So I would wonder if the already fitted coax is up to scratch?

Likely fitting the extra bit of boom will help but as to if really required is another question. But can't condone putting it in the bin.

 

[rjm2k]

As the boom becomes longer and one adds more elements so the spacing alters so can't see how one can expect half an aerial to work anywhere near as good as a full aerial with same amount of elements as the half one.

As to gold plated plugs these are specially designed to extract more money from the client and seems they work well!

The spacing is the same as the elements are in fixed positions, so there are half the number of elements that there should be at the moment, the others are on the discarded bit! It's not the connectors that are gold plated, the aerial itself is "gold". I've tried contacting the mfr (masterplug) but their helpline has an answerphone which doesn't get you a return call and their website has no mention of aerials! I'll have to get the ladder our and put the rest of the boom on.

The other thing he said was about an aerial socket I have on the wall (standard single socket from b&q), he said that he preferred "isolated" sockets, I had a look at b&q and couldn't see any mention of an isolated socket whatever one of those is.

 

[Sam Gangee]

The aerial extension will hold the shorter "director" elements. Omitting it will decrease the aerial gain at higher frequencies. Whether this will matter is impossible to say without knowing your postcode/transmitter.

Signal quality of 100% is unbeatable. Signal strength of 60% is generally OK, while analogue is still being broadcast. It's measuring Freeview signal strength not analogue - which is generally much higher and can "swamp" the tuner if too strong.

He told me that one of the cables feeding one of the tvs was poor quality because it wasn't double screened (i'd never had problems with it and even he agreed that if it works then fine). I noticed that he had cut off the loft end of this cable and spliced another bit of cable onto it which had an f connector on

If he couldn't replace all of the poor cable, that was the best compromise. Replace as much of it as possible. Is reception on that TV worse than the others?

I checked on a website which said that in my area I should fit an amplified high gain aerial.

In my experience, sites such as "Wolbane" tend to be overly pessimistic. However, if your cable runs are especially long (over 30 metres) then you could replace the passive splitter with a 4-output masthead amplifier, or simply connect a single-output one to the input of the splitter.

An "isolated" socket is one that includes a capacitor so it won't pass DC. The advantage is that you are unlikely to get a shock from it. The disadvantage is that you can't feed power through it for a masthead amplifier.

 

[ericmark]

If you read the books on building aerials you will soon realise how complex it can become. However unlike the aerials I build the TV aerial is quite wide band and one is not really worried about losing the odd S point. For a set frequency the element spacing does change according to how many are used. But although the HAM radio user who bounces his signals off the moon to talk to USA may have to ensure the spacing is spot on for TV work likely little difference will be seen.
However if one wants an aerial with less gain one buys a smaller aerial one does not cut bit of the end.

As to Gold aerial plugs odd if so good that radio hams don't use them?

 

[Mickymoody]

Leaving off half the element, as you are so close to the transmitter makes sense, otherwise the signal would overload your equipment.

But why go for overkill?

I think replacing the coax would improve the signal greatly, I think the installer is pulling a fast one..