Wednesday, January 14, 2009
An Iambic keyer rated for cathode keying
When using my vintage transmitters I've missed not having a keyer. Many older tube transmitters are cathode keyed. The voltage across the key terminals can be high enough to fry the output transistor of a typical modern keyer. In some cases the voltage can even be high enough to be a safety problem.
I already had a K1EL K10 keyer board ( http://k1el.tripod.com/K10.html ). I added a Keyall from Jackson Harbor Press ( http://wb9kzy.com/keyallhv.htm ) to make a keyer capable of keying up to 500V. It works great! I even installed a jack for a straight key so that I use the K10 CW monitor plus the Keyall isolator on Straight Key Night.