Maker Pro
Maker Pro

removing tuned frequency

cjdelphi

Oct 26, 2011
1,166
Joined
Oct 26, 2011
Messages
1,166
I could just build one, but there's little point wasting my time if someone has the answer...

Remove the tank circuit / crystal / vco etc etc and amplify the signal...

Will it just be static or will i hear lots of stations?
 

73's de Edd

Aug 21, 2015
3,606
Joined
Aug 21, 2015
Messages
3,606
.

Sir cjdelphi . . . . .


If this question is relevant to the separate post with the linearly biased inverter used in the front end of an AM receiver.
All strongly received signals will come in simultaneously, moderate ones will be lost down in the din.
Even with that simplistic single tuned L-C circuit, for its tuning differentiation, the use of a high Q coil there would be desirable.
Like a powdered iron or ferrite core and using a Litz wire winding.

73's de Edd

.
 

cjdelphi

Oct 26, 2011
1,166
Joined
Oct 26, 2011
Messages
1,166
Nothing to do with previous threads, and i never had any intention of using that IC.... as i stated a lm386/opamp to amplify...

Either way i need to build one to find out, since i have not, i thought i'd ask... 9/10 times i'm purely doing it for educational reasons, my area is DC (power supplies), but slowly getting the hang of biasing and ac coupling... but i'm hitting the point the stuff i'm building requires radio, so i'm delving into AC

So you think i'll hear a jumble of the most powerful stations, that would be the longer wavelengths first then as they travel further...

Got it, thanks!
 

davenn

Moderator
Sep 5, 2009
14,233
Joined
Sep 5, 2009
Messages
14,233
Remove the tank circuit / crystal / vco etc etc and amplify the signal...

if you remove the signal source ... there isn't going to be a signal to amplify, so the statement is meaningless ;)
 

davenn

Moderator
Sep 5, 2009
14,233
Joined
Sep 5, 2009
Messages
14,233
The signal source is directly from the Antenna...

yes you can put the signal from the antenna into an amplifier stage .... it's done is virtually every receiver before other stages ... misers, demodulators etc

so what is the point of this ?
what are you trying to achieve ?
 

davenn

Moderator
Sep 5, 2009
14,233
Joined
Sep 5, 2009
Messages
14,233
To hear as many radio stations at once

then you will need multiple tuned receiver stages and multiple demodulators else you wont hear anything
our ears cannot detect radio signals
 

davenn

Moderator
Sep 5, 2009
14,233
Joined
Sep 5, 2009
Messages
14,233
the most basic radio receiver, the crystal set, because of its poor tuning selectivity is capable of demodulating overlapping signals

Have you ever built a crystal set ?
 

cjdelphi

Oct 26, 2011
1,166
Joined
Oct 26, 2011
Messages
1,166
Why would you get nothing? Using a low foward drop diode (germanium or schottky diode to rectify 1 half of the wave form) dc bias offset an ac coupling , why not?
 
Last edited:

cjdelphi

Oct 26, 2011
1,166
Joined
Oct 26, 2011
Messages
1,166
Listening to electromagnetic waves?

No.. listening to AM signals then amplifying them and outputting them on a speaker
 

davenn

Moderator
Sep 5, 2009
14,233
Joined
Sep 5, 2009
Messages
14,233
Why would you get nothing? Using a low foward drop diode (germanium or schottky diode to rectify 1 half of the wave form) dc bias offset an ac coupling , why not?
Listening to electromagnetic waves?

No.. listening to AM signals then amplifying them and outputting them on a speaker

did you even read what I wrote ?

"the most basic radio receiver, the crystal set, because of its poor tuning selectivity is capable of demodulating overlapping signals

Have you ever built a crystal set ?"
 
Top