mb21 - ether.net - 'MSF' Rugby

	UK Broadcast Transmission

RUGBY

Photo by Peter Bigwood

One question which crops up regularly in correspondence to the Transmitter Gallery is: Can you tell me anything about the large collection of transmitters just to the NE of Rugby (inside of the M1/M6 corner)?

Pete Chambers fully illustrated 24-page booklet Something in The Air - A Guide to the Rugby Masts tells you all you need to know, and you can see a couple of Pete's photos here.

In the meantime here's a brief technical explanation:
The site is known as Rugby and is owned by BT. the site has quite a history. The National Physical Laboratory also has a presence there as they transmit a time-signal from the 'MSF' station on 60kHz. This signal controls some of the radio-controlled clocks which you may have in your home.

According to the NPL site:
The solid-state 60 kHz transmitter at MSF Rugby consumes 70 kW of mains power and generates 60kW of radio-frequency signal which is sent via a coaxial cable to the antenna tuning and matching unit. The T-shaped antenna is 180m high and 500m across the top. A current of 160A R.M.S. at 60kHz flows into the base of the antenna. Because it is the vertical part that radiates, the signal strength at a given distance is substantially the same in all directions. In the case of a low-frequency antenna it is conventional to calculate what power would be required into a vertical 'monopole', whose length is short compared to a wavelength, over a perfectly-reflecting ground plane (EMRP - equivalent monopole radiated power) to give a known field-strength. This gives an EMRP of 15kW.

The BT Rugby station has now closed and the VLF masts, previously used for submarine communications, have now been demolished. The NPL time signal will be kept on.

This message was sent at 2400UTC on the 31st of March:

VVV DE GBR VVV DE GBR. After 77 years, three months of almost continuous operation, the GBR 16kHz service from BT Radio Station Rugby ceases today. A thank you to our customers, mainly the Royal Navy, without whom the service would not have been required and whose co-operation has enabled the service to run so smoothly. A big thank you must go to all of those who over the years have been involved in the design, construction, maintenance and operation of GBR. They can feel very proud of providing a consistent high level of reliable service and a job well done. This is the final transmission and GBR will now be shut down for the last time. DE GBR GBR QRT.

VLF mast demolition | More Rugby photos >

Something in The Air - A Guide to the Rugby Masts

A History of Rugby Radio | A Brief History of the Greenwich Time Signal

Radio Station Rugby - The History of Rugby Radio