That the null is better? Just google the term "aural-null".LWD wrote:Sources PLS.wm wrote:I think we should spin the non-Adcock antenna as fast as its possible and observe received signals on a long persistence phosphor oscilloscope. And that's how it was done.
And the fix was usually at the null point, not at the maximum because almost any antenna has a better(narrower) null that maximum.
Although it has to be said because it's the simplest method available it wasn't used during the WW2 for any serious tasks (like searching for U-Boots). A spinning loop antenna on a top of a truck, operators slowly turning their antennas to the null (or max.) are more Hollywood movie props than reality.
The usually used crossed-loop and Adcock antennas didn't even have any usefull nulls (or maxs).
Please observe the instantaneous finding of a direction on a FH4 "Huff-Duff" simulator as demonstrated by Jerry Jones from the USS Slater museum. The FH4 had no rotating parts whatsoever:
Unfortunately the introduction note there is not precise. The Germans had their own Huff-Duff, better and faster that the British one (the Lichtbild-Kurzwelle apparatus and the Wullenwever technology). They simply had no mission for them.
They knew perfectly well that fast radio direction finding was possible, after all the Bellini-Tosi goniometer, that didn't require moving the antenna, was invented in 1907, and perfected by Watson-Watt in 1926, (and as I said they had their own instantaneous HF/DFs).
What they didn't know that this type of apparatus could be used successfully in the hostile environment of a warship. This seemingly impossible hard problem was successfully solved, as many surely know, by the Polish engineer Wacław Struszyński at the beginning of the WW2.
The mammoth 200kW Marconi's Caernarvon transatlantic station was huge even by today's standards. During the WW2 there were very few larger transmitters: the CH radar stations were comparable, the Goliath VLF transmitter for communication with submerged submarines was larger, maybe a few commercial stations. Those were huge and costly installations impossible to be built on a whim and for some limited purposes.LWD wrote:The point was that such transmitters were possible not that a spark gap one is the way to go. Indeed it wouldn't be for quite a few reasons. That doesn't mean that less broad band jammers couldn't be used effectively indeed it rather suggest that they could.
And as I said a transmitter has to match the antenna impedance, but the impedance of the antenna changes with frequency, so no broadband, high-power transmission is possible and will never be.
It's a fact that some of the V-1s were equipped with transmitters. And that the transmitters were used successfully, but that success was squandered by the technologically challenged Germans leadership.LWD wrote:And you don't think that the launch and vibrations much less temperature changes might cause some variations in the tuneing? For that matter if the transmitter is on it will be sending out a signal perhaps not a very substantial one but it will be there.
This a still from a German instructional film for the V 1 launching crews:
- v1a.jpg (13.73 KiB) Viewed 981 times
- v1b.jpg (10.37 KiB) Viewed 981 times
- v1c.jpg (10.52 KiB) Viewed 981 times
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