RadPhi cables, trigger, etc.

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I went down into the hall to inspect the ends of the RadPhi cables. Below I note what I found, with some questions. Please speak up if you can clarify things.

I recall Richard saying there are two main types of cables: black 250 ns and white 80 ns cables. I found additional black cables that looked like they were also 80 ns prompt cables, but I am not sure. Nor am I sure whether I was looking at both ends of the same cables for the shorter black cables. I also saw a number of other misc. cables.

Anyway, I found (or think I found):

- 80 ns white cables: BNC in the alcove, BNC at the racks

- 250 ns black cables: lemo in the alcove, lemo at the racks

- 80 ns (?) black cables: BNC in the alcove, BNC and lemo at the racks

Please comment or clarify if you have additional information.

The BCAL PMT's have dual BNC outputs. The discriminators take high-density lemo in, and have a ribbon differential output, which matches perfectly with the F1 TDC's. The discriminators also have a sum output (signal proportional to number of channels above threshold) which should suffice for the trigger. Finally the ADC's take ribbon in, but I have enough ribbon-to-male-lemo converters.

The prompt white 80 ns cables match the PMT's, but need conversion to high-density lemo into the discriminators unless there are enough prompt black cables with BNC in the alcove and lemo at the racks. The 250 ns cables need conversion from lemo to BNC to attach to the PMT's, and need lemo barrels to connect to the ADC's. Thus we need a number of converters. With luck we can scrounge them up.

Finally, I found many channels of what looked like 2U rack-mount BNC-lemo-lemo 50 ohm splitters, i.e. BNC in, two lemo out. Anyone know for sure? It does not appear we need them, though.