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WIRELESS TELEGRAPHY 1913© RN Communications Branch Museum/Library |
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WIRELESS TELEGRAPHY 1913© RN Communications Branch Museum/Library |
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| In this file:- | Index. List of plates.
W/T Appendix - General Summary. Note the irony of the statement that the signal book will be in general use before the 1914 Manoeuvres.
The Mk11 sets converted to Quenched Spark (QS) were subjected to a long distance trials between HMS Vernon and HMS Vindictive. BUT shortly after this event, the navy issued the following statement.
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| In this file:- | Motor Buzzer - continued from the last file above. Of interest here, is the variation in speed of the Motor's. To get the maximum power output coincident with the highest Morse musical note the Motor had to be run at full speed. For ease of explanation, let's say that full speed = 100 Watts and that the highest Morse note is 1000 c/s. However, by varying the Motor speed two objectives could be achieved; power output and pitch of note. Thus in a harbour (for example) in a training environment we could have three groups of ships each conducting an exercise. Group 'A', the battleships, might run their motor's at ½ speed resulting in a power output of 50 Watts and a Morse note of 500 c/s: Group 'B', the cruisers, at ¾ speed with a 750 c/s note/75 Watt output, and Group 'C', the destroyers using a ¼ speed Motor giving 25 Watts and a low note of 250 c/s. Obviously, all three could operate on the same wavelength each group of operators (as in real life) training their ears/brain/pencil arm to tune-in to their note and tune-out the other two notes as interference - excellent and realistic training. Mk11 sets - spark gaps - trials in HMS Albemarale and HMS Glory 30 miles apart. Alterations of the cooling system for the spark gap. Results look good and HMS Vernon wants to increase the p.s.i. Morse key standardisation - to be a mixture of new keys procured commercially and the old keys to be modified by Portsmouth Yard. Type IV Destroyers set - now fitted into 163 ships. The aerial fits are the weak link and cannot be used on the many different wavelengths soon to be introduced. Major study necessary. Experimenting with different types. 'Nelsonic' Buntings getting in the way of modern technology. No signal halliards to be near W/T wire aerials. W/T Installations in Torpedo Boots (no, not German, but ours mis-spelled or a typo - there are one of two in this file). Poor old seamen! Bet they just loved old sparks. New aerial tuner so that destroyers can tune to all the newly created wavelengths one of them being 1.3MHz (765 feet). Destroyers new 'Protection Switch (our send/receive relay). Earths the aerial input to receiver and also earths the detector stage. Ruby (red) glass device surrounding oscillators and the spark gap allowing one to see the spark whilst giving the spark a safe and near perfect environment (cooling etc) for its high-end efficient needs. Windows in doors of destroyers W/T Office with switch to switch off lights when the door is open? We can't fathom this one. Originally the Office is on the upper deck without any windows of any kind. Because we don't want lights showing at night, when the door is opened a micro-switch is broken putting the lights out, and when shut the lights come back on again that is assuming the main switch is not switched off. Now, a window is to be added to the door and...........? Heavy brushing on a destroyers Deck Insulator (DI) when transmitting on 490kHz. HMS Vernon to the rescue ! Experiments looking for a range of 150 miles on 196kHz from destroyers - Project abandoned. More trials and more modifications. Destroyer Type IV Set - hugely modified went into HMS Velox who was despatched West to Falmouth for trials. Reliable communications achieved out to 80 miles. From Portsmouth to Falmouth (as the crow flies ATCF) is 181 miles: from Portland it is 119 miles and from Devonport (HMS Defiance) it is 44 miles. If HMS Velox was fitted-out by HMS Vernon in Portsmouth (as most trial ships were) she was half way across Lyme Bay (West of Portland) when best communications were achieved, less than half way to Falmouth. HMS Velox' aerial strung between two 60 foot masts 50 foot above the sea, was thought to be capable of a range of 120 miles. Battleships are all fitted with 'Battleship Auxiliary Sets Type III. Some battlecruisers are also fitted. However, when the 'Cruiser Auxiliary Set' is available, battlecruisers will get that set along with all the other cruisers nominated - see lists page 5 of 10. The 'Cruiser Auxiliary Set' with be known as the Type IX set. Problems with the 'Battleship Auxiliary Sets'. The 'Cruiser Auxiliary Set was used for testing QS (quenched spark) but failed and all trials were abandoned. New kit was acquired and tested in the cruisers HMS Achilles and HMS Vindictive. These trials were successful and a purchase was placed for the new Cruiser Auxiliary Set. It is hoped to get a range of 25 miles on a wavelength of 4 or 6.2 LS (2.38MHz to 1.92MHz) and the equipment will have the very first automatic send/receive switch fitted. Diagram/drawings of the Cruiser Set (Fig 6 and Plate II in two parts for ease of copying a large picture) give a good indication of the full transmitter circuit. The tuned circuits (the primary 'E' quite sizable adjustable copper tubes) and the transmitter condensers (those that cause the discharging spark) sitting in a tank filled to the brim with oil, all 25 gallons of it. We will be covering the 1914 version of the Destroyer Type IV Set in full in the transmitter/transceiver section of this site. Looking at page 11 of this file it is of interest to read of the Cruiser Auxiliary W/T Office which is quite separate from the Main W/T Office. This is truly of midget submarine sizes with the complete office measuring just 7' 8" square, the transmitting cage (unmanned) 3' x 4' 8½" and the silent cabinet with the operator, his Morse key and receivers just 4' 8½" square. The scale shown in Fig 8 has been vitiated (copying has destroyed the scale of the original picture) and taken on face value, it measures 6½" representing 7' 8". | ||
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| In this file:- | Submarine Fits. Submarine Set Type X= Portable Form, and more or less a modified Type 4 Destroyer Set was fitted to HM Submarine B5 was not suitable for all boats. The system was subsequently much modified (and became the Type 10 proper) to be fitted into Classes B, C, D, E and X. The submarine motor alternator gives 1kW @ 100 c/s 70V RMS. Two versions. One working from 95 to 140 V DC for classes B, D, E and X, and the other from 155 to 200V DC for class C. Can be used at all times when on the surface whether charging main battery or not. The power oscillator tuned circuit will give a maximum of LS21 = 944' = 1.04MHz., (remember the maximum means the longest wave - we would talk about its lowest frequency). Normal Tunes permit the use of Harbour Defence Wave (New Tune C) = 514' = 1.9MHz; Submarine Wave (the forerunner of 4340kHz) (New Tune D) = 635' = 1.55Mhz; Destroyer Wave (New Tune E) = 756' = 1.3MHz.
The W/T Office with its traditional Silent Cabinet was quite an affair. Look at Fig 9 for example. Here, the material used is (a) substantial wooden support frame (b) lead (c) canvas (d) felt (e) 5-ply (plywood) (f) sound proofing wood.
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| In this file:- | First part continues from last file above.
Aerial tuner - 21000 feet = 46.78kHz = 10400 LS : wavelength in feet = 206 √LS.
Aerial Corrector for use on SIMPLEX circuits - addition of tuned circuit circuitry. When using DUPLEX it will be short circuited.
Although a highly detailed and technical paper which I am sure most of you will readily miss, there are a couple of pointers to articles of interest. In the "trials and results" section (page 3) they state two advantages in using the aerial corrector/acceptor namely a gain of 10% in QSA and greatly reduced QRM/QRN. The disadvantage (b) is indicative of either poorly tuned or unstable (wandering) transmitters and/or the TRF receiver where the bandwidth is fixed offering signals on-tune an uninhibited path whilst piling on the dB's of attenuation to those off-tune - no Intermediate Frequency very wide, wide or narrow filters: Intermediate Frequency is stated that way and not simply as IF. In these days, I/F also meant Intermediate Frequency, and although not used internationally, the navy used it as a frequency/wavelength designator. The navy has always used different frequency bands from those used by civilian organisations and their nomenclature was:-
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| In this file:- | This is a good exercise in understanding wavelengths, quarter-wavelengths and LS (tuned circuit values) with a quick reference to the capacity of an aerial.
At this time their symbols were very different from ours and whilst we have regularly mentioned things like 'jars' 'mics' 'LS' all now long gone measurements, we need to mention measurements still used/required but with different symbols. The symbol for Curve II is
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| In this file:- | Oberlaa is just outside Vienna the Capital of Austria.
Very impressive results from German built equipment. Wavelengths from 5000 to 20000 feet (196.5kHz to 49.12kHz), day ranges 960 miles overland to 1500 miles at night. 60 wpm MINIMUM SPEED OF MORSE! 1 year guarantee on parts and labour (first time we have seen that actually written down in a contract). The object is for Oberlaa (Vienna and AustroHungarian Empire Capital) to communicate will all its fortified posts throughout its Empire. Can you imagine just how 'red hot' those operators Morse keys would have been when the news of the assassination of the ArchDuke Franz Ferdinand in Serajevo came through, and this not that many months after this recorded visit ?
The Austrians had fully adopted the Poulsen Arc transmitting system for all Government Stations and the War Office in Vienna, but their kit was no better than ours which was being tested back in HMS Vernon.
The hissing of the Arc transmitter (as previously mentioned by us on these pages) was a major disadvantage of the system and the more power used and the closer one got to the transmitter the greater the problem. Here though they managed to prove by experimentation that the hissing effect could be minimised although they don't say how.
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| In this file:- | Goldschmidt HF Alternator. Remember, high frequency to them was anything you couldn't hear, RF to us, but in any event, anything above 15 kHz, though the longest wave ever recorded/reached in these years was in the high 30kHz area of the spectrum. This is not a document to read when your head is on the pillow - we guarantee that it won't send you off....! This system, which we saw much earlier on in these pages, is an alternator (AC Device) ready for connection to an aerial system which radiates on a frequency of 46 kHz and can be keyed with a Morse key producing a well defined and pure musical note. This is what this chunk of metal looked like and all just a send an ETA message ! AC Device - use your zooming tool to crawl over this monster. On first learning about it (some time ago) the navy weren't too sure. On a second read (although they haven't said so) they appear still to be unsure of its merits as a Service transmitter. | ||
| In this file:- | HMS Euryalus, a four-funnelled cruiser, flying the Flag of the "Umpire-in-Chief" for Fleet manoeuvres had the very first rig to be able to man 3 separate frequencies simultaneously, although she could either listen or transmit meaning that if the frequencies were nominated ABC, then when there was a requirement to transmit on A the operators listening on B and C lost their messages. The best way to understand this simple and illuminating file is to open it and the go to page 3. There you will see her 2 massive aerials (remember they are multi-stranded) with getting on for a mile of wire up aloft, RED and BLUE with a third (still a lot of wire in it) coloured YELLOW which is referred to as the Admiralty aerial which is a vertical aerial hoisted aloft on a halliard. Page 3 also shows the two wireless offices (the proper ships office and a hastily rigged dockyard office close by) in which sat the umpires one listening to the wavelength being used by ships of the RED force 'W' Tune, one listening to 'S' Tune used by the opposing ships in BLUE force and one listening to 'X' Tune for the destroyers and emergency use. The BLUE umpire and the SAFETY umpire sat in the same office. Remember that you are looking at Silent Cabinets where receiving equipment, a Morse key and the operators sat: no transmission equipment of any sort in these places. Much was learnt about the interaction of each aerial on the others which would be useful in the coming months, as more and more ships broke loose from the shackle of being able to transmit and receive on one frequency only without having to engage in a cumbersome change-over of circuitry.
Under the first mention of aerial (and thinking about the file above Goldschmidt) note the entry.
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| In this file:- | The introduction of Radio Time Signals and note that there are no British Stations. Fancy also seeing Timbuctoo of all places, in Africa, but no longer spelt that way. Timbuktu is in Mali on the River Niger. It is roughly 1000 miles east of the Port of Dakar which is in Senegal on the West Coast of Africa. Note the wavelength used for all stations (2500 metres = 8204 feet = 120kHz) and the time signals were made twice a day at midnight and at 10am (the international twenty four hour clock had not yet been established). The time signals used the Morse letters 'X' 'N' and 'G' plus three dashes (longs) at the end of the minute as clearly shown in the diagram within the file. | ||
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| In this file:- | Some of these titles alone make interesting reading. Look for example at Admiralty Circular Letters (Non Confidential) PERSONNEL near to the bottom of page 1, and to N4407 31 July 1908 (which we passed five years ago in this record) where signalmen from the V/S department were trained to assist in the W/T office. In our days, the MSO was usually in the W/T office (MCO) and was always manned by buntings with the Yeoman of Signals fully in charge. Look at N.12331 of the 12th May 1911 "Ability on Parchment Certificate" which we all knew as Satisfactory, Superior or Exceptional (also, walks on water) and always preceded by the Character assessment of VG (Very Good) and rarely (though occasionally) never less ! Other abbreviations of interest. On page 2 No 756 T.5454 'WT in R.I.M.S. etc' - meant Royal Indian Marine Service which later became the Royal Indian Navy (RIN). Also on page 2 under PERSONNEL, is the 1909 entry No 28 talking about the operating signal ZBM2, which meant put a competent operator on this circuit - the ultimate peer group insult? Many of the other entries in this section are of interest especially the 'coal ship perk' a telegraphist received - we wonder why?. Note the start of the end of the Gunners 'T' and 'G' trained in W/T! | ||
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| In this file:- | Poulsens Experiments (been going on for years).
Arlington (Washington DC) to North Front Gibraltar, as the crow flies 6000km (3728 miles) but by great circle route further or course.
Once again, the promise that the navy will be getting the Arc system. Various reasons as to why the Arc is now more reliable.
Range and wavelength - with Arc and the current ships aerials, radiation of wavelengths are from 1800' to 18000' (545.84kHz to 54.51kHz). Using Horsea Island aerial the longest wave yet achieved with the Arc transmitter is 80000LS = 16.8 kHz (Rugby callsign GBR used to transmit a VLF Broadcast to British submarines on 16kHz).
You will recall from our previous explanation of the Arc (see 1907.10.pdf) that it can be thought of as FST Morse where two frequencies are radiated, the FORWARD (or Front Wave) when the Morse key is pressed and the REVERSE (or Back Wave) when the key is not pressed. The receiver is of course tuned to the Front Wave.
In this little picture, we show the effect in the ether for both Transmission and Reception for the sending of the Morse letter 'Q'. Here we have an Arc transmitter (the Arc burns continuously like an candle would) crudely connected to a Morse Key the bar of which is the aerial. When sending Morse symbols the RED line (FRONT WAVE) is operative and when not, the BLUE line (BACK WAVE) is. Below, we show two receivers and their respective aerials, the BLUE picking off the 'between key frequency' - the BACK waves- and the RED, the FRONT waves, the proper keyed Morse Code. In the bottom table purposely barely discernable there are two rows each with sixteen columns. Sixteen represents the number of basic time elements in the transmission of the letter 'Q' where each DASH is 3 elements long, the gaps in between characters 1 element, and the DOT also 1 element and, after the 'Q' has been sent a wait of 3 elements before the next character is transmitted: obviously, if no more characters are transmitted then the BACK WAVE radiates a continuous SPACE - no, we haven't got that wrong, although to us a continuous tone would be called a Mark, but read on! Thus, the RED RECEIVER receives the letter 'Q' and the the BLUE RECEIVER receivers the letters 'E' 'I' and 'T'.
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| In this file:- | Report on Clifden W/T station. These are some of the aerial used at Glace Bay.
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| In this file:- | The Vielton System of W/T. The Admiralty recently purchased a Vielton system from the Lorenz Company. This Company has bought ALL the Poulsen and SOME of the Telefunken patents. They have supplied the German Navy and Military Authorities with W/T sets based on the Vielton principle. Several sets are also fitted in German merchant ships. So, Germany went to war using the Vielton !
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