Back to the stone age?

Radar from the Stone age:
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Radar Display unit type 155 B Class B. Serial No. R. 0637.
Safe compass distance standard 4 ft.
Decca Radar Ltd. Made in England
This unit was installed on the 1943 blt. US PCE 833 / HMS Kilham:
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Converted to RoPax Sognefjord in 1950:


Still existing as Orient Explorer. Now laying in Kota Kinabalu;

In near wreck condition after having been grounded in a storm and partly sunk in 2020;
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Anybody here that has operated this type of radars?