The DAT45 aerial has a gain of around 16dB which is quite high if you consider that an increase of 3dB represents a DOUBLING of signal. An "ordinary" TV aerial has a gain of about 12dB so the DAT45 can be considered to be around 200% better.
There is an "amplifier" supplied with the DAT45. It's actually reffered to as the "margin raising device (MRD)". What it does is to reduce problems of interference from "impulse noise" (such as you'd get from passing traffic, thermostats etc.) The "MRD" is a 13dB amplifier as well. For the MRD to work you must add the power supply unit. If the MRD is not powered then the aerial works normally, without amplification and without the "balun" effect to reduce impulse noise. Any 12v to 24v power supply will work, provided that it has the TV signal pass-through sockets
If you are unsure, you can order the aerial with the MRD alone. Install the aerial and, if the signal isn't strong enough, order the power supply.  | The power supply can be fitted anywhere in the cable from the aerial. MRD. There must be NOTHING else between the power supply and the aerial MRD! The power supply can feed one or two rooms with the TV signal. Connect the PSU output to your satellite receiver aerial input (analogue TV) or to your Freeview box (digital TV).
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Please note: These aerials have very high gain and should never be used when a transmitter is close by. They are for use in areas of very weak signal - i.e. where the nearest transmiter is no closer than 20 miles. Aerials of such high gain also have a very narrow "focus" so alignment is super-critical.
Specifactions:
Reference - 1095
Frequency range (MHz) - 470 - 862
Gain (dB) - 16,5
F/B ratio (dB) - 28
Offset angle (º) - 30
Elevation angle (º) - 35
Polarisation - Horizontal/Vertical
Length (mm) - 1.200
Number of elements - 45
Reference - 1095 with MRD
Frequency range (MHz) - 470 - 862
Gain (dB) - 29,5
Output level (dBuV) - 102
Noise figure (dB) - 2 typ.
Power supply (V=) - 24*
Consumption (mA) - 30
*DIN 45004B
* Optional 12 volts under order
USEFUL INFO
Impulsive noise does not last long and is characterised by a fast risetime. It can appear both in the UHF and in the VHF band. Man's industrial activity pollutes the RF spectrum with these signals that affect other carriers including the TV channels. The polluting agents are the power lines, car ignitions or home appliances. COFDM digital receivers can be affected and work incorrectly if the impulsive noise is considerable; the image freezes for a moment or disappears entirely. To solve this problem, a higher input signal level is necessary in the digital receiver.
The DAT45 antenna and MRD work together to achieve the best reception fordigital terrestrial TV. The impulsive noise can enter the network mainly via the antenna, the mast amplifier or the cable. An antenna with a high level of directivity like the DAT45, adequately orientated, will not receive the impulsive noise from the surroundings. On the other hand, the MRD (as it is located next to the dipole) avoids the amplification of the noise that would enter via the cable if it were situated on the mast. The diecast chassis helps to avoid the entrance of noise through the box. The 12 dB gain, makes the signal levels higher without making the analogue channels cause the saturation of the digital receivers. |
