[Elecraft] Collins 30L-1 amp with the K3

[Butch Schartau]

I want to use a Collins 30L-1 amp with my K3, when I plug the 30L-1 amp
control cable into the K3 KEY OUT jack, the 30L-1 keys.  The 30L-1 is keyed
by grounding it's key line (pulling -160 DC to ground).  The K3 specs says
+200 VDC, at 5 amps, I guess the K3 does not like the minus voltage on the
30L-1 key line, any suggestion other than an external relay?

Butch K0BS