> "Eeyore" wrote
> > Peter Parry wrote:
> >> Eeyore wrote:
> >>
> >> >> 10kW is way to low, even the AR1 found on every airfield ran 2 x
> >> >> 650kW transmitters at the same time. Pulse lengths varied from one
> >> >> microsecond for shorter range radars to 150 microseconds.
> >> >
> >> >These weren't microwave though. The previous poster mentioned
> >> >waveguides, hence microwave kit.
> >>
> >> The AR1 was about 3GHz, well into microwave (300MHz to 300GHz)
> >> territory.
> >
> > Not WW2.
>
> H2S ran at 3GHz initially (1942/3) and upped to nearer 18GHz (2/12/1945)
I know.
I simply said AR1 wasn't there in WW2.
Microwaves are normally taken to begin at 1GHz btw not 300MHz as you stated
above. 300MHz would be UHF.
On Mon, 06 Aug 2007 10:08:58 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>Peter Parry wrote:
>> That's just the magnetron output
>
>As it should be.
>
>
>> (and 6kW was true only for the very
>> early models). Radars such as the WW2 type 54 based on Navy 277 ran
>> 500kW Peak EIRP at 3GHz.
>
>You should know very well that EIRP includes 'antenna gain' compared to
>onmidirectional radiation. In short that's not a valid figure to use.
EIRP is the figure to use if Lenny's hypothesis - that there is harm
caused by non-thermal effects - is to be considered. His claim (or
at least that of the mast loonies) is that everything from ingrowing
toenails to hair falling out is caused by some as yet unrevealed RF
DNA damage mechanism which is caused by peak and pulsing emissions,
not average power. If that is so you would expect to see areas of
increased health effects both around radar sites and airfields and
also in the people who spent a lifetime servicing them.
There is no indication of any such areas of ill health and radar
technicians survive as long as any other retired servicemen. The
counter from the mastistas was initially the rather improbable one
that humans are only and specifically sensitive to the output of
mobile phones.
Now of course they have lumped DECT Phones and WiFi in the pot and
apart from the lack of credible evidence to support their hypothesis
it difficult to see why the human form should be uniquely susceptible
to WiFi at 2.4GHz and a few mW EIRP but not to a sodding great radar
going 24 hours a day at 3GHz and a few MW EIRP.
>For heating effect you can only count the actual average microwave output power. That
>was tens of watts.
Certainly for most WW2 radars, but by the end of the war power had
gone up quite a bit and in the 50's & 60's all sorts of things
started to appear.
The Type 85 didn't just produce prodigious peak powers but kW of
average power - and not a Magnetron in sight - it used Klystrons
(albeit very very big ones - not many valves are man sized!).
Quite a few later radars produced average powers >20kW. The infamous
Cobra Mist (FPS95) 6-40MHz Over the Horizon Radar at Orfordness was
designed for 10MW peak/600kW average power and although it never
achieved this it did produce sparks from ships rigging miles away
during high power testing.
The Pave Paw "pyramid" at Fylingdales stuffed out 175kW average power
per face on 433 MHz (it had a very long pulse length of up to 16
milliseconds) which explains why the car park some miles away was
always full of sightseers who couldn't get back into their cars as
their 433MHz key locks were losing the rather unequal battle with the
radar.
On Mon, 6 Aug 2007 10:05:14 +0100, "R. Mark Clayton"
<nospamclayton@btinternet.com> wrote:
>There was a tale (and I think it was just a tale) that in the 1960's an
>engineer claimed you could her the clicks on a big radar and so walked in
>front of one at RAF Leuchars. After a short period he fell down [dead?].
That was gravity - the radar head at Leuchars was 50ft above the
ground.
The magnetron in the 4Mk7 anti aircraft surveillance radar though had
a neat trick - for traveling you swung it down out of its position in
the waveguide and into a set of transit clamps. The Waveguide just
fitted a Gingsters meat pie, so to warm up lunch you swung the
magnetron down, put the meat pie in the waveguide, put the magnetron
back up and fired up the radar. A few minutes later you had a nice
warm pie.
--
Peter Parry. http://www.wpp.ltd.uk/
"Mortimer" <me@privacy.net> wrote in message
news:13bdtut9ui0vhbc@corp.supernews.com...
> "R. Mark Clayton" <nospamclayton@btinternet.com> wrote in message
> news:yZydndNSDLcgaSvbRVnygQA@bt.com...
>>
>> "Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
>> news:46B6E52A.8EB3124@hotmail.com...
>>>
>>>
>>> Peter Parry wrote:
>>>
>>>> Eeyore wrote:
>>>>
>>>> >> 10kW is way to low, even the AR1 found on every airfield ran 2 x
>>>> >> 650kW transmitters at the same time. Pulse lengths varied from one
>>>> >> microsecond for shorter range radars to 150 microseconds.
>>>> >
>>>> >These weren't microwave though. The previous poster mentioned
>>>> >waveguides, hence
>>>> >microwave kit.
>>>>
>>>> The AR1 was about 3GHz, well into microwave (300MHz to 300GHz)
>>>> territory.
>>>
>>> Not WW2.
>>
>> H2S ran at 3GHz initially (1942/3) and upped to nearer 18GHz (2/12/1945)
>
> Ah! H2S. I remembering him mentioning that name. He also talked about a
> modification to the system which was fitted to allow the bearing of the
> incoming planes to be determined by mixing between two orthogonal aerial
> arrays, adjusted using a "goniometer" (as a little boy, I thought this was
> a very funny word!) for minimum (or was it maximum) signal strength.
>
The goniometer was a feature of the early Chain Holme system. It would give
an approximate bearing of the incoming planes by balancing the incoming
signals. More accurate DF is possible by rotating the crossed antenna
(looking for a minimum in one plane and a maximum in the other). The delay
gave a more accurate range. The size and spread of the return signal (seen
on a screen) would give some information on the size and number of aircraft.
Rough height was calculated using different aerials at different heights on
the mast (depending on distance planes would be over the horizon for lower
antenna). Reports from two or more stations would be combined to give more
accurate data and a fix.
Later H2S had an oscilloscope display which rotated in sync with the
transceiver dish with pulsed transmission (like modern radars). It was
carried on bombers.
While the OP is clearly deranged, I've got to admit that this has turned
into one of the more interesting and informative threads I've read for a
long
time, even if totally OT for uk.telecom.broadband!
> Later H2S had an oscilloscope display which rotated in sync with the
> transceiver dish with pulsed transmission (like modern radars). It was
> carried on bombers.
The official name for this type of display that we'd recognise today is
PPI.(plan position indicator).
I've seen some naval versions where the scanning coils rotate around the tube. I
gather this was the common way of doing it before the advent of computer storage
that could use ordinary raster scan display tubes.
Even so, I was involved in 1989 in developing a PPI display that used 'spiral
scanning' (using sine and cosine waveforms to drive the deflection coils)
because although it was microprocessor based, doing this avoided the need (and
computational overhead) to convert R, theta data into x, y.
"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:46B71AA4.59D7FECB@hotmail.com...
>
>
> "R. Mark Clayton" wrote:
>
>> Later H2S had an oscilloscope display which rotated in sync with the
>> transceiver dish with pulsed transmission (like modern radars). It was
>> carried on bombers.
>
> The official name for this type of display that we'd recognise today is
> PPI.(plan position indicator).
>
> I've seen some naval versions where the scanning coils rotate around the
> tube. I
> gather this was the common way of doing it before the advent of computer
> storage
> that could use ordinary raster scan display tubes.
>
> Even so, I was involved in 1989 in developing a PPI display that used
> 'spiral
> scanning' (using sine and cosine waveforms to drive the deflection coils)
> because although it was microprocessor based, doing this avoided the need
> (and
> computational overhead) to convert R, theta data into x, y.
Oh come on al that is required is a sine and cos wave applied to the X & Y
plates (of an osciliscope) and a line scan (saw tooth) for the deflection -
all neatly analog. In fact the sine wave could be derived from the aerial
rotator and the cos by a simple delay, so the system would self
synchronising.
Having seen film of an H2S working over what is obviously The Wash, it is
fairly clear this is pretty much how it worked. The difficult bit was
compensating the gain of the return signal for the distance from the set so
that things close by are not to bright.
"Alastair" <email@address.invalid> wrote in message
news:46b71001$0$647$5a6aecb4@news.aaisp.net.uk...
> While the OP is clearly deranged, I've got to admit that this has turned
> into one of the more interesting and informative threads I've read for a
> long
> time, even if totally OT for uk.telecom.broadband!
Lenny thinks that broadband wi-fi is inherently dangerous...
> "Eeyore" wrote
> > "R. Mark Clayton" wrote:
> >
> >> Later H2S had an oscilloscope display which rotated in sync with the
> >> transceiver dish with pulsed transmission (like modern radars). It was
> >> carried on bombers.
> >
> > The official name for this type of display that we'd recognise today is
> > PPI.(plan position indicator).
> >
> > I've seen some naval versions where the scanning coils rotate around the
> > tube. I gather this was the common way of doing it before the advent of
> computer
> > storage that could use ordinary raster scan display tubes.
> >
> > Even so, I was involved in 1989 in developing a PPI display that used
> > 'spiral scanning' (using sine and cosine waveforms to drive the deflection
> coils)
> > because although it was microprocessor based, doing this avoided the need
> > (and computational overhead) to convert R, theta data into x, y.
>
> Oh come on al that is required is a sine and cos wave applied to the X & Y
> plates (of an osciliscope) and a line scan (saw tooth) for the deflection -
> all neatly analog. In fact the sine wave could be derived from the aerial
> rotator and the cos by a simple delay, so the system would self
> synchronising.
We're talking about a big bright daylight display tube that'll be be mounted on
the bridge, not an oscilloscope that you view under a hood.
I can tell you that there's more to it than you might imagine. In fact. that's
how the client company came to need some consultants to fix it. Yes, I do
electronics consultancy and I'm good at fixing 'runaways'.
> Having seen film of an H2S working over what is obviously The Wash, it is
> fairly clear this is pretty much how it worked. The difficult bit was
> compensating the gain of the return signal for the distance from the set so
> that things close by are not to bright.
Tell me about it ! I know a thing or two about that too. They didn't have very
good VCAs back then !
On Mon, 6 Aug 2007 14:32:23 +0100, "R. Mark Clayton"
<nospamclayton@btinternet.com> wrote:
>
>Oh come on al that is required is a sine and cos wave applied to the X & Y
>plates (of an osciliscope) and a line scan (saw tooth) for the deflection -
>all neatly analog. In fact the sine wave could be derived from the aerial
>rotator and the cos by a simple delay, so the system would self
>synchronising.
A common configuration was to use electrostatic deflection for
rangefinders and, as Graham has said, electromagnetic for PPI
displays. A Selsyn was used to keep the radar head and display
rotating together. Apart from allowing bright displays it was a
simple and reliable system. Alignment usually simply meant
unclamping and rotating the servo half of the Selsyn assembly until
north was where it should be.
A lot of early radars were very mechanical had noises to suit as
various bits clattered away. The British Army Thunderbird missile
system even had a computer which required regular oiling. The
missile guidance commands were modified as missile range increased by
an analogue computer using several variable resistors which ran on
differently shaped cams to model fuel consumption, weight, speed etc
in the calculations).
--
Peter Parry. http://www.wpp.ltd.uk/
> "R. Mark Clayton" wrote:
> >
> >Oh come on al that is required is a sine and cos wave applied to the X & Y
> >plates (of an osciliscope) and a line scan (saw tooth) for the deflection -
> >all neatly analog. In fact the sine wave could be derived from the aerial
> >rotator and the cos by a simple delay, so the system would self
> >synchronising.
>
> A common configuration was to use electrostatic deflection for
> rangefinders and, as Graham has said, electromagnetic for PPI
> displays. A Selsyn was used to keep the radar head and display
> rotating together. Apart from allowing bright displays it was a
> simple and reliable system. Alignment usually simply meant
> unclamping and rotating the servo half of the Selsyn assembly until
> north was where it should be.
>
> A lot of early radars were very mechanical had noises to suit as
> various bits clattered away. The British Army Thunderbird missile
> system even had a computer which required regular oiling. The
> missile guidance commands were modified as missile range increased by
> an analogue computer using several variable resistors which ran on
> differently shaped cams to model fuel consumption, weight, speed etc
> in the calculations).#
Mechanical 'analogue computers' were very popular for a time. Mostly in gunnery
and especially in the Navy AIUI. The USAAF Norden bomb sight was another
example.
"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:46B74C54.56A1D9B8@hotmail.com...
>
>
> Peter Parry wrote:
>
>> "R. Mark Clayton" wrote:
>> >
>> >Oh come on al that is required is a sine and cos wave applied to the X &
>> >Y
>> >plates (of an osciliscope) and a line scan (saw tooth) for the
>> >deflection -
>> >all neatly analog. In fact the sine wave could be derived from the
>> >aerial
>> >rotator and the cos by a simple delay, so the system would self
>> >synchronising.
>>
>> A common configuration was to use electrostatic deflection for
>> rangefinders and, as Graham has said, electromagnetic for PPI
>> displays. A Selsyn was used to keep the radar head and display
>> rotating together. Apart from allowing bright displays it was a
>> simple and reliable system. Alignment usually simply meant
>> unclamping and rotating the servo half of the Selsyn assembly until
>> north was where it should be.
>>
>> A lot of early radars were very mechanical had noises to suit as
>> various bits clattered away. The British Army Thunderbird missile
>> system even had a computer which required regular oiling. The
>> missile guidance commands were modified as missile range increased by
>> an analogue computer using several variable resistors which ran on
>> differently shaped cams to model fuel consumption, weight, speed etc
>> in the calculations).#
>
> Mechanical 'analogue computers' were very popular for a time. Mostly in
> gunnery
> and especially in the Navy AIUI. The USAAF Norden bomb sight was another
> example.
>
> Graham
I remember learning to use an RAF (mechanical - manual) navigational
computer when I was in the air cadets in the late 'fifties. It was a
hand-held box, with an internal belt on rollers, if I remember correctly,
with an etched metal dial on the front. No electrical power required - just
turn the dial/knobs! Akin to a three-dimensional slide-rule.
ISTR that it calculated the aircraft's track compared with its heading, when
given the wind-speed and direction - or the other way round. It was a long
time ago and Alzheimer's is setting in fast ;-)
"George Weston" <geoweston@googlemail.com> wrote in message
news:5hp4otF3lv078U1@mid.individual.net...
>
> "Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
> news:46B74C54.56A1D9B8@hotmail.com...
>>
>>
>> Peter Parry wrote:
>>
>>> "R. Mark Clayton" wrote:
>>> >
>>> >Oh come on al that is required is a sine and cos wave applied to the X
>>> >& Y
>>> >plates (of an osciliscope) and a line scan (saw tooth) for the
>>> >deflection -
>>> >all neatly analog. In fact the sine wave could be derived from the
>>> >aerial
>>> >rotator and the cos by a simple delay, so the system would self
>>> >synchronising.
>>>
>>> A common configuration was to use electrostatic deflection for
>>> rangefinders and, as Graham has said, electromagnetic for PPI
>>> displays. A Selsyn was used to keep the radar head and display
>>> rotating together. Apart from allowing bright displays it was a
>>> simple and reliable system. Alignment usually simply meant
>>> unclamping and rotating the servo half of the Selsyn assembly until
>>> north was where it should be.
>>>
>>> A lot of early radars were very mechanical had noises to suit as
>>> various bits clattered away. The British Army Thunderbird missile
>>> system even had a computer which required regular oiling. The
>>> missile guidance commands were modified as missile range increased by
>>> an analogue computer using several variable resistors which ran on
>>> differently shaped cams to model fuel consumption, weight, speed etc
>>> in the calculations).#
>>
>> Mechanical 'analogue computers' were very popular for a time. Mostly in
>> gunnery
>> and especially in the Navy AIUI. The USAAF Norden bomb sight was another
>> example.
>>
>> Graham
>
> I remember learning to use an RAF (mechanical - manual) navigational
> computer when I was in the air cadets in the late 'fifties. It was a
> hand-held box, with an internal belt on rollers, if I remember correctly,
> with an etched metal dial on the front. No electrical power required -
> just turn the dial/knobs! Akin to a three-dimensional slide-rule.
> ISTR that it calculated the aircraft's track compared with its heading,
> when given the wind-speed and direction - or the other way round. It was a
> long time ago and Alzheimer's is setting in fast ;-)
>
> George
Bad form to reply to one's own posts but I just found one of these on eBay. http://tinyurl.com/2t37zb
"George Weston" <geoweston@googlemail.com> wrote in message
news:5hp59oF3k5btmU1@mid.individual.net...
>
> "George Weston" <geoweston@googlemail.com> wrote in message
> news:5hp4otF3lv078U1@mid.individual.net...
>
>> I remember learning to use an RAF (mechanical - manual) navigational
>> computer when I was in the air cadets in the late 'fifties. It was a
>> hand-held box, with an internal belt on rollers, if I remember correctly,
>> with an etched metal dial on the front. No electrical power required -
>> just turn the dial/knobs! Akin to a three-dimensional slide-rule.
>> ISTR that it calculated the aircraft's track compared with its heading,
>> when given the wind-speed and direction - or the other way round. It was
>> a long time ago and Alzheimer's is setting in fast ;-)
You are not kidding.
>>
>> George
You already posted nine minutes ago...
>
> Bad form to reply to one's own posts but I just found one of these on
> eBay.
> http://tinyurl.com/2t37zb
>
> George
>
Peter Parry wrote:
>
> The Type 85 didn't just produce prodigious peak powers but kW of
> average power - and not a Magnetron in sight - it used Klystrons
> (albeit very very big ones - not many valves are man sized!).
Was it *ever* run at full power though?
--
Old Codger
e-mail use reply to field
What matters in politics is not what happens, but what you can make
people believe has happened. [Janet Daley 27/8/2003]
Mortimer wrote:
> "Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
> news:46B65724.705DD9F5@hotmail.com...
>>
>> Mortimer wrote:
>>
>>> "Eeyore" wrote
>>>
>>> It was (I think) Chain Home: Danby Beacon in the North York Moors,
>>> anyway.
>> http://maps.google.com/?ie=UTF8&ll=5...&t=k&z=18&om=1
>>
>> You can only make out the roads that were left behind now.
>
> Yes. I went up there when I was on holiday in the area and found the site,
> identified by a noticeboard beside the road. There's virtually nothing
> identifiable now, just a few cracked concrete slabs hidden among the
> heather, than may have been the floor of a building with a basement below
> it.
>
> I wish I'd listened more closely to the stories he told me about the work
> they did. I remember him telling me about the time he went into Whitby on
> his day off and phoned my grandma from a phone box and was rather alarmed to
> hear the talkback from the radar station to the central plotting site when
> he picked up the phone due to a crossed line!
There was a CH site at GT Bentley in Essex. Towards the end of the war
local rumours were that the ARP wardens climed to the top of the masts
from where they could hear the planes taking off in Germany.
--
Old Codger
e-mail use reply to field
What matters in politics is not what happens, but what you can make
people believe has happened. [Janet Daley 27/8/2003]
Eeyore wrote:
>
> tony h wrote:
>
>> "Eeyore" wrote
>>> Peter Parry wrote:
>>>
>>>> Amazing how none of these mysterious "clusters" of variegated
>>>> ailments never occurred around them or in people working on them.
>>> Naval radars can apparently cook seagulls in flight.
>> any evidence of this, or purely anecdotal?
>
> I've heard it claimed in the electronics groups. It was alleged that they could
> 'shoot down' birds with their radar beams.
I find that difficult to believe unless the bird if flying close to the
centre of the beam, in a circle and in sync with the rotating antenna.
I suppose it *might* work if the bird was hovering and the radar beam
was stationary with the bird at the centre.
--
Old Codger
e-mail use reply to field
What matters in politics is not what happens, but what you can make
people believe has happened. [Janet Daley 27/8/2003]
dennis@home wrote:
> "tony h" <me@home.com> wrote in message
> news:f96b82$30a1$1@energise.enta.net...
>> "Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
>> news:46B65937.9CF99FB8@hotmail.com...
>>>
>>> Peter Parry wrote:
>>>
>>>> Amazing how none of these mysterious "clusters" of variegated
>>>> ailments never occurred around them or in people working on them.
>>> Naval radars can apparently cook seagulls in flight.
>>>
>>> Graham
>>>
>> any evidence of this, or purely anecdotal?
>
> I once worked with an ex-army type who said they would unhook the rotation
> gear on their dish and cook wood pigeons from the trees when they fancied a
> change to the army rations. They certainly have enough power to do it but I
> am not sure you can stop the rotation on most radars which would have been
> about when he was in the army.
I am sure the rotation could always be stopped. However, once 'ealth
and safety got in the loop one would have to also overcome some
interlocks to keep the radiation going.
--
Old Codger
e-mail use reply to field
What matters in politics is not what happens, but what you can make
people believe has happened. [Janet Daley 27/8/2003]
In message <5hp4otF3lv078U1@mid.individual.net>, George Weston
<geoweston@googlemail.com> writes
>
>"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
>news:46B74C54.56A1D9B8@hotmail.com...
>>
>>
>> Peter Parry wrote:
>>
>>> "R. Mark Clayton" wrote:
>>> >
>>> >Oh come on al that is required is a sine and cos wave applied to the X &
>>> >Y
>>> >plates (of an osciliscope) and a line scan (saw tooth) for the
>>> >deflection -
>>> >all neatly analog. In fact the sine wave could be derived from the
>>> >aerial
>>> >rotator and the cos by a simple delay, so the system would self
>>> >synchronising.
>>>
>>> A common configuration was to use electrostatic deflection for
>>> rangefinders and, as Graham has said, electromagnetic for PPI
>>> displays. A Selsyn was used to keep the radar head and display
>>> rotating together. Apart from allowing bright displays it was a
>>> simple and reliable system. Alignment usually simply meant
>>> unclamping and rotating the servo half of the Selsyn assembly until
>>> north was where it should be.
>>>
>>> A lot of early radars were very mechanical had noises to suit as
>>> various bits clattered away. The British Army Thunderbird missile
>>> system even had a computer which required regular oiling. The
>>> missile guidance commands were modified as missile range increased by
>>> an analogue computer using several variable resistors which ran on
>>> differently shaped cams to model fuel consumption, weight, speed etc
>>> in the calculations).#
>>
>> Mechanical 'analogue computers' were very popular for a time. Mostly in
>> gunnery
>> and especially in the Navy AIUI. The USAAF Norden bomb sight was another
>> example.
>>
>> Graham
>
>I remember learning to use an RAF (mechanical - manual) navigational
>computer when I was in the air cadets in the late 'fifties. It was a
>hand-held box, with an internal belt on rollers, if I remember correctly,
>with an etched metal dial on the front. No electrical power required - just
>turn the dial/knobs! Akin to a three-dimensional slide-rule.
>ISTR that it calculated the aircraft's track compared with its heading, when
>given the wind-speed and direction - or the other way round. It was a long
>time ago and Alzheimer's is setting in fast ;-)
In message <46b76f0e$0$15216$fa0fcedb@news.zen.co.uk>, Old Codger
<oldcodger@anyoldwhere.net> writes
>Eeyore wrote:
>> tony h wrote:
>>
>>> "Eeyore" wrote
>>>> Peter Parry wrote:
>>>>
>>>>> Amazing how none of these mysterious "clusters" of variegated
>>>>> ailments never occurred around them or in people working on them.
>>>> Naval radars can apparently cook seagulls in flight.
>>> any evidence of this, or purely anecdotal?
>> I've heard it claimed in the electronics groups. It was alleged that
>>they could
>> 'shoot down' birds with their radar beams.
>
>I find that difficult to believe unless the bird if flying close to the
>centre of the beam, in a circle and in sync with the rotating antenna.
>I suppose it *might* work if the bird was hovering and the radar beam
>was stationary with the bird at the centre.
My boss at Marconis, Dr. Eastwood, wrote the only book on a subject,
'Radar Ornithology'.
Lenny wrote:
> http://nomasts.org.uk/index.php?opti...=50&Itemid=116
>
> A familiar piece of misinformation quoted by mobile phone operators is
> that the emissions of a mobile phone mast are comparable to that of only a
> 60W light bulb, and thus equally harmless. Quite apart from the fact that
> the light from a 60W light bulb can be harmful to a person with
> photo-sensitive epilepsy,
And if the 60 watt bulb is broken and the shards of glass cut someone's
throat, that 60 watt bulb could kill them instantly.
In fairness, the biggest risk from a mobile base station is probably the
mast falling on a bystander, so this is not such a far-fetched comparison.
All the crap you posted as "fact" is so far from the truth that it
doesn't deserve a reply.
What I am left wondering is why you keep spouting this erroneous
pseudo-scientific drivel. There are so many lethal products being sold,
so why don't you campaign abainst them?
Cigarettes kill most of their users, yet nothing about them from you.
Tattoos are sold to teenagers as a fashion item, but the victims have to
bear the scars for the rest of their lives, yet nothing about them from you.
Junk food is leading a whole generation towards diabetes and premature
death, yet nothing about that from you.
Food additives and pesticides are building up huge levels of toxins
within people's bodies, yet nothing about it from you.
Hard surfaces and building on flood plains is creating an environment
where tens of thousands of people are at risk of flooding, but nothing
about it from you.
Despite hundreds of millions of people using them for decades, there is
no good evidence of any harm what ever from mobile phones to anyone, yet
you keep on about their imagined dangers. Why?
On Mon, 06 Aug 2007 19:54:02 +0100, Old Codger
<oldcodger@anyoldwhere.net> wrote:
>There was a CH site at GT Bentley in Essex. Towards the end of the war
>local rumours were that the ARP wardens climed to the top of the masts
>from where they could hear the planes taking off in Germany.
On Mon, 06 Aug 2007 17:29:08 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>Mechanical 'analogue computers' were very popular for a time. Mostly in gunnery
>and especially in the Navy AIUI. The USAAF Norden bomb sight was another
>example
17 shillings and 6 pence from Proops in Tottenham Court Road. A
source of many cogs and gears!
On Mon, 06 Aug 2007 19:48:05 +0100, Old Codger
<oldcodger@anyoldwhere.net> wrote:
>Peter Parry wrote:
>>
>> The Type 85 didn't just produce prodigious peak powers but kW of
>> average power - and not a Magnetron in sight - it used Klystrons
>> (albeit very very big ones - not many valves are man sized!).
>
>Was it *ever* run at full power though?
Oh yes, usually only 4 of the 12 transmitters were used but on
occasion all 12 fired up at once. On one particular exercise a
Lightning did a low pass to the front of the radar at Neatishead and
managed to turn more or less as the aerial rotated thus staying in
the main beam for a few seconds. The driver discovered a valuable
lesson in EMC when two Firestreaks launched themselves into the North
Sea.
"Dennis Ferguson" <dcferguson@pacbell.net> wrote in message
news:slrnfbd00r.8f.dcferguson@akit-ferguson.com...
>...
> Those are the legal limits, but with a normal teeny-tiny handheld
> handset you'll be lucky if it puts out more than about 0.25W average,
> if that much. Since the radio link with the tower has reciprocal
> performance in both directions, the output power used by the
> tower to talk to the phone won't be much more than that.
Surely the average is way down anyway because it's a pulsed signal.
I understood the 2W / 1W (or is it 4W / 2W) to be the peak power, the
average being much lower.
--
Brian Gregory. (In the UK) ng@bgdsv.co.uk
To email me remove the letter vee.
On 2007-08-06, Brian Gregory [UK] <ng@bgdsv.co.uk> wrote:
> "Dennis Ferguson" <dcferguson@pacbell.net> wrote in message
> news:slrnfbd00r.8f.dcferguson@akit-ferguson.com...
>>...
>> Those are the legal limits, but with a normal teeny-tiny handheld
>> handset you'll be lucky if it puts out more than about 0.25W average,
>> if that much. Since the radio link with the tower has reciprocal
>> performance in both directions, the output power used by the
>> tower to talk to the phone won't be much more than that.
>
> Surely the average is way down anyway because it's a pulsed signal.
The average should be 1/8 of the peak for a voice call since a GSM
handset transmits 1/8 of the time (i.e. 8 timeslots per channel).
> I understood the 2W / 1W (or is it 4W / 2W) to be the peak power, the
> average being much lower.
In the USA the regulation is 2W/1W average power, and I'd thought the
UK regulations were the same. The Ofcom regulations here
> Eeyore wrote:
>
> >Mechanical 'analogue computers' were very popular for a time. Mostly in gunnery
> >and especially in the Navy AIUI. The USAAF Norden bomb sight was another
> >example
>
> 17 shillings and 6 pence from Proops in Tottenham Court Road. A
> source of many cogs and gears!
On Tue, 07 Aug 2007 06:29:12 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>You bought one ?
Yup - took several months pocket money but it came in its original
transit case that was a work of art and probably worth more than the
computer. I don't know how many Proops must have acquired but they
were advertised for many years. Actually I think it was the Sperry
MkXlV/T1 rather than the Norden, it had lots of barostats, motors,
cogs and gears. and kept me amused for many hours (although nothing
useful was ever made from the bits!).
--
Peter Parry. http://www.wpp.ltd.uk/
Re: the 60W light bulb misconception 
Linear Mode
