The Keyall HV kit
May 2, 2018 - new circuit board, R2 eliminated
The Keyall HV kit allows the owner of a keyer with a low voltage
positive (NPN or n-channel MOSFET) keying transistor to drive the vacuum tube
transmitters and transceivers of yesteryear. This unit will
key negative voltage rigs (grid block keying) or
positive voltage rigs (cathode keyed tube transmitters
and conventional +13.8V powered solid state rigs). The output transistors
and capacitor are rated at 1000 V and 3.1 A (3100 mA). The Keyall HV will normally key a single transmitter.
05/02/2018: Note that the board is now silk screened, solder masked - aso R2, the 100k ohm resistor, has been eliminated
The Keyall HV kit is an update of the original Keyall kit.
10/27/2022: 500 V version of the Keyall HV has been discontinued.
The Keyall HV circuit has been used for
high power external amplifier keying
by Gary, KD9SV.
W0VLZ provided this link to his experiences with the Keyall, thanks Niel.
Pat, W0BM, supplied this link to a 3D printed case design for the Keyall HV, Thanks Pat !
September 30, 2017: A customer has encountered keying problems with a Heathkit DX-40 (cathode keyed rig), the problem was solved by removing R2, the 100k ohm resistor.
This may lengthen the key down slightly (3 milliseconds?) - it's probably only needed IF the Keyall HV is used at higher current levels (175 mA and above ?).
The customer reported that the DX-40 keying sounded OK on a shack receiver.
design is a MOSFET based solid state relay, SPST-NO single pole, single throw, normally open
high voltage output is optically isolated from the low voltage input
kit includes a circuit board and all board mounted components
just add your enclosure, in/out jacks and a battery holder
Size is 1.25 x 1.5 inches - fits into a candy tin with room to spare
Price (no printed documentation) is $15.50 + shipping/handling
add another $2.00 for a 6 pin socket for the PVI
add another $18.00 for the enclosure
Printed manuals available for an additional charge or save money by downloading
(Right click/save target as)
and printing the revised
hookup diagram (unchanged) and
enclosure manual .
For kits purchased before May 2019: manual ,
Print out a Kit
order form to figure your order manually
to let your browser do the math
Downloadable files for the Keyall HV kit
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.
keyallhvsche2.pdf (123k) - an Acrobat file of the latest Keyall HV schematic
keyallhv2a.pdf (54k) - an Acrobat file of the latest Keyall HV manual
original doc files:
keyallhv.pdf (54k) - an Acrobat file of the Keyall HV schematic
keyallhvm.pdf (9k) - an Acrobat file of the Keyall HV manual
keyallhvhu.pdf (87k) - an Acrobat file of the Keyall HV hookup diagram
5msperdiv.JPG (1.1 Mb) - a JPG of the Keyall HV test fixture prototype rise/fall times
The top trace is the Keyall HV output
The bottom trace is the keyer input
The graduations are 5 mS per division horizontally and 1 volt vertically.
keyer speed is over 60 wpm