For sale bare boards for Delta Pulse/Sniffer XR-71

[dbanner]

Here we are. The national semiconductor sign looks a bit strange. Is there a way to test these ic's on a bench?

The original national semiconductors chip has a stripe on it. Texas instruments acquired national semiconductors in 2011, since then not sure about the appearance. So your chip look suspicious.
As far as testing, sheesh!

[dbanner]

It is time for redesign of Delta for use of NE5534 or some other chip in front end of circuit, and put lf357 to its graveyard. Too many fake chips of especially lf357.

[Wahyu]

It is time for redesign of Delta for use of NE5534 or some other chip in front end of circuit, and put lf357 to its graveyard. Too many fake chips of especially lf357.

I agree, and beware NE5534 Fake, i use Signetics, and NOS Philips for NE5534

[nonkapo]

Replacing of LF357 does not seam as easy task and 5534 is too slow for the application. Whatever i can see in the BOM of KT315 - OPA627, OPA637, AD744, AD845,AD877,OP42, LT1122,TLE2071,TLE2081 must be replacements and is mentioned the slew rate should be not less than 50v/us. However only Anatoly can say whether he personally try all of them. I'm confident that neither of these is a drop inn replacement and for sure they should be modifications done. The web is full of threads about suitable replacement of this chip but no solution.

About my chips, at this price i'm almost sure its fake. Will try to remove the top layer with solvent to see whats below. I have two anyway;-).

[dbanner]

These chips are too specialized and are seldom available at local shop, or doesn't anyone buy locally anymore. What is needed is a commonly available workhorse opamp that you can salvage or source from local supplier. NE5534 fits the bill.

[kt315]

ne5534/2 do not fit the bill and also fake. i had gave this link and give again. https://zeptobars.com/en/read/Ti-NE5532-real-vs-fake-opamp

https://www.eevblog.com/forum/review...-fake-op-amps/

[kt315]

PS.........Kt please keep me updated as and when you can on how things are coming along.

keeping updated http://ipic.su/img/img7/fs/P1090388.1535137734.jpg

[6666]

Kt315 have you tried a LM318 ?

[kt315]

lm318 is good on slew rate but we must use just JFET/mos-fet opamp. ne5534 does not work too, that was checked by russians.
look datasheet lt1122, op42, ad845.

[6666]

lm318 is good on slew rate but we must use just JFET/mos-fet opamp. ne5534 does not work too, that was checked by russians.
look datasheet lt1122, op42, ad845.

Thanks

[dbanner]

lm318 is good on slew rate but we must use just JFET/mos-fet opamp. ne5534 does not work too, that was checked by russians.
look datasheet lt1122, op42, ad845.

It obviously will not work simply by swapping it in existing circuit, duh. A small redesign of first stage of circuit will be required. Only Tl081 is like common duck in everyone's junk box of parts but not high performance.

[qute1]

KT544UD2A

[nonkapo]

yeah i've seen some on ebay but will not be surprised if these are also chinese counterfeit. Otherwise, someone on the russian forums was expressing opinion these are a bit better than 357.

[kt315]

KT544UD2A

KR544UD2 (KR means plastic capsule, one K means round metal glass one)
very popular in soviet time. popular like KT315s. low slew rate.

[kt315]

.... . cross