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Originally posted by okantex
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If the amplification of the lrl is too large, in addition to the compass effect there is also the sky effect, i.e. lowering or raising the lrl you have a signal, the two effects can be combined making it impossible to use. The lrl is a directional instrument, the maximum sensitivity is proceeding from north to south, the minimum is proceeding from south to north and proceeding from east to west and vice versa the sensitivity is medium. Furthermore, approaching the target, the signal increases but cancels right on the vertical where the target is buried. I find it difficult to believe that a target at 500 m can influence my lrl, to be true it should behave as described above, i.e. approaching the target (i.e. at 500m) the signal first weak and then increasingly strong until it decreases and cancels over the target (500m ahead). My lrl like almost all the others ultimately reveals an electrical or electromagnetic signal and therefore is subject to many disturbances.
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So, solution is easy
Another test with same adjustment
But without any target . At another place
İf there wont be change on leds...on east west
Then on south north. Directions.
Then on nort south , by increasing sensitivity if he will see compass effect and lose it by rotating to east south..voila..
Walkman will be right about his claim.
Am l right?Comment
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Hi Franco ,
I need some advises
I made circuit.. improved anttenna + 8mhz +display 3led +lm3919
I am detaching potansiometer middle leg..(4.k7) , to disable antenna input ..
buzzer is working..... circuit is single side pcb..but placed on aluminium case...and also ground ed to aluminium case. so , in a way it should act as double layer..
signal is strong..is it self osilation.. even playing with display stage pots ,it does not change
pcb paths seems good. I could not see any short cuts..
I used metal film resistors..ceramic condansators ,bc183c ,8mhz crystal
take care of yourself , stay at home.. stay away from corona risk factors.
wish good luck to all LRL family.
OkantexComment
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btw , after reading helps...I disconnect 4k7 pot of amplifier stage.. means antenna input is cut.
buzzer was active
so , I also disconnect cristal..but buzzer is still active
entrance of IC1A = out point of sensor stage = is 8,25V
is not this too much... changing 560p to 470 p ..will this help...I feel not...Comment
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Thanks for the good wishes, I certainly do not leave home, also because I am in the risk category (over 65 years of age). 8.5V at the sensor stage output is too high, it means that there is self oscillation. I recommend using a separate pcb for the sensor stage. Try using BC ... B type transistors with less gain, replacing one at a time. The important thing is to set up the sensor stage before connecting the amplifier antenna and keeping the original connections.Comment
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no antenna
no cristal..
what can cause osilation? just resistors and condansators
btw .. I placed the pcb abovealuminyum .and made ground connection ..now 2.7V first led is brillient.. second and 3th are blinking
do you still advise to replace transistorsComment
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Yes, try replacing the transistors one at a time. Yes, try replacing the transistors one at a time. Of course C9 must be connected to the antenna during calibration, this is to restore the original conditions without the amplifier antenna.Comment
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sorry , I did not understand.
on antenna amplifier addition.. C9 is connected to 4k7 pot's middle leg. I already disconnect it to disconnect antenna from sensor stage..
after seeing Null ( 0 V ) on sensor stage output ( on IC1A 's pin 3) , I will connect antenna.
what do you mean by calibration.. the calibration on field ?
cause your sentence " this is to restore the original conditions without the amplifier antenna." I am confused.
because during calibration of sensor stage.. you already write in HELPs file..to disconnect antenna.
if I connect C9 to Pots middle leg.. and just detach the telescopic antenna.. then I may receive field effects from bobbins.? but on the otherhand it may be better to calibrate the pcb with this disturbances too.
so , what should I do step by step
1. connect pot to C9
2. disconnect just telescopic antenna
3. decrease value of C13 and C14 , 560P to 470P
or 3th start replacing transistorsComment
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The initial calibration is done in the laboratory, therefore C9 is connected to the stylus antenna, the sensor stage output must always be present (even without phenomenon) and the optimal value is between 4 and 6V, to achieve this follow my helps .txt. When you have obtained the required values, you can connect the antenna amplifier, but it would be better to first try the original version in the field.Comment
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c13 and c14 ...I replaced 560p to 330p ,then to 100p then without any condansator..but all the time output is around 7V ..without cristalComment
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As I said before, the sensor stage is the critical part of my lrl, which was originally an rf sniffer that oscillated in my realization and I realized that it worked like lrl. Since I realized that reproducing this self oscillation in other specimens was very difficult I designed an oscillator independent from the rest of the circuit. I think that if your lrl oscillates without connections with the quartz oscillator and with reduced gain almost certainly the defect consists in the pcb. Use a pcb only for the sensor stage with the lower face connected to ground.Comment
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pcb is okay..no cuts or no short circuits.. but I will build new pcb..
I am doing same of Walkman's pcb...it is already proved itself by videos..Comment
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Well, however, it can happen that (as in every pcb) the connections are exact but that there are parasitic couplings between two tracks that are important in the sensor stage which has a very high gain.Comment
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hi
while getting close to end of second pcb..
I want to ask a question..
When I build my first zahori...I burned IC ..I think it was 2N35.. I realised that it was because of high voltage line close to my house
since the voltage is too high..on my outputs ... can it be because of AC high voltage
did you have any experience of HV..Comment
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