Battery Box Project for 40-81

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Arran
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#24

07-31-2026, 01:18 AM

It's preferable to operate battery tube filaments at slightly less voltage if anything, the book says 1.4 volts so I would guess that they were intended to run on a fresh 1.5 volt carbon zinc "A" battery under load. Some battery tubes don't like running at lower filament voltage, the 1R5 is notoriously fussy for the oscillator stopping, or not starting if it falls below 1.4 volts, a 1A7 doesn't seem to care as much. What kind of rechargeable are we speaking of, a Lithium, NiCad, Nickel Metal Hydride?
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Arran

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Messages In This Thread

Battery Box Project for 40-81 - by MZip - 07-26-2026, 01:46 PM

RE: Battery Box Project for 40-81 - by morzh - 07-26-2026, 04:45 PM

RE: Battery Box Project for 40-81 - by MZip - 07-26-2026, 05:02 PM

RE: Battery Box Project for 40-81 - by radiorich - 07-27-2026, 02:04 AM

RE: Battery Box Project for 40-81 - by MZip - 07-27-2026, 09:27 AM

RE: Battery Box Project for 40-81 - by MrFixr55 - 07-27-2026, 11:33 AM

RE: Battery Box Project for 40-81 - by MZip - 07-27-2026, 12:28 PM

RE: Battery Box Project for 40-81 - by Arran - 07-27-2026, 04:18 PM

RE: Battery Box Project for 40-81 - by MrFixr55 - 07-27-2026, 07:47 PM

RE: Battery Box Project for 40-81 - by MZip - 07-28-2026, 11:16 AM

RE: Battery Box Project for 40-81 - by radiorich - 07-28-2026, 11:29 AM

RE: Battery Box Project for 40-81 - by Arran - 07-28-2026, 01:15 PM

RE: Battery Box Project for 40-81 - by David - 07-28-2026, 02:15 PM

RE: Battery Box Project for 40-81 - by Arran - 07-28-2026, 10:30 PM

RE: Battery Box Project for 40-81 - by radiorich - 07-29-2026, 10:42 AM

RE: Battery Box Project for 40-81 - by MrFixr55 - 07-29-2026, 01:49 PM

RE: Battery Box Project for 40-81 - by Arran - 07-29-2026, 06:40 PM

RE: Battery Box Project for 40-81 - by RodB - 07-29-2026, 08:00 PM

RE: Battery Box Project for 40-81 - by Arran - 07-29-2026, 11:01 PM

RE: Battery Box Project for 40-81 - by radiorich - 07-30-2026, 02:41 AM

RE: Battery Box Project for 40-81 - by MZip - 07-30-2026, 12:31 PM

RE: Battery Box Project for 40-81 - by MrFixr55 - 07-30-2026, 06:11 PM

RE: Battery Box Project for 40-81 - by David - 07-30-2026, 09:16 PM

RE: Battery Box Project for 40-81 - by Arran - 07-31-2026, 01:18 AM

RE: Battery Box Project for 40-81 - by David - 08-01-2026, 09:56 AM

RE: Battery Box Project for 40-81 - by Arran - 08-04-2026, 12:51 PM

RE: Battery Box Project for 40-81 - by MrFixr55 - 08-06-2026, 10:25 PM

RE: Battery Box Project for 40-81 - by David - 08-07-2026, 12:31 PM

RE: Battery Box Project for 40-81 - by MrFixr55 - 08-07-2026, 11:42 PM

RE: Battery Box Project for 40-81 - by DaleHCook - 08-08-2026, 08:09 AM

MZip - by MZip - 08-18-2026, 07:43 PM

RE: Battery Box Project for 40-81 - by DaleHCook - 08-19-2026, 08:16 AM

RE: Battery Box Project for 40-81 - by MrFixr55 - 08-19-2026, 09:12 AM

RE: Battery Box Project for 40-81 - by MZip - 08-19-2026, 12:21 PM

RE: Battery Box Project for 40-81 - by DaleHCook - 08-19-2026, 12:36 PM

RE: Battery Box Project for 40-81 - by radiorich - 08-19-2026, 12:44 PM

RE: Battery Box Project for 40-81 - by radiorich - 08-19-2026, 12:51 PM

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