Replacement: the new Keyall kit
The Grid block keying adapter allows the owner of a keyer with a low voltage positive (NPN) keying transistor to drive the vacuum tube transmitters and transceivers of yesteryear. This unit will key negative voltages up to 150 volts. It uses the time proven MJE350 PNP transistor design from the Curtis keyer application note. This unit will not work with high positive keying voltages such as those found in cathode keyed vacuum tube transmitters.
The Acrobat files of complex diagrams (like the schematic) may not view well on your computer screen - suggestion: use the magnifier to zoom in for better detail or print out the file.
gridbsch.pdf (46k) - an Acrobat file of the Grid Block Keying Adapter schematic
gridb.pdf (21k) - an Acrobat file of the Grid Block Keying Adapter manual
gridblk2.gif (32k) - download a picture of the Grid Block Keying Adapter