"It's smart to be square"
- BSB Advertising Slogan
The UK satellite broadcast company, BSB - British Satellite Broadcasting, was well known for two reasons. Firstly, it was exceedingly short-lived, going on-air in March 1990, merging with Sky in November 1990, and ceasing transmission on 31st December, 1992.
The second item of note was its quirky antenna, known as a squarial, designed to receive signals from the pair of Marco Polo satellites launched specifically for the service.
The antenna was a thin square (45cm diagonal) mounted on a bracket allowing adjustment of elevation and direction on installation, which were then fixed with screws. Because this was intended for geostationary use, it would remain pointing in the same direction once set up.
The LNB convertor (the bit which actually receives the signal from the satellite and sends it to the decoder) was situated on the back of the antenna, not in front as you would find on a standard dish antenna. A coaxial output was provided from the LNB.
Although the antenna was too small to pick up many satellite signals, the Marco Polo signals were directed specifically at Britain, and the small size of the squarial, compared to the 60 or 80 centimetres of a Sky dish meant that planning permission was not required.
The squarial was a right-hand circular polarised DMAC receiver, optimised around the 12GHz band.
If you have a squarial in your attic (you didn't leave it attached to your house, did you?), it is of little use now. It is possible to convert the right-hand polarisation to left-hand by dismantling the case and reversing the plastic sheet inside. This will then be suitable for receiving signals from the Hispasat satellite - the Spanish communications satellite at 30° west.
In the north-east of England, and over Scandinavia, a squarial can be used to receive signals from Thor, one of the original Marco Polo satellites, which was renamed and redirected to cover that area.