It has to be simpler...

[mstechca]

I have found the following:
**broken link removed**

Talking electronics declares this a typical FM transmitter.
For my receiver, I made the oscillator circuit in such a way that the tank circuit is connected to ground instead of VCC. Why? because I wanted to achieve higher gain. and I'm sure a common emitter amplifier is better than a common collector one. and I can tell that it is a common base amplifier for AC.

But here is the question. If a receiver can almost be built the same way as a transmitter, and a receiver can cause interference (a.k.a. transmit signals), then why isn't there just an extremely simple method for me to take the transmitter above and convert it to a receiver without adding extra components (with the exception of the audio amplifier)?

and if there is, I would like to know, because my receiver partially uses this design.

 

[Nigel Goodwin]

Talking electronics declares this a typical FM transmitter.
For my receiver, I made the oscillator circuit in such a way that the tank circuit is connected to ground instead of VCC. Why? because I wanted to achieve higher gain. and I'm sure a common emitter amplifier is better than a common collector one. and I can tell that it is a common base amplifier for AC.

You might be 'sure', but you're completely wrong! - specific modes are better for specific purposes, there's no 'best' mode. For an oscillator the gain is almost completely irrelevant, it needs to provide just enough gain to provide oscillation - and NO MORE - any more will cause distortion, and provide nothing helpful at all.

But here is the question. If a receiver can almost be built the same way as a transmitter, and a receiver can cause interference (a.k.a. transmit signals), then why isn't there just an extremely simple method for me to take the transmitter above and convert it to a receiver without adding extra components (with the exception of the audio amplifier)?

You've been messing about with these for ages now, basically just changing things at random and seeing what happens. This isn't any way to build things!.

Why not build a proper radio?, instead of playing with crap super regen designs?.

I doubt you'll listen, or understand?, but I'll explain very simply about the evolution of these sorts of radios:

1) Crystal set - tuned circuit, detector, earpiece.

2) Amplified crystal set - tuned circuit, RF amplifier, detector, earpiece.

3) Regen receiver - same as 2), but you apply adjustable positive feedback around the RF amplifier, by adjusting the feedback to the point JUST BEFORE oscillation, you get the maximum possible gain from the single stage. You have to adjust the feedback control along with the tuning control all the time, in order to keep it just on the edge.

4) Super regen - basically the same as 3), except the continual complicated feedback adjustment has been removed - by making the RF stage oscillate as a lower frequency, you can make the RF stage burst in and out of RF oscillation, keeping it at the most sensitive point. An incoming signal will tend to stop the oscillation, and produce 'reasonably' clear audio. Big down side, it produces loads of RF interference, so isn't a good choice in these days!

Basically the regen and super regen were designed when active devices (either valves or transistors) were VERY expensive (think Pentium 4 processors!), so it was important to use as few as possible - who wants to build a PC and pay for four or five Pentium 4 processors?, when you could get 'almost' a similar performance from just one.

 

[mstechca]

I would rather start simple and work complex rather than create some complex superhet, or a superhet which requires IC's that are N/A in some places. The reason why I am persistent with superregens is because they are simpler to build than superhets.

 

[Nigel Goodwin]

I would rather start simple and work complex rather than create some complex superhet, or a superhet which requires IC's that are N/A in some places. The reason why I am persistent with superregens is because they are simpler to build than superhets.

But they don't work well! - particularly in these days, with many more stations out there.

 

[audioguru]

MStechca,
I don't know how your transistor can work with the collector's tank circuit connected to ground.

The pic that I posted in your other topic shows how easy it is to turn a simple FM transmitter circuit into a super-regen "receiver": just add a choke and capacitor in its emitter to make the RF oscillator squeg, where it begins an RF oscillation but a received signal is rectified at the transistor's emitter, charges the capacitor and cuts-off the transistor. When the capacitor discharges a little into the resistor then the oscillator starts again.

 

[mstechca]

This is my version. I don't know how it works with you, but this mode cooperates a bit with me.

EDIT: The resistor is actually a pull-up resistor not a pull-down resistor, so ignore the diagram if you are examining the pull-up resistor.

 

[audioguru]

Your transistor circuit doesn't do anything because it doesn't have a power supply. Both the collector and emitter are at 0VDC!

 

[mstechca]

you must of replied before I edited my post. The 27K is supposed to be a pull-up resistor.

Check this out:

**broken link removed**

That circuit looks like it can become a detector as well.

 

[audioguru]

EDIT: The resistor is actually a pull-up resistor not a pull-down resistor, so ignore the diagram if you are examining the pull-up resistor.

How can I ignore the diagram you posted. It shows the transistor without a power supply.
If you have the 27k resistor connected to the positive supply, then the transistor is saturated and still doesn't do anything.

 

[mstechca]

I will redo the diagram and then post it later.