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Section

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Someone has 'helpfully' included links to 'main' articles. As the main articles contain less information than this article, some rationalisation is clearly required.

Because the "#redirect" is broken and will not redirect to subsections, I have created articles for each subsection. This has several beneficial side effects:

  • It makes links in other articles easier to make.
  • It also helps navigation within the "World War II German electronics" Category.

It would be nice if someone who knows could write a section or an article on German use of radio navigation in other theatres. For example I have seen an article that says that the Germans used radar beams in the East as a navigation system. Philip Baird Shearer 23:59, 13 Oct 2004 (UTC)


A mention of moving of radar assisted AAA to the coast to deal with the V-1 flying bombs would be a useful addition.

It would be very useful if this could be expanded for the offensive defensive battle on the other side of the channel eg Operation Biting and the Wuerzburg radar saga, Josef Kammhuber and the Kammhuber Line etc. Philip Baird Shearer 09:39, 1 Jun 2005 (UTC)

How would a fake Elbe at 1km help?

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Shouldn't it be at 6km or 7 or 8 or 9 km? —The preceding unsigned comment was added by 66.114.69.71 (talk) 12:22, 14 January 2007 (UTC).[reply]

The system timed the distance between the last two beams, and dropped the bombs after traveling that distance (actually time) again. By making the last beam appear after only 1 km from the second, the bombs would be dropped after another 1 km, or 2 km total from the middle beam. This was well short of their targets, which were perhaps 10 km distant. Maury 15:28, 14 January 2007 (UTC)[reply]
I was confused by that sentence too:
X-Gerät was eventually defeated in another manner, by way of a "false Elbe" which was set up to cross the Weser guide beam not at 5km, but at 1km
Earlier the beams are described as being at 5km and 10km from the target, so this comes across as meaning "the false Elbe crosses Weser at 1km from the target." I've changed the wording to make it clear that the 1km refers to the distance after the previous beam crossing, as per your description. Thomjakobsen 20:49, 29 July 2007 (UTC)[reply]

Yes, much better! Thanks! Maury 22:12, 30 July 2007 (UTC)[reply]

Error in Knickebein section?

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The article as written states:

When Jones mentioned the possibility of bombing beams to Churchill, Churchill put two and two together and ordered more investigation. However, many in the Air Ministry didn't believe that the system was actually in use, and Frederick Lindemann, leading scientific adviser to the government, claimed that any such system would not be able to follow the curvature of the Earth, though T S Eckersley of the Marconi company had claimed it could.
Eckersley's claim was eventually demonstrated after Churchill ordered a flight to try to detect the beams. An Avro Anson was equipped with an American Hallicrafters S-27 amateur radio (then the only known receiver capable of receiving the 40 MHz signal) requisitioned from a shop in Lisle Street, London, operated by a member of the Y Service The flight was nearly cancelled when Eckersly withdrew his claim that the beams would bend round the earth enough to be received. Only R V Jones could save the flight by pointing out that Churchill himself had ordered it and he would make sure that Churchill would get to know who cancelled it.

However, according to the book "Ultra Goes to War" by Ronald Lewin (McGraw-Hill, 1978), Eckersley initially claimed that "any such system would not be able to follow the curvature of the Earth". Lindemann was an early skeptic of the system, but became convinced that it would work before the critical meeting at which Churchill ordered continued investigation of potential countermeasures. This version of events makes more sense, since Jones was a protege of Lindemann's, and Lindemann was a close confidant of Churchill's. Sir Henry Tizard had argued against the possibility of a beam system at "the critical meeting" and submitted his resignation after he realized his misjudgment.

Books have a habit of adopting 'literary licence'. I have a video of a documentary on the subject and R V Jones himself relates the story more or less as described (though there is some variance with the first sentence). 20.133.0.13 (talk) 07:48, 26 August 2009 (UTC)[reply]
The 1977 BBC series The Secret War is on YouTube with the relevant episode The Battle of the Beams being here: [1] — Preceding unsigned comment added by 86.112.68.219 (talk) 17:39, 28 May 2011 (UTC)[reply]
"American Hallicrafters S-27 amateur radio (then the only known receiver capable of receiving the 40 MHz signal)..."
I'm replying, in general, to the authors. This is just plain silly. The frequency band 30-40 MHz at that time carried few, if any, signals of civilian or military importance. For that reason, it attracted little interest from radio hams or the general public and commercially available receivers almost never made provision for reception in that band - why would they? In 1939/40, the RAF operated morse code and AM voice radio equipment in the much higher 100 MHz plus, UHF band (as it was then known) and in the MF (300 kHz-1 MHz) band and in the HF (2 MHz-12 MHz) band. The RAF did not wish to use frequencies in between. Why would they? They was no particular technical advantage gained by doing so.
It would have been technical child's play for the British military to build a radio receiver covering 30-40 MHz. It would also have been within the capabilities of many British amateur radio enthusiasts. But, the design, calibration and testing of such a receiver for RAF use would have occupied a number of weeks and there was a certain urgency to unravelling Knickebein transmissions.
Why not, therefore, pull some money from the departmental petty cash and send a junior out at lunchtime to the Soho area (close to the seats of government and military high command) - a walk of about 7 minutes - to purchase an 'off the shelf' ham radio rig that covered the necessary frequencies? The shop, Webb's, was a Mecca for radio amateurs as well as radio listeners wanting world coverage (overseas servants of the British Empire, for example) and it stocked equipment and supplies made all over the developed world - thus, some US made Hallicrafters equipment - and from other countries, including Germany.
The idea that 'American technology' saved Britain in the Battle of the Beams is just absurdly overblown. The acquisition of the Hallicrafters S-27 was one of convenience - nothing more. Suppose that junior, sent out to Webb's with War Department cash in his hot little hand had been persuaded to return with a set of German origin - Telefunken made - for example? Would we now be saying that Germany defeated itsef in the 'Beams' struggle?
Wikipedia is replete with these weasel claims of American exceptionalism. Trying to roll them back is a Canute-like task.2A01:4B00:AE0E:6200:E84E:D98:FD25:9FD6 (talk) 14:49, 6 May 2024 (UTC)[reply]
"An Avro Anson was equipped with an American Hallicrafters S-27 amateur radio (then the only known receiver capable of receiving the 40 MHz signal)..."
Actually, let's lay this bit of nonsense boasting, once and for all. The September 1939 issue of the British radio publication "Short Wave Magazine" page 5, has a full page advert for 'Trophy' brand Communications Receivers from the Peto Scott Co Ltd (London) - "British and Best..." according to the company. The Trophy 6 model operates from wavelength 6.5 meters (46 MHz) up to 545 meters (550 kHz), continuous tuning, the more expensive Trophy 8 receiver has similar frequency coverage 43 MHz - 545 kHz in five overlapping bands, and includes the interface circuitry for a associated transmitter. These are proper 'Communications Receivers' incorporating all the expected features - bandspread tuning, AGC, BFO etc. There is an optional 2-stage tuned preselector afterfit which can further increase sensitivity and selectivity without provoking 2nd channel interference.The only additional feature of the Hallicrafters SX-27 receiver is a Frequency Modulation (FM) reception module (Edwin Armstrong was making demonstration FM broadcasts on behalf of RCA at the NY Empire State Building at the time) The Lorenz system used an MCW (Amplitude Modulated) signal beam - it did not use FM and was not believed to do so by Jones and his team.
Surely this means the " only receiver... 40 MHz" can be removed? In any case Lorenz was found at 31.5 and 33.3 MHz - both frequencies which can be received by the Peto Scott sets above.2A01:4B00:AE0E:6200:F188:2DD7:29E4:8996 (talk) 21:27, 7 May 2024 (UTC)[reply]

Dates

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The article could do with some dates for the use of the various systems. --jmb (talk) 13:22, 11 May 2008 (UTC)[reply]

medical diathermy

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When the "Medical Diathermy devices were used to cause interference to German radio beams", I am curious: Which kind of medical diathermy? The diathermy article draws a distinction between "shortwave diathermy", "microwave diathermy", and electrosurgery. --68.0.124.33 (talk) 21:12, 9 August 2008 (UTC)[reply]

At that time it was very unlikely to be microwave diathermy and the "beams" were not microwave. The only reference that I can see if sets being modified to operate on 30 MHz (in Beam Benders). --jmb (talk) 21:38, 9 August 2008 (UTC)[reply]

40 MHz vs 60 MHz

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If Knickebein operated on 40 MHz and X-gerät on 60 MHz, I would not consider X-gerät's frequency to be "much higher" than Knickebein's. The precision would increase linearly, i.e. by a mere 50 percent, or am I wrong? Mumiemonstret (talk) 15:19, 10 March 2011 (UTC)[reply]

Well, it's 50% higher. I don't see that precision would increase linearly. The higher frequency allows you to install a more complex (i.e. directional) aerial in the same space. Thus part of the imporovement in directivity would be down to the increase in frequency and part due to the increase in aerial directivity. Thus, it seems to me, that the increase in precision would be much greater than 50%. If the Germans were to provide an even more directional aerial system on a larger site then the precision rises accordingly. 86.183.175.94 (talk) 13:56, 15 April 2011 (UTC)[reply]

Aiming the beams

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How could they aim the beams ? There is nothing on that here. They must have used spies. --Moritzgedig (talk) 08:41, 5 December 2014 (UTC)[reply]

A compass?--Ykraps (talk) 21:40, 5 December 2014 (UTC)[reply]

Confusion

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In the section about Y-Gerat (sorry, no umlaut here...), the article says "It turned out their conclusion about code name Wotan was incorrect as it did not in fact imply a single beam." But later on the article says the Y-Gerat did use a single beam. I guess what the quoted part is saying is that 'Wotan' did not refer to a one-eyed god, or that somehow the inference from a one-eyed god to a single beam was mistaken (although it sounds like it was in fact correct). I don't have access to the ref (Jones' book). Can someone who does clarify this quoted sentence? Mcswell (talk) 17:03, 18 September 2020 (UTC)[reply]

Translation of 'knickebein'

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Someone has provided a machine translation of 'knickebein' as 'bent leg'. This is the problem with machine (or literal) translations. The art of translating one language into another is to produce text that is grammatically and idiomatically correct in the target language (i.e. worded exactly as a native speaker of the language would write it). No (or very few) English speaker would use the expression 'bent leg'. Instead they would refer to such a leg as a 'crooked leg' and this is thus the correct translation of the German word. DieSwartzPunkt (talk) 17:23, 6 December 2014 (UTC)[reply]

"It was the shape of the aerials that gave the system its code name, Knickebein, which means "crooked leg", although the word is also the name of a magical raven in Germanic mythology."
It is not. It seems that this claim was first made in "The Secret War". It is wrong, however. The author confused "Knickebein" with "Hans Huckebein, der Unglücksrabe", an early comic strip by Wilhelm Busch that has nothing to do with Germanic mythology. The term "Knickebein" is used in Germany e. g. with easter eggs with a surprise filling, and that fits neatly with the surprise filling that was dicovered inside that He 111 and the crooked antenna array. Angeliter007 (talk) 14:53, 13 September 2023 (UTC)[reply]
Addition: In Norse methology, there exist two ravens, Huginn (thought) and Muninn (memory, mind). Nothing here with Knickebein either. Angeliter007 (talk) 20:39, 9 June 2024 (UTC)[reply]

Luftwaffe Training in Celestial Navigation

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I am sure celestial navigation from an aircraft is difficult and can be of uncertain value but to say that the Luftwaffe neglected any such training is an overstatement. The Science Museum in London has a small Zeiss planetarium projector that was originally the property of the Luftwaffe, "used to train navigators and pilots in celestial navigation. Such knowledge enabled them to fly bomber aircraft towards Britain, with devastating consequences." Of course, the Science Museum may be wrong in according so much credit to training in celestial navigation, but the object is fairly concrete proof that such training was not totally neglected. (See http://www.sciencemuseum.org.uk/objects/astronomy/1946-172.aspx). Moletrouser (talk) 07:59, 31 December 2015 (UTC)[reply]

Somewhat after the event but...
Indications are that the Luftwaffe did not train in celestial navigation while they were confident that their beam systems were of value. That confidence was heavily misplaced because they only ever got to use X-Gerat once (in the bombing of Coventry) and Y-Gerat not at all (we were jamming it from its first attempted use). The Germans were then forced to teach their crews celestial navigation in order to launch (among other operations) the blitz on London. The consequences were devastating but only because the targets were so large that they were hard to miss. One British navigator reported on "The Secret War" television series that he had no faith in celestial navigation at all. He stated that the best he could achieve from a Lancaster bomber parked firmly on the ground was to determine that the aircraft was twenty miles from where the airfield actually was.
The British had to rely on celestial navigation to bomb the V-weapon sites at Penemunde (They hadn't developed Gee yet - and even if they had Penemunde was beyond its range). They missed Penemunde completely and instead inadvertently bombed the Lumembourg work slaves who alerted us to its presence. The tragic consequence of that was that no Luxemburger provided us with any intelligence again. 86.153.129.239 (talk) 13:43, 11 April 2018 (UTC)[reply]

To the editors of this page; fantastic job

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I realize this is still start class, but I want to say that the language and structure of this article is very engaging. I read it start to finish, without skipping a word. Very well done. Thank you for the effort. Btw, you're on the front page of Reddit today. Ian Furst (talk) 18:46, 12 May 2019 (UTC) (update: not on mobile, and now see that it's B-class) Ian Furst (talk) 20:20, 12 May 2019 (UTC)[reply]

Line of sight

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The present article (as at 3 September 2019) includes the sentence: "It was subsequently realised that the argument over whether the beams would bend round the earth was entirely academic, as the transmitters were more or less in line-of-sight to high altitude bombers" . The source for this statement is given as page 533 of F H Hinsley's book on British Intelligence in WWII in the official UK history of the war. I have consulted this book in a reference library, but I find nothing on page 533 (of Volume 1) to justify the sentence I quoted. Nor could I find anything elsewhere in the book's discussion of Knickebein to support it. The fullest discussion is on page 553 (not 533), but this just concludes that R V Jones was 'proved right' when an RAF plane detected the signals. This does not say, or even imply, that the transmitters were in 'line of sight', nor that the argument was 'entirely academic'. Unless someone can find an explicit source quotation to support the sentence, I suggest it should be deleted, and I will do so myself if no-one comes up with a supporting source in the next few weeks.86.154.202.31 (talk) 10:37, 3 September 2019 (UTC)[reply]

I would be reluctant to delete this as plainly the beams worked. Line of sight from 20,000 feet is about 200 miles. Perhaps it might benefit from a more specific reference. --Wtshymanski (talk) 00:17, 4 September 2019 (UTC)[reply]
Altitude ceiling of the German Bombers (principally Dorniers) was 27,000 feet (let's say 25,000 feet for service ceiling). This gives a line of sight of about 175 miles per WP:CALC (See Horizon for formula). Siting the aerials at elevation (hill or tall mast - or both) extends this distance plus the 40+MHz beam will bend around the earth to some extent (even 1.7GHz GPS signals bend through the atmosphere which is the principal source of that system's inaccuracy). A range of 350 miles (which is how far away the transmitters were) would be quite possible and, as noted, the fact that the system worked shows that the range required must have been achieved. -86.158.241.234 (talk) 12:51, 4 September 2019 (UTC)[reply]
I (the initiator of this thread) am not disputing that the beams worked, whether by line-of-sight, atmospheric refraction or 'bouncing' from the ionosphere. I am just saying that the source cited (Hinsley) does not, as far as I can see, actually support the claim that it was by line of sight. The two other books I have read which cover the subject (Jones 'Most Secret War' and Alfred Price 'Instruments of Darkness') do not support it either. The matter is of more than purely academic interest because, believe it or not, 'Flat Earth' nutjobs are quoting the impossibility of line-of-sight transmission through the curvature of the earth as proof that the earth is flat! Incidentally, according to all the sources I have seen Knickebein worked at just over 30MHz, not 40MHz. Various sources state that ionospheric bouncing can work up to about 40MHz.86.141.32.73 (talk) 18:07, 4 September 2019 (UTC)[reply]
There are numerous sources for the frequency range used by Knickebein. Jones's book claims that the Kleve transmitter operated on 31.5 MHz. Other sources offer different frequencies and even frequency bands. Some sources put the frequency range at 42.1-47.9 MHz. Frequencies that high are easily discounted because the 1940 model of the Hallicrafters SX-28 receiver, the only receiver available to the allies capable of receiving the signals, had an upper limit of 43 MHz which would not cover most of the band. Bending of the beams occurs at any frequency, but the bend is less as the frequency rises. There is no set frequency at which the effect suddenly disappears. As I said above even GPS signals bend to some extent. That the beams made the 350 mile journey when geometry dictates that the (straight) line of sight is 247.3 miles means that the beams must bend around the earth. (I have now allowed for the elevation of Stollberg Hill at 1120 feet and used the correct formula plus the now determined actual flying height of 20,000 ft). The line of sight range of Kleve is less at 221.8 miles due to its lower elevation of 239 feet-yet the beam made the 300 mile journey with no difficulty. -86.158.241.234 (talk) 13:28, 5 September 2019 (UTC)[reply]
Please stop this nonsense about Hallicrafters. See my earlier response. Building a 30-40 MHz radio receiver would have been child's play for British radio designers, technicians and civilian factories; such receivers weren't commercially available because nobody would normally want such 'empty air' frequency coverage. The RAF was at the time evolving AM radio cockpit transceivers operating above 100 MHz - far higher than the Hallicrafters coverage - as well as powerful radios for the MF and HF bands below 12 MHz. No technical challenges there.
If asked, British civilian radio set makers - Pye, EKCO, Bush, Murphy, communications receiver makers - Eddystone - e.g. and military radio makers like Marconi and GEC could easily and quickly have manufactured a satisfactory radio capable of resolving Knickebein signals. But, if you can go to a shop selling ham radio equipment and buy, off the shelf, for modest cost, a satisfactory foreign made/import radio, then why on earth not?
The British did NOT resolve the Knickebein challenge because only American technology was available. Buying Hallicrafters saved the RAF two or three weeks - and with appropriate priority authority, this could have finished in days.2A01:4B00:AE0E:6200:E84E:D98:FD25:9FD6 (talk) 16:50, 6 May 2024 (UTC)[reply]

Footnote 24

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This is given as Hooton (1999). Is this a typo for 1994? 86.130.154.27 (talk) 21:22, 7 May 2020 (UTC)[reply]

Origin?

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The article says that the beam systems originally were "blind landing" systems. I'm not sure that's accurate; it seems the Low-frequency radio range is a closer fit. Also, judging by the discussion of that system and ILS systems in the 1939 "Practical air navigation" manual, radio ranges were fully operational then while the analogous beam-type instrument landing systems were still experimental (though what was being evaluated at that time indeed is exactly the still-current localizer and glide slop system used in ILS). Paul Koning (talk) 20:57, 18 August 2023 (UTC)[reply]