Thank you for all the replies. I think I will install the Harbach mod. As Dirk pointed out, the manual is sure confusing, but the Mark V cannot handle the power of the heath relay. I got out my Heath manual, and it says (on page 82 under "Relay") that there is 120 volts - it doesn't state the current. Thanks again, saved me from ruining the relay. Tom W6EIJ