[Heathkit] Keying Voltages Information Request

[Ken Miller K6CTW]

All,

I am putting together an interface to a DDS-based VFO (WA1FFL) and want to be able to key it from a number of Heathkit transmitters.  However, to do that I need to know what the open circuit voltage is across the key (or accessory socket equivalent connection) is.  I already have data from my DX-60 and a HW-16.  I'm looking for voltages for the following rigs:

DX-20 across the key
DX-35 across the key
DX-40 between pins 1 (ground) and 8 of the accessory socket

Thanks in advance for anyone who can measure the voltages specified and supply me with that information.

73 - Ken Miller, K6CTW