Roy Briggs Course 242 training notes



Roy Briggs Course 242 training notes


A notebook containing handwritten notes about wireless operator's responsibilities, procedures and operations.




Booklet with 24 handwritten sheets


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[underlined] 1893726 Sgt R. BRIGGS COURSE 242 [/underlined]

Form 619.


Notebook for use in Schools.

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Responsibilities of a Wop

[hierarchy of notes of responsibilities before, during & after flight] [very chart]

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H/F D/F and Flying Control Hours of op 24 hrs Fre 3 to 10 mgs

[hierarchy of notes describing the subject]

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[list of wireless codes & meanings]

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[continuing list of wireless codes & meanings]

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[diagram showing low power transmitters around a barrage perimeter]

The warning given is best described as similar to Air raid and is transmitted on all RT Freq being used at the time Bomber Freq 6410 to 6470. Times of operation Plymouth Hull Liverpool continuously 24 hrs a day other sights [sic] during dusk till Dawn except when [underlined] 1 [/underlined] Viserbility [sic] within 4 miles 2 When one or more ballons [sic] is flying in cloud There are no squeakers on normad ballon [sic] sight, a nomad ballon [sic] is any ballon [sic] not flying in barrage
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[table under the word HEADING showing radio telephonic report]

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Message Layout

[table continued from adjacent page]

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[diagram & notes showing the warning system]

M/F D/F Organisation

[diagram showing this organisation]

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Three or more stations all on one frequency Each station has a call sign of its own One of the stations is selected for control and normally all working is done through that station Therefore the C/S of control becomes the call sign of the whole section

There are 16 such sections throughout the British Ilse [sic] so situated that the whole of the approaches are covered

Each section is known by a letter.

Freq 500 to 200 Kcs Range in miles 300 by day 200 by night Times of operation 24 hrs a day.

Facilities [underlined] 1 [/underlined] pass Fixes The class is taken by the longest side of Cock Hat. [underlined] 2 [/underlined] True Bearings must not be ask for are only passed instead of Fix although control passes them the can be from any one of the section. [underlined] 3 [/underlined] use can use it for W/T

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identification. How to identify M/F DF C/S2 V A/C C/S2 [underlined] 15 sec [/underlined] A/C C/S K When to identify by W/T IFF. U/S. 2 If flying below 2000 ft 3 If making early or Late return 4 If coming in off of track 5 When shadowed by unidentified A/C 4 Recognised organisation in case of distress

Navigation Exercise
[underlined] 1 action by WOP HF [/underlined]
(A) Take off on D/F 1, give airborne signal QRV INT QMF answere [sic] QMF = TOO (B) one monitored HF DF station be contacted for QDM every thirty min. (C) First half hourly contact can be Base HF DF one but not before 30 min from WT go. (D) only HF DF stations with in 60 miles of A/C to be contacted 2 [underlined] Action by Wop M/F [/underlined] only one MF DF Fix Bearing or contact to be obtain [sic] on one flight – except in an emergency TFCC monitor some MF DF section those that are monitored are given at Briefing. [underlined] 3 General notes and action by Wop [/underlined]

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On all changes of Freq wop must give signal QOF followed by C/S of station to which he is changing freq (B) all messages from A/C to Ground are repeated to A/C for Ramsey to monitor (C) all operators must listen [sic] at ½ hr and hour to Group Broadcast 7BB 7BB 7BB – 1 to 9 – VVVVVV for 2½ min =& timing signal. When intending to change receiver to Group Broadcast give QYF & Group C/S. If there is a message ABC1 V 7BB F QTC CAB3 IMI E Wop must acknowledge all messages for his A/C on the nearest monitored HF DF station BC2 V CAB3 – RNR1 V 7BB TOO W/T serviceable but A/C u/s give landing signal on nearest monitored HF DF 9G0 When [deleted] wh [/deleted] within 20 mls of Base on last leg of flight w/op will change to DF2 and if nessarsary [sic] get homing QDM. Wop Will alway [sic] pass landing signal on DF2

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Distress Procedure

IFF TO [inserted] over sea [/inserted] DISTRESS
IMMEDIATE M/F DF SOS3v A/C C/S3 [inserted] CHAPT [/inserted] [underlined] 15 sec [/underlined] [inserted] FIX [/inserted] A/C C/S K A/C C/S v MFDF C/S RRR SOS K SOS3 v A/C C/S3 R [underlined] clamp [/underlined] Key NON IMMEDIATE MFDFC?S2 v A/C C/S2 – O- [inserted] Bomber Code [/inserted] [underlined] 15 sec [/underlined] [inserted] QTF [/inserted] A/C C/S K M EVERY TEN MIN MFDF C/S v A/CC/S – O --- A/C C/S K

CACELLING [sic] Distress
If you want Non immediate distress put O before cancell [sic] distress OP & P can also be used cancelling O MFDF C/S2 v A/C C/S2 – QQZ – O – K


A pundit is a flashing Beacon flashing two letters charactirstics [sic] in red 6WPM X12 R1234 X They are part of an airfield equipment and is always with in R/T range of Airfield Facilities. Pin Point Fixes, Visual line bearing On demand Air field direction Airfield name

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and servicability [sic] to demand [deleted] to [/deleted] beacon scircle [sic] signal on downward ident light Q and letter of period.

A flashing beacon flashing one letter in white. Facilities Pin Point Fixing. visual line bearing.

Is the use of low power [deleted] sh [/deleted] searchlights at aerodrome
1 Homing with cloud [diagram] 2 Homing with no cloud [diagram] 3 DIVERSION [diagram] 4 WARNING [diagram]

M F Beacons
15 Fixed beacons sending same call sign on same frequency from same place. Hours of operation 23½ hrs out of 24 Freq 200 to 1000Kcs

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Facilites [sic] [underlined] 1 [/underlined] Relative Bearing [underlined] 2 [/underlined] Fixing [underlined] 3 [/underlined] Running fix [underlined] 4 [/underlined] Visual Homing

[2 diagrams]

Visual Homing [underlined] 1 [/underlined] make sure that beacon is going to work will you want to use [underlined] 2 [/underlined] Identify Beacon [underlined] 3 [/underlined] tuning of beacon. 4 Take bearing and make note of it. 5 then change meter deflect to low 6 check Balance, 7 set loop at 000˚ and lock it. 8 switch to visual, 9 instruct pilot to intersect needles. [underlined] 10 [/underlined] turn A/C to left slightly if needle swing to right

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course right if needle fall to left pilot must continue left until needle rebalance, and then continue so as you can sence [sic] .
Needle dropping [underlined] 1 [/underlined] Passing over signal 2 The loop base plug out 3 Beacon transmission stopping 4 Loop damaged by flak 5 R1155 u/s D/F circuit Check sence [sic] of loop every ten minutes and decrease or [deleted] int [/deleted] increase meter amplitude, When listening to group broadcast tell pilot to keep on course give bearing to navigator which you took at first and find out weather [sic] it agrees to within 5˚ of course

Advantages. Can get nav aids if TX is u/s. [underlined] 2 [/underlined] nav aid if under WT silence 3 Nav aid if MF DF channels full 4. Any number of a/c can get same bearing at same time from same place

Disadvantage. [underlined] 1 [/underlined] QE [underlined] 2 [/underlined] coastal refraction and night effect [underlined] 3 [/underlined] meackoning 4 jamming Range 200 by night 300 by day

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Limitation. Height. Obstruction such as mountains. Weather classing of loop 1st 0 to 7 2nd 7 to 15 3rd over 15

[underlined] DAILY INSPECTION (F700) [/underlined]
[underlined] Aerial system. [/underlined] Type J test plugs make sure they are clean. inspect HF TR9 & IFF aerial for tautness and connected. Trailing aerial make sure winch is fixed, try track Rachet [sic] and free position. Chlamping [sic] ratchet make sure it screws down. Make sure earth plug is OK clean and secure, check Cord and leads. Loop aerial check for Clean and secure of plug and security of all equipment. Check sence [sic] of loop. Make sure that you have Q.E. and loop turns 360˚. SBA aerial make sure its [sic] not dented bent and that it is secure.
[underlined] R1155 [/underlined]
Check all controls and make sure they do what they are suppose to. Tune on ranges make sure you can hear RT. MeM. & CW. Make sure plug tight. Pull receiver out.

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[underlined] T1154 [/underlined]
Check plug and wires connection tune up on all three ranges check vernier make sure readings are correct check plugs interlock. 750 milliamp fuse spare’s valves
[underlined] A1134 [/underlined]
Check plugs and connections check ABC switch powers supply 120v over 100 2v over 2.1 on load
Spares. Valves for RX & [deleted] [indecipherable] [/deleted] TX [deleted] 12 [/undeleted] 2:12 6 2v spare trailing aerial. Ten foot lead. Spare wire and clipers [sic] spare fuses screwdriver
[underlined] Fuses [/underlined] Change fuses with spares ODD and SOD’S the pilots [sic] morse key your own key the aldis and four shields longdex relay. Pilots RT remote control IFF remote control 47 or 52 res. Longdex relay now and again. Dinghy TX and equipment inspection lampd and leads. Checking of crews headset. Spare bulbs for aldis and pilot lamps

[underlined] Internal and external lighting [/underlined]
Formation navigation landing light check reostat [sic] on all the internal

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light test for security also call light. Make sure of main lights. On air test check all readings. Intercom check each point from every other point

[underlined] IFF [/underlined]
Check power supplies, check D curcuit [sic]. Pilots and your distress switch. Check all plugs and external connection. Check aurally Check inert and det [sic] switch

[underlined] Power Supply [/underlined]
Check 120v vibrating unit if fitted LTPU LTPU Check all plug all sockets all leads, Check starter relay of HTPU Check 750 ma fuse in HTPU

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[table of loop calibration figures]

[underlined] 1 [/underlined] Select Base (A) Harding standing (B) Free from metallic surrounding
[underlined] 2 [/underlined] Select Beacon (A) Position about 100 miles away (B) Make sure it is opperating [sic] for duration of loop swinging [underlined] 3 [/underlined] Tune Beacon (A) Identify (B) Get dead space [underlined] 4 [/underlined] Acquire bearing of Beacon, from the Nav (354) [underlined] 5 [/underlined] Head A/C on to 354˚ (Loop should read 000˚) [underlined] 6 [/underlined] Head A/C on to Compass heading of 360. Take Bearing 002

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[underlined] DARKY ORGANISATION [/underlined]
Freq [sic]6440 Darky Watch kept on. All Bomber Command airfields. Specially selected airfields of other commands. Occult sites. R.O.C. Posts 24 hour watch. Airfields 24 hour watch Occult kept for duration of the flashing of beacon, gives rough fix B.C airfield facilities Rough fix [deleted] shea [/deleted] searchlight homing airfields lighting. Componant [sic] parts of weather reports. Special instructions & medical aid. Diversions to other airfields. Other airfields the same. ROC Post Rough fixing. Course to steer to a selected airfield

QDM Weather reports, state of landing ground, W/T Link, Height to fly, obstruction.
Height of cloud base, Barometric Pressure messages
GCN Enemy A/C GGB unidentified A/C

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[latitude & longitude table with notes of actions dependant on position]



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This transmitter is a general purpose transmitter fixed for CW MCW & RT transmission. The transmitter consists of three main curcuit [sic] [underlined] 1 ]/underlined] MO 2 PA 3 modulator and sidetone [sic] fre [sic] Range [underlined] 1 [/underlined] Blue 10 to 5.5 mgs (HF) 2 Red 5.5 to 3 mgs (HF) 3 Yellow 500 to 200 kc (MF) [underlined] Valves [/underlined] V [underlined] 1 [/underlined] MO VT105 indirectly heated triode V2 & 3 PA VT104 directly heated Pentodes V4 modulator VT105 ind H triode

[underlined] MO Curcuit [sic] [/underlined] Consists of a hartly type oscilator [sic] – VT 105 there are three separate tuned curcuits [sic] one for each range selected by the range selector switch consisting of fixed inductance and a variable condenser. Precaution to ensure a stable pre output [underlined] 1 [/underlined] completely screened to stop other oscilation [sic] effecting [sic] the curcuit [sic] [underlined] 2 [/underlined] Indirectly heated valve to prevent small changes in filiament [sic] voltage effecting [sic] fre [sic] [underlined] 3 [/underlined] Low power working (approx. 200v) [underlined] 4 [/underlined] allowance is made for temperature variation by means of the vernier fine tuneing [sic] if temperature decreases the componance [sic]

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contract so [underlined] decreasing [/underlined] inductance and capacity of valve’s therefore [underlined] increasing [/underlined the frequency ([mathematical formula]) This is only used when working a click stopped fre [sic]. to decrease pre move vernier up

[underlined] PA Curcuit [sic] [/underlined] valves 2 and 3 VT 104 directly heated pentode a pentode valve is used to prevent it from breaking into self oscilation [sic] due to feed back through the inter electrode capacity – therefore no nutralization [sic] unit is nesersary [sic]. The HF ranges are tuned by variable condenser and a variable nine position tapped aerial inductance the MF has three tuning controls anode tap switch, (18 to 24). Aerial tap switch (1 to 17), and fine tuning. The anode taps give a pre [deleted] of [/deleted] variation of 17 Kcs. The variable permeability fine tuning (from dust core) has a fre [sic] coverage of 20Kcs, for fine tuning between the anode taps.

[underlined] Modulator and sidetone [sic] curcuit [sic] [/underlined] V4 modulator valve VT 105 [indecipherable word] triode

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is a low pre oscilator [sic], [deleted] osc [/deleted] ocsilating [sic] at 1200 Kc the curcuit [sic] oscilates [sic] all the time the transmiter [sic] is working weather [sic] the key is up or down in Tune CW and MCW position of the transmiter [sic] master switch When the key is pressed the phones are connected to the modulator curcuit [sic] (by means of the Keying relay) to enable us to hear what we are sending, [deleted] alth [/deleted] although the modulator is oscilating [sic] it is no indication that the rest of the set is serviceable. The second fuction [sic] of the sidetone [sic] curcuit [sic] is to modulate our CW output at 1200CPS for MCW. The third function of the curcuit [sic] is to provide amplification of the mic [sic] speech fre [sic] to be superimposed upon the CW output when on R/T Position, of TR master switch. Either EM or Carbon mics [sic] can be used :- with EM mics [sic] the A1134 is used for High impeadance [sic] curcuit [sic] A1134A for Low Impeadance [sic] curcuits [sic]

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With Carbon mics [sic] the 6.3 LT is used to energise the mic [sic] the is also sidetone [sic] in the RT position
[diagram of T1154 Block Circuit]

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[drawing of R1155 Block diagram (Comm [sic])]

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The R1155 is a ten valve super set, capable of receiving CW and MCW on the following range of fre [sic] Range [underlined] 1 [/underlined] 18.5 to 7.5 mgs (HF) 2 7.5 to 3 mgs (HF) 3 1500 to 600Kcs MF) 4 500 to 20 Kcs MF) 5 200 to 75 Kcs Where applicable ranges are coulour [sic] coded to link up with T1154 coulour [sic] extra ranges are coulred [sic] black. Note There is no receiver coverage between 600 and 500 or 1500 and 3000Kcs Valves V 1 & 2 VR99 A Tri Hex DF switching V3 VR100 Pentiode (Vari Mu) RF amp VR99 Tri – Hex FC V5 & V6 VR100 Pentodes Vari Mu 1st & 2nd 1 Famp V7 VR101 DDT AVC & BFO V8 VR 101 DDT Detecor [sic] output meter VR102 Double Triode visual switching V10 VI 103 cathode ray tuning indicator Power Supplies Heaters take 6.3v HT 217volts communications receiver Both fixed and Trailing aerials

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are connected to receiver via an external switch device, and trans The correct aerial for connection is selected by the pre range switch and master switch

RF Stage This has a tuned grid curcuit [sic] and is RF transformer coupled to the mixer, the secondary of the RF transformer is also tuned and this is the grid curcuit [sic] for the Hexode portion of V4 Freqency [sic] Changer The incoming signal amp by V3 is fed to the control grid of Hexode portion of V4. The screened grids are internally joined and screen the internal ejector grid which is directly connected to the grid of triode portion. The triode portion is the RF oscilator [sic] and always works 560 Kcs above incoming signal (when correctly tuned) the signal and osc [sic] fre [sic] are mixed in the

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Hex portion and the diferent [sic] fre 560Kcs apears [sic] in the anode curcuit [sic].

IF Stages These consist of pre tuned parallel rejector [sic] curcuits [sic] and are tuned to 560 Kcs they give maximum amplification only of freq [sic] of 560 Kcs and freq [sic] very near the incoming signal receive little or no amplification, thus overcoming second channel interference therefore giving a greater degree of selectivity and by means of Valves 5 & 6 the to IFA a greater degree of senceativity [sic]

AVC and BFO [underlined] BFO [/underlined] This is the triode portion of valve seven which is an independa [sic] oscilator [sic] oscilating [sic] at 280.5 Kc. The first harmonic of this pre ie [sic] 561 Kc is fed into the Detector portion of valve eight where it beat with signal of 560 coming from valve 6 so producing our 1 Kc note. The BFO oscilate [sic] basicly [sic] at 280.5 for this reason :-

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a pre of 561 Kc is desired but if the BFO was to oscilate [sic] at this pre there would be a tendency for the IF stages at 560 and the BFO at 561 Kcs to pull each other off freq [sic] due to the fact that both freq [sic] are so very near each other. Therefore the BFO oscilates [sic] at 280.5 which is far removed in freq [sic] from the IF stages, and in the anode curcuit [sic] of BFO we have a curcuit [sic] pre tuned to 561Kcs the Het adjuster (a variable condenser) provide a three Kc variation of the BFO freq [sic]. The Het switch is used to make or break the HT to BFO curcuit [sic] on for CW off for R/T. [underlined] AVC [/underlined] The two Diodes in V7 provide our delayed A.V.C. – the delayed voltage is thirteen volts the to [sic] Diode are connected to form one Diode.

Audio Freq amplif [sic] AFA is effected [sic] by V8 this valve is a DDT. One diode is used for DF

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the other diode acts as a detector and detect in the case of CW signs the 1 Kc AF being the differese [sic] between 560 & 561 Kcs mixing in detector stage – and in the case of R/T it detects the AF componant [sic] which is modulating the 560Kc carrier wave the triode portion mearly [sic] amplifies and passes on to phones the AF componant [sic]

[underlined] D/F Curcuit [sic] [/underlined] Fixed & loop aerial trimming condensers These are provided to ensure maximum senceativity [sic] accuratly [sic] is obtained when sencing [sic] bearings. Fixed aerial trimmer [underlined] 1 [/underlined] Tune in a known signal between 200 & 500 Kcs [underlined] 2 [/underlined] Meter Deflection high [underlined] 3 [/underlined] Balance needles [underlined 4 [/underlined] switch to aural and take bearing [underlined] 5 [/underlined] Reduce Loop scale Reading [underlined] exactly [/underlined] 30˚ [underlined] 6 [/underlined] hold aural sence [sic] switch [underlined] left [/underlined] and adjust fixed aerial trimmer with an insulated screwdriver for a fade out of signal Loop Aerial trimming condenser [underlined] 1 [/underlined] Tune in a known signal

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[diagram of R1155 comm & DF]

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near 1500 Kcs [underlined] 2 [/underlined] Balance needles [underlined] 3 [/underlined] take an aural Bearing 4 Reduce loop scale reading exactly 90˚ (max signal position – check by magic eye) 5 hold sence [sic] switch right and adjust trimmer for maximum note in phones [underlined] 6 [/underlined] inspect trimmer and if fully in mesh add the small fixed condenser in parallel if fully out of mesh add small fixed condenser in series
[diagram of in mesh] [diagram of out of mesh]
BFO Adjustment excluding permeableity [sic] tuning of inductare [sic] inside BFO screening can. [underlined] 1 [/underlined] tune in a strong signal (BBC) by magic eye 2 Het switch one 3 insurt [sic] a small screwdriver in het adj [sic] and turn until a 1 Kc note is heard in Phones (check note against that of sidetone [sic] N.B. If the BFO requires further adj [sic] return set to maintainance [sic] section. A Marconi screwdriver

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will not fit fixed or loop aerial condenser or Het adj [sic] Emergency Back Tuneing [sic] – Magic eye U/S A(1) Tune incoming signal to dead space in receiver (2) T1154 master switch to R/T press key and tune MO for dead space having first tuned PA stage B(1) Tune incoming signal to dead space in receiver (2) set up MO to approx [sic] frequency [sic] (3) place tip of Telephone plug on second pin from batton [sic]on left of centre receiver plug (P2) [underlined] 4 [/underlined] Switch to tune and lock key [underlined] 5 [/underlined] adjust MO for dead space of very loud signal heard 6 Tune PA stage in normal manner


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The type 47 is used with a 12V A/C system, and has a total resistance of 13 [omega symbol], and is connected in positive lead between Acc [sic] & LT PU. its purpose is to reduce the input voltage to the LT PU to 10.5 volts to give a stable and correct 6.3 LT output. All the type 47 resistance is switched in or out of curcuit [sic]
[diagram of type 52]
Type 52 is used with 24 volts system and has a total resistance of .735 [omega symbol] and is connected in positive lead between AC ACC and LT PU the portion 3 to 6 only is switched in or out of curcuit [sic] and its value is .355 of an [omega symbol] – the portion one to three is alway [sic] in curcuit [sic] its value is .38 of an [omega symbol]

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The Longdex relay is used in conjunction with the A/C ACC cut out type E or F (E-12v F- 24v). This cut out has two extra cut out for the Londex relay known as the aux contacts. The leads to the longdex relay solenoid are connected directly to the cut out via the two aux contact so that the full Acc voltage is passing through the coil, due to the charging from the EDG the solenoid becomes an electro magnet and its magnetic pulling effect upon switch A is enough to over come the tention [sic] of the spring thus opening the curcuit [sic] and

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bringing in all type 47 or the portion 3 to 6 of type 52 to drop the input to the LT PU down to 10.5 or 18 volts. In the event of break in type 47 remove two 5 amp Longdex relay fuses, With regards to type 52 for a break in portion 1 to 3 insert 40 amp emergency fuse, and for a break in portion 3 to 6 remove the two 5 amp longdex relay fuse’s

All the equipment comprising the electrical system together with fuse’s and where situated in curcuit [sic] are shown in diagram if either EDG or any of its assosiate [sic]equipment including 60 amp main charging fuse goes U/S A reduce reading in volt meter will follow. When LT PU starts up and the HT PU a downward ficker [sic] in volt meter will show this fact. The purpose of the 3 [omega symbol] res

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diagram of simplified anson parallel charging circuit]

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in longdex relay line is to prevent the Acc being charged through the longdex relay line in the event of either of the main Charging fuse’s blowing

VR35 Double Pentode VR21 TRIODE 4 pin plug 2 mic [sic] leads for crew & 2 for Wop The other plug crew & Wop phone leads and leads to T1196 and R1155 Switch on EM for R/T on T1154 and CM for Tinselling

T1154 supplies plug [underlined] 1 [/underlined] 220v HT +- 6.34 – 1200 –ve 6.3 HT starter 24v LT starter plug 2 1200HT+ plug 3 Telephone + Key Key relay Bias

Plug 4 220v O 220visual 6.3+- MF & HF aerials

TUNING 1154 TO CLICK STOPS [underlined] 1 [/underlined] check power supplies 120 HT 2v LT 2 plug in crystal & phones to monitor switch on select crystal [underlined] 3 [/underlined] select click stop [underlined] 4 [/underlined] switch to tune press key rotate MO for dead space. 5 TUNE PA recheck MO for deadspace [sic] 6 Tighten screw 7 move vernier make sure dead space two from bottom 8 switch

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[diagram of Anson A/C w/t & electric supply layout]

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[diagram of electrical circuit]

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[diagram of D circuit]

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[diagram of a 192 panel]

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[diagram of TR 1196]



Roy Briggs, “Roy Briggs Course 242 training notes,” IBCC Digital Archive, accessed June 22, 2024,

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