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Monday, March 17, 2014
The Ladybird TRF (Regen!) Receiver
http://www.mds975.co.uk/Content/trfradios02.html
My feelings about regenerative receivers and their possible connections to the nether-world are well known. But the receiver described on this beautiful British web site is almost enough to make me change my mind. Thanks to Stephen, G7VFY, for alerting me to this (and to so many other great sites!) I also find myself forced to give regens another chance because George Dobbs, G3RJV, was the original source of this design. It comes from a book he wrote in 1972. I love the wooden bread-board construction. Thanks Stephen! Thanks George!
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Regens are like 1st generation direct conversion receivers.
ReplyDeleteAnd face it, where would oscillators be if Howard Armstrong hadn't cooked up the regen? Reality says you can see the regen as a stage that goes into oscillation, or an oscillator that can be stopped from oscillating.
And don't forget "supergainers" a concept from the thirties launched by Frank C. Jones apparently. A regen with a converter ahead of it, or looked at differently, a superheterodyen receiver with a regen receiver as the IF strip.
That sort of receiver got a lot of play towards the end of the regen time, simple receivers that were better than just a regen (if nothing else, putting them on a fixed or limited range makes tuning easier, and the converter stage isolates them from the antenna). Late fifties/early sixties, they seemed to thrive, especially in portable or mobile equipment, a last gasp before direct conversion receivers took over from regen receivers in the "simple receiver category".
And then don't forget the q-multiplier a regen stage added to the mixer output of a 455KHz IF superhet, to add selectivity. You could get those even for fancier receivers like the Collins 75S receivers, except there, they were generally used as a notch filter, rather than for peaking.
Michael VE2VBW
This lady bird radio was from my first book at 7 years old. All the "lady bird" books were kids books. I never built this one but I did build the crystal set earlier in the book. Colin.
ReplyDeleteK0lIN