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Groups > uk.tech.broadcast > #70556 > unrolled thread
| Started by | "J. P. Gilliver" <G6JPG@255soft.uk> |
|---|---|
| First post | 2026-09-26 19:08 +0100 |
| Last post | 2026-09-27 13:12 +0200 |
| Articles | 20 on this page of 143 — 23 participants |
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Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 19:08 +0100
Re: OT - TV Scott <newsgroups@gefion.myzen.co.uk> - 2026-09-26 19:58 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 20:30 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-27 09:39 +0100
Re: OT - TV JMB99 <mb@nospam.net> - 2026-09-28 08:08 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-09-26 19:10 +0000
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 21:02 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-26 21:03 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-09-27 18:20 +0000
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-28 16:26 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-09-28 15:45 +0000
Re: OT - TV Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-28 16:30 +0000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-28 17:46 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-28 22:25 +0100
Re: OT - TV NY <me@privacy.net> - 2026-09-29 16:40 +0100
OT - Lehrer (was: Re: OT - TV) "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-29 16:58 +0100
Re: OT - Lehrer (was: Re: OT - TV) Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-29 18:19 +0000
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-29 20:57 +0100
Re: OT - Lehrer Charles Hope <clh@candehope.me.uk> - 2026-09-29 20:00 +0000
Re: OT - Lehrer (was: Re: OT - TV) André Coutanche <acoutanche@gmx.co.uk> - 2026-09-29 21:50 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-29 22:33 +0100
Re: OT - Lehrer Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-29 22:48 +0000
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 01:07 +0100
Re: OT - Lehrer John Ames <commodorejohn@gmail.com> - 2026-09-30 15:51 -0700
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 10:57 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-30 08:10 +0100
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 01:39 +0100
Re: OT - Lehrer Roger Blake <rogblake@iname.invalid> - 2026-09-30 00:46 +0000
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-29 22:39 +0100
Re: OT - Lehrer Frank Slootweg <this@ddress.is.invalid> - 2026-09-30 12:25 +0000
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 13:34 +0100
Re: OT - Lehrer The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 14:31 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-09-30 14:47 +0100
Re: OT - Lehrer John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 14:58 +0100
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 02:36 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 11:12 +0100
Re: OT - Lehrer Frank Slootweg <this@ddress.is.invalid> - 2026-10-01 14:35 +0000
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 16:14 +0100
Re: OT - Lehrer Frank Slootweg <this@ddress.is.invalid> - 2026-10-01 17:35 +0000
Re: OT - Lehrer Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-10-01 17:53 +0000
Re: OT - Lehrer John Williamson <johnwilliamson@btinternet.com> - 2026-10-01 19:03 +0100
Re: OT - Lehrer "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 21:50 +0100
Re: OT - Lehrer The Natural Philosopher <tnp@invalid.invalid> - 2026-10-02 12:25 +0100
Re: OT - Lehrer The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 11:13 +0100
Re: OT - Lehrer NY <me@privacy.net> - 2026-10-01 11:51 +0100
Re: OT - Lehrer John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 14:55 +0100
Re: OT - Lehrer Charles Hope <clh@candehope.me.uk> - 2026-09-30 14:15 +0000
Re: OT - TV Daniel70 <daniel47@nomail.afraid.org> - 2026-09-27 19:58 +1000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-27 12:52 +0100
Re: OT - TV Daniel70 <daniel47@nomail.afraid.org> - 2026-09-27 22:13 +1000
[OT] - audio distribution, Rediffusion-style (was: Re: OT - TV) "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-28 16:43 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-27 11:44 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-27 16:12 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-27 18:12 +0100
Re: OT - TV Andy Burns <usenet@andyburns.uk> - 2026-09-27 18:23 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-27 18:34 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-28 14:03 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-28 15:56 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-28 16:46 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-28 17:16 +0100
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-09-29 12:01 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-29 13:05 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-29 13:25 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-29 14:13 +0100
Re: OT - TV The Other John <nomail@here.org> - 2026-09-29 16:53 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-29 17:12 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-30 10:22 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-09-30 13:36 +0100
Re: OT - TV "Carlos E.R." <robin_listas@es.invalid> - 2026-09-30 11:23 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 11:48 +0100
Re: OT - TV Paul <nospam@needed.invalid> - 2026-09-30 07:37 -0400
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 14:28 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 00:35 +0200
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 02:15 +0100
Re: OT - TV Paul <nospam@needed.invalid> - 2026-10-01 00:15 -0400
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 12:50 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 14:24 +0200
Re: OT - TV Max Demian <max_demian@bigfoot.com> - 2026-10-01 17:17 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 12:48 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 13:10 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-01 13:42 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-01 13:32 +0100
Re: OT - TV Frank Slootweg <this@ddress.is.invalid> - 2026-10-01 14:52 +0000
Re: OT - TV Daniel70 <daniel47@nomail.afraid.org> - 2026-10-03 21:10 +1000
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-03 13:39 +0200
Re: OT - TV Daniel70 <daniel47@nomail.afraid.org> - 2026-10-04 21:26 +1100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-04 13:19 +0200
Re: OT - TV Paul <nospam@needed.invalid> - 2026-10-04 10:36 -0400
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-04 19:18 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-03 12:47 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-03 12:50 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-03 13:09 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-03 15:59 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-03 15:56 +0000
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-03 17:19 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-04 10:54 +0000
Re: OT - TV c186282 <c186282@nnada.net> - 2026-10-05 01:27 -0400
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-05 07:55 +0000
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-05 14:54 +0200
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-05 11:29 +0100
Re: OT - TV Andy Burns <usenet@andyburns.uk> - 2026-10-05 11:46 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-05 12:47 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-03 18:41 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-03 22:52 +0100
Re: OT - TV Paul <nospam@needed.invalid> - 2026-10-03 21:24 -0400
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-04 08:08 +0000
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-10-04 09:29 +0100
Re: OT - TV Roderick Stewart <rjfs@escapetime.myzen.co.uk> - 2026-09-30 15:13 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-29 13:16 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-09-29 15:54 +0000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-29 17:15 +0100
Re: OT - TV "Carlos E.R." <robin_listas@es.invalid> - 2026-09-30 11:27 +0200
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 11:13 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 11:19 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 11:57 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-30 13:29 +0100
Re: OT - TV John Williamson <johnwilliamson@btinternet.com> - 2026-09-30 13:54 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 14:34 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-09-30 18:08 +0100
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-01 02:22 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-01 06:37 +0000
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 10:32 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 09:41 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 00:37 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-09-30 11:50 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-09-30 13:08 +0000
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 00:50 +0200
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-01 06:12 +0000
Re: OT - TV c186282 <c186282@nnada.net> - 2026-10-01 03:29 -0400
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 14:53 +0200
Re: OT - TV Paul <nospam@needed.invalid> - 2026-10-01 03:32 -0400
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 14:49 +0200
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 12:57 +0100
Re: OT - TV liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2026-10-01 13:27 +0100
Re: OT - TV "Carlos E. R." <robin_listas@es.invalid> - 2026-10-01 15:19 +0200
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-01 14:34 +0000
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-01 15:51 +0100
Re: OT - TV Jan Panteltje <alien@comet.invalid> - 2026-10-02 06:52 +0000
Re: OT - TV Andy Burns <usenet@andyburns.uk> - 2026-10-04 07:52 +0100
Re: OT - TV c186282 <c186282@nnada.net> - 2026-10-04 03:15 -0400
Re: OT - TV "J. P. Gilliver" <G6JPG@255soft.uk> - 2026-10-04 15:51 +0100
Re: OT - TV The Natural Philosopher <tnp@invalid.invalid> - 2026-10-04 18:16 +0100
Re: OT - TV "Carlos E.R." <robin_listas@es.invalid> - 2026-09-27 13:12 +0200
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| From | Andy Burns <usenet@andyburns.uk> |
|---|---|
| Date | 2026-10-05 11:46 +0100 |
| Message-ID | <nihdh7FepipU1@mid.individual.net> |
| In reply to | #70721 |
John Williamson wrote: > c186282 wrote: > >> Future/NOW ... look into sodium batteries. Plenty >> on Amazon. Almost as good as LIPo bur DON'T blow >> up in your face and set everything on fire. Seems >> the usual charge circuits for lead-acid work fine >> for sodium, though sodium CAN be charged faster. >> > I just searched for "sodium battery" on Amazon UK. Not a single one in > the resuktys, but I *was* offered lead acid of various types, as well as > a number of Lithium based batteries of various tyoes. > > Do you have a link for a sodium battery on Amazon? I've seen it demonstrated that a Sodium-ion battery is basically just as easy to puncture causing thermal runaway and catching fire as a Lithium-ion battery ...
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-10-05 12:47 +0100 |
| Message-ID | <11a02np$sln7$7@dont-email.me> |
| In reply to | #70721 |
On 05/10/2026 11:29, John Williamson wrote: > On 05/10/2026 06:27, c186282 wrote: >> On 10/4/26 06:54, Jan Panteltje wrote: > >>> I have these for on a boat: >>> 250_Ah_12V_to_230V_sinewave_IXXIMG_0796.JPG >>> >>> Now in use as backup for my computers, as the UPS battery gave up after >>> constantly coming in since the power company changed their meter for a >>> 'smart' >>> one and removed the connection of neutral to local ground, >>> causing a voltage drop. >>> So much for improvement, now you pay more for their cable losses?? >>> >>> That battery pack runs microwave and fridge too if needed >>> I have 3 large flexible solar panels for on a boat. >>> And a small fixed 80 W one upstair in a window. >>> Several solar powered flashights too, some with hand crank. >> >> >> LIPo batts CAN still explode for no obvious >> reason. Got a scar to prove it. >> > Lithium Polymer batteries are, as you say, prone to thermal runaway if > overcharged, run too flat or the day has a "y" in it. They are currently > used in phones, laptops, tablets, e-bikes and some cars. > > LiFePO4 batteries, on the other hand are currently being used in many > thousands of boats as power supplies for the domestic stuff, and I have > yet to hear one report of an explosion or fire that was not started by > ancillary equipment. The cells are usually still intact after the fire. > You *can*, if you are determined enough, make the cells ignite by, say, > repeatedly using an ice pick to puncture them, but it needs to be a > metal pick, so that it shorts out the internal structures and even then, > as long as you stand upwind, the fumes won't hurt you. > However they are heavier >> Future/NOW ... look into sodium batteries. Plenty >> on Amazon. Almost as good as LIPo bur DON'T blow >> up in your face and set everything on fire. Seems >> the usual charge circuits for lead-acid work fine >> for sodium, though sodium CAN be charged faster. >> > I just searched for "sodium battery" on Amazon UK. Not a single one in > the resuktys, but I *was* offered lead acid of various types, as well as > a number of Lithium based batteries of various tyoes. > They are little different to lead acid. A tad lighter. Just as expensive. o no one is buying > > > -- “it should be clear by now to everyone that activist environmentalism (or environmental activism) is becoming a general ideology about humans, about their freedom, about the relationship between the individual and the state, and about the manipulation of people under the guise of a 'noble' idea. It is not an honest pursuit of 'sustainable development,' a matter of elementary environmental protection, or a search for rational mechanisms designed to achieve a healthy environment. Yet things do occur that make you shake your head and remind yourself that you live neither in Joseph Stalin’s Communist era, nor in the Orwellian utopia of 1984.” Vaclav Klaus
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-10-03 18:41 +0100 |
| Message-ID | <119reoe$37dqq$1@dont-email.me> |
| In reply to | #70699 |
On 03/10/2026 15:59, John Williamson wrote: > On 03/10/2026 13:09, The Natural Philosopher wrote: >> On 03/10/2026 12:50, John Williamson wrote: >>> On occasion, 15 Volt or slightly more can be used ro equalise the >>> charge between the cells, but this will cause some of the water in the >>> electrolyte to split into hydrogen and oxygen. >> And some of the cells to split into plastic, lead, acid and a loud bang >> DAMHIKT... > > That needs a spark nearby > Yes. Removing the battery charger was plenty. -- Microsoft : the best reason to go to Linux that ever existed.
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| From | "J. P. Gilliver" <G6JPG@255soft.uk> |
|---|---|
| Date | 2026-10-03 22:52 +0100 |
| Message-ID | <119rtfl$3cufj$1@dont-email.me> |
| In reply to | #70696 |
On 2026/10/3 12:50:51, John Williamson wrote: [] > On occasion, 15 Volt or slightly more can be used ro equalise the charge > between the cells, but this will cause some of the water in the > electrolyte to split into hydrogen and oxygen. > > Which won't recombine (except explosively), so reducing the amount of electrolyte in the gassing cell, so reducing the capacity - which will thus cause that cell to be the first to start gassing next time, i. e. (slow) positive feedback. Whether this can be remedied by topping up the affected cell(s), I do not know. -- J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf
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| From | Paul <nospam@needed.invalid> |
|---|---|
| Date | 2026-10-03 21:24 -0400 |
| Message-ID | <119s9s8$3gl64$1@dont-email.me> |
| In reply to | #70703 |
On Sat, 10/3/2026 5:52 PM, J. P. Gilliver wrote: > On 2026/10/3 12:50:51, John Williamson wrote: > [] >> On occasion, 15 Volt or slightly more can be used ro equalise the charge >> between the cells, but this will cause some of the water in the >> electrolyte to split into hydrogen and oxygen. >> >> > Which won't recombine (except explosively), so reducing the amount of > electrolyte in the gassing cell, so reducing the capacity - which will > thus cause that cell to be the first to start gassing next time, i. e. > (slow) positive feedback. Whether this can be remedied by topping up the > affected cell(s), I do not know. > "The Basic Chemistry of Gas Recombination in Lead-Acid Batteries" https://www.tms.org/pubs/journals/jom/0101/nelson-0101.html It appears the process takes care of the oxygen. Paul
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| From | Jan Panteltje <alien@comet.invalid> |
|---|---|
| Date | 2026-10-04 08:08 +0000 |
| Message-ID | <119t1ip$3nfmp$1@dont-email.me> |
| In reply to | #70704 |
>Paul <nospam@needed.invalid>wrote: >>On Sat, 10/3/2026 5:52 PM, J. P. Gilliver wrote: >> On 2026/10/3 12:50:51, John Williamson wrote: >> [] >>> On occasion, 15 Volt or slightly more can be used ro equalise the charge >>> between the cells, but this will cause some of the water in the >>> electrolyte to split into hydrogen and oxygen. >>> >>> >> Which won't recombine (except explosively), so reducing the amount of >> electrolyte in the gassing cell, so reducing the capacity - which will >> thus cause that cell to be the first to start gassing next time, i. e. >> (slow) positive feedback. Whether this can be remedied by topping up the >> affected cell(s), I do not know. >> > >"The Basic Chemistry of Gas Recombination in Lead-Acid Batteries" > > https://www.tms.org/pubs/journals/jom/0101/nelson-0101.html > >It appears the process takes care of the oxygen. > > Paul Thank you, nice link!
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-10-04 09:29 +0100 |
| Message-ID | <nieh2gF1e64U1@mid.individual.net> |
| In reply to | #70703 |
On 03/10/2026 22:52, J. P. Gilliver wrote: > On 2026/10/3 12:50:51, John Williamson wrote: > [] >> On occasion, 15 Volt or slightly more can be used ro equalise the charge >> between the cells, but this will cause some of the water in the >> electrolyte to split into hydrogen and oxygen. >> >> > Which won't recombine (except explosively), so reducing the amount of > electrolyte in the gassing cell, so reducing the capacity - which will > thus cause that cell to be the first to start gassing next time, i. e. > (slow) positive feedback. Whether this can be remedied by topping up the > affected cell(s), I do not know. > Some batteries have plugs with a catalyst which partially recombine the two into water, but mostly, we just add pure water (Distilled or de-ionised) after equalisation. For some applications such as electric vehicles, this is automated. These batteries can last much longer than sealed cells. Lead acid batteries are not maintenance free, except in the limited sense that sealed cells with a catalytic cap can outlast the warranty period by a small margin with suitably controlled charging. Eventually, though, the lead in all lead acid batteries gets sulphated by the acid and needs to be reprocessed no matter what you do. -- Tciao for Now! John.
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| From | Roderick Stewart <rjfs@escapetime.myzen.co.uk> |
|---|---|
| Date | 2026-09-30 15:13 +0100 |
| Message-ID | <iv5qbltcnrg3t63mdjnbqdlrmn4vmrvorr@4ax.com> |
| In reply to | #70620 |
On Wed, 30 Sep 2026 11:23:21 +0200, "Carlos E.R." <robin_listas@es.invalid> wrote: >> Its NOT juts a matter of impedance - its a matter of DC bias. You cannot >> build a >> valve amplifier that delivers true AC without an isolation transformer. >> Loudspeakers don't like DC bias > >That's true also for transistors, and we don't normally use >transformers. We use capacitors. You don't need an isolating capacitor in the output of a transistor amplifier if it has a +/- power supply so that the output voltage has a DC component of zero. You still need big capacitors, but audio isn't going through them because they're smoothing the DC supply instead. Rod.
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| From | liz@poppyrecords.invalid.invalid (Liz Tuddenham) |
|---|---|
| Date | 2026-09-29 13:16 +0100 |
| Message-ID | <1s278ix.1exku2ij8p4zkN%liz@poppyrecords.invalid.invalid> |
| In reply to | #70594 |
Max Demian <max_demian@bigfoot.com> wrote: > On 28/09/2026 16:46, The Natural Philosopher wrote: > > On 28/09/2026 14:03, Max Demian wrote: > >> Yes, I suppose there could be a matching transformer, in the same way > >> that there were boxes you connected to the "extension speaker" socket > >> of the main (valve) radio so you could listen in the kitchen. I had > >> one which had a transformer and a wander plug arrangement so you could > >> match it. Some valve radios had a high impedance output, so presumably > >> both connections would be at (more or less) HT voltage above the radio > >> chassis (which would be earth if the earth socket was connected). I > >> think there were high impedance horn extension speakers at one time. > > > Valve amps ALWAYS have an output transformer. Not least because there > > are no 'P channel ' valves. > > I think there were high impedance horn speakers, which wouldn't require > a transformer. And, of course, high impedance headphones if you don't > want a loudspeaker. The moving-iron loudspeakers were higher impedance and could be connected directly into the anode circuit of a valve but the sound quality was much poorer than a moving coil loudspeaker. Some used a large paper diaphragm, others used a small metal diaphragm with a horn for acoustic impedance matching. Some early horn loudspeakers were little more than a high-impedance earphone joined to a horn. Most post-1930s horn loudspeakers have a low impedance moving coil drive unit and some have a matching transformer built into the back of the housing. Eddystone communication receivers still had a separate high impedance headphone socket, in addition to loudspeaker connections, right up to the last valve models. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
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| From | Jan Panteltje <alien@comet.invalid> |
|---|---|
| Date | 2026-09-29 15:54 +0000 |
| Message-ID | <119gmur$3e4ln$1@dont-email.me> |
| In reply to | #70594 |
>Max Demian <max_demian@bigfoot.com>wrote: >>On 28/09/2026 16:46, The Natural Philosopher wrote: >> On 28/09/2026 14:03, Max Demian wrote: >>> Yes, I suppose there could be a matching transformer, in the same way >>> that there were boxes you connected to the "extension speaker" socket >>> of the main (valve) radio so you could listen in the kitchen. I had >>> one which had a transformer and a wander plug arrangement so you could >>> match it. Some valve radios had a high impedance output, so presumably >>> both connections would be at (more or less) HT voltage above the radio >>> chassis (which would be earth if the earth socket was connected). I >>> think there were high impedance horn extension speakers at one time. > >> Valve amps ALWAYS have an output transformer. Not least because there >> are no 'P channel ' valves. > >I think there were high impedance horn speakers, which wouldn't require >a transformer. And, of course, high impedance headphones if you don't >want a loudspeaker. Yes some tube TVs had 800 Ohm speakers without transformers. Example of a tube output stage without transformer to drive a 800 Ohm speaker: https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-09-29 17:15 +0100 |
| Message-ID | <119go7i$3cdrk$3@dont-email.me> |
| In reply to | #70602 |
On 29/09/2026 16:54, Jan Panteltje wrote: >> Max Demian <max_demian@bigfoot.com>wrote: >>> On 28/09/2026 16:46, The Natural Philosopher wrote: >>> On 28/09/2026 14:03, Max Demian wrote: >>>> Yes, I suppose there could be a matching transformer, in the same way >>>> that there were boxes you connected to the "extension speaker" socket >>>> of the main (valve) radio so you could listen in the kitchen. I had >>>> one which had a transformer and a wander plug arrangement so you could >>>> match it. Some valve radios had a high impedance output, so presumably >>>> both connections would be at (more or less) HT voltage above the radio >>>> chassis (which would be earth if the earth socket was connected). I >>>> think there were high impedance horn extension speakers at one time. >> >>> Valve amps ALWAYS have an output transformer. Not least because there >>> are no 'P channel ' valves. >> >> I think there were high impedance horn speakers, which wouldn't require >> a transformer. And, of course, high impedance headphones if you don't >> want a loudspeaker. > > Yes some tube TVs had 800 Ohm speakers without transformers. > > Example of a tube output stage without transformer to drive a 800 Ohm speaker: > https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png STAGGERINGLY inefficient circuit, but yes, it works. -- The urge to save humanity is almost always a false front for the urge to rule. – H. L. Mencken, American journalist, 1880-1956
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| From | "Carlos E.R." <robin_listas@es.invalid> |
|---|---|
| Date | 2026-09-30 11:27 +0200 |
| Message-ID | <j91vomxksl.ln2@Telcontar.valinor> |
| In reply to | #70602 |
On 2026-09-29 17:54, Jan Panteltje wrote: >> Max Demian <max_demian@bigfoot.com>wrote: >>> On 28/09/2026 16:46, The Natural Philosopher wrote: >>> On 28/09/2026 14:03, Max Demian wrote: >>>> Yes, I suppose there could be a matching transformer, in the same way >>>> that there were boxes you connected to the "extension speaker" socket >>>> of the main (valve) radio so you could listen in the kitchen. I had >>>> one which had a transformer and a wander plug arrangement so you could >>>> match it. Some valve radios had a high impedance output, so presumably >>>> both connections would be at (more or less) HT voltage above the radio >>>> chassis (which would be earth if the earth socket was connected). I >>>> think there were high impedance horn extension speakers at one time. >> >>> Valve amps ALWAYS have an output transformer. Not least because there >>> are no 'P channel ' valves. >> >> I think there were high impedance horn speakers, which wouldn't require >> a transformer. And, of course, high impedance headphones if you don't >> want a loudspeaker. > > Yes some tube TVs had 800 Ohm speakers without transformers. > > Example of a tube output stage without transformer to drive a 800 Ohm speaker: > https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png I'm not familiar with valves EZ80 and 6CA4, I don't understand the drawings. :-? -- Cheers, Carlos. ES🇪🇸, EU🇪🇺;
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-09-30 11:13 +0100 |
| Message-ID | <ni45lsFdufrU1@mid.individual.net> |
| In reply to | #70621 |
On 30/09/2026 10:27, Carlos E.R. wrote: > On 2026-09-29 17:54, Jan Panteltje wrote: >> Yes some tube TVs had 800 Ohm speakers without transformers. >> >> Example of a tube output stage without transformer to drive a 800 Ohm >> speaker: >> >> https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png >> > > I'm not familiar with valves EZ80 and 6CA4, I don't understand the > drawings. :-? > The EZZ80 and BCA4 valves are full wave rectifiers in the power supply. (Equivalent to two diodes in each valve, with a tapped transformer secondary. Back when semiconductors were expensive, I've done similar with a pair of germanium diodes, as it was cheaper than a bridge rectifier.)i The relevant stage for this thread is the output stage, which is two EL504 pentodes being driven in a sort of push-pull configuration by the input triode. The EL504s each have an independent DC supply. The circuit specifies an 800 ohm load, but I first expected to see a more standard 600 ohm load... -- Tciao for Now! John.
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-09-30 11:19 +0100 |
| Message-ID | <ni461gFe04aU1@mid.individual.net> |
| In reply to | #70622 |
On 30/09/2026 11:13, John Williamson wrote: > On 30/09/2026 10:27, Carlos E.R. wrote: >> On 2026-09-29 17:54, Jan Panteltje wrote: > >>> Yes some tube TVs had 800 Ohm speakers without transformers. >>> >>> Example of a tube output stage without transformer to drive a 800 Ohm >>> speaker: >>> >>> https://2.bp.blogspot.com/-GaJkZ9klfLw/VOecHjVgPuI/AAAAAAAAA4g/H2qcMWJ3tuA/s1600/Schema.png >>> >>> >> >> I'm not familiar with valves EZ80 and 6CA4, I don't understand the >> drawings. :-? >> > The EZZ80 and BCA4 valves are full wave rectifiers in the power supply. > (Equivalent to two diodes in each valve, with a tapped transformer > secondary. Back when semiconductors were expensive, I've done similar > with a pair of germanium diodes, as it was cheaper than a bridge > rectifier.)i > > The relevant stage for this thread is the output stage, which is two > EL504 pentodes being driven in a sort of push-pull configuration by the > input triode. The EL504s each have an independent DC supply. > > The circuit specifies an 800 ohm load, but I first expected to see a > more standard 600 ohm load... > Sorry, my mistake, the EL504s use the bottom one being driven to conduct more which pulls the cathode voltage of the other down, making it a class A output stage. <Note to self. Visit the optician>:-) The other supply is for the input triode. -- Tciao for Now! John.
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-09-30 11:57 +0100 |
| Message-ID | <119ipu1$4i1s$7@dont-email.me> |
| In reply to | #70623 |
On 30/09/2026 11:19, John Williamson wrote: > the EL504s use the bottom one being driven to conduct more which pulls > the cathode voltage of the other down, making it a class A output stage. Yes, the use of the top one is something I hadn't seen before, but it certainly works. Lot of heat for not much power, and You would get more out of e.g. a single EL34 with a transformer. Or a pair. Back in the day transformers were cheap. Today they are sadly not. The output transformer is probably at least half the component cost of a valve amplifier... -- I was brought up to believe that you should never give offence if you can avoid it; the new culture tells us you should always take offence if you can. There are now experts in the art of taking offence, indeed whole academic subjects, such as 'gender studies', devoted to it. Sir Roger Scruton
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| From | liz@poppyrecords.invalid.invalid (Liz Tuddenham) |
|---|---|
| Date | 2026-09-30 13:29 +0100 |
| Message-ID | <1s293ju.13joq5r1awzwqkN%liz@poppyrecords.invalid.invalid> |
| In reply to | #70626 |
The Natural Philosopher <tnp@invalid.invalid> wrote: > On 30/09/2026 11:19, John Williamson wrote: > > the EL504s use the bottom one being driven to conduct more which pulls > > the cathode voltage of the other down, making it a class A output stage. > > Yes, the use of the top one is something I hadn't seen before, but it > certainly works. > > Lot of heat for not much power, and You would get more out of e.g. a > single EL34 with a transformer. > > Or a pair. > > Back in the day transformers were cheap. Today they are sadly not. The > output transformer is probably at least half the component cost of a > valve amplifier... It was the second-most-expensive component 'back in the day', that is why they were often skimped. When valves with lowish anode voltages and high peak emissions were developed for television receivers, that opened the way for totem-pole valve output stages capable of driving a loudspeaker directly. In some cases it was no more complex than the equivalent push-pull cicuit with its signal-inverter stage - it didn't even need a separate heater winding for the top valve because telelvision valves were designed for use in heater chains with high heater-cathode voltages. With no output transformer there were more-benign overall phase shifts in the amplifier, so more feedback could be used, giving better linearity and lower noise. It also gave worse behaviour under overload conditions, as designers of transformerless transistor amplifiers with large amounts of feedback were to discover later. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
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| From | John Williamson <johnwilliamson@btinternet.com> |
|---|---|
| Date | 2026-09-30 13:54 +0100 |
| Message-ID | <ni4f4cFfdl0U1@mid.individual.net> |
| In reply to | #70626 |
On 30/09/2026 11:57, The Natural Philosopher wrote: > On 30/09/2026 11:19, John Williamson wrote: >> the EL504s use the bottom one being driven to conduct more which pulls >> the cathode voltage of the other down, making it a class A output stage. > > Yes, the use of the top one is something I hadn't seen before, but it > certainly works. > > Lot of heat for not much power, and You would get more out of e.g. a > single EL34 with a transformer. > Assuming the transformer could handle the bandwidth. The output from the circuit given would be flatter and less distorted, even across the audio bandwidth, assuming a resistive load. As the designer saw fit to use smoothed DC for the heater of the input valve, avoiding noise and hum were obviously a priority. -- Tciao for Now! John.
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| From | The Natural Philosopher <tnp@invalid.invalid> |
|---|---|
| Date | 2026-09-30 14:34 +0100 |
| Message-ID | <119j35i$8pgq$4@dont-email.me> |
| In reply to | #70632 |
On 30/09/2026 13:54, John Williamson wrote: > On 30/09/2026 11:57, The Natural Philosopher wrote: >> On 30/09/2026 11:19, John Williamson wrote: >>> the EL504s use the bottom one being driven to conduct more which pulls >>> the cathode voltage of the other down, making it a class A output stage. >> >> Yes, the use of the top one is something I hadn't seen before, but it >> certainly works. >> >> Lot of heat for not much power, and You would get more out of e.g. a >> single EL34 with a transformer. >> > Assuming the transformer could handle the bandwidth. The output from the > circuit given would be flatter and less distorted, even across the audio > bandwidth, assuming a resistive load. > Not hard to do a 50-30Khz transformer . > As the designer saw fit to use smoothed DC for the heater of the input > valve, avoiding noise and hum were obviously a priority. > > Any mains powered amplifier hums a bit. And even ones that are not. mains hum fields are all pervasive The best one I have has an SMPS power supply feeding a class D amplifier. Feels way too light for the power -- For every complex problem there is an answer that is clear, simple, and wrong. H.L.Mencken
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| From | liz@poppyrecords.invalid.invalid (Liz Tuddenham) |
|---|---|
| Date | 2026-09-30 18:08 +0100 |
| Message-ID | <1s29g8x.1vtoj2z9nbyyuN%liz@poppyrecords.invalid.invalid> |
| In reply to | #70636 |
The Natural Philosopher <tnp@invalid.invalid> wrote: > On 30/09/2026 13:54, John Williamson wrote: > > On 30/09/2026 11:57, The Natural Philosopher wrote: > >> On 30/09/2026 11:19, John Williamson wrote: > >>> the EL504s use the bottom one being driven to conduct more which pulls > >>> the cathode voltage of the other down, making it a class A output stage. > >> > >> Yes, the use of the top one is something I hadn't seen before, but it > >> certainly works. > >> > >> Lot of heat for not much power, and You would get more out of e.g. a > >> single EL34 with a transformer. > >> > > Assuming the transformer could handle the bandwidth. The output from the > > circuit given would be flatter and less distorted, even across the audio > > bandwidth, assuming a resistive load. > > > Not hard to do a 50-30Khz transformer . Tell that to the researchers who have spent their entire lifetimes designing broadband audio transformers for valves. Have you ever tried? I have. I wouldn't normally worry about minor misunderstandings but you have been putting forward a whole string of misconceptions as extablished truths.and then subtlely backing down when presented with the historical facts that prove them false. It concerns me that these erroneous ideas are so commonly believed and propagated, so I will continue to challenge them. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
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| From | "J. P. Gilliver" <G6JPG@255soft.uk> |
|---|---|
| Date | 2026-10-01 02:22 +0100 |
| Message-ID | <119kcl0$ok4n$1@dont-email.me> |
| In reply to | #70636 |
On 2026/9/30 14:34:42, The Natural Philosopher wrote: [] > Any mains powered amplifier hums a bit. And even ones that are not. > mains hum fields are all pervasive > > > The best one I have has an SMPS power supply feeding a class D > amplifier. Feels way too light for the power > > Yes, I have one of those - came with an external supply, similar to (probably identical to) the sort that comes with laptops (or did a few years ago: modern laptop ones are tiny). Yes, far too small and light for the power - because with modern transistors, class D dissipates hardly any (waste, heating) power in the output transistors, so needs hardly any heatsinking, which is much of the weight in a transistor amplifier. I think mine is rated something like 50W (might be per channel!), and is about fag-packet size - really just big enough to support the connectors and volume knob. -- J. P. Gilliver. UMRA: 1960/<1985 MB++G()ALIS-Ch++(p)Ar++T+H+Sh0!:`)DNAf "Bother," said the Borg, "we assimilated a Pooh."
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