STL – Studio to Transmitter Links

Analogue links, Digital links, internet, leased lines or even WiFi – they can all be used for STL Studio-Transmitter links. As with most things in life they each have their own pros and cons which need to be considered to know if they are suitable for your station or not. Associated Broadcast Consultants can give you independent advice on this key aspect of your transmission chain

We are on the record as strong advocates of Digital STL Studio-Transmitter links. Their key drawback is that they need line of sight and a bit more between your studio and the transmitter site (see diagram below)

Line of sight and the fresnel zone

If you can achieve clear line of sight like this, then they are often the optimum solution in terms of cost and quality. What’s more Associated Broadcast Consultants know some tricks to squeeze even more quality from them than they normally deliver out of the box!

You can get an indication of the terrain between your studio and your transmitter using a Path profile tool – there is a good example of a simple to use (and free) path profile tool on our “Tools” page in the menu above.

You can buy complete link packages using this technology from broadcast equipment suppliers. If money is tight you can do it for less money. As an indication of price, the equipment for the link alone need only cost £200 or less. Then you need a solution to create an audio stream over the link – hardware units can be purchased for a few hundred pounds to a few thousand pounds (the budget ones are great), or if you have spare PC’s, then free or low cost software can do that for you.

Simplified illustration of 5GHz studio-transmitter link

In the UK you have a choice whether to go (legally) unlicenced or licenced when using one of these 5GHz links. You may use Band A and B unlicenced. However for only £50 per year per link you may go licenced in Band C – this permits higher power, may give better protection from interference, and you may even get support from Ofcom if you did get interference problems (although we are not aware of interference being an issue in this band). Note – your equipment needs to conform to Ofcom’s interface specification IR2007 to be permitted for use legally in Band C. This specification requires features like automatic frequency selection and transmit power control which not all equipments have.  You may find out more and download the licence application form from the Ofcom website in their 5.8GHz Fixed Wireless Access Link section

Even if you don’t use one of these links as your main programme feed, they are an excellent and affordable backup, or could be used just to provide a data link to your transmitter site for alarms etc.

If you want some help with selecting a STL Studio to Transmitter Link and/or understanding about path profiles etc,  contact us and we can guide you through the maze of available options for your STL studio to transmitter link, helping you to achieve optimum quality and cost.

Associated Broadcast Consultants - Independent help and advice for Radio Broadcasters