IGSL

[jladre]

Im trying ti build this great project but i cannot find bf247 and j107 in my country..can someone suggest me a replacement transistor? Please...

[porkluvr]

Im trying ti build this great project but i cannot find bf247 and j107 in my country..can someone suggest me a replacement transistor? Please...

J112, J113, 2N5484, 2N5485, 2N4392, 2N4393 should all work with some degree of success, but pinouts may be different.

You will need to be able to identify the gate lead; do so by measuring between all the different pins to each other, in both directions (+/- and -/+). The two pins that measure the same resistance in both directions, are S and D.

So long as you make sure the other pin (G, gate) matches the PCB, the S and D pins can go either way.

[jladre]

Thanks porkluvr i do that

[sevar12]

hi all , is this correct decision IGSL.rar

[Davor]

I did not see this one yet, but mostly makes sense. You might run into problems with Tx if your coil's resistance is too high, and you'll most certainly run into problems with U12c and U12d if you put TL064 there. LM358 at this stage is a much better choice since these run into a comparator-like regime, and that affects bias voltages of all chips in a package.
Balanced mixer is a nice touch.
Is there a PCB that goes with this one?

[sevar12]

not yet, but soon there will be

[Davor]

In that case I strongly suggest you to make a few changes. First, U12a and b should be separate device from U12c and d. Next, to do it right you'll need a proper Tx oscillator.
Also you have far too much filtration. With filters you must know what you want to achieve, and if you are up to fast recovery speeds and good audio compression, this design is not going to provide.
The 22k/47n are just useless there and they better go out. Also 100n capacitors there are not large enough. With half wave switchers and 20k resistors (effectively doubled due to 50% duty cycle) C12, C26 and C27 would provide ~35Hz corner, but here you have full wave switching, thus corner frequency is ~70Hz. You may consider changing those capacitors to 220n.
Diode compressors in parallel with a filter capacitor ... no. It is a bad idea. Just remove them. There is no way you can tame a non-linear compressor with filtering capacitors. Also 100k in series with diodes is too much.
You may also wish to replace bipolar capacitors with larger ones for lower motion speed.
Also make sure you use 32 or 50ohm speaker. 8ohm speakers are not optimal here.

[sevar12]

Ок many thanks for the direction .Change each tl064 to 2X tl072 and lm339 =2X lm393.More easier for experimentation .But first but first do the board these days .

[Davor]

Actually, it is only necessary to change the opamps in audio to LM358, and avoid placing quad opamp there because of strong crosstalk due to the common bias generation, and the fact those 2 in audio go to comparator regime. Beware of LM339 as it has a bit touchy pinout - be sure to clean all residues of resin there.

[altrix]

Hello nakky!
i would like to make your pcb."igsl-tgsl", ivconic-nakky,but i dont no,it is working good?you made it?

[altrix]

In post 259.

[sevar12]

Hi all,
This what i did . Generator run 35V p-p , but cant null the coil ,too many noice in the hous minimum Rx voltage is 80-100 mV.On pin 9,10 and 11 of 4053 have signal but on pin 14,15 and 4 have signal only on pin 14 another one is konstant (+5V i am not shure) and nothing on pin 4 .I think first proper tuning coil .R1 is 120 om , I=30.6mA (only generator) ,frequency is 16,9 KHz. this is scheme.IGSL - Copy123.rar

[Davor]

See what you have on pin 1 of LM833

[sevar12]

Hi Davor, this is with green pin 7 and pin 1

[Davor]

I can explain pin1 with poor coil balance, and pin7 with too much signal at its input. You'll need to reduce it for the phase shifters if you wish to keep that huge Tx voltage.