On any Tube Linear Amplifier with a Tune and Load on the output, always tune for max output except you can over couple the load down a little maybe 3, not 10% or 50% as I hear some talk about. When you tune an amp for less output, the watts that you tuned down stay in the tube instead of going out to your antenna. Simply put, your tube(s) eat those watts. If your amp has a Volt and Plate current meter, the watts your tube is seeing is the voltage times the plate current, but minus the watts the amp is putting out. Say you got an amp with 2kv voltage at 1 amp current thats 2000 watts. If the amp is doing 1000 watts out then the tube is eating the other 1000 watts. This is normal. Amps run at 50-60% efficiency. However if you tune down or detune the amp to 500 watts out, that 2000 watts - 500 watts so the tubes are now eating 1500 watts. It drives me crazy when operators say I tune mine down so it will last a long time. I tune my 1000 watt amp down to 250 watts. There are many bad things you can do to an amp. Over drive it, high SWR, Hot Key the keying relay, but not tuning for max is 0ne of the worst, IMHO
2 янв 2021
