A.T.V (Aerials and Television) est. 1994
419 Langsett Rd
Hillsborough
Sheffield
S6 2LL
Hillsborough
Sheffield
S6 2LL
Tel : 0114 285 4254
© 2008 Justin Smith A.T.V
All Rights reserved
All Rights reserved
Aerial Array`s
The subjects on this page are listed on the following order,
ATV`s Aerial Array
Amateur Radio Aerial Arrays
ATV`s Aerial Array
The transmitter of choice is Emley and the (bottom) unamplified Yagi13B gives good pictures on all channels. At the top of the 16ft semi-stayed pole is a XB10A (amplified) on Crosspool. This provides pictures which vary from awful (C4 on CH21) to mediocre (BBC1
on CH31). The XB10A in the middle is amplified as well and is on Belmont. Depending upon climatic conditions we get poor or almost reasonable results. The fact that it faces East
(i.e. toward the Continent) means that in certain weather conditions co-channel interference can be a big problem, as it is with many customers on Belmont in Sheffield.
In addition we have an FM dipole horizontally polarised on Crosspool. This works fine on
the latter TX because with VHF "line of sight" is not so critical. We would normally advise
an FM dipole to be vertically polarised (to enable it to work more omni-directionally) but as we are only interested in Crosspool, and we have limited room on our mast, our`s is
horizontally mounted, see FM/DAB aerials.
Picture of our shops aerial array. We need some kind of signal off all the main transmitters around here in case we have to repair a TV for which we have no remote (to retune it) so we
didn`t put up this array just out of interest !
Note the way we have used side poles to mount the two Horizontally polarised aerials
which are aligned on Emley Moor (bottom aerial) and Belmont (middle aerial) respectively.
Doing this enables the antennas cradles to be mounted perpendicular to the dipoles and
we experimented with the Belmont aerial, to see how much difference it would make to dispense with the side pole, and just use the cradle (parallel with the directors) to attach
the antenna to the mast. The difference was significant, in fact we were amazed how big
the improvement was when the cradle was mounted correctly, i.e. perpendicularly.
Amateur Radio Aerial Arrays
Amateur radio aerial arrays show the differences in element size most clearly as there is such a huge difference in the frequencies used. On the array below top antenna is for transmitting and receiving at a frequency of 1.3Ghz which has a wavelength of 23 cm.
The next one down does the same thing but on 14 to 28MHz which equates to wavelengths of 10 to 20 metres. It can be seen that as the frequency rises (and the wavelength
shortens) the antenna dipole/elements become smaller. By the same token an A group TV (UHF) aerial has a larger dipole and elements than a C/D group. See Aerial Groups.
Just to emphasise the differing size of the elements, the smaller 1.3GHz antenna (at the top) is a 44 element, whereas the huge aerial below it is only a 3 (three ! ) element....
The subjects on this page are listed on the following order,
ATV`s Aerial Array
Amateur Radio Aerial Arrays
ATV`s Aerial Array
The transmitter of choice is Emley and the (bottom) unamplified Yagi13B gives good pictures on all channels. At the top of the 16ft semi-
(i.e. toward the Continent) means that in certain weather conditions co-
the latter TX because with VHF "line of sight" is not so critical. We would normally advise
an FM dipole to be vertically polarised (to enable it to work more omni-
Picture of our shops aerial array. We need some kind of signal off all the main transmitters around here in case we have to repair a TV for which we have no remote (to retune it) so we
didn`t put up this array just out of interest !
Note the way we have used side poles to mount the two Horizontally polarised aerials
which are aligned on Emley Moor (bottom aerial) and Belmont (middle aerial) respectively.
Doing this enables the antennas cradles to be mounted perpendicular to the dipoles and
we experimented with the Belmont aerial, to see how much difference it would make to dispense with the side pole, and just use the cradle (parallel with the directors) to attach
the antenna to the mast. The difference was significant, in fact we were amazed how big
the improvement was when the cradle was mounted correctly, i.e. perpendicularly.
Amateur Radio Aerial Arrays
Amateur radio aerial arrays show the differences in element size most clearly as there is such a huge difference in the frequencies used. On the array below top antenna is for transmitting and receiving at a frequency of 1.3Ghz which has a wavelength of 23 cm.
The next one down does the same thing but on 14 to 28MHz which equates to wavelengths of 10 to 20 metres. It can be seen that as the frequency rises (and the wavelength
shortens) the antenna dipole/elements become smaller. By the same token an A group TV (UHF) aerial has a larger dipole and elements than a C/D group. See Aerial Groups.
Just to emphasise the differing size of the elements, the smaller 1.3GHz antenna (at the top) is a 44 element, whereas the huge aerial below it is only a 3 (three ! ) element....
Amateur Radio antenna array. Note the rotator to “aim” the array where required.
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