Modifying old LRLs

[Geo]

Hi.
For this winter there are n't new projcts... i have construct a lot of lrls.
So i decided to modify some of them.
I started with the Andy's Flind MFD.
The main problem of this project is that it oscillates when buzer is near to coil and u try to give more sensitivity.
I found the solution and now i can give more... more gain, so i believe that its a super lrl.
Problem is that the weather is not good to try it. Later....
Also i connected a FM radio with TDA7000 so to have a "second" EMF detector.

Here photos...

[Geo]

Sorry but the last photo is npt a final photo...

[abdou2014]

good luck dear friend, may i know what are the components between the output of LM386 and NE555 ?

[Geo]

Originally Posted by abdou2014

good luck dear friend, may i know what are the components between the output of LM386 and NE555 ?

clasic components as transistors... resistors etc. It is a clasic beeper by Esteban modificated a little by me.
Don't try to find a complete schematic, maybe will not work for you. Connect a signal generator and an osciloscope at your device and start the modifications. Instruments will give u all the info!!!!

[abdou2014]

what are the properties of the input signal and the final property of the signal required on the oscilloscope ???

[Geo]

The second LRL that i will try to modify is a simple pd with coil stimulator. This lrl is the one that i had with me when i visited Morgan at Portugal (2009). At photo it has a different coil.
First modify is the connection of a 18650 li-ion battery in place of 2x 9V 9F22. Also an up converter is needed so to convert the 3.7v of 18650 to 12V.

[abdou2014]

what are the other modifications Mr Geo ?

[Geo]

When I make them I will write here.
At the moment I have a problem with my eyes, so I'm not going down to my lab..

[Geo]

also i plan to replace diodes 1N60... with other more sensitive....(rusian)

[abdou2014]

Originally Posted by Geo

When I make them I will write here.
At the moment I have a problem with my eyes, so I'm not going down to my lab..

I wish you a quick recovery

[rider]

Hi Geo.maybe the operating frequency of the converter affect the reception? maybe it create interference.

[Pahom]

Originally Posted by Geo

also i plan to replace diodes 1N60... with other more sensitive....(rusian)

I tried different diodes. The most that I personally liked in the work is the germanic d220 and the sensitivity increased and the stability of the receiver itself, if there are any, then try it. The d310 still doesn?t work badly, but it?s very difficult to find a pair for this series, they are made with a wide spread, maybe I came across such a batch.

[Geo]

Hi Pahom.
I don't remember the number of diodes now but i think that it is D9B. I tried them on a crystal radio and they had better sensitivity with more clear audio. There is big difference between them and 1N60 or IN914 or AA... that you find on ebay.

[Geo]

Originally Posted by rider

Hi Geo.maybe the operating frequency of the converter affect the reception? maybe it create interference.

Hello Bill.
On second lrl (pd with coil stimulator) there is n't problem like this because i use external signal for coil stimulator.... from the other side the coil of the converter is shielded...
On first lrl (Andy's MFD) there is n't up converter...

Regards

ps.. How are the guys....

[Geo]

Originally Posted by abdou2014

I wish you a quick recovery

Thank you Abdou.
Today i visited doctor again and said me that next week i'll be fine.

[Mike(Mont)]

Good news, Geo!

[Geo]

Originally Posted by Geo

Hi Pahom.
I don't remember the number of diodes now but i think that it is D9B. I tried them on a crystal radio and they had better sensitivity with more clear audio. There is big difference between them and 1N60 or IN914 or AA... that you find on ebay.

Pahom.. i checked diodes, yes D9B.

[Pahom]

Originally Posted by Geo

Pahom.. i checked diodes, yes D9B.

I understood you. Previously, they were put by d9B a red stripe or two red stripes or red dots. Then he refused. Ask Kostas Russian d9b sent him something like that. If he didn?t spend them all.

[Geo]

No problem with D9B, i bought 100 pieces before 3..4 years..

[Geo]

Pcb at right is an equaliser (schematic by Esteban). I plan to deconect it because i did n't see it to doing something better
Also i plan to connect a potentiometer so to reduce the gain at places where there are strong magnetic fields, but i did n't decided how to do this.... by playing with the receiver pcb or by connecting a potentiometer in series with coil....

[Geo]

Originally Posted by Mike(Mont)

Good news, Geo!

Now i am ok... i have eagle's eyes...
Yesterday and today i visited my lab and finished the mod of PD. Results inside the lab are fantastic... it has at least twice and more sensitivity. If outside the lab be stable then will be a lrl near the top of all i have.

[Geo]

Originally Posted by abdou2014

what are the other modifications Mr Geo ?

as i wrote at previous post i replaced in60 with d9b.
also i gave a little pore power at stimulator oscillator. i wanted to connect a one stage preamplifier on coil but sensitivity is so big.
frequency of Rx = 62khz and from stimulator 125khz

[Pahom]

Originally Posted by Geo

as i wrote at previous post i replaced in60 with d9b.
also i gave a little pore power at stimulator oscillator. i wanted to connect a one stage preamplifier on coil but sensitivity is so big.
frequency of Rx = 62khz and from stimulator 125khz

Happy New Year! It's good that everything is fine with the eyes! Tell me, in this variant of RX -62kHz and TX -125kHz, which registers better Argentum or Aurum?

[Geo]

Pahom Happy New Year for u and for all members!!!

Sorry but i don't understand what u mean with ""which registers better Argentum or Aurum""

[Pahom]

Originally Posted by Geo

Pahom Happy New Year for u and for all members!!!

Sorry but i don't understand what u mean with ""which registers better Argentum or Aurum""

In your experience, these frequencies are what kind of metal they found more.