Richard Harrison wrote:

At the time
of the magnetron gift to the U.S., British war production was already
bursting at the seams and the U.S. was well advanced in radar and had a
few tricks up its sleeve to improve the British gear.

All the major powers were well advanced in radar at the time. All the
ideas were already in place, and engineers everywhere were starting to
put them together. However, as Reg points out, freedom from bombing
raids is a wonderful aid to creativity.

The USA developed ways to mass-produce the magnetron, notably a method
of building up the cavity from laminations rather than needing to have a
skilled machinist mill it out from solid (and before Roy gets a word in,
they fixed the oil leaks too).

I`ve noticed early British airborne radar using yagi antennas. That
seemed quaint to me.

Those were the phased arrays for the earlier VHF radar, and consisted of
two or four two-element yagis clustered around the nose (of a
two-engined aircraft, obviously). This gave a fairly good
forward-looking capability. Both sides did much the same, and given the
relatively long wavelength, it's hard to think how better to do it.

The huge benefit of the magnetron was that it operated at much shorter
wavelengths, which frees up the antenna design and provides much better
spatial resolution - witness the downward-looking "H2S" radar which was
the magnetron's first major deployment.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

"Ian White GM3SEK" wrote in message
...


Those were the phased arrays for the earlier VHF radar, and consisted of
two or four two-element yagis clustered around the nose (of a
two-engined aircraft, obviously). This gave a fairly good
forward-looking capability. Both sides did much the same, and given the
relatively long wavelength, it's hard to think how better to do it.

The huge benefit of the magnetron was that it operated at much shorter
wavelengths, which frees up the antenna design and provides much better
spatial resolution - witness the downward-looking "H2S" radar which was
the magnetron's first major deployment.

The VHF radars were still around into the late 1970's, maybe beyond. The US
Navy had them on carriers for air search. I think the nomenclature was
AN/SPS-29 and/or AN/SPS-37. The one I recall was in the 218 - 220 MHz and
it was hell on TV channel 13! The antenna was referred to as a bedspring
array; the rectangular framework for the dipole radiating elements resembled
a giant bedspring.

Sal M. Onella wrote:

"Ian White GM3SEK" wrote in message
...


Those were the phased arrays for the earlier VHF radar, and consisted of
two or four two-element yagis clustered around the nose (of a
two-engined aircraft, obviously). This gave a fairly good
forward-looking capability. Both sides did much the same, and given the
relatively long wavelength, it's hard to think how better to do it.

The huge benefit of the magnetron was that it operated at much shorter
wavelengths, which frees up the antenna design and provides much better
spatial resolution - witness the downward-looking "H2S" radar which was
the magnetron's first major deployment.

The VHF radars were still around into the late 1970's, maybe beyond. The US
Navy had them on carriers for air search. I think the nomenclature was
AN/SPS-29 and/or AN/SPS-37. The one I recall was in the 218 - 220 MHz and
it was hell on TV channel 13! The antenna was referred to as a bedspring
array; the rectangular framework for the dipole radiating elements resembled
a giant bedspring.


Sure, but none of those would fly very well. The discussion was really
about airborne radar, where there are tough limits on antenna size.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Back in the early 70's I got a pair of magetron magnets that came out
of old airborne radio set - can't remember the nomenclature - that the
USAF converted into a weather radio. They were quite large and strong,
and 'U' shaped. Someone swiped them in a move. Anybody know where I
might find a set? Google and eBay haven't turned up anything.

Ian, GM3SEK wrote:
"Sure, but none of those (bedapring antenna arrays) would fly very
well."

It`s been a long time now but I believe investigation showed the army`s
new radar (earthborne) got good echos from the approaching Japanese
arircraft on December 7, 1941, but the top brass rejected the reports in
disbelief of either the new equipment or the audacity of the Japanese
Navy. That attack changed naval warfare forever. Lot more respect for
both aircraft and radar ever since.

Best regards, Richard Harrison, KB5WZI

Richard Harrison wrote:
Ian, GM3SEK wrote:
"Sure, but none of those (bedapring antenna arrays) would fly very
well."

It`s been a long time now but I believe investigation showed the army`s
new radar (earthborne) got good echos from the approaching Japanese
arircraft on December 7, 1941, but the top brass rejected the reports in
disbelief of either the new equipment or the audacity of the Japanese
Navy. That attack changed naval warfare forever. Lot more respect for
both aircraft and radar ever since.

Best regards, Richard Harrison, KB5WZI

as I understand the Matter the radar sighting never made past a LT to
the top brass that one of the problem that day was the still pecetime
armed forces were quick to discount anything with the number of "false
sighting" etc