Something for mstechca?

[audioguru]

Dit, Dit, Dit, Daw, Daw Daw, Dit, Dit, Dit. Dit, Dit, Dit. Send Over Some Sandwiches! :lol:

Has every one else realised that the little tune that is now associated with SMS messages is actually Morse for SMS - Dit, Dit, Dit, Daw Daw, Dit, Dit, Dit.

Mike.

Isn't the SOS ??

I don't think the fire department would care it they heard "Sleep More Soon".
I added the extra "S" to SOS to make it sound funnier.

 

[audioguru]

may be it is using AGC so that , if the RX is placed in the tv ant: itself , it won't saturate 8)

His "radio" is a super-regen that are known to overload easily.
With a medium or strong signal, the quench oscillation completely and continuously quenches the darn thing. Then the "radio" is just a resistor in series with the antenna and a capacitor to ground.

 

[akg]

may be it is using AGC so that , if the RX is placed in the tv ant: itself , it won't saturate 8)

His "radio" is a super-regen that are known to overload easily.
With a medium or strong signal, the quench oscillation completely and continuously quenches the darn thing. Then the "radio" is just a resistor in series with the antenna and a capacitor to ground.

"Then the "radio" is just a resistor in series with the antenna and a capacitor to ground " :lol: :lol:

 

[audioguru]

"Then the "radio" is just a resistor in series with the antenna and a capacitor to ground " :lol: :lol:

Yes when overloaded by a medium or strong signal. A resistor and a capacitor isn't a radio, is it?
A super-regen radio works if its positive feedback is manually adjusted. Then it can pickup low to medium signal levels.
What do you expect from a one-transistor "radio"?

 

[mstechca]

A super-regen radio works if its positive feedback is manually adjusted. Then it can pickup low to medium signal levels.

mine is digitally adjusted. I'm using a varactor in place of the capacitor.

What do you expect from a one-transistor "radio"?

My detector has 1 transistor. the other 4 amplify the signal. Therefore it is a 5-transistor radio with speaker output.

 

[audioguru]

My detector has 1 transistor. the other 4 amplify the signal. Therefore it is a 5-transistor radio with speaker output.

A real radio has a tuned RF amplifier with AGC, a local oscillator/mixer, 3 or 4 tuned IF amplifiers then a detector. Usually a very high gain limiting IC is used as an FM IF amp and detector. A single IC is used as an audio amplifier.

A super-regen uses only a single transistor for its RF and detector parts.
You can use as many transistors in an audio amp as you want. An LM386 little power amp IC has at least 11 transistors and costs only $1.17 at digikey.ca.

 

[JimB]

My detector has 1 transistor. the other 4 amplify the signal. Therefore it is a 5-transistor radio with speaker output.

Just out of interest, how many of those 5 transistors came from the bargain bag of 25 faulty 2N3904s ?

JimB

 

[audioguru]

Hi Jim,
MStechca posted a pretty good amplifier. It was like the output stage of an LM386. He says it works so most of its 4 transistors must be good. Maybe he had to try all 25 transistors in the bag to find the 4 good ones. :lol:
He used a real RF transistor for the "radio's" RF transistor. The super-regen caused so much interference that it messed up his mom's TV.

 

[JimB]

Hi Jim,
MStechca posted a pretty good amplifier. It was like the output stage of an LM386. He says it works so most of its 4 transistors must be good. Maybe he had to try all 25 transistors in the bag to find the 4 good ones. :lol:
He used a real RF transistor for the "radio's" RF transistor. The super-regen caused so much interference that it messed up his mom's TV.

Thats super-regen receivers for you, unless you have an RF amplifier stage to isolate that squegging oscillator from the antenna.

And to mis-quote some literary dude : Hell hath no fury like a mom who cant see her favourite TV programme.

JimB

 

[audioguru]

Hell hath no fury like a mom who cant see her favourite TV programme.

Hi Jim,
I know all about it. My wifey is behind me watching her daily "soap" right now. I hear them talking about which skinny actress on the show is pregnant in the script, and they all seem to cry about every 10 minutes. Then all those ads for women's stuff!
I just peeked and asked my wifey, "Why is that young woman in jail?"
She answered, "She isn't in jail, he is." :lol:

 

[mstechca]

Just out of interest, how many of those 5 transistors came from the bargain bag of 25 faulty 2N3904s ?

ZERO!
I use 2N2222's for the NPN's and the detector uses the PN3563.
The PNP transistor is the 2N4403.

 

[akg]

mstechca .. u some day said that ur avtar (running on knuckles) means the rate in which u learn things.. now u changed it.. why ?? pain in the knuckles ?? ..

Now what is the new thing , a bomb ?? representing information explosion ??

 

[john1]

'Bargain Bag'
Now there's a term i haven't heard for years.
Didn't know they still did them.

I used to get them regularly.

John

 

[eblc1388]

Now what is the new thing , a bomb ?? representing information explosion ??

I think he is showing us the quickest way to make a DIY "dark emitting diode" aka DED by driving 12V through it with no current limiting resistor.