In article .com, "Joe
in Tennessee" wrote:

My weather station has been fully functional for many years, but the
wind direction and velocity has stopped working. I suspect one or more
of the IR diodes and/or the photo transistors have failed. I have been
unable to locate replacement parts or to cross-reference the original
part numbers.
The diodes are TIL-32 and the transistors are TIL-78.
I would appreciate any information on where I might find these parts or
where I might cross- reference them to an available substitute.

Joe-

These numbers appear to be from Texas Instruments.

The best Heath cross-reference I've come across is at
http://www.d8apro.com/heath3.htm listed by the Heath part number.

Have you tried contacting Heath? They are still there, just in the
educational equipment business. I've heard they still have some parts.
http://www.heathkit.com/ There is an 800 number listed on their web site.

Fred