It might be worth saving the bases and buying "grain of wheat" lamps to rebuild the lights. I see ~70ma 6v lamps available. That sounds similar to the original specification.
Dwight ________________________________ From: cctalk <cctalk-boun...@classiccmp.org> on behalf of Brent Hilpert via cctalk <cctalk@classiccmp.org> Sent: Wednesday, July 25, 2018 8:21:58 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: HP-2116 front panel lamps On 2018-Jul-25, at 6:47 AM, Christian Corti via cctalk wrote: > On Wed, 25 Jul 2018, it was written >> Christian, when I was restoring the HP Computer Museum's 2116A I ordered a >> bunch of these 345 bulbs from 1000bulbs.com - but it seems they no longer >> stock them. >> >> I did find this listing though which looks current... >> https://www.lighting-pros.com/eiko-345-t-1-3-4-midget-flanged-sx6s-case-of-1 >> 0 >> >> They are around 0.04A current draw - not 0.75A! > > Yes, the Installation and Maintenance Manual on bitsavers > (02116-9153_2116B_Vol2_Oct70.pdf) contains several errors. > Interesting enough, my printed copy of this manual from 1968 (that is > completely different from the 1970 one; it only has parts lists and > schematics, the chapters for installation and maintenance are simply not > there) is right: 2140-0035 6.3V 0.04A > > In the meantime I've ordered a bunch of JKL 345 from Mouser (60 Ecent/piece) To mention, they are actually run below-spec in the processor, which of course improves longevity and reduces the heat next to the plastic front panel. >From actual measurements in my 2116C the lamps (CM345) draw: register-bit positions: ~ 31ma @ 4.1V inside the push-buttons: ~ 36mA @ 5.4V compared to the spec: 40mA @ 6V ( I obtained CM345s from Mouser in 2013. "95 in stock", that would have left 83 after my purchase).
