"Steven Swift" wrote in message
...
According to my DuMont handbook of CRTs, a yellow filter can be
used with a P7 phosphor CRT to allow viewing of the long decay
part without being "blinded" by the bright blue trace.

The really (really) old marine radars had such a filter, the RCA, some
of the Decca, and similar post WWII radars are mostly in the junk pile by
now, but any old-time marine radar repair shop will probably have old
displays that seem a shame to junk. I suspect some of those places might pay
you to haul off the entire display (including the filters). Seems like the
filter for that phosphor had almost an orange cast to it, no?

Old Chief Lynn