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2007-01-25 06:20:00 PM
On 24 Jan, 09:39, Toby Inkster <usenet200...@tobyinkster.co.uk>wrote:
the canal-dwellers of Mars with optical telegraphs.
Perhaps dorayme could ask one of their grand-siblings?
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Andy Dingley wrote:
--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~ tobyinkster.co.uk/contact
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On 25 Jan, 11:53, Toby Inkster <usenet200...@tobyinkster.co.uk>wrote:
sure.
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On 25 Jan, 12:34, Toby Inkster <usenet200...@tobyinkster.co.uk>wrote:
Power isn't the problem in long-range radio comms, it's noise. Although
the distance is high and so inverse square law losses are too, then
there's less trouble with noise sources than you can find inside the
atmosphere.
Also Apollo did have long comms blackouts. There was never more than
one body (the Moon) in the way as they had a global network of
basestations (one was a ship now being scrapped on Teesside). Far side
of the Moon was still a hoel though.
vintage high-end amateur kit in the 2m band.
1930s terrestrial comms was also surprisingly sophisticated. Look at
the cross-channel microwave link. There's little in the Apollo-vintage
comms that was fundamentally different from the best of the late '30s.
Some of the engineering was different, but not the physics. Magnetrons
and klystrons were much the same, travelling wave tubes were new but I
don't think any of the downlinks even used MASERs.
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On 2007-01-25, Andy Dingley <dingbat@codesmiths.com>wrote:
transmitter, so it travels parallel like a spotlight beam, or perhaps
you let it fan out a bit but not inverse-square law.
[snip]
EME comms (Moonbounce) is twice as far and can be done with '50s
vintage high-end amateur kit in the 2m band.

1930s terrestrial comms was also surprisingly sophisticated. Look at
the cross-channel microwave link. There's little in the Apollo-vintage
comms that was fundamentally different from the best of the late '30s.
Some of the engineering was different, but not the physics. Magnetrons
and klystrons were much the same, travelling wave tubes were new but I
don't think any of the downlinks even used MASERs.
People overestimate the rate of development of technology because of

On 25 Jan, 15:19, Ben C <spams...@spam.eggs>wrote:
field". This is the same for spotlights or for radio, although as
antenna sizes are measured in terms of wavelength, it's generally
easier to make usefully "large" focussing devices for light than for
radio. Once you get to lunar distances though, it's the far field.
See en.wikipedia.org/wiki/Near_field
The big dish is just to capture more signal on reception.
have been possible and demonstrated once in the 1930s but then didn't
become common until the late '60s. Whether it was in Apollo or not then
demands on whether NASA trusted it. In some ways Apollo was technically
adventurous, in others it was distinctly backward looking for
reliability's sake. Given the poor reliability of missile systems and
the US Navy space program, compared to NASA's good record, then it was
the right choice.
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In article
<1169720373.296814.221120@l53g2000cwa.googlegroups.com>,
"Andy Dingley" <dingbat@codesmiths.com>wrote:
problems when I probed the matter.
--
dorayme
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In article <6aim84-nho.ln1@ophelia.g5n.co.uk>,
Toby Inkster <usenet200701@tobyinkster.co.uk>wrote:
century humans were gods.
--
dorayme
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