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Hawker Typhoon 1B Car Door Heated Pressure Head.

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    Hawker Typhoon 1B Car Door Heated Pressure Head.

    Seeking info on a component fitted exclusively to the car door version of the Hawker Typhoon 1B.
    It's no use checking out the other survivors as they are all bubble canopy versions and had a different system fitted.
    The component in question is the Heated Pressure Head (circled in the pic below); and is fitted aft of the radio aerial,
    protected by a horseshoe-shaped ice shroud (P/No: A.111757) on top of the insulation panel attached to the rear perspex panel
    It appears in the A.P. wiring list diagram but gives no further information.
    Any information would be much appreciated.
    Click image for larger version

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    The Heated Pressure Head was the external temperature sensor unit of the I.F.F. system and sent a signal to the Contactor Master Unit (10A/10994) high precision clockwork mechanism with a built-in thermostatically controlled heater ensuring that its temperature remained stable, whatever the height of the aircraft. It may well be that the Hurricane employed a similar sensor unit
    Last edited by windhover; 12th June 2018, 19:12. Reason: additional info

    So; having scratched around and come up empty; it's back to the "Sod it... we'll make it ourselves" department.
    A replica Heated Pressure Head was constructed from the Bakelite screwed base ferrule of a damaged 6a/1775 Oil Thermometer transmitter attached to a suitable AGS1114 Bulkhead screwed sleeve.
    The external diameters of both ends of the Bulkhead screwed sleeve were reduced to allow an interference fit with the drilled interior of the replica sensor head; and allowing provision for successful cutting of a 7/16" BSF thread to engage with the Bakelite screwed base ferrule.
    The Bakelite ferrule was successfully tapped with a 7/16" BSF thread... (without shattering... see, it can be done!)... and screwed onto the prepared Bulkhead screwed sleeve.
    The sensor head replica was fabricated from a scrap 6a/3076 Leading edge Pitot tube head of the correct external diameter, cut down to a suitable length, and pressed on to the opposite end of the Bulkhead screwed sleeve.
    A suitable length of the correct original Ducel 4amp Cel cable: (2-core Cotton braided, waterproofed by coloured cellulose) was salvaged from existing stock and connected.
    Click image for larger version

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    Almost looks like a "Bought one" !


      Bingo! looks good.