[Elecraft] KPA-500 from Orlando

[Phil & Debbie Salas]

"Another way is to add series diodes between the driver and the amplifier. 
You will want to have pullups on the amplifier side....  Jack Brindle, W6FB"

This is a good solution.  The HL2.5 has internal pull-up resistors so you 
would just need the series diodes in the interface cable (anode towards the 
HL2.5 amp).  The HL2.5 uses a DB15 connector, so it would be easy to add the 
diodes inside the mating connector.  The HL1.5 does NOT have internal 
pull-up resistors.  So if this idea is used with the HL1.5, pull-up 
resistors must be added inside the amp or in the interface cable with a 
means of connecting to a pull-up voltage source.  The HL1.5 uses a 
240-degree 5-pin DIN, so there is not much room inside that connector.

Phil - AD5X