Peter Stickney
July 1st 03, 05:28 AM
In article >,
(William Donzelli) writes:
> (Peter Stickney) wrote in message >...
>
>> The impetus wasn't there. The German radars wer also susceptible to
>> active jamming as well. It's not that they weren't clever, they just
>> forgot that the Allies were clever, too. (As I remember it, Nurenberg
>> wasn't "chirping", as we understand the term. Instead, it looked for
>> the scintillation that a revolving propeller produces to the radar
>> retorn.)
>
> This is similar to the AN/APX-15 "Ella", fitted to the AN/APG-15
> radars late-ish in the war. The concept really is very simple,
> involving just a small amount of circuitry.
Yes, that's true.
>> Everybody invented chaff/rope/window at about the same time,
>> (including the Japanese), and everybody held off on using it, becasue
>> they wer afraid of the effects on their own systems. One of the war's
>> ironies.
>
> Interesting that with almost all aspects of early radar - almost
> everything was invented by everyone at the same time, with the key
> difference being if the things actually made it out of the labs. The
> British were the quickest to get things out of the labs and into the
> military (sometimes a bit too quick), but others a bit more slow...
Absolutely. Although the Brit panchant for shoving stuff out got them
in trouble in the early days. When the first Brit techs carrying an
early Cavity Magnetron, and the drawings for the same, arrived at
Harvard, they go themselves into a bit of hot water when it was found
that the innards of the Magnetron didn't even closely match the
drawings. (The first thing they did was X-Ray it to see what was
inside, not wanting to damage the only copy they had. It had a
different number of cavities, and the dimensions were all different.)
As it turns out, while the Brits had a big advantage in microwave
transmitters, our receivers were superior. Matching the two
technologies produced the benchmark systems. (Some studies done back
in the '60s indicated that, for most uses, the old AN/CPS-1 Air Search
radar, with teh addition of sidelobe cancellation, was ideal)
It's pretty amazing what could be done with wire & tubes back then.
>
>> Is that 13 KW peak radiated power? I'm thinking of power into the
>> system, not out. Aircraft Generators at that time were usually
>> capable of not more than 2.4 kw, each.
>
> I would think this would be the peak radiated power. If not, something
> was very wrong with the German sets. Even the biggest US shipboard
> radars, like the VHF model SR, needed only 3.8 kW when the set was
> radiating with the antenna spinning at full speed.
I'd think it would have to be. But even then, aircraft electrical
generating systems were a bit on the marginal side.
> --
> William Donzelli
--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster
(William Donzelli) writes:
> (Peter Stickney) wrote in message >...
>
>> The impetus wasn't there. The German radars wer also susceptible to
>> active jamming as well. It's not that they weren't clever, they just
>> forgot that the Allies were clever, too. (As I remember it, Nurenberg
>> wasn't "chirping", as we understand the term. Instead, it looked for
>> the scintillation that a revolving propeller produces to the radar
>> retorn.)
>
> This is similar to the AN/APX-15 "Ella", fitted to the AN/APG-15
> radars late-ish in the war. The concept really is very simple,
> involving just a small amount of circuitry.
Yes, that's true.
>> Everybody invented chaff/rope/window at about the same time,
>> (including the Japanese), and everybody held off on using it, becasue
>> they wer afraid of the effects on their own systems. One of the war's
>> ironies.
>
> Interesting that with almost all aspects of early radar - almost
> everything was invented by everyone at the same time, with the key
> difference being if the things actually made it out of the labs. The
> British were the quickest to get things out of the labs and into the
> military (sometimes a bit too quick), but others a bit more slow...
Absolutely. Although the Brit panchant for shoving stuff out got them
in trouble in the early days. When the first Brit techs carrying an
early Cavity Magnetron, and the drawings for the same, arrived at
Harvard, they go themselves into a bit of hot water when it was found
that the innards of the Magnetron didn't even closely match the
drawings. (The first thing they did was X-Ray it to see what was
inside, not wanting to damage the only copy they had. It had a
different number of cavities, and the dimensions were all different.)
As it turns out, while the Brits had a big advantage in microwave
transmitters, our receivers were superior. Matching the two
technologies produced the benchmark systems. (Some studies done back
in the '60s indicated that, for most uses, the old AN/CPS-1 Air Search
radar, with teh addition of sidelobe cancellation, was ideal)
It's pretty amazing what could be done with wire & tubes back then.
>
>> Is that 13 KW peak radiated power? I'm thinking of power into the
>> system, not out. Aircraft Generators at that time were usually
>> capable of not more than 2.4 kw, each.
>
> I would think this would be the peak radiated power. If not, something
> was very wrong with the German sets. Even the biggest US shipboard
> radars, like the VHF model SR, needed only 3.8 kW when the set was
> radiating with the antenna spinning at full speed.
I'd think it would have to be. But even then, aircraft electrical
generating systems were a bit on the marginal side.
> --
> William Donzelli
--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster