Full Freeview on the Rowridge (Isle Of Wight, England) transmitter

_{sentiment_very_satisfied}Platinum

3:08 AM

Roy Barton: A yagi is not a good idea for a Group A .

Log periodic aerials have very flat curves and therefore the same issue does not apply; they are fine. See:

Rowridge Transmitter

Using the is fine. It needs to be as close to the aerial as possible because it will be amplifying the noise picked up in the aerial lead, which is what you don't want (poorer snr). See:

Television Aerial Boosters / Amplifiers, Splitters, Diplexers & Triplexers

If you have a Group A aerial, then you should re-orientate it for vertical polarisation. A wideband aerial isn't necessary (over that of a Group A one) because all of 's are within Group A.

_{sentiment_very_satisfied}Platinum

3:44 AM

Roy Barton: Here is a plot of the terrain between you and the :

Terrain between ( m a.g.l.) and (antenna m a.g.l.) - Optimising UK DTT Freeview and Radio aerial location

You will note that one mile away, the ground obscures line-of-sight. This corresponds to Holt Heath.

Therefore, your task is to receive what is "coming over" the brow. (Imagine if it were a light.) As far as the COMs go, you may have to contend with from 's COMs, which are co-.

You are only 28 miles away; that said, we don't know how the COMs might have restriction WRT the PSBs, in your direction. The UK Coverage Checker suggests that they may be a bit inferior to the PSBs. The predicted figures are that one third of viewers won't get the COMs, so they must be inferior in some way.

Obviously, with Stockland being in the opposite direction, the reflector is important WRT blocking interference.

As I say, I would start by changing the existing to vertical polarisation and take it from there. Only then will you know whether it is sufficient to pull in the COMs or not.

_{sentiment_very_satisfied}Platinum

3:59 AM

Roy Barton: See:

http://www.wrightsaerials….pdf

R

Roy Barton
12:59 PM

Roy Barton:
John Lindsay. I really do appreciate the detail in your answers. I have checked with the manufacturers of my aerial (not yet fitted). It is a labgear LAB450/WS

Labgear

They say it is not a Yagi, but when pressed they said it was based upon a Yagi but having 3 booms they say it was strictly not a Yagi. They went on to say as regards a log periodic it would perform as well as a group A on 28 where we have the problem. Some local stockists only stock wideband, but one distributor offers just one item in Group A, and it less than 25% of the cheapest wideband. Labgear only manufacture wideband.
You have made it clear what I should do. I will try to get a refund on the wideband and fit the cheap group A on vertical polarisation. To me this seems to be an aerial jungle. I would appreciate your comment. LAB450/WS is it worth messing with? (BH217DX)

Roy Barton's 13 posts GB flag

_{sentiment_very_satisfied}Platinum

1:46 PM

Roy Barton: As you say, the tri-boom is based on the yagi principle: there is a dipole, which is the active part (the bit that the connects onto), and elements whose purpose is to focus the onto the dipole. The elements are connected electrically to the cable.

With a yagi there are a number of factors which result in it being a compromise to make it more sensitive across the whole band at the expense of a level curve.

With a log periodic there is a double-boom. The cable connects across the two booms at the -facing end and the boom are connected together at the end. Each element acts to receive at a particular .

I wouldn't bother with the tri-boom . Don't buy a crappy contract aerial either. If you get a log then wideband is fine because their gain curves are much flatter than yagis.

There are plenty of aerial suppliers online selling the aerials that the professionals fit. No longer do you have to rely on what the DIY shops sell.

If you were using an aerial horizontally, have you tried turning it vertical?

Just going back to your original posting, have you checked the cable for signs of damage and water ingress? This could perhaps be chafing on guttering on guttering or a tile.

I'm not a professional, but at 28 miles, and just out of line-of-sight approximately 1 mile away, I think that the signal strength will be quite good.

If you're in a good signal area then a log will be fine. If (and I say this as your "Plan B" incase Plan A doesn't work) it doesn't have enough gain then you can use the .

I came across this shop which sells a range of logs for less than £20 including delivery:

Aerials [Aerial Type: Uhf Log-periodic] > AerialSat.com

J

jamie

_{sentiment_satisfied}Silver

4:13 PM
Portsmouth

ROY BARTON -

Hi, I am a professional installer who is a approved member.

With regards to the log periodic they have flat so perform pretty much like a group A . Not one that I would fit, however I have seen them performing well.

Something which people seem to not advise on this site is one simple thing, your received can change from location to location, so I would try testing the aerial on different parts of the building, simply moving the aerial a few feet can make all the difference when receiving signal, location is key to making it all work properly.

this helps :)

jamie's 207 posts GB flag

jamie's: J's Freeview map J's terrain plot J's frequency data J's Freeview Detailed Coverage

D

Doug Cheney
4:45 PM
Wimborne

ROY BARTON

I live in BH21 1BD and don't have line of sight to , my installer fitted a log periodic in the vertical position with a amp and I get very good

Doug Cheney's 1 post GB flag

Doug's: D's Freeview map D's terrain plot D's frequency data D's Freeview Detailed Coverage

J

jb38

_{sentiment_very_satisfied}Platinum

5:27 PM

Doug Cheney: An excellent combination that performs well under a whole range of conditions, and unlike the so called high types is generally capable of providing a much less glitch prone when used in circumstances that could be described as being less than ideal for .

The problem a log does have though is "image", as most make the mistake of equating a large structure on their as being somewhat superior.

jb38's 7,179 posts GB flag

R

Roy Barton
5:48 PM
Wimborne

Roy Barton:
I nearly fell out of my chair when the distributor said their Group A was only £6.99 plus VAT. I think it was trade price. He said all the installers use them. I am now confused what a log periodic is. I thought log periodic was the simple aerial with a single boom. (I thought that all aerials were Yagis... but what do I know?) There is so much complexity. I have left the TV on all day displaying strength and signal . All day long while sun was shining the signal strength was around 99 and the signal quality was fluctuating between 40 and 70. When the sun went down the signal strength dropped to 90 and the signal quality fell to the lowest reading of just 1 (that is the same as 0) but occasionally the signal quality bounces up to 10 or 14 for a minute or so before returning to 0.

This is all very curious. I really intend to experiment with V polarisation using the tri boom and the cheapy just out of interest. Unfortunately I won't be messing with the aerial on the as that is inaccessible without cherry pickers or similar. (Or a very light footed installer with good equipment.)

I suspect that the G4 being introduced to Southampton my be the culprit?

My signal has to pass through the pylons of thw national grid half a mile away and some large conifers... but these were never a problem.

Roy Barton's 13 posts GB flag

Roy's: R's Freeview map R's terrain plot R's frequency data R's Freeview Detailed Coverage

J

jamie

_{sentiment_satisfied}Silver

6:43 PM
Portsmouth

ROY BARTON=

If you use a group A and avoid using an you should not have issues with 4G

:)