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Reflex receiver circuits and reflexed-regen comparison

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neazoi

neazoi

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Hello,
I have constructed with great success the circuit of the reflex AM receiver on that page http://www.techlib.com/electronics/reflex.htm about at the middle of the page. This amplifies the audio signal many times but not the RF, as far as I can understand.

Recently I have found the circuit attached in the PDF, on page 11. I believe it amplifies multiple times, both the RF and the AF, so it is more like a two transistors reflexed-regen, as far as I can understand.

Can you please verify if this is true? (amplifies many times both RF and AF, i.e feedback on both RF and AF).

I am not sure how TR1 amplifies RF (the rf path), since the diode will rectify rf and produce only audio...?
 

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  • practical-radio-circuits-raymond-haigh.pdf
    5.6 MB · Views: 125

All reflex receivers were created in the old times when RF transistors (and earlier the vacuum tubes) were rare and expensive.
The active elements can be utilized at once for RF and audio, but often instability occurs. I would rather advise to design standard superhet circuits which can be optimized, and now nice IC s. are available to make nice designs.
 

just an observation

ho,no not another one.......how many have you built
now? interesting.

RF feed back is via the ratio of the diode capacitance
the cap connected to the input coil and the coin will
also give out of phase feed back.
 
Last edited:

THINKER_KAM_MAN said:
just an observation

ho,no not another one.......how many have you built
now? interesting.

RF feed back is via the ratio of the diode capacitance
the cap connected to the input coil and the coin will
also give out of phase feed back.
Click to expand...

Thanks :)
this circuit worked fine!
Applying a Q multiplier worked even finer!
 

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