#76
|
|||
|
|||
Point well taken
J_Player,
Ok now I see where you're coming from,fair enough. Well I still would like to lash up a simple circuit to modulate my little laser with the 400hz square wave and see if I notice anything as it's got me interested. If it involved alot of building I wouldn't bother at the moment unless it's well documented so I'm not wasting precious time and effort. Sounds good and hope you have a great Christmas, Randy |
#77
|
||||
|
||||
Quote:
yes, I would be interested to see what you come up with too. I have never seen anyone do this with a laser. I think a 50% duty cycle works ok, and you probably will get better results if you use a very thin metal foil or shim placed in a jar with a closed top that you can seal a microphone inside. Maybe the disk needs to be big enough to make audible sounds in a range you can hear, or at least the microphone can, not sure. This is also supposed to work with sunlight.... make up a slotted disk and spin it above the target so the shadow of the slots hit the target. Maybe best to put the target inside a light-proof container with a clear top that has the spinning disk above. For the observations Esteban made, I don't think it was caused by photoacoustic effects of the buried target. But this leads me to wonder what did make a change in the FM radio sound. Maybe something in the air above the buried metal? RF refractions caused by soil conductivity anomalies? Something different? If we had a circuit to experiment with, maybe we could find out... Best wishes, J_P |
#78
|
||||
|
||||
Quote:
|
#79
|
||||
|
||||
Quote:
Merry Xmas to you and all!!! |
#80
|
||||
|
||||
Quote:
I wish you a lot of fun with your hobby in the new year.
__________________
Global capital is ruining your life? You have right to self-defence! |
#81
|
||||
|
||||
Quote:
Merry Christmas Esteban! |
#82
|
||||
|
||||
|
#83
|
||||
|
||||
say esteban:
If you can't reproduce the phenomenon, maybe also is diffucult to identify it. But I don't waste time, this is my hobby. Maybe other wasting more time watching TV, for example. yes this true, waste middle life of they in look football, and se tiran de los pelos por derrota, and suicide, and kill for these idiot sport arreglado for lucrative directives" juar juar! i prefer major the excentrice of lrls! |
#84
|
||||
|
||||
I would like to wish ALL forum members here a Merry Christmas and a Happy New year.
Thanks
__________________
Astrodetect |
#85
|
||||
|
||||
Quote:
|
#86
|
||||
|
||||
They get the heart attack when their team gets GOaL. You're safe from heart attack, because you never get GOLd.
__________________
Global capital is ruining your life? You have right to self-defence! |
#87
|
||||
|
||||
the gol--d of esteban give he $$, and the gol for phanatics sport give they $$ for pay in the account of electric's comision federal, by see tv and take hemorroides for sit in chair
hups! what bad is my english |
#88
|
|||
|
|||
Quote:
I have access to a nice HP spectrum analyzer, good to 22GHz, along with a set of near field sniffer probes. Should I be able to IR radiate a gold coin and detect frequency emissions? What frequency range? You are suggesting that these emissions distort the FM receiver, right? Otherwise maybe they just distort your hearing of the receiver... a bionic detector effect.... Anyway, let me know what to try and I'll try to do it when I can. Barry |
#89
|
||||
|
||||
Quote:
Regards |
#90
|
|||
|
|||
Quote:
Is your FM receiver set to a station or just noise? What is the change in sound? |
#91
|
||||
|
||||
Quote:
Regards.
__________________
"Should exist injustice and untruths towards working LRLs, I'll show up to debunker the big mouths" |
#92
|
||||
|
||||
555 have to be robust as 666 one, because we are compelled to beat by pistol the first in pocket found coin, to push them tell us where the remaining coins are buried.
__________________
Global capital is ruining your life? You have right to self-defence! |
#93
|
|||
|
|||
Quote:
If a ttl 555 dies from what you suggest, so would my cellphone and anything else around. I can put a tvs diode across the supply to totally prevent ESD from killing it. But anyway it is cheap. Besides those things would make the day a lousy detecting day anyway because they would obliterate the fields intended to detect.... Did you really evaluate one vs the other? |
#94
|
||||
|
||||
Quote:
The circuit is a simple square wave oscillator. You could make two of them. One with each type of 555. Then you could see for yourself which works. Personally I don't think it matters. The cmos version has better noise immunity, but I think you will find the same results with each. Cmos also does not require any special power supply. A plain battery works, and does not matter too much about the exact voltage. If a thunderbolt fries it, then you can unplug the IC and put another in it's socket. They're cheap. You might also want to stick to the exact circuit Esteban describes. If you add noise-reducing enhancements or a regulated supply, you may find someone tells you you built it wrong. It could turn out that the noise you described is necessary in order to see the circuit response. Your spectrum analyzer will show the small signal variations you are looking for change a lot when you modify the exact circuit that was described. Best wishes, J_P |
#95
|
|||
|
|||
Quote:
|
#96
|
||||
|
||||
Quote:
I suppose this is why you never find a complete (real) schematic around here. |
#97
|
|||
|
|||
hi
look thes
|
#98
|
||||
|
||||
BFO
This is primitive BFO,works with one radio,i build this many years ago,it works great,detects one coin underground,not more than 5 cm |
#99
|
||||
|
||||
hi, i too build these, but your should put an radio very adecuate to oscilation tx coil, not all can work here, is major an radio very early, what has audio transformer and transformer for conversion, any radio sound here pretty, other no, then need put the tune in an point of dial with sound white, then emit radio reponse, these put detect discriminate, only put an adecuate transistor radio and frecuence due
right tx, right radio, right calibration, wtb,true morgan, this is short depth, may be can convert in lrl, whit complex, esteban implementation very good sound, strong potente, and clear can emit these stuff no movement, no ground affected, little comsume, but is all metal |
#100
|
||||
|
||||
is major for these project, any radio what other, put preference mini radio old,of pioners, due modern radio base ics, may be not work ok in conjunction, or only emitt distant sound, no good new radios, may be exist any exception
|
|
|