SBG-PID

[Andi68]

The NTE 937M is no alternative, it is even harder to obtain in Europe than the LF357.
Well, I'll see which operational amplifier is suitable as a replacement.
It takes time and my motivation to finish the circuit quickly is not great
For me it's the last circuit with obsolete semiconductors that I build.

[scs]

Leave the soldering iron. The beach is more pleasant.

[sinclairuser]

hi, we always get the inevitable questions "can i swap this chip with that chip?", "can this transistor be used instead of that mosfet?".
etc etc my own view is that it is better to use the correct components even if they cost a bit more, having said that some builders seem to have real problems getting the right parts, and through no fault of their own too.

some of the older projects have parts that are considered obsolete like the lf357n though dbanner has given you an excellent viable alternative, sometimes parts can be substituted with careful datasheet checks, but others while alternative parts will work they wont work right, sometimes its due to a particular feature or even a quirk or bug in the component that the original designer exploited, in a case like that its very difficult to replicate with a modern alternative.

luckily the newer projects are mostly designed with common parts so having to source "wildcard" components is not a problem, though you still get those who try to make apple pie with pears and tomatoes.
thanks,
aly.

[dbanner]

I use NE5534 to replace lf357 on another project some time aback, pin 1,8 balance/compensation. get rid of coupling cap on input. etc.etc. Worked excellently. Obviously requiring bodge work on pcb.
Direct replacements for lf357n are for fishing expidition of Dr. Livingstone. However I have said it before and I'll say again, buy genuine NTE replacement for LF357N. It performs exactly like original. It is NTE937M. Order it directly from NTE electronics. I used one and it works a treat.

[Carl-NC]

Which?
And then does the wiring have to be changed?

Figure out which specs matter. In this case, GBW certainly and probably IBias. Maybe more. Then use a search engine to find other opamps. I personally like Digi-key's search, you can easily filter on various specs.

[ionut_mtb]

If you want to play safe; this is the only way:

https://octopart.com/lf357h-national...SAAEgKxdfD_BwE

this is a search engine for electronic components, this does not means that supplyers can be trusted..

[6666]

Just to get the circuit working try using a pin compatible op amp

[Andi68]

Which?
And then does the wiring have to be changed?

[Carl-NC]

Why was the circuit not constructed with an easy-to-procure operational amplifier, I do not understand

So use a different opamp.

[Andi68]

Why was the circuit not constructed with an easy-to-procure operational amplifier, I do not understand

[scs]

I think LF357 can be replaced with any fast amplifier, for example NE5534.

[ionut_mtb]

On my last FelezJoo PI i put the "H" version.
No compromises at all. Real deal.
That's why my FelezJoo PI detectors are working just right.

that's why i'm searching for original lf357. i'm planing to build Felezjoo Pi also. how do you find it in the field? deus is not that deep and don't work good in mineralised soil... anyway i dig a lot of deep small rusty pcs, also big iron and dodgy signals (especially deep signals) because you never know what it ca be. one detector that made me interested is aka intronic stf, i'm waiting for it.

[moorejl57]

LF357 analog-CA3130, OP42, Maybe TL071,.

If you want to play safe; this is the only way:

https://octopart.com/lf357h-national...SAAEgKxdfD_BwE

Will a LT1122 do the trick?

[ivconic]

On my last FelezJoo PI i put the "H" version.
No compromises at all. Real deal.
That's why my FelezJoo PI detectors are working just right.

[ivconic]

Does anyone know good source for lf357 in europe? Or have extra? I?ve searched all the internet, electronic component shop and secondhand ones. Some ebay sellers are not reliable. I also found lf357h and mba357 yet again, i don?t know if they are original or not.

If you want to play safe; this is the only way:

https://octopart.com/lf357h-national+semiconductor-2771238?gclid=EAIaIQobChMIuLnD7dyT4wIVyh0YCh135gJlEAAYASAAEgKxdfD_BwE