Help Identify IC's from 1984 Pulse detector

[Ken H.]

Could use help in identifying these two DIP 16 IC's used in a Garrett (XL 500) PI detector (circa '84).

These are used to delay the sampling of the signal. Pin 4 of the left IC receives a pulse signal from the initial 555 timer that drives the search coil.

Pins 6 and 10 of the right IC send the signal to the gates of the dual FET (which is between the preamp and amp).

The "Eliminator" control is a form of discrimination.

The red triangles are the + battery (+8.4v)
The -5 in a circle is -5 volts.

Thanks for any ideas.

[JC]

Re: Help Identify IC's from 1984 Pulse detector

Hi Ken,

Looks like this might be it. Pin 1 and 15 should also go to -5v I would guess, maybe it will work without this, not sure. Anyway, thats my guess, some form of CMOS 4538.

JC



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[alex]

Re: Help Identify IC's from 1984 Pulse detector

Hello Ken , 100% it is the CD 4538 , the same circuit that i have posted few month ago in the Foster circuit of the GOLDSCAN. Have a good day and enjoy your Delay circuit...

[Ken H.]

Re: Help Identify IC's from 1984 Pulse detector

JC,

Thanks for your reply and for the link. I have been looking for an IC with the right pinout, but with no luck so far (74211 and 74123)

Just glancing at the data sheets show that this one at least has the correct input and output pins. I also note the date on the data sheet...1987

Don't know how you made the connection, but it is appreciated.

[Ken H.]

Re: Help Identify IC's from 1984 Pulse detector

Thanks for the help Alex. I will look through the archives and see if I can find your posting on the Goldscan.

[Eric Foster]

Re: Help Identify IC's from 1984 Pulse detector

Correct.

Eric.