On 12/11/2016 14:38, Dave Plowman (News) wrote:
In article ,
Iain Churches wrote:
I remember a long time ago new when worked at Pye TVT they used to use
DA100's IIRC in high power PA distribution PA amps and also in Band 3 TV
Sound modulators;!
--
Tony Sayer


The venerable QB5 can dissipate 565W so as a single ended
Class "A" triode one can easily achieve 120W.

Who said SET is for wimps? :-)

I'm thinking you could probably make a hybrid car based around a steam
engine. The question being why would you bother?


No, it wouldn't be practical. It would take ages to warm up and waste
loads of power.

Oh wait...

In article ,
Vir Campestris wrote:
On 12/11/2016 14:38, Dave Plowman (News) wrote:
In article ,
Iain Churches wrote:
I remember a long time ago new when worked at Pye TVT they used to use
DA100's IIRC in high power PA distribution PA amps and also in Band 3 TV
Sound modulators;!
--
Tony Sayer


The venerable QB5 can dissipate 565W so as a single ended
Class "A" triode one can easily achieve 120W.

Who said SET is for wimps? :-)

I'm thinking you could probably make a hybrid car based around a steam
engine. The question being why would you bother?


No, it wouldn't be practical. It would take ages to warm up and waste
loads of power.

Oh wait...


;-)

--
*It doesn't take a genius to spot a goat in a flock of sheep *

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Vir
Campestris wrote:

I'm thinking you could probably make a hybrid car based around a steam
engine. The question being why would you bother?


No, it wouldn't be practical. It would take ages to warm up and waste
loads of power.

Drifiting even further from my orginal topic: The above reminded me that
some years ago work was done on small flash-tube boilers which apparently
heated up within a few seconds and were very efficient. In general,
external combustion does have some advantages. However I can't recall who
did the work, now.

Maybe the heat from output valves could be used to generate steam to
generate electricity to help power the amplifier. Might improve the
efficiency and the lifespan of the amp. :-)

That said, the closest I've got to the this was water-cooling of 100 GHz
klystrons.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article ,
Jim Lesurf wrote:
Maybe the heat from output valves could be used to generate steam to
generate electricity to help power the amplifier. Might improve the
efficiency and the lifespan of the amp. :-)

Is that a form of positive feedback? ;-)

--
*Time is fun when you're having flies... Kermit

Dave Plowman London SW
To e-mail, change noise into sound.

On 14/11/2016 09:32, Jim Lesurf wrote:
In article , Vir
Campestris wrote:

I'm thinking you could probably make a hybrid car based around a steam
engine. The question being why would you bother?


No, it wouldn't be practical. It would take ages to warm up and waste
loads of power.

Drifiting even further from my orginal topic: The above reminded me that
some years ago work was done on small flash-tube boilers which apparently
heated up within a few seconds and were very efficient. In general,
external combustion does have some advantages. However I can't recall who
did the work, now.

Maybe the heat from output valves could be used to generate steam to
generate electricity to help power the amplifier. Might improve the
efficiency and the lifespan of the amp. :-)

That said, the closest I've got to the this was water-cooling of 100 GHz
klystrons.


With or without goldfish?

--
Graeme Wall
This account not read.

In article , Graeme Wall
wrote:
That said, the closest I've got to the this was water-cooling of 100
GHz klystrons.


With or without goldfish?

We always felt it was cruel to use goldfish to check that the water flow
was on. So we used to use a small sphere of plastic that revolved around a
circular racetrack attached to the pipes.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article ,
Jim Lesurf wrote:
In article , Vir
Campestris wrote:

I'm thinking you could probably make a hybrid car based around a steam
engine. The question being why would you bother?


No, it wouldn't be practical. It would take ages to warm up and waste
loads of power.

Drifiting even further from my orginal topic: The above reminded me that
some years ago work was done on small flash-tube boilers which apparently
heated up within a few seconds and were very efficient. In general,
external combustion does have some advantages. However I can't recall who
did the work, now.

Maybe the heat from output valves could be used to generate steam to
generate electricity to help power the amplifier. Might improve the
efficiency and the lifespan of the amp. :-)

But how do you convert that steam into hot air to get back on topic?

Odd, isn't it. In this day and age, some are still so unhappy with the
performance of power amps they seek to use ancient technology. Not to
produce something smaller, cheaper, more efficient etc.

Which basically means they are searching for a goal they can't define and
will never reach.

--
*Welcome to **** Creek - sorry, we're out of paddles*

Dave Plowman London SW
To e-mail, change noise into sound.

On 14/11/2016 12:01, Jim Lesurf wrote:
In article , Graeme Wall
wrote:
That said, the closest I've got to the this was water-cooling of 100
GHz klystrons.


With or without goldfish?

We always felt it was cruel to use goldfish to check that the water flow
was on. So we used to use a small sphere of plastic that revolved around a
circular racetrack attached to the pipes.


On my Evesham course (back in the dark ages) we were told that the water
cooling systems at TX sites had goldfish to prevent the build up of
algae. The Senior site engineer was supposed to get an allowance for
goldfish food. Never discovered whether the goldfish were issued with
BBC staff numbers.


--
Graeme Wall
This account not read.

On 14/11/2016 13:44, Dave Plowman (News) wrote:
In article ,
Jim Lesurf wrote:
In article , Vir
Campestris wrote:

I'm thinking you could probably make a hybrid car based around a steam
engine. The question being why would you bother?


No, it wouldn't be practical. It would take ages to warm up and waste
loads of power.

Drifiting even further from my orginal topic: The above reminded me that
some years ago work was done on small flash-tube boilers which apparently
heated up within a few seconds and were very efficient. In general,
external combustion does have some advantages. However I can't recall who
did the work, now.

Maybe the heat from output valves could be used to generate steam to
generate electricity to help power the amplifier. Might improve the
efficiency and the lifespan of the amp. :-)

But how do you convert that steam into hot air to get back on topic?

Odd, isn't it. In this day and age, some are still so unhappy with the
performance of power amps they seek to use ancient technology. Not to
produce something smaller, cheaper, more efficient etc.


It's partly a retro thing - much like clothes, cars and all manner of
tat that people like.

On performance, some (including me) like the sound produced by decent
valve amplifiers.

Which basically means they are searching for a goal they can't define and
will never reach.


I think if you have an interest in 'hifi', that's not uncommon.
Certainly, for time to time, I think 'what if . . .' when listening to
my music system.


--
Cheers, Rob

In article , RJH
wrote:
Odd, isn't it. In this day and age, some are still so unhappy with the
performance of power amps they seek to use ancient technology. Not to
produce something smaller, cheaper, more efficient etc.


It's partly a retro thing - much like clothes, cars and all manner of
tat that people like.

On performance, some (including me) like the sound produced by decent
valve amplifiers.

Which basically means they are searching for a goal they can't define
and will never reach.


I think if you have an interest in 'hifi', that's not uncommon.
Certainly, for time to time, I think 'what if . . .' when listening to
my music system.

There are cheaper ways than buying a valve amp to replace what you have,
though. :-)

e.g. A few weeks ago I put my QUAD 2805s onto a set of '28p' speaker
stands. I think this has improved the sound. The stands consist of a stack
of seven 1p coins under each front spike of the speakers. These angle up
the output and get the beam centers closer to ear level at my listening
seat.

I have also found that adding some resistors in series with the amp output
seems to do a good job of faking the relatively high output impedance of
low-feedback valve amps. This interacts with the impedance of the speakers
and alters the tonal balance.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html