[Notes on the Link intercom]

Some extra notes for those attempting to build the Link intercom:

1. Best to build it up on your SK-10 panels to ensure that all parts are working, before you go soldering them to a board.
2. Adjust R6 by making a call, then taking the called party's handset off hook - adjust R6 until the ring tone in your earpiece has halted.
3. Transformer must be 1K/8R type - 500R types won't do.
4. Some 556 timer chips don't fully switch their outputs off.
5. All phone handsets must be the same - all rotary dial or all pushbutton dial.
6. Use 9 volt buzzers as 12 volt ones aren't reliable due to the current drain pulling the supply voltage below thier operating voltage.

regards