I knew I'd seen the number, and found them just now: http://www.tube-tester.com/sites/nixie/dat_arch/Numitron_RCA_01.pdf at the bottom of the page, they are development numbers for the DR2200 series.
/Martin On Tuesday, 26 October 2021 at 22:21:47 UTC+2 Dekatron42 wrote: > Tubes designated DTF are development numbers used by Apollo/RCA - it says > so at the bottom of their datasheets. > > /Martin > > On Tuesday, 26 October 2021 at 21:43:52 UTC+2 Bartek Ogryz wrote: > >> Hi! >> They appeared on eBay last days: DTF137, DTF138, DTF140 (or maybe DTF/37, >> DTF/38, DTF/40). What are theese? Anyone has some more knowledge about them? >> >> Bartek. >> >> BTW: If someone is interested in numitrons, quite rare Apollo DA-2500 are >> hiding on eBay: item no 254866404573. Unfortunatelly, as the seller told >> me, all that have left, are without markings... >> > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/2c9ef490-64b9-49b0-b6d0-62b5b8e93682n%40googlegroups.com.
