I've been asked to fit a tv. aerial for an old customer, He has a 6yr old tv and an aerial that he tells me is at least 30yrs old which has failed. His current one looks to be a basic standard aerial. When looking for a replacement is more elements better? There seems to be a lot of choice!
T.v Aerial
- Thread starter catlad
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More elements equals more gain but also requires more accuracy in installing (pointing at the transmitter site). They will also be narrower bandwidth.
I'd the aerial looks OK it might just be better to change the co-ax cable.
Also check if the aerial is correct for the Transmitter band.
this will help
www.freeview.co.uk
I'd the aerial looks OK it might just be better to change the co-ax cable.
Also check if the aerial is correct for the Transmitter band.
this will help
Detailed transmitter information for industry professionals
If you're an industry professional, use this tool to check local DTT transmitter coverage and UHF channel allocation for an address.
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Beware double or even quadruple counting of elements. Marketeers like big numbers. Shoppers aren't experts, and so in the absence of any solid knowledge they fall back on numbers, because 'more is better, right?' This is how we end up with this being called a 48 element when it's nothing of the sort.
You can read more here: https://www.aerialsandtv.com/knowle...Now we come to the,was counted as one element.
The next crafty con is the gain figures, because again, 'more is better, right?'
We'll start off with how much gain is needed. This depends on local conditions such as living on the other side of a wooded area, or in a dip, or behind a mill. Somewhere that's in a signal shadow case by some obstruction. It also depends on the proximity to the local transmitter. You're in Lancashire, so the main transmitter for the Granada region is Winter Hill. It's pretty powerful (100,000W for the main muxes). However, Lancashire ranges from somewhere at the foot of the hill where the Winter Hill transmitter is located - which means you could stick a bit of fuse wire into the aerial socket and get a signal - all the way over to the Fylde coast which is mostly flat so good signal. The flip side could be somewhere in the Pennine foothills where the geography is very different.
More gain increases the chance of pulling in decent reception where the field strength from the transmitter is weakened due to some local conditions. However, manufacturers know that shoppers don't understand how gain figures can be misleading. It's possible to have an aerial with a tonne of gain, but in the wrong place on the reception range for the local transmissions.
Prior to the Government selling off bits of the TV transmitter range for mobile phones, we used to have a tuning range from ch21 to ch68. They have now whittled that down to 21~49. However, there are still a lot of aerials just like the one above that are suited to the old range, and they have their peek gain in part of the tuning range we no longer use.
Takeaway: Just reading the peak gain figure without seeing the graph for the aerial can result in buying something where there's less gain where you actually need it.
On paper, Log Periodic aerials have lower gain than most other types. However, you might not need that much gain in the first place. Somewhere out on the Flyde or where I am in mid-Cheshire can get a tonne of signal with a Log because the surrounding areas are pretty flat.
The amount of gain also improves the more the reception range is concentrated by the aerial design. One designed for the old 21~68 range has the gain spread over a larger area compared to an aerial built for 21~49.
To get an idea how strong the signal is for the location, use this tool: https://www.freeview.co.uk/corporate/detailed-transmitter-information
This is what the reception prediction looks like for an Oldham postcode
Remember too, she had an aerial 30 years old. Probably an old contract aerial, and that's been working okay up to now. You don't need to go mad with some huge Tri-Boom or 6ft long Yagi. I'm running an old ch21-68 Log that has been installed for at least 10 years. There's no amplification, and I'm about 30 miles from Winter Hill. There's enough signal that I can split 3 ways and still get 100% quality and 80% strength.
Use good cable.
This is a shot from a recent installation. It's a newbuild. The cable on the left is what the builders installed. It's a bit better than your typical bog standard RG6. The foil shield is still Mylar - like the inside of a crisp packet - but there's a copper braid albeit with very sparse coverage. Bog standard RG6 uses aluminium braid. The centre core was steel with a thin layer of copper anodised over the top (not seen in this image). Steel has higher electrical resistance than copper.
The stuff on the right is what I use. Webro 100. It's all copper, no plastic, no aluminium, no steel. There's more shielding, of better quality, and - should the worst happen and water get into the cable - copper survives a drowning where as aluminium corrodes to a mush.
Webro isn't the only manufacturer of good aerial coax. Labgear (PF100) and Triax TX100 are very close equivalents.
Thanks guys for the info
I'll do some studying . Lucid the aerial you posted a picture of is pretty much like the one he has now but with small round bars going down the length ( about 6 ) if memory serves. He is about 10 miles from winter hill and its pretty flat generally.
My main concern was how or if things had changed since we went digital a few years ago?
I'll do some studying . Lucid the aerial you posted a picture of is pretty much like the one he has now but with small round bars going down the length ( about 6 ) if memory serves. He is about 10 miles from winter hill and its pretty flat generally.
My main concern was how or if things had changed since we went digital a few years ago?
His aerial will be one of the early wideband high-gain types from when there was panic about needing a 'digital aerial'. (There's no such thing.)
All the dust has pretty much settled regarding changes to terrestrial broadcasting. They've spent almost two decades jugglingbaround frequencies regarding analogue switch off and the digital clearance. We're across the finish line on that.
The next major change will be when they switch off digital and everything gets put on broadband like Freeview Play works now. That was meant to be later this decade, but the date is slipping.
Have a readof the link to the ATV site from my previous post. Then look around the site for its aerial recommendations. I would go with one of the new breed of Logs. They have a version where the aerial bracket allows the aerial to be tilted up/down. This improves signal reception further.
All the dust has pretty much settled regarding changes to terrestrial broadcasting. They've spent almost two decades jugglingbaround frequencies regarding analogue switch off and the digital clearance. We're across the finish line on that.
The next major change will be when they switch off digital and everything gets put on broadband like Freeview Play works now. That was meant to be later this decade, but the date is slipping.
Have a readof the link to the ATV site from my previous post. Then look around the site for its aerial recommendations. I would go with one of the new breed of Logs. They have a version where the aerial bracket allows the aerial to be tilted up/down. This improves signal reception further.
DO read the link Lucid posted to ATV aerials website it's a wealth of information freely provided.
A truly 30 year old Winter Hill aerial will most likely to be a group C/D and most don't have a lot of gain for the low frequencies now used at Winter Hill. One of the earliest lists of DTT transmitters I have is from 2003 - but Wikipedia says it started there at a low power in 1998 (26 years ago).
See https://www.aerialsandtv.com/knowle...s#cd-group-aerial-gain-curves-and-comparisons
Even so, if it's been OK since the last major 700 MHz clearance (12 August 2020) and whether C/D or wideband aerial performance (gain) is probably not the sole cause.
I'd start with checking the connections and cable for damage... Many reception problems are due to poor connections and even cable damage.
Without a close by postcode or even rough location (village/suburb) it's not always simple to suggest a suitable receive aerial. Justin at ATV is a fan of log periodics and the ones he sells are more robust than some others on sale elsewhere.
NB The Freeview reception predictor does not calculate the signal level received at the location 100 metre x 100 metre square (other than it is above a minimum threshold). Rather it is all to do with interference from other transmitters: the two numbers are % of locations in the square that are Served (interference <1% of time) and Marginally served (>1 but < 50% of time).
Another prediction tool, on the Wolfbane website, does an estimate of signal (field strength) level but is out of date using the older frequency allocations... nevertheless that can be used to do gain/loss calculations and aid aerial selection if the numbers are taken with due caution.
A truly 30 year old Winter Hill aerial will most likely to be a group C/D and most don't have a lot of gain for the low frequencies now used at Winter Hill. One of the earliest lists of DTT transmitters I have is from 2003 - but Wikipedia says it started there at a low power in 1998 (26 years ago).
See https://www.aerialsandtv.com/knowle...s#cd-group-aerial-gain-curves-and-comparisons
Even so, if it's been OK since the last major 700 MHz clearance (12 August 2020) and whether C/D or wideband aerial performance (gain) is probably not the sole cause.
I'd start with checking the connections and cable for damage... Many reception problems are due to poor connections and even cable damage.
Without a close by postcode or even rough location (village/suburb) it's not always simple to suggest a suitable receive aerial. Justin at ATV is a fan of log periodics and the ones he sells are more robust than some others on sale elsewhere.
NB The Freeview reception predictor does not calculate the signal level received at the location 100 metre x 100 metre square (other than it is above a minimum threshold). Rather it is all to do with interference from other transmitters: the two numbers are % of locations in the square that are Served (interference <1% of time) and Marginally served (>1 but < 50% of time).
Another prediction tool, on the Wolfbane website, does an estimate of signal (field strength) level but is out of date using the older frequency allocations... nevertheless that can be used to do gain/loss calculations and aid aerial selection if the numbers are taken with due caution.
There are certain contributors on this site that I pretty much trust implicitly, @Lucid is one of them.
Following @Rodders53 comprehensive post, I will add him to that list...
I have now installed the new T.V aerial and thanks to all the advice He now has a 100% signal
Lucid I took your advice and bought the webro copper cable to go with it. He now has good picture Cheers.
Lucid I took your advice and bought the webro copper cable to go with it. He now has good picture Cheers.