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Author Topic: Super regenerative receiver : testing a separate quench oscillator  (Read 203 times)

F1CUJ

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Hi,

I have built 4 different solid state super regenerative receivers for the aircraft band.

Unfortunately, it is very difficult to find information to improve the performance.
Here are my specific questions about quench :

It is said that “The performance is better when the circuit is not self-quenched but using a separate quench oscillator”.

So I have built a separate sawtooth generator. It is connected to the 2N2369A emitter after the VK200 choke with disconnecting the 1nF capacitor (See the schematic).
The sawtooth as a stand alone generator works fine.

But the problem is when connected it to the receiver the sawtooth signal is strongly attenuated.
I have tried to insert a buffer circuit with a common collector transistor but it doesn’t work !
Do you have any idea for solving this issue ?

Thanks for your help

73 Philippe



https://drive.google.com/file/d/1-UFDdpoL3ZYJafie9P9wloaexcLaxihA/view?usp=sharing
« Last Edit: November 24, 2021, 06:49:57 AM by F1CUJ »
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G3RZP

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Re: Super regenerative receiver : testing a separate quench oscillator
« Reply #1 on: December 08, 2021, 02:58:30 AM »

What frequency is the quench? The basic problem is that at the quench frequency, the 2N2369 is grounded base stage and so has a very low input impedance. You would be better to use an emitter follower or alternatively, apply the quench to the base of the 2N2369.  Remember  also that a slow build of oscillations give best sensitivity and selectivity, and you may well find that a sine wave quench is better.

73

Peter G3RZP
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G3RZP

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Re: Super regenerative receiver : testing a separate quench oscillator
« Reply #2 on: December 10, 2021, 04:13:57 AM »

Philippe,

Another interesting reference may be found in the MIT Radiation Laboratory series.

https://www.febo.com/pages/docs/RadLab in Volume 23 'Microwave Receivers', pages 545 - 578

vy 73

Peter G3RZP
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F1CUJ

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Re: Super regenerative receiver : testing a separate quench oscillator
« Reply #3 on: December 11, 2021, 03:15:08 AM »

Hello Peter,

Thank you for your 2 messages.
Sorry for replying late.
I have caught a strong cold and was very tired.

I have made some new tests and have to test again.

I will modify the emitter follower circuit.

I'll get back yo you to keep you posted about the results.

Have you built some superegenerative rx ?

Thank you
Best 73
Philippe
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G3RZP

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Re: Super regenerative receiver : testing a separate quench oscillator
« Reply #4 on: December 11, 2021, 06:35:07 AM »

Not for many years!

For the cold, try mixing some whisky, some lemon juice, 15mL of honey  and the same amount of hot water as whisky!


73

Peter
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