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Re: OT - TV

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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 Jan Panteltje <alien@comet.invalid> - 2026-10-05 15:17 +0000
                                              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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#70721

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.

>   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?

The problem is that the cell voltages need clever electronics to use 
them with normal equipment, as it varies between 3.1 and 1.5 volts per 
cell in normal use. The energy density is not much more than half that 
of Lithium based batteries.

>   AM looking to make a semi-decent DC power storage
>   unit - probably solar charged. Doesn't have to be
>   huge, maybe ten or fifteen thousand kva, above the
>   'consumer' UPS units. A 120vac take-off is required
>   of course, but want 12vdc too. NOT an 'off-grid
>   solution' ... just a 'fill-in'. But, DO want the
>   sodium batteries.
>
You want ten to 15 megawatt hours and you call it "small"? :-0


That is well into pumped electrolyte utility company territory.


(I have about 4kVA on the boat, and that lasts me a couple of days, as 
long as I don't use the immersion heater.)

>   Fair, stackable, commercial units :
>
>   https://xpcc.com/xtreme-power-sodium-ups/
>
I'd want rather more run time than they offer. At full power, you don't 
even get enough time to log off....




-- 
Tciao for Now!

John.

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#70722

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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#70724

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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#70702

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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#70703

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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#70704

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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#70709

>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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#70710

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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#70640

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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#70596

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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#70602

>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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#70605

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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#70621

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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#70622

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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#70623

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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#70626

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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#70629

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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#70632

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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#70636

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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#70642

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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