Decca - that takes me back to my NRAST course and exams, Decca was still (just) alive then as was LoranC
I worked on flight control computers fitted to helicopters in '64. Also computers fitted to Decca Nav equipment in the same year. Later worked/repaired them for a living. But I must admit these days I find it difficult to understand the things.
Decca was very innovated in it's day. The original Mk 1, which was designed for maretine work used a mechanical computer..
Sounds like Charles Babbage's Analytical Engine.
Yes I think it was similar. I could expand my reply but it would be completely off topic.
And................................?
Never used that particular model, but saw a few and yes, very clicky and wirrrrrrrrry the machines we had when I started on the boats were pretty advanced, digital displays and you could switch from Decca to GPS in a thrice - most of us didn't bother switching them back! most of our charts were still Decca grids though and even long after Decca was history I can remember the excitement when someone came across the few remaining decca charts in the folio. I think I was on watch the day they finally switched Decca off.
There were 10 inputs to the computer, but usually only 4 were used, the Master Tx, and you could choose from Green, Blue, Yellow, Red, Purple etc. The inputs were driven by electric motors that "counted" the "standing sine waves" generated by the Decca TX Chains.. The output from the computer, being mechanical could be used to drive mechanical clock type displays which could be "translated" into map references.. The input drives to the computer were obtained from 4/6 x RF receivers usually tuned individualy to the ( usualy). 4 transmitters in a chain. Hope this helps..
Like being back in school! yes, and the Decca charts had gridlines corresponding to transmission chains and were colour coded so the Decca 'coordinates' were totally different to Lat and Long. LoranC was more or less identical but was international as opposed to Decca which was just the British isles and surrounding areas, most of the transmitters were in coast radio stations. The analogue Decca sets had been superseded by the digital sets by the time I joined so the sets could translate the Decca coordinates to Lat and Long (Now WGS) coordinates. Sometimes the skipper would make us use Decca just to exercise our brains!
The last Decca chain to close was the one in S Wales.. On the Wessex helicopters they had the MK 8A. The chart was a roll approx 14 inches wide that scrolled up or down and a pointer would move side to side. Srangely, looking at the chart Oxford was "south" of London. We fitted the Decca to the choppers ready for an exersize to north Africa, Tobruk. We had good coverage all the way down and back.
Please reread my post I said according to the paper work!
