Why distribute 10MHz over Fibre?

Most teleports have multiple pieces of RF equipment that requires a 10MHz reference signal. For example, this reference signal can be used to lock the local oscillator in the LNB to maximise stability of the oscillator frequency and increase accuracy of the translated signal. For these situations, ETL has designed a fibre module capable of receiving and transmitting this 10MHz signal over fibre. The diagram below shows the path of a 10MHz signal from the source being distributed to various equipment in the control room, as well as being sent over fibre to the LNB at the antenna. This is being carried on its own single fibre, alongside the L-band signals being sent in the opposite direction, from the antenna through to the control room.

The control rooms at these teleports are rarely located within a short distance. To meet this need, ETL has designed the StingRay RF over fibre product which allows an RF signal to be converted into fibre and transmitted up to 10 kilometres. With the growing need of a reference signal, ETL has expanded the StingRay product line with the 10MHz transmit module which fits conveniently into the existing StingRay chassis. This transmit module communicates directly with a paired receive module that is housed in the outdoor chassis located next to the teleport’s antenna field. The form factor is the same as the RF over fibre transmit and receive modules, so there is no need for an extra chassis to accommodate the 10MHz reference modules.

ETL’s model 24500 is a 10MHz source that fits into a 1 rack unit chassis. This system generates a 10MHz reference signal and can be used in conjunction with the StingRay RF over Fibre system to carry the 10MHz to the antenna’s LNB. ETL also offers a variety of 10MHz splitters that allow this single 10MHz signal to be distributed across multiple hardware systems out in the field, thus eliminating the need for several links or sources within an antenna network. As well as multiplexers to enable 10MHz and L-band to be multiplexed on to a single LNB feed.

If you have a requirement for 10Hz over fibre, to find out more about ETL solutions please contact Lumina Broadcast Systems.