Note sure tbh re the equipment on the roof as there is little explanation about the technology. I honestly dont know.
"The interesting piece is fitted in under the transmitter with lots of special circuits which have not only been dealing with the conversational side but the dialing mechanism part which is the tricky bit.
If you use your mobile phone within a 7 mile radius you should be able to .....// ..... ideal for people who havent got a proper telephone handy."
Doesnt say much about the 'special equipment' under the transmitter but its sounding more than a bog standard cordless extension type phone - especially with a range of 7 miles.
They also mention mobile car phones but say what is unique is that it doesn't require dialling through an operator.
A version of the cordless phone was invented in 1968, but Bell Labs had also been dabbling since 1963 and in '64-65 had invented this cordless phone:
http://www.telephonecollectors.info/index.php/wiring-diagrams/doc_view/11603-67jun-blr-p202-experimental-lineless-cordless-telephone or
here.
Seems a bit odd that if Bell Labs had already invented a cordless phone, that Blue Peter should be reporting this one in 1976. Look at the size of that box on the roof compared to what Bell labs had invented.
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ETA Just got warning of another reply as I was about to hit send.
Appears phi2008 has managed to track down the model
The base station for mobile telephone system was developed by Chelmsford Radio Amateur, Lew Schnurr
, which was the guy mentioned by Peter Purvis.