F4U-1A Cockpit Radio Equipment

[JayW]

I am in the process of modeling a large scale F4U-1A Corsair, as accurate as I can get it.  To help, I have a subscription to Aircorp Library which has reams of engineering and service data for many makes of aircraft including the F4U. 

 

But it has failed me with the radio configuration for early Corsairs.  The pictures of the engineering drawing that would define that configuration are too faint to be read.  Matter of fact, even the military-produced parts catalogue fails me, in that it mysteriously has omitted the early radio configurations yet includes the later -1D configuration which is very different.

 

Does anyone have any pictures of the RH side of the cockpit of either F4U-1 or F4U-1A aircraft, where this equipment is mounted?  Or any other sources that would give me a clue as to what to model? 

 

BTW - Dana Bell volume 7, which covers early Corsairs, has a picture or two.  But those are pictures of aircraft with their radio equipment stripped away!  Ugh!  

Edited June 24, 2021 by JayW

[Finn]

Don't know if this helps:

 

even bigger pic:

 

Jari

Edited June 25, 2021 by Finn

[JayW]

12 hours ago, Finn said:

Don't know if this helps:

 

Thank You Finn.  Those pictures are of the configuration that replaced the -1 and -1A configuration, and what we would see in very late F4U-1A's and the F4U-1D.  Now, to get similar ones for the earlier config!!  Unfortunately for me, the earlier config was very different, and I believe there were more than one!

Edited June 25, 2021 by JayW

[Finn]

There is this one:

 

 

Jari

[JayW]

Jari - yeah I think that is it!  And bonus - I think I know what all the different thingie's look like, as they are present in other configurations, only placed differently.  Except for one, which I circle in red:

 

 

And it isn't labelled.  Maybe it's nothing....  Any ideas?

[Dana Bell]

Hi Jay,

 

I had assembled a pile of data on Corsair radios for the 2 books, but details became too complicated, and there was little room for the number of photos needed to illustrate everything.  Here are my rough notes from a variety of sources and documents (I think you'll understand why it was so hard to illustrate all the variations:

 

    RADIOS

COMMAND SETS and ANTENNAS
GF-12/RU-17 – radios installed on first 123 F4U-1s.  It is listed with two transmitter coil sets, 3000-4525 KC and 6000-9050 KC. The RU-17 receiver coil sets do cover from the LF band to 9050 KC, but have a coverage gap between 4525 KC and and 5200 KC.  After 1941, the new-fangled GT/RBD (later renamed ATA/ARA) eclipsed the GF/RU, although the "roogy-foo" remained in service with front-line units well into WW-II.  The ATA/ARA itself was to be eclipsed by AN/ARC-5.

ATA/ARA – voice equipment.  antecedent of the AN/ARC-5, with initial deployment in 1940. The major units of the ARA are five receivers covering 0.19 to 9.1 MHz, each unit with its own dynamotor power supply. The major units of the ATA are five transmitters covering 2.1 to 9.1 MHz, using a common transmitter dynamotor/screen modulator unit. Most units were made by the Aircraft Radio Corporation (USN manufacturer's code CBY). Many units were also made by Stromberg-Carlson (USN manufacturer's code CCT).

ATB/ARB – AN/ARC-5 – command set - MF, HF, VHF.  Improved ARA/ATA.  The AN/ARC-5 command set was used by the US Navy from the latter part of World War II into the post-war era. It was fitted in many different aircraft types for communication between aircraft, navigation, and communication back to base. Units were available that covered much of the MF, HF, and VHF spectrum. 

SCR-274-N – Army command set adopted in 1941 a reduced set that was electrically almost identical to their ARA/ATA equivalents, except for receiver output and modulator sidetone audio transformer output impedance. It was mechanically almost identical except for most later units being left unpainted aluminum in contrast to the black wrinkle finish of the Navy sets.

CBY – Aircraft Radio Corp code for ATA/ARA

R-1147 – British - not needed after 14 Apr 44 - appears to be VHF and homing, possibly command set also

VS-10585 – (1)(39-1/4") original plastic/phenolic mast (this mast can be shortened by cutting 6 inches to end with 33-1/4 inches

CVS-6223 – (2)(33-1/4) shortened VS-10585 plastic/phenolic mast

VS-33585 – (3)(32-1/2") metal mast 3/4-inch shorter than CVS-6223 - (this mast can also be shortened by 8 inches to 24 inches; leaves 16 inches over canopy) - to be introduced after raised cockpit

CVS-8407 – (4)(24") VS-33585 metal mast - shortened by 8" 

VS-10582 – (5) fixed antenna mast installation 26 May 43, urgently needed by sq in Norfolk area
VS-37585 – 6) short mast (equivalent to shortened VS-33585)

VS-33586 – (7) same mast, but with thicker gauge aluminum sheet

VHF SETS and ANTENNAS
AN/ARC-1    VHF - developed from ARC-4, far more sophisticated
AN/ARC-4    VHF voice
WE-233A    (233A) Western Electric VHF voice transceiver unit - designated AN/ARC-4

AN74A
AN74BX    wooden insulating section
AN704A    pregwood mast expected to replace AN74BX
AN104AX    VHF mast to be substituted for AN74BX, VS-33527 - differs from AN104A only in color
VS-33507    "after mast"

IFF SETS and ANTENNAS
ABA-1    IFF
ABC        IFF
ABD/ABE    series of IFF transponders (ABD, ABD-1, ABD-2, ABD-3, ABE, ABE-1)
ABE/ABK    IFF
ABK-1    IFF
AN/APX-1    IFF transponder to replace ABK
AN/APX-2    IFF    

HOMING SETS and ANTENNAS
ZB        homing equipment
ZB-3        homing equipment redesignated AN/ARR-1
ZB-X        homing equipment redesignated AN/ARR-2 by 4 Jun 43
VS-17051    new (Oct 44) homing antenna base

OTHER SYSTEMS
AN/APG-4    L-Band LAB System (used with APN-1) 
AN/APN-1    altimeter
AN/APS-4    radar
AN/APS-13    Tail warning radar tested in F3A BuNo 04691
AN/ASG-10    toss bombing director
AYD

CHRONOLOGY
4 Aug 42 – request permission for contractors to install ATA/ARA in lieu of GF-12/RU-12 for first 324 F4U-1s.
27 Oct 42 – inspection of radios on BuNo 02156 (C/N 4).  Includes IFF (move control box), phenolic antenna mast (reinforce root), ZB homing adapter with retractable antenna.  Command set not identified.
5 Nov 42 – retractable ZB-3 antenna was designed by Vought-Sikorsky
8 Dec42 – plans to install 700 R-1147 radios in British Corsairs, with Brit-furnished Type 68 or 91 mast antenna and alternate antenna located with ZB antenna.  This will also apply to 420 British F3A-1s.

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2 Feb 43 – antenna mast failure - contractor redesigned mast shortened by 6 inches; new mast appears to begin installation in 02307 (C/N 155), though this may represent a single installation.
2 Feb 43 – request to relocate ATA/ARA to make room for future installation of ZB-X and VHF.
8 Feb 43 – 02280 (C/N 0128) shows high level of noise on ATA/ARA
11 Feb 43 – Anacostia pix showing relocation of radios on 02280
20 Feb 43 – redesigned [phenolic] mast does not deminish reception
26 Feb 43 – request for AN74BX antenna mast for VHF unit ot ATA/ARA.  Also, see if commmand set antenna can be re-rigged to VHF mast
1 Apr 43 – 10 fixed ZB antenna were shipped to Goodyear by mistake; shift them to another project
3 Apr 43 – relocate ATA/ARA and ZB-3 to make room for VHF set and antenna
14 Apr 43 – present installation will not accommodate VHF components of ATA/ARA; engineering data on VHF SCR-274-N not available from Army until recently - change could not be initiated until complete data was available
19 Apr 43 – redesign fuselage structure to fit VHF radio beginning FG-1 BuNo 14292 (-1A)
27 Apr 43 – Raised cabin is top priority!!  Can't give schedule for shortened plastic mast; hope to introduce metal mast soon, with or shortly after raised cabin.  Shortening of plastic mast to be covered in Service Bulletin 226
6 May 43 – CominC and CincPac demand VHF as soon as possible
7 May 1943 – Anacostia tests 3 new ATA/ARA antenna designs.  Best is fuselage to VHF mast to tail to left wingtip [seen in photos of 17-F-21 and 17-F-4 on Bunker Hill in June 43]
11 May 43.  notes that GF/RU was installed in first 123 F4U-1s - replace this with ATA/ARA [lists end of GF/RU as 02278, which was C/N 126] 
13 May 43 – shortening of masts.  All birdcages started with phenolic masts (which need to be replaced with metal or shortened).  Raised cockpit started with phenolic, but switched to metal (also needing to be shortened) on following serials: F4U 17930, FG 13311, F3A 04673.  Contractors will install shortened metal masts in production on: F4U 56184, FG 13792, F3A 08667.
1 Jun 43 – Anacostia (for VF-17) to install WE-233A VHF transceiver and AN74BX antenna as prototype installations AND install MF antenna system #4.  return to VF-17 with equipment after mockup and flight test.
8 Jun 43 – AN74BX being installed by Vought for VHF - permission sought to also use that mast for MF antenna.
10 Jun 43 – permission granted
12 Jun 43 – WE-233A approved for CAG-17; plans to install in CAGs 30, 31, and 32 - PROOF that F4Us were going to carriers
17 Jun 43 – contractor to check cables in ABK-1 IFF equipment
15 Jul 43 – ABK cable 24-inches too short when set is relocated
23 Jun 43 – AN74BX mast installed 2 inches forward of bulkhead 218, 7/8th inch to port of centerline.  MF antenna runs from lead-through insulator to point 7.5 inces aft of strain insulator on VHF mast, to forward side of rubber strain link to mast atop rudder, to mast atop pitot tube
30 Jun 43 – per VF-17, ARA/ATA antenna to pitot shown markedly unsatisfactory due to breeakage when wings are folded,  Original installation worked up to 85 miles, possibly farther.  Blackburn asks that future tests be performed by another unit, as VF-17 is preparing for enbarkation.
8 Jul 43 – based on VF-17 comments, ComAirLant asks to retain forward mast in production
12 Jul 43 – resume fore-aft installation
17 Jul 43 – re: 223A equipment to be installed in F4Us for Air Groups 5 and 17 - quality control failures of 4 out of 6 sets received
30 Jul 43 – per 12 Jul TWX, pitot mast antenna will be discontinued and eliminated as soon as possible
6 Aug 43 – ZB-3 should read AN/ARR-1
7 Aug 43 – AN74BX failed on first test flight (12 Aug notes that no other failures have been reported)
7 Aug 43 – CVA told to revert to MF antenna mast forward of cockpit ASAP
18 Sep 43 – VF-17 notes new all-metal mast VS-10582 has broken on two planes (both 1As)
6 Oct 43 – ABD/ABE IFF no longer required - eliminate antenna plug, horizontal V antenna, and feeder wire.  Contractors to make change in as many aircraft as possible without delaying deliveries
16 Oct 43 – contractor reinforcing antenna mast with new 24-inch design, leaving 16 inches over cabin
20 Oct 43 – FG-1s currently have ATB/ARB installed so that antenna relay is inaccessible to pilot
3 Nov 43 – F4U-1 BuNo 55820 assigned for prototype installation of AN/ARC-5
9 Nov 43 – second AN74BX failure
15 Nov 43 – SB 369 will be issued to replace plastic masts with metal masts which may be obtained as spares.  NEW shortened metal masts are available for production and replacements
17 Nov 43 – AN74BX to be replaced by AN704A as soon as can be obtained
18 Nov 43 – ATA/ARA to be superceded by AN/ARC-5, though control and junction boxes are interchangeable with older model.  WE-233A is only VHF currently available
22 Nov 43 – shortage of ATA/ARA will mean contractors will have to use SCR-247-N when preferred equipment supplies are exhausted.  Contractors are to switch to AN/ARC-5 not later than 30 days after that equipment arrives at their plants.  For mockup purposes, BuAer will send ARC-5 VHF components to Goodyear and Brewster
27 Nov 43 – ARC-5 is first VHF to be factory installed - should enter aircraft production lines about 25 Jan 44
29 Nov 43 – BuNo 55820 still expected to test installation of ARC-5
3 Dec 43 – Vought currently testing two new mast designs, one of steel and one of aluminum
18 Dec 43 – SB 369, shortening of metal mast to 24 inches.  Raised cockpit started with phenolic, but switched to metal (also needing to be shortened) on following serials: F4U 17930, FG 13311, F3A 04675.  Contractors will install shortened metal masts in production on: F4U 56184 - shortened metal mast on FG and F3A not yet scheduled
29 Dec 43 – BuAer still waiting for information on new antenna masts

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15 Jan 44 – ARC-5 to be installed in 751st FG-1 [BuNo 13742]
15 Jan 44 – Flight test of ARC-5 and ARR-2; AN74BX antenna used (Paint on the wood insulating section of the antenna was removed)
26 Jan 44 – 298 modified ARC-5 receivers will be shipped for first VHF installation on 4 Feb 44
3 Feb 44 – shortening of metal mast VS-33586 by cutting off 8" begins on FG #801 BuNo 13792
4 Feb 44 – Substitute AN104AX for AN74BX (VS-33527) beginning on FG #751 BuNo 13742
7 Feb 44 – delete ABD/ABE series IFF on FG #401 BuNo 13392
11 Feb 44 – APN altimeter tests
16 Feb 44 – ABC/ABE IFF has been eliminated beginning #401 BuNo 13392
21 Feb 44 – revisions to ATA/ARA beginning FG 652 BuNo 13533
21 Feb 44 – new ID stamping on SCR-274-N used until ARC-5 available starting FG 652 #13533
23 Feb 44 – BuAer change 107 in F4U 49760m FG 13742, and F3A 08649 (and subseqent on all) NOT required since those aircraft have ARC-5 incorporated; change 107 mandatory for any earlier aircraft that do not have ARC-5
10 Mar 44 – F4Us arriving in SoPac have 3 receiver racks, but need 4
14 mar 44 – SoPac needs radio range receiver and ARR-2 for maximum navigational aid
14 Mar 44 – BuAer plans to install range receivers once approved
15 Mar 44 – MCR 429M installs APX-1 instead of ABK - begin FG 800 BuNo 13791
16 Mar 44 – combined MCR 165/369: metal mast 33585 first installed at  factory on:
                F4U 17930      F3A  04673     FG  13111
    factory shortened on    F4U 56184    F3A  08667    FG  13792
3 Apr 44 – remove ZB homing relay and control box when used with ATA/ARA - save 4.12 pounds.  Incorporated by contractors beginning with:
        F4U 17647 and JT195; F3A 04624;  FG 13217
may be accomplished on earlier aircraft if ATA/ARA installed:
        F4U 02153-17646; F3A 04515-04623; FG 12992-13216; RAF JT100-JT194
6 Apr 44 – notes inadequate supply of ARC-5 components
6 Apr 44 – changes in ABK IIF equipment begin FG #750, BuNo 13741
7 Apr 44 – first note on grounding of MF antenna with canopy open
7 Apr 44 – replace AN74BX with AN104A or AX or install AN104A or AX (A and AX differ only in color
        install (1st VHF): F4U 02153-02476
        replace and install: F4U 02477>   F3A 04515>   FG 12992  (minor fitting and position changes in later aircraft
        install at factory F4U 49660>   F3A 08640>   FG 13742>
10 Apr 44 – installation of VHF ARC-5 and homing ARR-2 in place of ATA/ARA and ZB-3.  FG 13741>
10 Apr 44 – install AN-104AX in FG 13742>
13 Apr 44 – remove GF/RU from first 126 F4U-1s (02153 - 02278)
         – modify installation to accommodate future ARC-5, install ATA/ARA - F4U 02153-02736; 03802-03841; 17392-18191; 55784-56483; 49660-49759.  F3A 04515-04774; 08550-08639.  FG 12992-13741.
        – eliminate ZB relay and control box - 02153-02736; 03802-03841; 17392-17646.  F3A 04515-04623.  FG 12992-13216,
        – install ARC-5 and ARR-2 at factory: F4U 49760-50659; 57084>.  F3A 08640>.  FG 13742>
19 Apr 44 – provisions for installing ARC-5 and ARR-2
25 Apr 44 – instructions to Goodyear to develop waterproof covering in front of radios
29 Apr 44 – service reports of grounding of MF radios with canopy open
5 May 44 – Goodyear modification of IFF mounting bracket
9 May 44 – 50 x ARC-5 assemblies to be shipped to Goodyear
13 May 44 – Service Change 136: Shortening of metal (equivalent to CV SBs 165 & 369) and phenolic masts (equivilent to CV SB 226)
    metal F4U         17930 thru 17951
                17963 thru 18081
                18107 thru 18121
                55784 thru 55838
                55864 thru 55943
                55969 thru 56048
                56074 thru 56163
    metal F3A        04673 thru 04774
                08551 thru 08666
    metal FG            13111 thru 13791
        Where spare metal masts are available, they may be used to replace the phenolic mast, otherwise shorten phenolic mast on:
    Phenolic F4U        02153 thru 02736
                03802 thru 03841
                17392 thru 17591
                17617 thru 17696
                17722 thru 17751
                17777 thru 17846
                17872 thru 17929
    Phenolic F3A        04515 thru 04673
    Phenolic FG        12992 thru 13291
                13293 thru 13298
                13300 thru 13308
                13310
    Short metal mast intended to be installed by mfgs on:
    F4U            56184 thru 56483
                49660 thru 50659
                57084 & subsequent
    F3A            08667 & subsequent
    FG            13792 & subsequent
16 May 44 – in order to comply with operational requirements, it will be necessary to replace the VHF components of the ARC-5 with the ARC-1 VHF transmitter/receiver.  Goodyear will begin with airplane 2601 [BuNo 76739].  Installation will then comprise ARC-5 transmitter and receiver, ARR-2 navigation receiver, ARC-1 transitter/receiver, and APX-1 IFF equip (with alternate provisions for ABK and ABA-1.  3rd receiver position in 3-unit rack is to be left vacant but is to be wired for ARC-5 3-6 mc receiver
27 May 44 – Goodyear was authorized to install provisions for ABA-1, but this has not been accomplished in production due to low priority
Jun 44 – prototype APG-4 installed starboard of APN-1 radio altimeter on F4U-1 55976.
8 Jun 44 – problem notes on installation of APN-1  with APX-1, ABA-1, ARC-5, and ARR-2
9 Jun 44 – Goodyear to make provision for APX-1 IFF in place of present ABK
10 Jun 44 – government-furnished AN-104AX antenna mast to be substituted for contractor-furnished AN-74BX (VS-33527) beginning on #750 BuNo 13741
14 Jun 44 – Vought looking into grounding of antenna by cockpit hood.  Notch introduced on F4U-1 BuNo 57804 and all F4U-4 until ARC-1 is installed.  MCR 605 will address adding notch to aircraft in service
20 Jun 44 – change for installation of ABA-1 when ARC-5 is installed: rework radio floor and radio deck, relocate IFF control box, and rework ABA antenna installation
21 Jun 44 – AirLant standardizes F4U-1 radios as ATA/ARA, ARC-4, ABK (to be replaced by APX when enough are available), and ARR-2
29 Jun 44 – IFF provision for APX-1 in place of ABF to begin on FG-1 BuNo 13791
5 Jul 44 – ZB adapter relay was removed by contractor on FG-1 #228 BuNo 13217 and subsequent
14 Jul 44 – ARC-5 and ARR-2 ferry installation permits low-frequency range flying; installation may be modified by fleet for combat operation.  Found on following aircraft and subsequent: F4U BuNo 49760, F3A BuNo 08649, and FG BuNo 13741.
17 Jul 44 –  appears that F4U-1 BuNos 50370 thru 50469 have new homing antenna base VS-17501
17 Jul 44 – all US raised cockpit -1 Corsairs are to have cockpit hood antenna grounding cutout
18 Jul 44 – VHF components of ARC-5 are to be replaced by ARC-1 to comply with operational requirements.  Engineering to be provided by Goodyear, Service Bulletin to then be prepared by Vought
25 Jul 44 – Install ATA/ARA and ZB homing adapters in lieu of GF12/RU17 and make provisions for IFF on entire first production block of FG-1s: 12992 thru 19287
27 Jul 44 – request for installation of ARC-1 in F4U-1 aircraft, replacing ARC-5
Aug 44 – F4U-1D noted with ARC-5 and ARR-2 - no clear note on IFF; WAS IT INTEGRATED?
Aug 44 – installation of ARC-1 begun 28 Jul 44, completed 17 Aug 44
5 Aug 44 – substitute AN-104AX for AN-74BX on F4U-1s 56433 and subsequent
7 Sep 44 – AirLant standardizes ATA/ARA, ARC-4, ABK (or APX-1 when available) and ARR-2.  Corsairs with ARC-5 will not require ATA/ARA and ARC-4.  When ATA/ARA supply is exhausted, ARC-5 (less VHF) will be substituted
21 Sep 44 – APS-13 tail warning tested in F3A 04691
30 Sep 44 – ABA-1 radio installation in place of IFF equipment
3 Oct 44 – AN-104AX instead of AN-74BX for F4U-1 56266, 56433 and subsequent
17 Oct 44 – SCR-274N radio was installed in FG-1s 669 [13660] through 750 [13741]; some of the gear was also installed in earlier aircraft
21 Oct 44 – five F4U-1Ds have new homing antenna bases: VS-17501
31 Oct 44 – APX-1 to replace ABK as IFF equipment
5 Nov 44 – ARR-2 retactable antenna failures noted
6 Nov 44 – to provide 10-channel VHF communications, ARC-5 VHF components to be replaced by ARC-1 on following aircraft
    F4U-1        49760 thru 50079
            50151 thru 50229
            50265 thru 50324
            50360 thru 50459
            50496 thru 50574
            50610 thru 50659
            57084 thru 57108
            57144 thru 57214
            57250 thru 57983
            82178 thru 82852            total of 2192 aircraft
    F3A-1        11163 thru 11293            total of 131 aircraft
    FG-1        13742 thru 14591            total of 850 aircraft
21 Nov 44 – Flight test of ARC-1 in F4U-1D 57534
13 Dec 44 – Goodyear installs upper radio deck for ARC-1 in 76446 and subs
15 Dec 44 – APG-4 tested in F4U-1 55976
28 Dec 44 – Norfolk to install ARC-1 in 63 F4U-1s for AG-85

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18 Jan 45 – FG-1D getting a waterproof seal of rubberized cloth; F4U-1D no longer in production
22 Jan 45 – Preparatory installation for APS-4 radar, APX-2 IFF, and APN-1 radar altimeter authorized in F4U-1D 50360 and subs and FG-1D 76140 and subs.  Not applicable to F3A-1
    ARC-1 installed in FG-1D 76447 and subs
24 Jan 45 – Willow Grove to mockup installation of ASG-10 toss bombing radar in F4U-1
25 Jan 45 – VMF-124 reports ZB antenna picking up grease and dirt
1 Feb 45 – to eliminate IFF interference with ARC-5
7 Feb 45 – test to install plywood fin with integral VHF antenna
9 Feb 45 – critical nature of ARC-1 means that installation will cover only aircraft bound for AirPac.  AirLant will use ARC-4 or -5
13 Feb 45 – retractable ZB antenna cannot be bent or dirty without chance of breakage.  Recommending change in control
14 Mar 45 – failure of VS-33586 forward mast; recommend use of the after mast
30 Mar 45 – Vought claims no other reports of VS-33586 mast failures, but will study use of aft mast for MHF
6 Apr 45 – tests of ASG-10 on 8 FG-1s in squadron service
17 Apr 45 – retractable ARR-1 antenna to be replaced by fixed unit
24 Apr 45 – on FG-1, ARC-1 antenna lead-in moved from right side to left side on 76446 (rework) and 92041 (in production)
28 Apr 45 – move APX-1 code selector in F4U-1 57184 and subs, and FG-1 76140 and subs.  Not applicable to F3A.
1 May 45 – do not rig MHF antenna to aft mast; performance is diminished and all communications could be carried away by loss of one mast
12 May 45 – relocation of remote transmitting compass
17 May 45 – replace retracting ZBX antenna with fixed type
22 May 45 – Jacksonville local changes to install ARC-1 vice ARC-4 as soon as -1 is available; see serials in Bu Change 201
26 May 45 – Jax local changes to install APX-1 in lieu of ABK per service bulletin 420 [approved below on 5 Jul]
28 May 45 – Jax local changes to install ARC-1 and ARC-5 per Service Change 201 [rejected below on 5 Jul]
14 Jun 45 – Contractors have been asked to reinforce forward antenna
16 Jun 45 – install ABA-1 IFF control bracket (1939 FG-1s: 76162-76739; 87788-88453; 92007-92701) and new remote control switch (1860 FG-1s: 76241-76739; 87788-88453; 92007-92701)
18 Jun 45 – install cables for ABK IFF equipment as relocated for ARC-5 in 1251 FG-1s: 13741-14991
26 Jun 45 – 20 Mar had authorized local installation of ARC-1 if available.  25 May authorized ARC-4 in lieu of ARC-1.  Current desire is ARC-1 for all reconditioned Corsairs, but due to scarcity, this will be installed only in "those Corsairs for which it is mandatory," and ARC-4 will be installed in all others
27 Jun 45 – notes three production designs for MF masts: original plastic, .064 aluminum alloy, and .081 aluminum alloy.  Third design is marked improvement, but continues to break.  Mast failures are most prevalent in those mfg'd by Brown-Morse Co, and somewhat better in those mfg'd by Hedstrom-Union Co.  Vought recommendation for new mast made of .083 steel, heat treated to 125,000 psi.  Weight increase will be 1.8 pounds
5 Jul 45 – response to earlier JAX orders of 26 and 28 May: use of ABK or APX-1 IFF approved.  Replacement of ATA/ARA with ARC-5 not approved as there are not enough ARC-5 spares available; only advantage is with subsequent installation of ARC-1 VHF
10 Aug 45 – Make provisions to install APX-1 in lieu of ABK: 1201 FG-1s 13791-14991 and 102 FG-1s 76140-76241
10 Aug 45 – revise radio compartment door panel on 1750 FG-1s 76551-76739, 87788-88453, 92007-92701, 67055-67254 and an additional 200 FG-1s 67055-67254
10 Aug 45 – install ARC-1 in lieu of ARC-5 on 1854 FG-1s: 76447-76739, 87788-88453, 92007-92701, and 67055-67254.  Relocate antenna lead to left side on same aircraft.
11 Aug 45 – appears to relate to "ADA-1" installation
17 Aug 45 – install ARC-5 in lieu of ATA/ARA in 1251 FG-1s: 13741-14991.  Install new radio brackets in 700 FG-1s: 14292-14991
4 Sep 45 – reinstallation instructions for ARC-5 and ARC-1 at JAX
25 Oct 45 – antenna AT-8/AR may be used for APX-1 and -2 antenna rods; cut off to length of 16 inches

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18 May 48 – revision (details unknown) of May 45 Service Bulletin for removal of ATA/ARA (or SCR-274-N, if that was installed), rework of radio floor, installation of VHF (ARC-5), and relocation of ZB homing adapter, ARR-2, and IFF (ABK-1).  Aft antenna mast is AN104AX.  ARC-5 transmitters: VHF and MHF.  ARC-5 receivers: MHF and VHF.  1 x ARR-2 receiver.  This arrangement to be installed (should be past tense) on following and subsequent: F4U-1A 49760 and JT425; FG-1 13741A and KD161; F3A-1A 11163 and JS654.

 

BTW, the photo on page 19 of Pictorial #7 was one of the first F4U-1s, photographed on 20 May 1942.  The radio equipment is there, but very limited.  Pictorial #8 has a later shot of an F4U-1A's radio gear on page 27.

 

One of these days I'd love to take a week, collect all of my Corsair radio photos and drawings, and write up the story - just for my own amusement!  Until then, I hope these notes will help you determine which radio switches you'd like to include in your F4U-1A.

 

Cheers,

 

 

Dana

[D.B. Andrus]

[Hawkwrench]

I can honestly say that THAT'S the longest post I've ever seen!!!!!

 

Tim

[JayW]

On 6/26/2021 at 5:53 PM, Dana Bell said:

BTW, the photo on page 19 of Pictorial #7 was one of the first F4U-1s, photographed on 20 May 1942.  The radio equipment is there, but very limited.  Pictorial #8 has a later shot of an F4U-1A's radio gear on page 27.

 

Dana - sorry for the late response; I had ceased paying attention to this thread as I thought it had run its course.  Boy was I wrong!  And thank you for all this data - now to make heads or tails of it.  

 

First - I am modelling BU no 55995 (Line number 1636).  This aircraft went to VF-17 in the South Pacific and was land based for some or all of its service.  

 

That said, page 27 of Bell #8 appears to show the radio arrangement defined on Vought drawing VS-33535 "Radio & Cable Install - Useful Load - AN/ARC-5 AN/ARR-2".  The parts catalogue specifies the introduction of this configuration at BU no 49760 (Line number 2135).  If that be the case, then the radio's for my aircraft precede this by several hundred units.   The Vought drawing that defines the radio configuration for L/N 1636 is VS-17490.  This drawing (provided by Aircorps library) is all but unreadable it is so faint.  However I can just make out the outline of ATA/ARA receivers & transmitters, probably arranged like I show below.   

 

Would you agree that L/N 1636 was equipped with ATA/ARA plus ZB plus IFF?  Look at this picture taken from Vought drawing VS-33600 "Inboard Profile - Fuselage Installation - Side View":

 

 

 

Also this picture from a gov't publication of some kind (probably pilot's manual):

 

 

These two pictures appear to show the same, or nearly the same, radio config, and I believe what one would find on drawing VS-17490 if only it could be read.  I have some reason to believe L/N 1636 got this too, am wondering if you would agree.  I am hoping you recognize some or all of the equipment.  

 

If you agree, then my next problem is identifying the unlabeled equipment in the middle portion of the grouping, just aft of the large ATA/ARA receiver box, and just forward of the diamond shaped IFF junction box.  Notice the red circle in the last picture.  Any ideas?  I can define the rest.    

 

 

 

Edited July 2, 2021 by JayW