I still say, forget the linear, and use less money to build a plate modulator for the DX60. It will work better, sound better, cost less, and heat the shack up less. As I recall the DX 60 has a 6146 in the final for class C CW and puts out about 40-50 watts of carrier if it were plate modulated it would do at least 200 watts PEP and sound great. There is a number of different ways to do the modulator. A lot of guys just find and old PA and a transformer to match to the final. Some build the modulator output stages only, input XFMR tubes and modulation XFMR. Then they drive it with a small microphone amp. That's more stuff to set around on the desk but it works. There are a lot of self contained 25 and 50 watt modulator circuits around and probably a lot of complete one piece store bought modulators as well. As I recall, EICO had a pretty nice one that was to go with the EICO model 720 but it was used on many different rigs as well as being used as a driver for big modulators. A buddy of mine had an ECIO 720 and built a nice home brewed modulator for it using 1625s in AB1. It sounded real good. I built one similar to it with less power output for my Knight Kit T60. The T60 had the same control carrier AM that the DX60 does. What a difference it made when it was plate modulated. Very little modification is necessary in the DX60 to accommodate the external modulator.
John, WA5BXO
