Old Receivers

[urban hype]

Hello all,

I have a bunch of old receivers that have just stopped working. I took the cases off of them and in most cases there is nothing that is burnt or leaking that I could see. Are there schematics available for any of the old equipment? In most cases I have 2 or 3 of the same type so I am hoping that I can put 2 together to make one good working unit.

[jwscab]

i'm sure schematics can be found, but probably not easily. Most of the time when the receiver stops working it's because it needs to be retuned. This takes some specific test equipment, which normally a person wouldn't have, and you would also need the tuning procedure. But if you are really dedicated, you can find what you need.

one thing you could do is check to see if any of the IC's in the receiver has a standard part number, and look it up for it's datasheet. from there, you can usually see a test circuit or even examples of a typical circuit which is generally how it's designed, and you can pick out what parts are doing what.

[urban hype]

Well I am kind of lucky in the respect that I have been around electronic repair for most of my life. If I don't have the correct test equipment I can get me hand on it. But having the correct information will save be a whole lot of trouble. That is what I am looking for. A repair schematic, correct testing procedures ect.

[urban hype]

Well I started poking around with one of my old tekin receivers that stopped working. Besides the crystal holder being worn out which I have already replaced. It looks like that the unit is controlled by 1 IC, LM1872N produced by national semiconductor back in 1989. Does anyone know where I can get one of these IC's? Digikey, Mouser and the other usual suspects seem to not have this component listed.