My 1 transistor FM Super-Regen Receiver!

Also, in most super-regen radios there are interference sounds when the quenching frequency is near a frequency of the stereo sidebands (23kHz to 53kHz) or SCA storecast (67kHz) music.

For people who are interested for regens -superregens here is another super-reaction fm radio:
https://aurelsoft.ucoz.com/Regen3.png

How does the simple regen "FM radio" prevent overload and cross-modulation in the first transistor caused by many strong local stations?
How do you adjust the amount of regen?

Here is something different known as - pulse counting receiver...
https://aurelsoft.ucoz.com/FMpulsar1.png

Your odd schematic with white lines on a black background is a negative image that is difficult to look at.
Most schematics are the reverse, a positive image with black lines on a white background.

I don't think any manufacturer has produced an "odd" radio with a pulse counting detector or a Mickey Mouse regen or super regen FM radio.

Here is an inverted color version

I don't think any manufacturer has produced an "odd" radio with a pulse counting detector or a Mickey Mouse regen or super regen FM radio.

Click to expand...

Why you constantly attack any of my post here?
If you don't know nothing or you not interested don't respond on my posts...

IS ANY of ADMIN here see what this troublemaker Audioguru do with any of my post?

alexan_e said:

Here is an inverted color version
View attachment 88940

Click to expand...

Thank you.
I do not understand why some foreign SIM programs invert the image. It looks AWFUL and uses a lot of ink if it is printed.
I have never printed one of those awful schematics and I have hardly ever looked at one.

Here is one schematic of pulse counting rec ...which is manufactured :
https://aurelsoft.ucoz.com/FMBBT.png

I have one schematic who is manufactured by Sinclair ,but i need time to build and test....

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Oups..sorry i forget to add .
For any additional information .of course if you interested you can visit:
http://groups.yahoo.com/group/regenrx/

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About RegenRX group:
The purpose of this group is to facilitate the exchange of information, experiences and ideas aimed at the promotion of and encouragement in operating, designing and building these amazing receivers.

Regenerative detectors are simple enough for children to build, yet can challenge even the most experienced builders. Usually, the receivers utilizing these detectors require a minimum of parts. However, some can be complex indeed, and can be incorporated into superhet designs such as the Super Gainer and the Regenerodyne.

Since 1990 there has been renewed interest in the old fashioned Regenerative receiver, many are even being used in active communication service. Join us as we explore these classic circuits and use them as they were intended to be used. You just might get hooked.

Note: Regenerative receivers embrace a wide spectrii of subjects, and span a wide area of time, thus thread topic can range widely, from circuit dynamics to old radio lore. It is hoped that Olde Tymers might feel free to share their own stories and experiences of their past with the ol' stand-by 'genny, and as well the Not So Old Timers.

Folks just starting out are encouraged to share their questions, successes, and frustrations too. Remember: for every page that Thomas Alva Edison (Al) entered in his journals about his successes, he devoted reams of pages for his failures. He studied his mistakes and turned them into successes. I think we can learn something from Al. And each other!

Actually, superregen receivers are far more common than most people think. They are widely used in pager systems and some 'pocket' comms systems because of their small size and low battery consumption. Of course in those designs the receiver is well shielded and isolated from the antenna to prevent cross-interference. I've even come across them in wireless doorbell systems.

Pulse counting detectors using low IF should in theory give far better audio quality and without a quench oscillator they do not suffer from pilot tone beats and RDS/Storecast 'whistles'. I remember the Sinclair receiver well and although it can't match the selectivity and sensitivity of modern receivers, it did remarkably well for it's size and cost. Be cautious of Sinclairs original performance claims though, as with most advertizing at the time they were prone to 'enlarge' the truth somewhat, for example their Class D amplifiers that consumed less power than they apparently produced!

I think I built my first superregen receiver to pick up the 144MHz 'Ham' band around 1968/1969 and if I remember correctly it used an AF117 germanium transistor although I also experimented with 6J6 double-triodes around the same time. In those days vacuum tube technology was generally better than semiconductors at VHF and beyond.

Brian.

I am amazed to see the very old FM radio without IF transformers and with a tunnel diode for an oscillator. The germanium transistors are also amazing to see.
My first FM transmitter used a tunnel diode and my first transistors were also germanium. I still have some AC127 and AC128.

Regen receivers are used in very cheap kids walkie-talkies and in very cheap kids radio controlled cars.

Here is the schematic to patrick cambre's circuit.



let me know if you have any questions

Tejdeep Kochar said:

Here is the schematic to patrick cambre's circuit.

Click to expand...

No, you did not post the schematic. Instead you posted a pcb design and a parts layout showing some but not all of the parts.
Please post the schematic and parts list.

I think Patrick Cambre's super-regen radio project was a long time ago. He improved it a few years later. I do not know if you posted the pcb for the original circuit or for the improved circuit.

The last time I looked Patrick Cambre's website was closed. His original super-regen radio is on the web called RSS (Radio Shack Special) in Google.

It is the RSS design. Top layer just no have mentioned the name of all the components, however copper layer has them all.

Did you substitute any parts? Do you have a lot (20 or more) of strong local stations? Do you have a lot (20 or more) of weak distant stations? Did the super-regen radio have good selectivity and good sensitivity? Did you hear interference whistles from its quench oscillator beating with stereo or SCA? Was it difficult to tune to one side of a station? Was the sound distorted? Was the sound muffled (high audio frequencies attenuated)?

Superregen receivers look and are simple, but: in principle the circuit is an oscillator adjusted (or externally controlled) so that the RF oscillations are quenched by an ultrasonic frequency. Such oscillator simultaneously oscillates at RF and the quenching frequency.
The base of the high sensitivity is in that the RF oscillations start from noise, either inherent in the circuit, or coupled b the antenna. Once a signal enters the circuit, then it starts the RF oscillations, and at the output, instead of noise one can hear the AM modulation of such signal.
The tricky part is that such circuit needs a skilled operator, to tune and to adjust the desired signal. Due to a low Q of the RF LC circuit, selectivity is poor. There is no way to filter the input signals other than adding a RF preamplifier with such filter. Tuning on the side of resonant curve allows to detect also FM signals but usually with a distortion.
The SR circuit as the oscillator also strongly radiates its quenched RF signal outside by the antenna.
All above is good to know. SR receivers are looking nice but need a skilled operator. For jamming one can be fined, too.
Due to technical progress we now have wonderful ICs allowing to make a fantastic FM receiver, with no distortion, easy to tune, no jamming, etc. SRs are good for cheap stuff. They are a past, nice to try but not good for the future.

Everybody knows that suprerregen or regen receivers cannot replace
or beat modern tuners BUT that is not main point here.
This is in first place useful for young people or enthusiast who
whish to try how things works..right ?

By the way there is big group of people who are on regen.rx
yahoo group with lot of material and experience in radio builds.

i will show you soon my another regen with power MOSFET.

Maybe a super-regen radio is OK on a farm far from a city so there are few stations and they are not strong.
But a super-regen "radio" works very poorly in a large city where there are almost one hundred very powerful local and weak distant stations.
Then a half-decent ordinary super-heterodyne radio works fine.

I bought a crummy clock radio for only $1.75. In my large city on FM it is overloaded by strong local stations and does not have enough sensitivity to pickup weak distant stations. It is very difficult to tune since there is severe distortion on both sides of each station. Its selectivity causes adjacent stations to interfere with each other. Maybe it is a super-regen "radio".

@betwixt

You say that you have Sinclar micro FM and WHAT is about sound
he produce.
One guy told me that he build version of pulse counting
fm reveiver with two fets - BF247 and that sound same as
any ordinary small classic fm superheterodine radio with
transistors...
So what you can tell about sound of micro FM.

I have in plan to build version with BF256 BJT HF transistors...

I didn't own one but I know people who did. A well designed pulse counting discriminator can give excellent results but I doubt a good receiver using one could be built from just two FETs. For a pulse counting system to work, the pulses must be rectangular and that implies high gain and an amplitude limiter. That would need more stages than two BF256/7. If you look at various designs, you will see they all have a chain of high gain non-linear amplifiers before the discriminator, they are to ensure the pulses are the same amplitude regardless of the signal strength.

Brian.