"Paul Lonsdale" wrote in message
...
In article , Walt Davidson
wrote:
When I worked at the Science Museum in the mid 1960s, one of my duties
was to start the Foucault Pendulum at 2 pm on a Sunday afternoon. Its
purpose was to demonstrate and measure the effect of the earth's
rotation on the direction of swing of the pendulum.

Another much loved exhibit that is no longer on show!

Do you mean Walt or the pendulum? ;-)

Consoling yourself by consorting with the NEGATIVE NERDS
and muttering in the corner of the room with them will not restore the loss
of face that you have experienced by supporting the gangrenous
degeneration that is the M3/CB licence, OM.

As to your comment about being out of my depth, it is noticeable that
you have turned tail in response to my standing up to you.

Hardly surprising when your latest acadaemic achievement was an
upgrade to an M3/CB licence?

Brian Reay wrote in message
...
"F1LBY" phil[AT]kajagoogoo[DOT]co[DOT]uk wrote in message
...
Judging by the copious numbers of posts by the LID, I think you've
struck
a raw nerve somewhere Brian.
Cheers all round!
Oh he always gets like that when he gets out of his depth, as happens
quite
often ;-)

Consoling yourself by consorting with the NEGATIVE NERDS
and muttering in the corner of the room with them will not restore the loss
of face that you have experienced by supporting the gangrenous
degeneration that is the M3/CB licence, OM.

As to your comment about being out of my depth, it is noticeable that
you have turned tail in response to my standing up to you.

Hardly surprising when your latest acadaemic achievement was an
upgrade to an M3/CB licence?

Brian Reay wrote in message
...
"F1LBY" phil[AT]kajagoogoo[DOT]co[DOT]uk wrote in message
...
Judging by the copious numbers of posts by the LID, I think you've
struck
a raw nerve somewhere Brian.
Cheers all round!
Oh he always gets like that when he gets out of his depth, as happens
quite
often ;-)

I think you are on the wrong frequency with this one OM. The world of
telecommunications must run on one master oscillator. Call it GOD if you
will. There is a heavily guarded master oscillator somewhere on earth that
keeps everything in sync. I think it is somewhere in New England. All you
have to do is get a feed if this master clock and phase lock loop all your
ham junk to this frequency. What do you think would happen to all the worlds
telephone, television and satellite gear if everyone had their own free
running oscillators? Chaos. I doubt you can cut a piece of quartz to any
predictable frequency without specialized equipment nor keep it at a
predetermined frequency without a very accurate crystal oven. Remove just a
pubic hair of quartz and all is lost.

John
VA3JQ

"Airy R. Bean" wrote in message
...
I wish to make a master oscillator for the shack, and am considering
cutting my own crystals in order to reduce ageing. Is there a source
of raw material?

Also, for temperature compensation, I am considering the use of bi-metals.
(I've never seen one, but what is the mechanism used in Oxley's
Tempatrimmer?)

I think you are on the wrong frequency with this one OM. The world of
telecommunications must run on one master oscillator. Call it GOD if you
will. There is a heavily guarded master oscillator somewhere on earth that
keeps everything in sync. I think it is somewhere in New England. All you
have to do is get a feed if this master clock and phase lock loop all your
ham junk to this frequency. What do you think would happen to all the worlds
telephone, television and satellite gear if everyone had their own free
running oscillators? Chaos. I doubt you can cut a piece of quartz to any
predictable frequency without specialized equipment nor keep it at a
predetermined frequency without a very accurate crystal oven. Remove just a
pubic hair of quartz and all is lost.

John
VA3JQ

"Airy R. Bean" wrote in message
...
I wish to make a master oscillator for the shack, and am considering
cutting my own crystals in order to reduce ageing. Is there a source
of raw material?

Also, for temperature compensation, I am considering the use of bi-metals.
(I've never seen one, but what is the mechanism used in Oxley's
Tempatrimmer?)

Well, there was the HRG (Hemispherical Resonator Gyro)which was touted
as a low cost replacement for the Litton and GM Carousel systems, but,
as you rightly comment they were beaten out by IRUs with RLGs.

The Boeing 777 has a unit called an ADIRU which comprises 3 IRUs and 3
ADCs in one unit with built in redundancy.

GPS inputs to the Flight Management Function come from MMRs (Multi-Mode
Receivers) which comprise VOR/ILS/MMR/GPS/Marker in one box. (There are
three of these per aircraft).

All very reliable compared to the 70s/80s type gear.

Well, there was the HRG (Hemispherical Resonator Gyro)which was touted
as a low cost replacement for the Litton and GM Carousel systems, but,
as you rightly comment they were beaten out by IRUs with RLGs.

The Boeing 777 has a unit called an ADIRU which comprises 3 IRUs and 3
ADCs in one unit with built in redundancy.

GPS inputs to the Flight Management Function come from MMRs (Multi-Mode
Receivers) which comprise VOR/ILS/MMR/GPS/Marker in one box. (There are
three of these per aircraft).

All very reliable compared to the 70s/80s type gear.

On Mon, 13 Oct 2003 19:16:22 +0000 (UTC), Paul Lonsdale
wrote:

The Boeing 777 has a unit called an ADIRU which comprises 3 IRUs and 3
ADCs in one unit with built in redundancy.

GPS inputs to the Flight Management Function come from MMRs (Multi-Mode
Receivers) which comprise VOR/ILS/MMR/GPS/Marker in one box. (There are
three of these per aircraft).

enter Mr Ray to mention things like KALMAN filters and use phrases
like 'when i learned to fly' 'i used to design navigation systems'

On Mon, 13 Oct 2003 19:16:22 +0000 (UTC), Paul Lonsdale
wrote:

The Boeing 777 has a unit called an ADIRU which comprises 3 IRUs and 3
ADCs in one unit with built in redundancy.

GPS inputs to the Flight Management Function come from MMRs (Multi-Mode
Receivers) which comprise VOR/ILS/MMR/GPS/Marker in one box. (There are
three of these per aircraft).

enter Mr Ray to mention things like KALMAN filters and use phrases
like 'when i learned to fly' 'i used to design navigation systems'

"class_a_zpk_12wpm"
.uk.net wrote in message
...
On Mon, 13 Oct 2003 19:16:22 +0000 (UTC), Paul Lonsdale
wrote:

The Boeing 777 has a unit called an ADIRU which comprises 3 IRUs and 3
ADCs in one unit with built in redundancy.

GPS inputs to the Flight Management Function come from MMRs (Multi-Mode
Receivers) which comprise VOR/ILS/MMR/GPS/Marker in one box. (There are
three of these per aircraft).

enter Mr Ray to mention things like KALMAN filters and use phrases
like 'when i learned to fly' 'i used to design navigation systems'


Cue The Anus to inform us that a _REAL_ Radio Ham would teach himself to fly
by jumping off a high building with a Morse key in his hand.
--
;)
73 de Frank Turner-Smith G3VKI - mine's a pint.