deforest: R 3 (R3)
deforest: R 3 (R3)
I have just bought from an eBay auction a radio which seems to be a R 3 from De Forest - Crosley. There was not case, only the chassis. It is in fair condition, all components inside, transformers OK... I have drawn the schematic, is a reflex with regeneration like Trirdyne, or 3R3 from Crosley. The sockets are mounted on a hard rubber board which is marked "R 3 1906" . Last number seems to be a year but it could not, at 1906 there are not this kind of receivers.. I am enclosing some photos.
Regards.
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Crosley Reflex
DeForest-Crosley R-Series were introduced in 1925. The Chassis of Your radio looks similar to the (US) Crosley Trirdyn 3R3 here. Only the front panel elements are rearranged. There is only a single filament rheostat, and the reaction control moved to the place of the former 2nd rheostat..
In particular Crosley did such rearrangements to create "new" models, which really inside used the existing chassis structure. Rationalization was it.
The schematic given for Trirdyn may slightly differ. Anyway there is a mystery for me:
Crosley praised in advertisments the Reflex circuit, which shall do the job of 5 tubes, but employed only 3. this is achieved by double use of two tubes. So far, so good.
But as I can see there is only the first tube in double duty. The second one is an audion with reaction, feeding the AF back to the first tube. The first one now drives the output tube.
The signal flow is 1 - 2 - 1 - 3. Is the schematic in error? Do I need new spectacles? I don't think so, since my own Super Trirdyn Regular has the same arrangement.
The (rather poor) schematic in Riders 1-16 notes
for the 1st tube 1.RF&AF,
for the 2nd tube DET, and
for the 3rd tube 2.AF....... makes only 4 stages by 3 tubes.
Why did Crosley pretend to employ 5 stages ? Swindling ?
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