Here in the US, standard voltage of electrical outlets is 120 VAC via a tapped 240 VAC service available at the breaker panel. Everything in my shack operates from the normal 120V outlets, including my AL-811/AL-80BQ.
I thought it might be interesting to measure the voltage drop caused by transmitting while QRO. The extent of that drop surprised me but what really caught me off guard was the voltage drop caused by transmitting at near-QRP levels.
Here are the measured (Fluke 87) voltages at different RF output levels from the K3/AL-811:
|RF Out||Outlet Voltage|
I’m not sure if this is typical or the result of my shack being located at the opposite end of the house from the electrical service entrance with the subsequent copper loss.
I’m also not sure what the current draw is on the AL-811 when producing 500 watts out, but with an 8-1/2 volt drop at every Morse character, I’m starting to question the commonly advertised notion of such amps being operated at 120V.
Yes, they can be, but…
On another note, I have recently replaced some of the incandescent light bulbs here with those new low-wattage flourescents and notice that they do not flicker in tempo with my CW keying like the incandescent ones did. No additional noise was noticed with these bulbs as some have reported.