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Could you please clarify what you mean by the doppler feature? Do you mean the suppression of function when fired at low angles over water? Or the limit of detection bandwidth? Or suppressing the microphone effectOr are you talking about Countermeasures now?So the reason the doppler feature is involved is to correct for the effect of speed on frequency?
I think those L70 versions were beyond WW2 technically , brought in around 1951? possibly an altgrrred tech mini-tube? Or early transistors? THis os why so many US Navy vessels changed Bofors 40mm quad mounts with 3" guns, or so I'm reading. VT was available in 3" in period Mk45 in May 1944..[/QUOTE][QUOTE="", The smallest sheill i know with VT is 40mm for L70 Bofors.
The guns may date form 1951 or so but the proximity fused ammo for them was a much later development.[/QUOTE]I think those L70 versions were beyond WW2 technically , brought in around 1951? possibly an altgrrred tech mini-tube? Or early transistors? THis os why so many US Navy vessels changed Bofors 40mm quad mounts with 3" guns, or so I'm reading. VT was available in 3" in period Mk45 in May 1944..
One of the documents (I think you) listed mentioned the doppler effect. Usually doppler effects involve closure rates as the frequencies change as you move towards/away from something.Could you please clarify what you mean by the doppler feature?
One of the documents (I think you) listed mentioned the doppler effect. Usually doppler effects involve closure rates as the frequencies change as you move towards/away from something.
From what I read, the system seemed to transmit a series of pulses which were cancelled out or amplified by the reflecting currents being out of phase or in phase, which produced "beats" as the frequency was cancelled out and reappeared. And the system effectively measured the change in the frequency of these beats due to the closure rates.
I'm often perplexed, but that often drives me to learn stuff. Then I stop being perplexed. Until something else catches my curiosity anywayIf so I'm notv surprised you were prerplexed.
So it emits a steady frequency tone?The VT fuze is a Continuous wave not a pulsed wave device
Actually older people know more stuff, our education system (particularly in the United States) is a disaster. There's rules on this forum about politics, so I'll try and avoid getting up on the soap-box...I'd like to have a go at explaining it myself, this would be risky as
1. I'm an aging nit and no one understands more than 1/2 of what i say these days.
You probably forgot more than I've learned...2. I never finished my electronics training
That, I actually understand...200 MHz emission, speed of light 300 x million metres/ sec wavelength 2/3 m or about 66cm
Not necessarily. The doppler effect has effects that can be felt in real time (an airplane coming in for a landing, a train, etc), as well as other matters like the movement of other galaxies and things of that nature.There are two ways to explain most electronics of this kind, frequency and time (phase).
The frequency description is boring - doppler, yawn
A wavelength is 360, so every half wavelength it travels, you'll get a cancellation of the signal as it's out of phase?For me the real story is in the phase
Each 33cm that the shell advances the phase of the reflected signal changes by 2Pi or 360 degrees, one half wavelength less to get there, one half wavelength faster less getting back
But until you get close the amplitude of that phase shifted return is zip.
Meaning it's slightly overshot the target and is no longer heading towards, but heading away?As the shell comes to its closest approach there is an inflection in the beat frequency (rising to falling doppler)
Don't worry, teaching and learning takes time.[/quote]oh dear, I'm afraid I rather ran on
[/QUOTE]I'm often perplexed, but that often drives me to learn stuff. Then I stop being perplexed. Until something else catches my curiosity anyway.
So it emits a steady frequency tone?
Actually older people know more stuff, our education system (particularly in the United States) is a disaster. There's rules on this forum about politics, so I'll try and avoid getting up on the soap-box...
You probably forgot more than I've learned...
That, I actually understand...
Not necessarily. The doppler effect has effects that can be felt in real time (an airplane coming in for a landing, a train, etc), as well as other matters like the movement of other galaxies and things of that nature.
A wavelength is 360, so every half wavelength it travels, you'll get a cancellation of the signal as it's out of phase?
Meaning it's slightly overshot the target and is no longer heading towards, but heading away?
Don't worry, teaching and learning takes time.
[/QUOTE]I'm often perplexed, but that often drives me to learn stuff. Then I stop being perplexed. Until something else catches my curiosity anyway.
So it emits a steady frequency tone?
Actually older people know more stuff, our education system (particularly in the United States) is a disaster. There's rules on this forum about politics, so I'll try and avoid getting up on the soap-box...
You probably forgot more than I've learned...
That, I actually understand...
Not necessarily. The doppler effect has effects that can be felt in real time (an airplane coming in for a landing, a train, etc), as well as other matters like the movement of other galaxies and things of that nature.
A wavelength is 360, so every half wavelength it travels, you'll get a cancellation of the signal as it's out of phase?
Meaning it's slightly overshot the target and is no longer heading towards, but heading away?
Don't worry, teaching and learning takes time.