Thankyou Ioannis for you great help ,

i contacted Vishay engineer and he confirmed that the TSOP7000 ( 455khz ) receiver is no longer being made , and no item in there range suites the 455khz now.

Although i was able to get some good pricing for the receiver , still alot of them about and can be found
cant seem to find any other manufactures that now do a 455Khz receiver else id go with TSOP7000

if you know of another 455khz receiver in production let me know please, i do a bit of search today as well.

Also as it turns out there is no IR led in Vishay range at 10deg 940/950nm at 1000mw/sr or higher with a switching speed lower than 800ns. but if used at 38Khz should not be a factor.

but is far more preferable for the design to use a higher frequency IR receiver at 455Khz than at 38Khz as it takes less time to dectect a missing pulse

eg when using a IR reciever at 38khz then scan time = 26.3us x 11 = 300us ( min detect time for proposed IR reciever TSSP4038 )
so 20leds x 300us = 6ms per scan
3 scans of the array = 18ms

eg when using a IR reciever at 455khz then scan time = 2.2us x 12 = 26.4s ( min detect time for proposed IR reciever TSSP7000 )
so 20leds x 26.4us = 528us per scan
3 scans of the array = 1.58 ms

more scans can be done for shorter time using 455Khz


speed is everything sometimes lol

cheers

sheldon