4 hours ago
I'm restoring probably the only remaining Marconi Type M Vigilant ship's auto alarm dating from the late 1930s. Auto alarms were introduced around 1920 to keep Morse watch on 500 kHz during off watch periods prompted by the loss of the Titanic a decade earlier.
My Vigilant has suffered extensive water damage since ending it Service in the late 1940s. Oxford Uni holds an incomplete example in its Marconi archive.
The four stage fixed tuned TRF incorporates a Ferranti AF6 1:7 step up transformer. Now totally dismantled, both windings appeared to be in good condition but are in fact O.C.
Is any member prepared to undertake the rewind, or can point me to someone who can?
The AF6 has only two bobbins whereas other AF versions had three. The windings are of very fine gauge and could possibly be resistance wire to match the Ra of the preceding stage.
In hope,
Roger
My Vigilant has suffered extensive water damage since ending it Service in the late 1940s. Oxford Uni holds an incomplete example in its Marconi archive.
The four stage fixed tuned TRF incorporates a Ferranti AF6 1:7 step up transformer. Now totally dismantled, both windings appeared to be in good condition but are in fact O.C.
Is any member prepared to undertake the rewind, or can point me to someone who can?
The AF6 has only two bobbins whereas other AF versions had three. The windings are of very fine gauge and could possibly be resistance wire to match the Ra of the preceding stage.
In hope,
Roger
