QRSS600 (= 10 min dot rate) requires a TX, RX and propagation stability of 1mHz (milli Herz) so for that reason it will probably be used only on VLF (ie. 9kHz or less)
Class D transmistters on 9kHz can have an efficiency of 90% and there are plenty of cheap power FET's or IGBT's rated >300W dissipation and > 700V (what means you could run them right of mains voltage).
A 2kW amplifier should dissipate no more than 200W, in an H-bridge amp this power is spread over 4 transistors, so 50W each.
73, Rik ON7YD - OR7T
How many transmitters could stand this duty cycle, especially the QRO versions. The time needed to send a full callsign for ID could well burn the TX out.
Those using QRS 120 in the past for prolonged periods reported problems.
g3kev
