FBCS-Series, A Lighter Touch--Zero Input Power

[tomas]

Attached is a schematic of a simple crystal radio. The diode is a 1N34. Lets say you don't need the cap or external antenna because you are making a coil tuned to the precise frequency. The speaker shown is normally a high impedance crystal earphone.  As you can see the simple set needs no other energy to operate, it comes from the stations transmitter. I think you can attach an audio amp in place of the crystal earphone as a test to hear the signal. I have heard of crystal sets being built with large inductors that can actually light an LED when tuned to a carrier, I have not seen this in person or know of a schematic on-line. It would be a neat trick if it could be accomplished.

RD

here is what they call an "ambient power module"
it supose to put out 36 volt/9 watts.

http://www.youtube.com/watch?v=5mpYl3Yk8a8
http://peswiki.com/index.php/OS:Ambient_Energy_Collection_Device
http://www.angelfire.com/ak5/energy21/ambientpower.htm

[hartiberlin]

36 Volts and 9 Watts is very much overexagerated...
Maybe during a very heavy thunderstorm and with a
very long and high antenna, but not normally.

Have a look at the "Stromsauger":

http://www.t-spark.de

He could only light up a few LEDs very dimmly
with it and the power is normally only in the mikro to milliwatts
range...

Otherwise you would need an antenna with electret effect
to attract free electrons, then you could gain some
more charge and so some more output power...

Regards, Stefan.

[Spherenot]

gyulasun & argona369, I still need to locate those pF cap's and variable cap's that you asked me to try.  Is this something in which you both are still interested in seeing?

Yamanashi Jr, have you tried a cilinder type also insted of a flat coil?

pucella, how is that copper tape working out for you?

retrod, thanks for the crystal radio schematic.  I had been meaning to look this up for a time.

kingrs: "Try your scope on some of the lower frequency settings.
I think it may have been 1ms/div.
I saw what looked like a train of square blocks of two different sizes."

I did this.  The only time I see what you are seeing at 1 ms/div is when I disconnect my coil.  Do you have continuity throughout your replication?

However, when my coil is connected at this 1 ms/div setting I see packets of waves seeming to move in both directions on my scope.  These may be radio waves.  I will try to find a way to jack my coil to an off-the shelf amp.

Your waveform does not look like a smooth sine wave.  Try placing the unit on your knee, after checking continuity.  Put your hand on top.  Do you get a higher amplitude sine wave?

What frequency are you getting with your 'body' antenna?

The FBCS-22-2D.A has a measured resistance value of 0.3 ~ 0.5 ohms.  (~25 feet--22 gauge solid hook-up & lead wire)

The FBC-30-4W has a measured resistance value of 18.2 ~ 18.4 ohms.  (171 ft., 8 in.--30 gauge enamel-coated magnet wire)

I will post pic's and results of the completed FBC-30-4W later.

Anyone care to guess which device picks up a stronger signal?

[gyulasun]

gyulasun & argona369, I still need to locate those pF cap's and variable cap's that you asked me to try.  Is this something in which you both are still interested in seeing?
....Anyone care to guess which device picks up a stronger signal?

Hi,

Yes because this way you could make sure you tune to the biggest signal amplitude just like in case of a parallel tuned resonant circuit is fed by a signal generator and you search for voltage maximum by turning the knob of the generator.
Because your scope input capacitance is around 30-40pF this adds in parallel to your pancake coil  and make it off-tuned, even if you use a 10:1 probe, it has a 14-15pF self capacitance too and cause off-tuning with respect to your calculated resonant frequency.

Your FBC-30-4W coil is supposed to pick up a stronger signal, however I wonder it will be of the same frequency like that comes from FBCS-22-2D ??

thanks

Gyula

[argona369]

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