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]

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]

PD with coil stimulator...

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]

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]

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]

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]

I wish you a quick recovery

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