Marshon wrote:
Does anyone know of a site that gives a list of alternative or
equivalent parts?

Not really... and if I did, I wouldn't trust it. They can't possibly
know what is important in your particular circuit.

When the same device is made by several different manufacturers, each
one may give it a slightly different label. The only worthwhile thing
that so-called "equivalents" lists do is help you recognise the root
number that they all share. Devices that share the same root number are
directly interchangeable in most cases - because they are intended to be
the same.

But devices with different numbers are usually intended to be different
devices.

Be literal-minded about this: a true substitute can only be another
device of exactly the same type. In all other cases, think of it as a
*different* device that does *some* of the same things... namely, the
things that you need in that particular circuit.


As an example, I have hundreds of 2N2222 transistors but the
requirement is for a single BC547 of which I have none. The datasheets
would suggest that the 2N2222 would do the job, but is it always going
to be a 'suck it and see'?

If you've actually compared datasheets, you've already done far more
than most people. Think about what a transistor needs to do in that
particular circuit, and trust your own judgement.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)