Quote:
Originally Posted by Dave Mills
And more....
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The still-wrapped J1 box is the control unit for almost any of the vehicle-mounted sets. It's the same as the large one on the tray to its immediate right.
The tray on the right (with a J1 and an 'O' box fitted (the latter is incorrect, I think) is the 'top tray' for a C11/R210 setup, and normally carries the J1 box and an LT (power distribution) box for the setup.
The J1 box does all the audio switching and headset feeds for a 'one set' vehicle installation (it provides a couple of headset connections and 12-way feed for other audio distribution (C = Crew, D = Driver) boxes), and contains the very important Voltage Control Relay for the harness - this allows the batteries to be float-charged from the vehicle alternator and tells the set when to switch to the 'low voltage' setting as the batteries run down. (The default is 28-30 volt input to protect the valve heaters, with the VCR in play the set will continue to operate well with an input voltage down around 20-22 volts).
The tubular handles on the top trays are a lesson learned from WW2. They are so that you can remove kit from a vehicle easily: the bottom tray remains in place, you simply disconnect the power, harness and audio cables, undo the clamps holding the set and supply unit to the bottom tray, and lift the entire assembly out as a single unit. (Without the danger of the thing turning turtle on you as was a favourite with the WS19 on the demountable carriers (3, 23 or 25).)
Chris.