[TenTec] KR-5 keyer

[Stuart Rohre]

The TT kit I mentioned has a flip flop in it as I recall.
There are a lot of one chip keyers out now, usually based on a one chip
microcomputer. Those have a lot of features.

Hopefully, you can get as schematic or trace out the circuit yourself.  IF
your chip is equivalent to the listed TTL chip, then the connections are
likely the same. There was a lot of standardization of 74xx compatible
chips.  Also of the 54xx series which were same functions for different
temperature range.  The chips pins interchange pin for pin.

If I come upon the original maker, I will post.  We have years of IC
catalogs stored.  That letter prefix just did not ring a bell.  A logo might
help, as I pointed out in my ARRL Chap. 24 sidebar in the 2005 edition.

73,
Stuart
K5KVH